C5Z Track Toy

Post Your Delco Powered Ride Here
User avatar
NSFW
Posts: 679
Joined: Fri Feb 02, 2018 3:13 pm

C5Z Track Toy

Post by NSFW »

Power mods:

Haltech Killer Bee air intake
LS2 throttle body (tried to use a Nick Williams 102, failed so far)
FAST LSXR 102 intake manifold
Heads were ported and milled by a previous owner, 11:1 compression ratio
232/234 @ 112+4, .600/.600 camshaft
Kooks 2" headers, 3" midpipe, 3" mufflers (mufflers are heavy, drone is terrible)

Misc motor mods:

DeWitt radiator with engine oil cooler (oil still hits 245F / 118C on track)
Melling high-pressure oil pump
LS7 lifters and pushrods
BTR 660 springs
RPC Billet Carbon Twin clutch, lightened by Tony Mamo (32 pounds if I remember correctly)
Cheap ebay catch-can

Other:

StopTech ST60/ST40 brake kit
CarboTech 1521 pads for (street, because I liked them in my Subaru)
CarboTech XP12/XP8 pads (track days, since I like their street pads)
Lowered on stock ride-height adjusters
C6 reproduction wheels 18x8.5 and 19x10 (street)
TSW Nurburgring wheels, 18x10.5 front and rear (track)
Cobra Imola seats
Brey-Krause harness bar
Sparco harnesses (track)
C6 3-point belts (street - no lap belt retractor = more room for seats)
Carpeted wood divider to separate the trunk from the cabin (makes the drone tolerable)

In boxes:

ACP heat-extractor hood (hoping to get the oil down around 220F / 105C)
Bare aluminum Holley valve covers (will have them painted along with the hood)
4EyeC5 headlight kit (low-rise popups, projectors, LEDs)

[Pictures to come - my internet connection is not cooperating right now.]
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
User avatar
NSFW
Posts: 679
Joined: Fri Feb 02, 2018 3:13 pm

Re: C5Z Track Toy

Post by NSFW »

Story:

I started racing a Ford Escort in the ChampCar budget endurance series with some friends back in 2009, and loved it. It's a bit like LeMons - long races with cheap cars, but less circus and more race. Later we switched to a 96 Mustang in the Lucky Dog series (same format, slightly nicer cars). Every year I thought we'd get more track time, every year there was one obstacle or another, so I started looking for a car of my own... It had to be street legal so I could easily drive to the track and easily drive it so a shop if it needs work (as opposed to coordinating a trailer / tow vehicle / friends' schedules). And I wanted rear wheel drive, and since the Mustang's power was so much fun I wanted to go up a notch from there. And it was supposed to be black, white, or silver, but in late 2017 there was a blue Corvette for sale that I couldn't pass up.

Not sure how 2018 passed so quickly (this didn't help) but I got my first 4 track days in the summer of 2019 and I'm looking forward to a bunch more next year.

Sidebar:

In the Subaru world there's a company called Tactrix with a product called OpenPort that costs very little and lets you read and write the ECU. It's closed-source, but inexpensive, and they have a synergistic relationship with a community of people that created open source tools for ROM editing, data logging, and reverse engineering of the ECUs. That was actually the deciding factor in me buying a Subaru when I was looking for daily driver back in 2006. Initially I just wanted to use those tools learn how engines worked... that led to logging, and then tuning, and then reverse engineering, and then finding tools to compile code for the chip in the ECU, and writing a little utility to apply patches of that compiled code.

So when I bought a car that's a couple years older and 10x more popular, I was a little surprised to find that the open source community was just getting started. PeteS / Loud160 introduced me to Antus and Tazzi. I've been doing Windows development for a long time, but didn't know where to start with PCM stuff. Antus had already solved the hard problems but needed help with the Windows-application side of things. PCM Hammer started coming together.

Story continues:

Between not having a dyno and not wanting to miss a second summer of track days, I paid a local guy to tune my car. It made great power, but it barely idled and would stall at every third stop light. Fortunately by that point PCM Hammer had full support for the P01, and both cmaje and LRT had XDFs for the operating system on my car. Idle isn't perfect yet, but the car doesn't die anymore.

With the 2019 upgrades (heads, cam, intake tract, exhaust) the car made 475whp on a local shop's DynoJet. I think that might be generous, but I won't argue with it.

So far I've only had it on track at The Ridge Motorsports Park in Shelton, Washington, USA. On the last track day of 2019, the best lap time I saw on the timer was 2:03, but that was with me lifting on the straights to stay avoid passing/outrunning my friend in the aforementioned Mustang. I suspect I was doing around 2:00 on my own, and another 3-5 seconds faster still for a few laps chasing an E46 M3 (a little bit outside my comfort zone, but I learned a lot in those laps).

Hopefully in 2020 I'll take it to Portland International Raceway where my best time in the Mustang was a high 1:32. And maybe to Oregon Raceway Park where I'll demote myself to the novice class for a while, since I've never been there before.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
User avatar
NSFW
Posts: 679
Joined: Fri Feb 02, 2018 3:13 pm

Re: C5Z Track Toy

Post by NSFW »

This space reserved, just in case.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
User avatar
NSFW
Posts: 679
Joined: Fri Feb 02, 2018 3:13 pm

Re: C5Z Track Toy

Post by NSFW »

I've done a terrible job updating this thread for two reasons:

1) I'm lazy.
2) The motor broke last summer, and I've been waiting forever on parts.

I'm pretty sure it dropped a valve (possibly due to a broken timing chain?) but it definitely shattered a piston and sent half of that piston into the intake manifold. And it cracked a sleeve, dumping coolant into the oil pan. Sleeve replacement on LS6 blocks seems a little sketchy, and I wanted more cubic inches anyway, so the car will be getting a 454 with LS3 heads and a dry sump.

Mostly I've been waiting for Dart to deliver a block that was supposed to be ready almost six months ago. But, if all goes well, I might have a new engine at the end of this month (today is November 1).
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
immortality
Posts: 3416
Joined: Thu Apr 09, 2009 12:31 pm
cars: VH, VN, VS, VX

Re: C5Z Track Toy

Post by immortality »

Pardon my ignorance but what was the original motor?

Fairly sure there was an issue with valves failing/dropping on a particular engine used in Corvettes back in the day.
User avatar
NSFW
Posts: 679
Joined: Fri Feb 02, 2018 3:13 pm

Re: C5Z Track Toy

Post by NSFW »

The original was an LS6. It had an ASP crank pulley when I bought it, and I saw a post from a guy who thinks those are associated with broken timing chains, so maybe he was right. Or maybe it was just a freak valve failure - I won't know for sure until the motor comes out, I'm too lazy to take it apart while it's still in the car.

I heard about LS7s having issues with the heads, and I think that was related to valves in particular, but I don't know much about it.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
User avatar
NSFW
Posts: 679
Joined: Fri Feb 02, 2018 3:13 pm

Re: C5Z Track Toy

Post by NSFW »

The new motor is built, tested, and paid for, and is on a freight truck crossing the country right now.
Meanwhile I swapped from the stock P01 to a P59 last weekend, which was even easier than expected - I had forgotten that the pin numbers are printed on the backs of the connectors. :)
The car turns on and the security light turns off, so I think I did it right.
The shop that's going to do the motor swap will probably need at least a couple weeks to get me into their schedule, but the day is getting closer...
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
Cincinnatus
Posts: 305
Joined: Fri Jul 30, 2021 5:49 pm
cars: 97 Corvette
92 Camaro
2005 Silverado
2001 Savana 2500
1998 c3500hd
1998 tahoe

Re: C5Z Track Toy

Post by Cincinnatus »

Would love to know details on your dart engine. Iron? Bore and stroke? You using any stock internals? I have a c5 I rebuilt but drivetrain was undamaged though I'm considering building a 6.2l for it. I thought most of those race groups require following class rules for engine and suspension. Ls6 and ls3 used sodium filled hollow stem exhaust valves. Ls7 had guide failures I believe, and maybe titanium valves. Because of failures, I hear they go to stainless solid stems. Titanium are lighter, but I read they eat guides. Good luck racing!
User avatar
vlad01
Posts: 7780
Joined: Mon Oct 08, 2012 6:41 pm
cars: VP I S
VP I executive
VP II executive
VP II executive #2
VR II executive
Location: Kyneton, Vic

Re: C5Z Track Toy

Post by vlad01 »

Yeah although Titanium is strong and light and pretty malleable it cold welds/galls very easily which will chew other metals out that it contacts, also Titanium is very notch sensitive, meaning even a scratch or slight notch can easily initiate a fracture despite the metal being pretty malleable.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
User avatar
NSFW
Posts: 679
Joined: Fri Feb 02, 2018 3:13 pm

Re: C5Z Track Toy

Post by NSFW »

I won't be racing it, so I don't need to worry about rules. I'm just building it to be fun, and hopefully reliable.

Bore is 4.185, stroke is 4.125.
Dart aluminum block, Golen's heads and cam.
The valves are stainless if I remember right.
Stock rockers, aftermarket bushings (I don't recall which).
Daily 2-stage dry sump.
Wiseco pistons, but I don't recall who made the rods or crank.
Fast 102 manifold. Katech 103 throttle body, Haltech Killer Bee intake.
Kooks 2" headers, 3" x-pipe and mufflers.
ID injectors, Fore FPR, Aeromotive 340 pump.

It made 690hp on their engine dyno, so I'm guessing 620ish at the wheels. With the original LS6, third gear was right at the limit of what the tires could handle. My hope is that 4th gear will pull just as hard now. I'm sure it will be a lot of fun regardless.

The engine has arrived at the shop, but I'm still waiting to get into the schedule.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
Post Reply