J-Rho's '67 Camaro Z28 STX build Jason Rhoades builds a 1967 Camaro Z28 clone for SCCA STX autocross

8Nov/180

These are a few of my favorite things…

One project nearing completion, another about to begin...

9Oct/180

Cool photo found on Internet

I don't think Dodge ever made the Gen4 ACR in blue, too bad as I think it looks pretty good with silver stripes.

 

Filed under: General No Comments
28Aug/180

Motor and goodies and getting it going again

Soooo.... what's happened with the Camaro over the last 3 years...

What started as a fix-up-a-few-things quickly snowballed into a big mess. I'd really been burnt by all the valvetrain failures in STX trim and wanted to shore that up. The car was never going to be competitive again in Street Touring, and it didn't/doesn't really have a fit in Street Prepared or Street Modified either. There's a lot of unlimited-style builds out there where the cars are legal for CAM class but not much else - I didn't want to go that far, nor do I want to cut it up in the mold of a traditional CP car.

Much of the time spent over the years was just deciding on the vision for how the car will be in its next iteration. Where I arrived is at something like a light CP build, that can also run in CAM with some ballast. I'd like to get it down near 2700 pounds using a < 5.1 liter motor, so it's CP legal weight-wise, but it'll keep the lights and wipers and things that are needed for CAM. For now I just want to make it drivable again but it'll get a quieter exhaust, bigger wheels/tires (with room to turn), and better suspension.

Ordered a set of AFR aluminum heads, sized a bit on the small side (180cc) to maximize midrange torque from the 302 short block. Mike Jones did a nice bumpity solid roller cam for it, and I had ProSystems build a mechanical secondary carb to match.

Was originally going to try to hot rod the thing with the block kept in the car, but with the trans out it all became a bit of a pain, so I pulled the short block out too, so I could assemble the new motor on the stand.

With the short block out, might as well check the bearings and things, since some metal had been through the motor once or twice with the valvetrain failures. Plus oil pressure had gone to zero - or very close to it - several times under hard braking.

Unfortunately in this check, found some pretty serious scoring on the rod and main bearings. The dilemma now, have this (old, 60's GM, 2-bolt-main) short block repaired, or just get a new one? I opted for the latter, a basic Dart SHP cast iron piece, a 4" bore 3" stroke, from Chris at CNC Motorsports. Only special ask was to use 6" rods over the default 5.7", though it probably won't make much difference.

So what had started as a simple bolt-on hot rodding project was now a completely new longblock needing assembly. A bunch of things you'd think would be simple and sorted in SBC, weren't. Finding a set of rocker arms to clear the big retainers of the extra-zoot valvesprings I'd had AFR spec, was one tricky part. Had to use lash caps to get it to work with the right valvetrain geometry.

The other tricky part was the oiling system. Used a similar but new Milodon roadrace oil pan (dipstick on other side with this block), but had a hard time finding an oil pickup that'd clear the internal baffle system. Eventually found the parts needed to go along with one of the Melling shark-pattern oil pumps.

With it all put together it went into the car over 4th of July weekend 2017.

The OEM '67 belt system was a catastrophe so a March setup replaced it. The old-school alternator is replaced by a high-output one-wire, belt driven water pump now electric. Valve covers provide extra internal clearance for the rocker arm setup. They should provide room for a shaft mount system if things ever go that way.

My invaluable engine install helper:

There was still lots to do. The fuel was years old at this point, the wiring was a mess I wasn't happy with, trans needed install. Another sign of not having gotten over 2013's valvetrain drama was my insistence there be room in the engine bay to pull the (oversized) valve covers quickly and easily without too much stuff in the way.

Here's how it sits today - many many hours of labor later-

Coil is relocated up and out of the way. The big brake booster and heavy cast iron master cylinder have been replaced by a small and lightweight (20+ pounds saved!) manual balance-bar system.

The aluminum radiator and dual electric fan setup is from C&R. Can't see it but in front of the radiator, there's a modestly sized C&R oil cooler with remote oil filter mount. The filter was a nightmare to get to with those headers, should be tons easier now. I'd run a cooler on the 370z and saw what a tremendous difference it made in oil temps. This cooling system is overkill for a little 450-ish hp (hoping, not sure exactly) 302 but

The Accusump with EPC valve is housed down there in front, nice short run to the motor from the unit. Placement of these things is always an argument between the chassis guy and the motor guy - motor guy wants it close to the motor, chassis guy wants it back to favor CG. Motor guy won here.

From the other side, showing the new mechanical fuel pump-

With work and life and everything I haven't had the spare time to give the car what it needs. It's at Best of Show Coachworks in nearby Escondido, where Dean (mechanic) and Matt (owner) are doing a really fantastic job with it. I'm much happier with their work and the progress being made than I thought I'd be, as a consummate DIY-er.

Motor should be running again soon..wiring is still being fixed up, I'd done some naughty things to get it put together on time, Dean is repairing all my badness...

Exhaust buttoned back up:

Last bit is on the suspension. The OE style spring-over-shock thing was a mess I really didn't like, so the car is getting the ATS upper coilover mounts. This will simplify and clean up how the what is now a front coilover, mounts to the chassis.

Still brainstorming with Matt on how to improve the motion ratio, by altering some aftermarket lower control arms to locate the coilover's lower mount much further outboard, closer to the lower ball joint. May eventually do some custom fabbed arms and spindles and things but for now, looking for improvements to off the shelf pieces.

More to come in the coming weeks!

Filed under: General No Comments
28Aug/180

All blue

Whew, 3 years, been a while!

Some updates...

Returned that 370z to stock and sold it to a dealer, what a meh experience that whole thing was. So much for normal cars for me. It's been reclassed to STU, where it'd probably be pretty fun on 285s on 11s, so if you've got one, don't let my bad experience with 255s on 9's be a deterrent.

Somewhere out there somebody's riding around with powder coated chassis braces and a Quaife in what was probably presented to them as a stock 370 - lucky person.

The Z was gray, but before that I'd had 1 red truck, 2 black trucks, 4 red cars, and 3 black cars. The Camaro (red when I bought it) once painted blue, was my first non-black-or-red car. Now, all my cars are blue.

 

Shortly after selling the 370, decided to buy my friend Gary Thomason's blue 2008 Viper. I ran it at Nats in 2017 (6th, meh) and Spring Nats 2018. It's got the Koni 28's and front sway bar design of my old black Viper. This one has about 90hp more than my old one that comes on in a vtec-ish fashion around 4k. We rarely see those engine speeds in autox but when we do it's a lot of fun.

Video from Spring Nats Pro. Didn't finish where I wanted, but this is about the best I've driven it yet:

This car has a bit of a push that I haven't been able to get dialed out yet, though I had in the black car. Perhaps due to the stiffer coupe chassis. Have some ideas of ways to get the car to work better I plan to try out next season. SSR is a tough class!

Another change is in trailers. Had been making-do with a dilapidated old Pace. The big box style trailers are like a garage on wheels. Great when you're out at the event/track - lots of room for stuff, easy to get around the car and get to things.

The problems are they're big, heavy, and womp fuel economy. I wanted to eventually replace the Tundra with something smaller, more economical, and more comfortable - but such a beast would probably have reduced tow capacity. Towed out to Nats '17 with the old girl, had arranged sale to a fellow from Texas, we'd meet up there.

Purchased a Montrose aluminum enclosed, had delivered to the site so I could switch out there. They're made in Wisconsin, so it was a lot cheaper having it delivered to Lincoln, than to San Diego.

Moved from big old trailer to new small one while out there. A bit of an adjustment - definitely a lot tricker to live with out at an event. But on the road it's great, closer to an open trailer in trailering dynamics, than a full enclosed. For Spring Nats '18, towed up the Ike Gauntlet, which I'd purposely avoided with the Pace.

With the lighter trailer secured, the next change was to the daily driver. After 11 years, 160k miles, and ZERO issues, decided to part with the 2007 Tundra this year. It was everything you'd hope for from a Toyota, a paragon of reliability.

Part of what triggered the Tundra's departure was a family trip done in a modern rented minivan. We loved all the accommodations, especially the power doors. Started researching minivans to see if any of them could tow - 5k would be the absolute minimum to be useful. Unfortunately they're all limited to 3500lbs. It might have been possible to beef things up with airbags and tranny/oil coolers, but it might also just be pushing things too much. The MB Metris had 5k capacity but no amenities, it's like a broom closet on wheels.

Much research went into SUVs, a gigantic spreadsheet showing the stats of every almost new SUV available was compiled. Nothing really appealed. The Toyota Land Cruiser was a top pick due to how happy we'd been with the Tundra, but with more comfort and amenities. But they still guzzle gas and probably wouldn't be that much fun to drive daily, on paved roads.

The wife wondered if there were any electric ones, since I have free charging at work. Eueka! Isn't there a Tesla SUV that can tow? There is, the Model X (in blue!), rated for 5000-ish pounds-

This 100d has a 100KWh battery, which will take it close to 300 miles on a full charge with normal/sedate driving. Maybe a bit less at high speeds, but 250+ miles in So Cal weather we've done in it already.

It's seriously quick too. Didn't opt for the big-extra-$ Performance model (which is much faster still) but this one will do the 1/4 mile in 13.0, 4.7 0-60, but its real strength is freeway merging speed, 40-70. It feels like this thing folds space when presented with a yellow light - you make lights you couldn't make in anything else, with no external drama (tire spin, engine noise).

Towing, the range is going to get cut way down - remains to be seen, but probably 100-120 miles. Thankfully Tesla has a fairly well distributed "Supercharger" network out on the highways which makes this just enough range. It'd still take a lot longer with all those stops to cover any significant distance. Plan is to use the Tesla for in-state races, but rent a truck for anything further.

When the weather is right, with some clouds, the view out the panoramic aircraft-style windshield is killer!

Then, there's the Camaro...

More to come in the next post...

Filed under: General No Comments
17Oct/150

Gear jammin

Back in the day, The General provided first gen Camaro owners a wide range of choices in final drive ratio.  I've seen everything from high 2.xx's to low 5.xx's available as factory options.

For this thing in 2013 STX trim I went with 4.88, which netted high 60's mph at the top of second gear with the original redline and rear tires I'd chosen.  About right for an STX car. With eventually shorter rear tires and a lower redline after a lot of broken valvetrain parts, the max speed ended up in the low 60's, not so good.

Another shortcoming revealed itself the following year when I took the car on the freeway for the first time - with the >27" tall vintage tires, 4000rpm in top (fourth gear, 1:1), netted 62mph.  Not very relaxing.

J-Rho's Camaro on the freeway

Not looking to track the car any time soon, I only had two requirements of the gearing situation:

  1. Produce the right top speed in second gear for autocross use
  2. Produce a reasonable cruising RPM for any trips on the freeway

Below is a cut from one tab of my super-duper everything-I-know-about-cars spreadsheet.  Getting gearing right is important and key to understanding thrust.  By messing with the stuff in green I can see the resulting outputs.  Column K, 2nd Gear Max, is important to ensure your car has "long enough legs" for autocross.  Column M, RPM @30mph, tells you about where the engine will be coming off the slowest of corners - especially important for peaky or boosted engines.  Plugging the highest transmission ratio into the second gear column and them multiplying column M by 2-2.5, gives me a quick idea of cruise RPM.

gearing_xls

The problem with the old school Muncies is second gear (1.64 typical) tends to be too close to top gear (always 1:1).  So while 10mph per 1000rpm is perfectly reasonable for second gear (column N), with a Muncie that means you're only getting 16.4mph per 1000rpm in top - which puts you in a situation like the above.

This is where the world kinda explodes for me.  Every car I've monkeyed with in the last 15 years, has been done within the tight constraints of an autocross ruleset.  The only exception maybe was building the 240sx for Street Mod in 2007, where sizing and building a turbo system was a ton of fun - but where I also learned that there was such a thing as too hardcore of a race car for me.  Every time before and since, the rules had kept me from going too far - and in my current frame of "just don't do anything that's illegal in CP or CAM" - the sky is the limit.

One option would be to stick with the Muncie.  To produce a good autocross gear and a decent highway gear, would mean having to autocross in first gear.  For regular Solo that might kinda work but for anything with a launch it would not.  The little 302 just doesn't have the beans to get off the line with a 70+mph first gear.  An 8 liter Viper with a 60mph first barely does.

Another is the Gear Vendors overdrive unit, which adapt to the Muncie and give a quick overdrive at the touch of a button.  Thought about this for a while, and it might be neat in an autocross setting, to basically be able to paddle-shift up or down on course between second gear and "second-over".  The biggest concern I had with this, is the "upshift" into overdrive wasn't instantaneous ("down"shifts out of OD are) - the engagement of overdrive is actuated by a pump on the transmission output shaft, and the faster it's turning, the quicker the engagement.  In videos where they show it engaging in first gear, there's a delay of maybe three quarters of a second before it kicks in.  That maybe doesn't sound like a long time, but when you're trying to time that on an autocross course, it's an eternity.  Seemed likely that it wouldn't be totally consistent either.

The other issues were the unit is pricey (more than a good new 5 speed trans) and the overdrive is "only" .78.  Better than nothing, but not as much of an overdrive as offered elsewhere.  Lastly, my M21 leaked like oil was going out of style.  Not an easy fix either, a worn countershaft hole in the case, the only way to repair is to drill out the hole and put in a new bushing, or buy a whole new case.  So to fix the M21 and do the GV Overdrive was quickly becoming a $4k proposition

Elsewhere, there are some really beefy 4 speeds, like the Jerico transmissions commonly used in circle track racing.  Common now in Street Modified and Prepared classes autocross, they are strong and light, and for this common RWD Chevy application, not that much more than some of these other options.  Their non-synchronized straight cut gears sound great too.  Problems there, they're quite noisy, a bit of a pain to use on the street, and I've heard stories of them actually having a hard time with extended durations at light load, like cruising on the highway.

The most common swaps for these cars are Tremec 5 or 6 speeds.  The 5-speed come in the TKO500 and 600 flavor (the number representative of their steady-state torque limits) and the six speed is the T56 Magnum, good for ~700.

Tremec TKO600 in box

An advantage of the T56 is you get 5 well spaced gears and a good cruising overdrive.  If you want your car to stay in a narrow rpm range from 50 to 150mph, you want a 6 speed.   With the 5 speed you get 1-4 similar to the 6-speed, but you have to choose whether you want your fifth gear to be like a T56's fifth - maintaining good acceleration on a racetrack, but a bit buzzier on the highway (.82) - or more the like the T56's 6th, where acceleration on track would be feeble, but you get a more relaxed cruise (.64).

For its superior strength and flexibility across speeds the 6-speed can't be beat.  The cost isn't that much more either, only a few hundred bucks more than a TKO600.

There are some downsides though.  First, is it's a physically much larger transmission than the 5-speeds, which themselves are already a fair bit bigger than the 4-speed Muncies.  While the TKOs can fit these old Camaros without tunnel mods, the same isn't really the case for the T56.  The other, is they're heavy - over 130 pounds.

 

Tremec TKO600 in box

Long story coming to an end, I went with a TKO600.  I don't plan on acceleration above 4th gear speeds to be something I need to worry about (just don't want to go that fast in this old thing) - and the fitment and weight benefits sealed the deal.

My motor is nowhere near 500 ft-lbs. of torque even after its planned upgrades so the TKO500 would have been fine, but the 600 was only a little bit more and should provide some future-proofing if things escalate in the future.

Tremec TKO600 vs Muncie M21

That paper has my notes on weight:

Stock M21 Muncie: 70lbs.

TKO600 with shifter assembly: 101lbs.

Hurst shifter assembly for Muncie: 8lbs.

So, in a heads-up comparison, the TKO is 23 lbs. heavier than the Muncie.  The TKO installation kit comes with a new crossmember for mounting in the car which saves a couple pounds, for a net +21.

Last bit in this space are a new flywheel/clutch/pp.  Flywheel is an aluminum Fidanza, clutch kit is a McLeod RST street twin disc.  The clutch is rated to 800hp (future-proofing again!) but by virtue of being twin-disc, retains a lightweight and smooth, streetable engagement.  The cost is the clutch assembly is heavy!  Every pound the light flywheel saved over the OE iron piece, the clutch takes back.  Oh well, at least no net gain there.

 

McLeod RST twin disc clutch and Fidanza aluminum flywheel

Looking forward to eliminating the biggest leak on the car, and taking the revs down to a reasonable place on the freeway.  Lots more to do though!

8Oct/150

Wrenches turning again

A vision for the Camaro's next iteration has come into clear view, and progress has begun.

More details later - in the meantime, I'm reminded of a passage from Peter Egan I read a long time ago.  His context was one of restoration vs. modification, but much of the things are the same.  Though today, getting the pieces brought together is a mixture of modern online shopping with phone calls to cottage industries and folks who sometimes, were there for the heyday of the Trans-Am and Can-Am series.

http://www.roadandtrack.com/car-culture/a26444/side-glances-girding-oneself-for-battle-with-the-restorable-car/

Knowing all this, I paused. Walked around the car many afternoons, gazed at the dirty engine under the hood, tapped fingers on a faded fender, jingled the change in my pocket and tried to assume the bleakest possible expression of realistic hardheaded disinterest.

A car restoration, like marriage, is not to be entered into lightly. It is a fork in the road.

If we look at an old car in need and do nothing, it just sits there. The sun rises and the sun sets. Seasons come and go. The robin builds its nest, morning dew drips from a pitted chrome bumper, children grow up and need bigger shoes, and sediment in the sediment bowl turns to anthracite. A clock ticks on a wall and old men sit on a park bench and watch shadows lengthen in the town square. The car gets older, your checkbook sits on the dresser. Nothing changes.

Not restoring a car is almost the perfect embodiment of stasis. It makes a stagnant pond look like a three-ring circus.

But if you take the other fork in the road, toward restoration, everything changes: your life, your finances and the destinations of a hundred UPS trucks. It is, as Marcus Antoninus said, "like letting slip the dogs of war."

A set of narrow whitewall tires is shipped across the country; a water pump in Cleveland gets taken off a dusty shelf by a Clevelander and sent to a Wisconsinite; telephone calls in search of superannuated oil seals crackle across a continent; a man in a Texas scrapyard pulls the front bumper off a car rear-ended when Lyndon Johnson was president; old oil comes out the bottom of an engine and new oil from new cans (for today's higher-revving engines?) goes in the top. A bright orange oil filter spins into place, and a huge breaker bar is unlimbered from the bottom of a toolbox; Liquid Wrench flows like champagne; clean amber brake fluid courses to the car's four corners, pushing brand-new brake shoes against freshly turned drums.

For sheer unleashed energy, it's like one of those World War II propaganda newsreels showing American industrial workers giving Hitler a bust in the chops, everything spinning, gushing and throwing off showers of sparks. Tanks and airplanes on parade. Stand back! We are in motion here and we will not stop. We are on a holy mission and our eyes have a zealous glaze; we never sleep.

Car restoration is its own life form; the decision to go ahead and do one is a strange pivotal moment, a headlong act of resolve and suspended logic combined, like lighting the fuse for the first cannon shot at Fort Sumter.

Blow out the match and life remains simple and quiet. Maybe a little too quiet. Light the fuse and there is no peace in the world until the car is restored and rolling. In the meantime, all is glorious havoc.

Filed under: Background No Comments
21Jun/150

It’s back!

Got the Camaro out of storage today.  The Z is pretty much "done" for now, so they traded places.  Mag wheels overdue for a polish, and it hadn't been run in a long time.  Fortunately it started right up and made the drive home just fine.

20150621_174659760_iOS

Not sure what's next but it's nice to have it back - distance makes the heart grow fonder and all that.  I'd gotten pretty burnt out working on it after 2013 - putting the Z together for STR was a refreshing break.

Lots of potential places to consider as targets for its next iteration.  STU, STP (for non-National competition), CAM (also non-National), ESP, SM, CP?  Make it even more like a Penske/Donohue close with a cage?  Maybe some non-SCCA stuff?

For now, just gonna get those wheels shiny again 🙂

Filed under: Background No Comments
21Jun/150

Spring Nationals 2015

Well that was a lot of meh.

Couldn't make the Crows Landing events in CA this year so I hauled the Z out to Nebraska for 4 days of racing - ProSolo followed by a National Tour - they call Spring Nationals.20150520_224059949_iOS

Lincoln is a long way from San Diego.  Reset the Trip B odometer in the driveway on my way out one morning.  And here it is stopped in my paddock spot the next afternoon:

1597.4

Towing an open trailer is a lot more serene an experience than the enclosed, with the Tundra.  Power and brakes are fine and stability is good in most cases, but the range is sooo much better with the open trailer.  Mileage is about 10 (+/- 2 depending on geography) where it averaged about 13.5 pulling the open trailer.  That means it was easy to go 250 miles between stops with the open, where you're looking for gas between 150-180 with the enclosed.  Next truck will have a much bigger tank!

The weekend started with the ProSolo.  First pair of runs Saturday morning were decent, but I failed to improve basically at all the whole event- whereas the rest of the class had no trouble doing so.  Was a little unnerved in that upon coming in from my third run smoke was billowing out from the front of the car.  Given all the work I'd just done with the headers, was worried something might be getting cooked underhood.  Turns out it was just the brakes bedding to the new front rotors but uggg, what a distraction.

z_prosolo_1

z_prosolo_2

z_prosolo_3

After reviewing some of the photos, am surprised how much steering input the car has into it in spots.   Have since upped the rear spring rate from 700 to 800 - but that wasn't until I got back.

An in-car from a left-side run Sunday morning.

Since El Toro, I'd moved from 245-40 to 255-40-18 RE71R Bridgestones.  Went down a click in front bump (from 6 to 5 of 13) up half a turn in front rebound (from 1.5 to 2 out of 2.5 turns).  Also up in rear bump and rebound (from 3 to 5 of 13 clicks on both).  Also went up from full soft to the middle setting on the rear bar.  Did the headers and front brake rotors mentioned earlier too.

Car felt great in the slaloms - best it's been so far, and really, the first time it'd ever felt good in a slalom since I'd owned it.  Mid-corner balance was better, but maybe still not quite there yet.

The Tour that followed wasn't really any better.  The first day was wet to drying, and I learned a little about the nannies the hard way.

 

The second day went a bit better, but still a full second off the pace.  There was one big mistake early on that cost a few tenths, but most of the rest of it felt about as fast as I could make the car go.

Hopefully the spring rate change will free the car up a bit more and help its overall speed.  It's never even hinted at inside wheelspin and only got a little bit loose once or twice.

Hopefully will get once local practice at El Toro before Nats, but might not, not sure yet.  Car is a lot of fun, and have the full OBD data acquisition hooked up now, will post some more on that later.

Filed under: 370z No Comments
18May/150

Exhaust work and dyno session

Street Touring rules allow for headers but we must retain catalytic converters no further than 6" down the flow path from the stock unit.  In the previous post detailing header install the Berk high-flow cats (which sit in roughly the stock place but are much shorter in length) went bye-bye.

Spent the morning at A&A muffler here in town (and recommend them if you need exhaust work done in San Diego) - first project was to get a new pair of high flow cats welded in just aft of the new longtubes, where the garageline mid-pipe provided a flex joint.  These cats are 100cpi high-flow units from my buddy Rick at Ciro Racing. Given how far back they are, and how large and not dense their cell structure, they should be providing very little backpressure.

20150518_173055608_iOS

From there it was back to where garageline provided a pair of resonators.  They have a ~10" body length and help knock the noise down a little - but there's room for more.  The garageline midpipe provided a great canvas for the next evolution of the car's exhaust.

20150518_173833684_iOS

 

Inside view of one of the resonators removed:

20150518_191249829_iOS

In their place, a pair of 2.5" 17" long Burns Stainless single-stage mufflers.  Very lightweight but also very effective.  Installed with v-bands to they can be swapped out for straight pipes later if needed.  These mufflers *shouldn't* cost much if any power but I didn't back-to-back with straight pipes.  I don't think they're any more restrictive than the resonators that were in there already.

20150518_194320530_iOS

The car is actually a little quieter now than it was before with stock manifolds, the Berks, and the unmolested garageline midpipe (kept the stock muffler on throughout).  Hit 95db in San Diego with that setup - hopefully this gets it under, hard to say.

From there, 100 miles north for a dyno touch-up at Shawn Church's in LA.  This is probably maxing out the iPhone microphone, but believe it or now, was a noticeably a little quieter than last time.

Here's how she did:

 

20150519_025032940_iOS

The bummer point first - there's a new 1000rpm-wide torque dip centered around 4400rpm.  I don't know that I've seen this before on other Z's with longtubes - need to keep looking.  I suppose it's possible it's some artifact of either the new cats or mufflers, but it's so pronounced, hard to say.  It was actually worse than this on the first couple tunes, this is the result with the dip minimized via tuning.

Two good areas more than make up for it.  First is the far left, from ~2800-3500rpm - those are some real gains, something like 15ft-lbs. in places.  With the car's gearing it does ~8.8mph per 1000rpm, so our slowest corners (~25mph) work out to about 2850rpm.

The car is stronger once out of the dip all the way to redline, especially above 6000.  It doesn't seem as coarse and choked as it did from the factory, now it zings all the way to the top.  Makes the car a lot more fun to wring out, with the sounds it made stock, it sounded like you were hurting it, now it seems to love to rev 🙂

The sound is a little bit "buzzy", not sure how else to describe it.   You can kinda hear it in the video.  370 folks who switch to high-flow cats hear a buzz on decel through certain parts of the rev range - the car now does that everywhere.  There's a bit of vibration through the pedal at 3500rpm under heavy throttle but nothing terrible.  Glad I kept the stock motor and trans mounts!

Last thought on another benefit - the headers saved 10 pounds over the stock manifolds + Berk HFC.

Filed under: 370z No Comments
18May/150

PPE Long-Tube Header install

This is one of the more gnarly projects for these cars.  Headers, particularly long-tubes, can be tricky to install on any car but it's especially the case with the 370.

I've read a few stories of people working through it, but haven't seen the journey well documented yet.  Tried to take a lot of photos and mental notes along the way.

By myself using jackstands, it took me about 12 hours to do it over 5 evenings.  I work pretty slowly and made some oopsies along the way, but at the same time my car only has 1400 miles and I didn't have any issues with stripped/rusted/seized fasteners.  I've seen people pay anywhere from $600-1000 to shops to do the install - point being, have a good idea of what your own time is worth to you before beginning.

1: get the car in the air

1_inair

2: remove factory strut bar.  You don't have to remove all the panels at rear, just the middle portion.  Nuts and bolts are 14mm

2_strutbarout

Step 3: View of the driver's side heat shield.  Held in with 4x 10mm bolts.  Got to all of them from above.

3_driver_intake_out

4: View of the passenger heat shield.  Same thing, 4x10mm bolts accessed from above.  Both heat shields come out up/forward.

4_passenger_intake_out

5: Time to get underneath the car.  There are about 8,000 10mm/phillips bolts holding in the undertray, with three of the push-snaps in the middle.  Easiest to remove all the bolts and the snaps last so it isn't hitting you in the face half the time.

5_undertray_out

Better be still smiling here, if not you better turn back!

6: Before shot of the cats.  Car already has Berk HFC on it, but the stock would look similar here.

6_cats_starting

7: Passenger cat "before".  Cat removal/replacement is covered in HFC install DIY articles.  Some people have removed the OE headers keeping the cats attached, and I suppose you could.  The Berks came back off pretty easily.

7_passenger_cat

8:  Driver's side "before".  Little bit busier in there 🙂

8_driver_cat

9: Passenger cat out.  With the HFC you can get to all three fasteners from underneath which is nice, no crazy 3' snake of extenders like you have to do when removing the OE cats.

9_pass_cat_out

10: Driver's side out.  Only a little tougher than passenger.

10_driver_cat_out

The above took me about 2 hours, that was evening 1.

Evening 2 begin:

11: View of the passenger header before removal.  Both sides are held in with 6 nuts on studs.  The studs are diagonally opposed across each cylinder's exhaust port.

11_pass_heatshield_off

12: View of the driver's side header.  Also in view are a big coolant tube (shiny metal), clump of electrical (black plastic), and A/C lines (black and silver at bottom).  For this project you spend a lot of time trying to squeeze in between those things - it pays to have small forearms here.  In addition to the squeeze there are some sharp parts which will slice you up.

12_driver_heatshield_off

13:  To remove all 12 nuts (14mm), I used a deep 6-point 1/2" drive socket on a swivel-head ratcheting breaker bar thing.  Been working on cars a long time and only bought it recently for some other project, glad I had it here.

13_pass_loosen

14:  Before you can pull the headers you need to disconnect the o2 sensors.  I thought it'd be easier to unbolt the sensors after the manifolds were removed to I unplugged the sensors up top and undid them from their little guide brackets on the back of the block.  The passenger side, it's buried back in there.

14_pass_o2_remove

15:  Passenger side stock manifold out!  yay!

15_pass_out

16: View of the passenger cylinder head with the manifold removed.  Unlike the black hole of the driver side, light can travel into this space to illuminate its shape 🙂

16_pass_removed

17: The driver's side o2 sensor plug is harder to get to (a consistent theme).  It helped to unplug the connector going to the throttle body.

17_driver_o2_prep

18: Driver side o2 sensor slid off its little post and unplugged

18_driver_o2_unplug

19: Driver side - out!  Got it out without having to remove the studs, or mess with the steering.

19_driver_out

20: Is there a manifold in there still?  Eh, can't tell...

20_driver_mani_out

21: The factory manifolds are actually really nice looking for an OE piece.  Some guy in Japan (or wherever they are designed) probably shakes his head when he sees people swapping headers.

Header primary diameter is a big factor in the shape of an engine's power curve.  Stock pieces are about 1.5" - which in a super overgeneralized hand-wave, is a little "torquey/small" for an engine making 50-60 whp per cylinder.

21_primary_diameter

22: Collector size is appropriate for the primaries but a little choked overall.

22_collector_ID

Evening 2 ends here, another 2 hours.

Evening 3 begin - this was the long one:

23: Unboxing the PPE's

23_PPE_kitchen

24: First to attempt install was the passenger side.  I recommend doing that with everything because it's a massively more accessible mirror image of the driver's side. What you learn here without a ton of pain, you can apply to the other side.

It wouldn't go in and something seemed really wrong here. This was one of my first heart attack moments. Check out the flange compared to stock:

24_flange_comparison

For a while I was surveying the shipping materials to be sure I could send them back. The flange seemed upside down, but then I saw the front (left-most in pic) cylinder was correct.  Took me a while to figure out, the gasket had holes in the right places, but also the cylinder head had the holes already tapped in the perfect spots?!?

So I swapped the diagonal positioning of the rear ones - it still wouldn't go in,  but now because of a lack of room.

Left the middle cylinder's studs in (original holes) and got the header on, and re-installed the other studs.  A ways into securing things I realized the middle would have to be swapped too..

Eventually got it in, studs in (they have a 6-point star end that needs a 1/4" wrench or socket - 6mm too small, 7mm too big) and nuts tightened.

25: Passenger side header in.  Three top nuts and forward lower tightened from above.  Middle and rear lower tightened from below with wrenches.

25_passenger_in

26: Starting point for driver's side install.  Lots in the way. Had to raise the front of the car a bunch more to allow it to be angled past the clutch parts.  The steering shaft MUST be disconnected and slid way up inside the column. To do that, remove the red-headed 12mm bolt, and remove the white plastic clip thing on the shaft.  The splined end of the column is keyed to the receiving end on the rack.  The problem is once you slide the shaft up past where the white plastic piece is, it becomes unkeyed internally up in the steering mechanism.  Take care to not alter the relative clocking of these components!

26_steering_shaft

27: The lessons from the passenger side helped but getting this far is awful.  To get the very tip of your fingertips holding the exhaust studs to the place they need to be, requires sacrificing your forearm in the jaws of the surrounding tubes and things.  It's extra painful because as you are moving your fingers, it makes the forearm area hurt more, as your finger's tendors try to move while clamped in a vice.

27_driver_in

28: The three top nuts aren't too bad, same for lower front.  The rearmost lower is accessible with a wrench from underneath (again way harder than passenger side) but the middle lower nut...well, all I could picture in my head is IMPOSSIBRU

That is the single toughest fastener to deal with in this whole project.

This is a view from directly underneath, an unobstructed column way too narrow to allow for any tool angularity.  Making it worse, I was too lazy/dumb to bring the front of the car lower again after raising in step 26.  That meant doing anything from underneath meant holding an abdominal crunch to get the arms/shoulders high enough to reach stuff.  I'm a typically beer bellied american so I called it a night at this point so I could look at it fresh the next day - was past 2am, a 5 hour work session.

28_impossibru

Evening 3 (Friday night) done, evening 4 begin.

29: Contemplating the problem, I thought I'd get some swivel-head wrenches, on the hopes I could find some plane that would allow me to tighten it.  Because of the V shape of the motor, tools want to fall off if not held in place.  But there's not much in the way of access to hold in place, not to mention allow for any installation motion.

The other problem was the nut was close enough to the primary tube, not enough room to fit the closed end of a ratcheting wrench (at least my mediocre-quality gearwrench stuff) on it.

What I ended up stumbling into, was to use the open end of the swivel-head wrench like so:

29_solution

This shortened the effective length of the wrench enough that I could move it 1 "flat" (1/6th of a turn) at a time within the space available. At the same time, the flex head being in that perpendicular plane allowed me to both hold it onto the fastener, but also torque it, with one hand.

After a few complete revolutions I had to keep stopping every 4-5 flats to let the blood flow back into my arm.  Access was from above the lower control arm and up through the maze of tubes. But at last, the hard mechanical part was done.

30: An unprepped o2 sensor extension

30_o2_extend_start

31: Ends stripped and crimped

31_o2_extend_done

32: I extended up near the factory plug to keep the nice factory head shielding in place down at the header end.

32_heatshield_remove

33: Some people have had trouble with this.  There are 2 black wires, 1 blue, 1 white.  I recommend cutting 1 black wire, crimping on one side, then checking continuity to ensure you're attaching the correct end on the other side.  Once that's done, you can cut the other 3 (since there's now 1 of each color).

33_find_right_wire

34: One of my forward o2 sensors boogered its threads upon removal from the factory manifold, even though I treated it nicely on the bench.  It wouldn't thread into the PPE header, and it was midnight on a Saturday night - exhaust shop and dyno appt Monday, leaving for big race Wednesday, no time to wait for a new one, and I don't have a tap/die tool in that size.  What to do?

What I did was use the other factory manifold where the sensor had come out cleanly.  Lubed it up a little and with some finesse, was able to use it to repair the o2 sensor's threads enough to get it to tighten and seal nicely in the new header.  Heart attack #2 averted!

34_o2_sensor_threadfix

35: Passenger side installed and wired up.

35_passenger_done

36: Driver's side installed and wired up.  The o2 sensor wires on both sides need some help getting secured in a way that keeps them from getting melted.  This wasn't too hard but at this point I discovered the transmission (which is right there and you'll contact at this step) has some weird casting bumps that are extremely painful to touch, much less rub against.  It feels like 20 grit sandpaper that also delivers an electric shock!

36_driver_done
37: From above, you can barely see the header in place once the intake is reinstalled.

37_intake_back_in

38: Driver's side you can't see it all, despite all the suffering!

38_intake_back_in_driver

That was evening 4 which included buttoning up the rest of the things, about 2.5 hours.

Drove it the next day (today, Sunday 5/17) and the steering was clocked about 20 degrees left.  A minute into the test drive the car freaked out and applied abs in a wacky way, then threw a light.

Evening 5 (tonight) was spent re-clocking the steering, which mercifully can be done without having to remove anything else.

..........

Test drive was short.  My car has the Takeda CAI, garageline midpipe, and stock muffler.  Compared to stock manifolds + Berk HFC, it was a fair bit louder on cold start, but maybe only a little louder at normal idle.  Louder on the street and it sounds quite a bit different now at high RPM.  Dyno'ing tomorrow and seat of the pants it feels like there was a gain in top end - the car always felt a little "choked" up there before (even with HFC) but that seems gone now.  However before that I'm having some super-high-flow cats installed just aft of the headers (per SCCA class rules) so the sound may be changing somewhat.

More to come soon, stay tuned!

Filed under: 370z No Comments