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2021 is shaping up to be a big year for this car, so this time around, I wanted to at least document the build, changes, and some of the ideology behind what I'm doing.
Its been posted here before, in various iterations (and usernames), but I've never done much for it as far as backstory or build.
2021 Goals:
1. Finish the new setup for less than $2500 out of pocket.
2. Race weight below 2500 lbs (with a driver and full tank).
3. Make 4-digit power.
4. Re-take the record for quickest/fastest IRS Dana 36 (Currently 9.5x @ 138)
5. Take the record for the quickest/fastest IRS C4 (8.40 @ 170)
6. ???
The car:
1989 C4 Corvette. Bought for $1500 with 81k miles on it, but it had been sitting for several years with no top.
I picked this up in 2016 after seeing Roadkill race their Vette Kart against a C7 and do incredibly well.
I IMMEDIATELY stripped the car, parted out the body, sold off the TPI L98/700R4 combo, made more than I spent, and started on something... different.
The original setup:
C4 Vette Kart, LS swapped, with quad turbos.
No idea beyond that. I just wanted something that could handle well, and go fast.
I threw a RCI top feed fuel cell in the back with a single AEM380, wired up a microsquirt, and it fired up on the first try without any issues.
The rundown on the car at this point in time (EARLY 2017):
-Bone stock 2001 240k mile 4.8, never even took off the valve covers.
-F-body pan, ICT billet adapter plates, stock flexplate with a cheap pilot bushing and I opened up the holes to fit the stock TH400 converter.
-Quad 5056 Internally gated T3 turbos from DNA Motoring. They were the anti-surge polished housings, so they were $160 each.
-Custom turbo manifolds, 2.5" downpipes, 3" sidepipes
-Decapped stock truck injectors.
-Ebay 2-1 intercooler.
-Slipping, leaking, smoking, storage unit bought TH400.
-$2000 invested total in engine/trans at this point.
-A MASSIVE 300whp. It did melt tires like nobody's business though.
Right around the this time, Leroy became a thing, and over the years I've learned to absolutely hate something that I've spent so much time on, because the world refuses to let me enjoy it.
Skip forward to the end of 2017, when I decided things needed to be taken a little more serious.
The car was a lot of fun, but had no seat belts, no roll cage, no brakes, no traction, no reliability, no power, no torque, no.... you get it.
So, I started working to completely revamp the ENTIRE car, every single aspect, that took ~6-7 months between the end of 2017 up to early spring 2018.
First, the engine.
I left the stock 4.8 in it, even though it was a disappointing 300whp.
I added a Howard's 226/232 110 LSA .578/.587 cam, some PAC1218s, and replaced the head gaskets with OEM LS1 head gaskets. Nothing else was touched.
I fired it up on a run stand a few times, and it sounded AMAZING.
I swapped to Dual AEM380 pumps, E85, and spin-on pre/post filters.
I mounted them underneath the current top feed RCI cell.
Microsquirt remained. Nothing with the turbo setup changed. Even the stock TH400 remained for a while (although paddle shifted).
Before all of this went back in, I decided it was time to upgrade the car as a whole.
That means wheels/tires, cage, paint, brakes, seat belts, coilovers, etc.
I can't remember the exact order of things, so I'll just buzz through some of it here.
I grabbed some C6Z wheels for $200 in pretty bad shape. 18x10 and 19x10. The were spray painted and peeling.
I picked up some Cooper Zeon RS3-R tires in 325/30/19, and some cheap Achillies 275/35/18 fronts, all new, for a total of less than $500 shipped.
I cleaned up the wheels, had a buddy mount/balance the tires for me, and peel coated the wheels in black (meh).
I had about $800 total invested in the wheel/tire upgrade.
For coilovers, I grabbed some Kawasaki ZX10R (2011-2015) coilovers individually from ebay for $35-40 shipped each.
This was CONSIDERABLY cheaper than any available coilovers for the C4 and I'm glad I did it honestly.
Double adjustable, FAR nicer ride than the stock leafs which were topped out because of the weight reduction.
For the fronts, I basically bolted them in.
The rears were almost the exact same, but for the upper mounting, the front hole became the new rear, as I leaned them forward so the reservoirs cleared the axles.
Overall, $200 in the coilover upgrade if you count metric nuts and stuff I had to go buy.
Brakes, pretty basic stuff. C5 conversion in the front, stock rears. I paid $300 or so for front C5 calipers, brackets, and adapters to bolt them to my spindles.
I did get Powerstop Z26 rotors and pads for the C5 fronts and C4 rears. I also ran all new brake lines with a JEGS line lock.
I also went with stainless braided lines front and rear.
$800 total invested in brakes.
Then, the car.
I grabbed some conduit and used it to do a mockup of a cage in a few different iterations.
Turns out, cheap conduit makes for amazing mockup.
I also grabbed a big 69" NRG wing and bought a ton of Chromoly tubing, heim joints, and even linear actuators to have a HUGE wing with a functional air-brake.
Total invested here for wing, tubing, heims, actuators, conduit, bender: $600
Did all of the mockup, and then started on the cage.
I stripped it BARE, almost nothing in it. I pressure washed it repeatedly. I painted the inside of it Army green, and the outside of it flat black.
A local place sold 1.75" .134 wall tubing for $1.90 a foot. I put about 100 feet of tubing into the car. Total weight and total cost were both under 200.
A forum member here on LS1tech loaned me a tubing bender (LIFE SAVER).
Trial/error, but I eventually got it.
The car was looking pretty amazing with the new wheels, tires, brakes, cage, and rear wing.
2018 ended on both good and bad notes, though.
I managed to get it on the dyno again. 300whp on gate the first time. With just cam/springs/E85, it went to 570whp on gate. Nearly doubled the power.
Also, that first trip to the dyno made the stock TH400 let go. I had to limp it home, not wanting to shift.
So.... with 2019 came more changes.
Last edited by AwesomeAuto; 11-23-2020 at 09:20 PM.
The 1st thing I did? Bought an MS3Pro Evo and tossed that in.
The 2nd thing I did? Had a house built.
That 2nd one slowed progress a LOT. The car sat for the first 6 months out of the year at my sister's house, waiting for me to pick it up and bring it home.
When I finally got it here, it had no trans. Engine was still in it and running, but no trans. It had never moved under its own power on the MS3Pro.
I didn't end up with a trans until May.
A point I skipped, is that if you look in the original pictures of my FIRST doing the LS swap into the car, it had a fresh trans on it.
A local guy that claimed to be an expert sold me a fresh TH400 for $350. I ordered a manual valve body and took it to him and had him add that in.
Before he finished it, he did ~6 transmission for friends of mine. The fact that most of them never worked or failed immediately should've been a hint.
After 3 attempts to use his trans (the car never moved with this trans), I sent it back to him to FINALLY fix it, just so I could sell it.
It sat there for 3 months, before I go to pick it up (he called saying it was done) and he hands me the parts he was supposed to install and tells me how to do it.
The trans didn't work for the new guy either. I split the cost with him getting it finally fixed. What a disaster.
So in May, a buddy of mine recommended me to someone that does transmissions.
I picked up a good TH400 core for $150, ordered a CK 1+2 gear leave brake (buttonless reverse), a custom PTC converter, and dropped it all off.
$700 is what he charged me for disassembly, rebuild, lots of upgraded parts, and extras.
I put it in, and it worked. I couldn't have been happier.
Then tragedy strikes again. The ground strap falls off of the battery at a car show.
I go to crank the car, and it tries pulling all of the ground through the fuse/relay panel that is grounded to the engine.
It welds shut the trans brake relay that is connected directly to the grounding block.
I can't move. I try every gear. Eventually, it brakes free in neutral, and kicks backwards. That's when I realize the brake was on.
Reverse band broke. I had it repaired, and we were off to the track.
The IRS Dana 36 record at the time was 10.77. This is the glass-geared 7.75" differential available in the automatic C4 Corvettes.
Most people were breaking them running mid 11s. I tossed on some MT ET Drags that I bought for $100 mounted on Soft 8s.
Pull up to the starting line, launch at 3200 on the brake, super lazy launch and a 1.6x 60 foot.
At the top of first gear, I get slight ignition cut, and then it comes to life shifting back into 2nd.
I realized the oil pressure safety had kicked in. I was sucking the stock F-body pan dry.
I stay in it, and get to the end of the track and on my FIRST pass, am rewarded with a 10.61 time slip, and the quickest/fastest Dana 36.
Not long after, dyno again. This was in the fall some time.
I put it on the rollers with the built TH400 and small PTC converter, and on gate pressure was rewarded with IDENTICAL numbers to the stock TH400/converter combo.
570whp, and basically no torque. This was at 7000 RPM.
I shredded the belt on the dyno. Also shredded it the next time on the dyno after I made changes to the oil pan to see if I had fixed my oiling issue (I did).
To close out 2019, one last dyno trip.
Same 560-570whp I had done every time at 7000-7200 RPM. Then, parts failure.
The ground wire on the 3-port MAC had fallen off of the terminal bus and grounded itself to the aluminum plate the bus was mounted on.
The result? The gates didn't open. Around 6000 RPM, I hit boost cut and it shut the engine down. The Deka 80s were at 130+%.
I take a peak at the results on the screen, 889whp and climbing hard. The little gen 3 4.8 was a warrior.
I drove it home and parked it for the winter.
2020 was a busy busy year.
At the end of 2019, after my track outing and dyno visits, I found out there was yet another little one on the way.
I rushed to finish up a few winter projects on the car.
-I swapped to a ratchet shifter, and its AMAZING to drive with the manual valve body.
-I finished a few MS3pro features I had been messing with but never really finished, like using the stock C4 ABS for traction control.
-I installed a Saturn Vue electric power steering column (amazing having power steering again).
-I put an Improved Racing baffle in my stock F-body pan.
-I put removed the huge spin-on filters and went with small china stainless fuel filters.
-I added a rear sway bar back onto the car.
-I removed the top feed fuel cell and swapped in a sumped cell.
-Other than this, minor changes, and still NOTHING to the engine (its lived a hard life, and never let me down).
The first thing I do with the car for 2020? Gender reveal at the end of winter.
We give a buddy of mine the results of the Sonogram and he ordered colored smoke tires from Highway Max (EXPENSIVE).
By the time I pay for shipping, buy spare wheels, and have him mount them, I was out $700.
Dozens show up for the burnout. We go to the park at the end of my street, and I give it hell.
Line lock on. Trans brake on. Foot to the floor, let off the brake, bang 7600 RPM in every gear, through the top of third with tire speeds over 200 mph.
The results?
After the gender reveal, I didn't touch the car until probably June. We went for a few cruises when she was 7-8 months pregnant, but I didn't actually do any work.
I stockpiled parts for a bit.
Then around June/July, I got a few things done.
-I upgraded the lower strut rods on the rear end (lower control arms) and added brackets that prevent camber change on squat.
-I added a catch can.
-I added an overflow that was only half garbage.
-I bought new 5-star jegs wheels and new front skinnies, and transferred over my old dry rotting MT ET Drags onto the new wheels.
2020 was also the year of the joyride.
Dozens of people have been in the car this year. Friends, family, friends of friends, strangers, etc.
Lots of wide open pulls, donuts, burnouts, etc. It became a weekly thing.
I even let my girlfriends BFF drive the car. She's the 2nd person that isn't me to drive it. She's also the ONLY other person to drive it without me in it.
She scared the hell out of me, my gf, herself, etc. I only let her because she's been drag racing for years.
I went to an old dead end road and tested trans brake settings. 4000 RPM was about all I could get out of it, and ~4-5 PSI.
Got everything ready, went to the track.
First trip, multiple low-10 passes. I had issues tossing belts every single pass. Even when I didn't, it would run hot by the end of the track.
I also noticed that my rear wing was folding down 45 degrees by the end of the track.
I bought a shorter belt, re-routed everything, went with a manual tensioner.
Next outing, removed the wing. Flat 10 second pass with a tossed belt. Put on a 1-inch shorter belt and did 5 consecutive 9-second passes on just 9 PSI.
This is with a converter so tight that I'm dropping 1600-1800 RPM on shifts, and a 3.07 rear gear.
The car had 9.50s or better on single digit boost with better gearing/converter, but I never got there.
Was briefly the quickest/fastest Dana 36 again (another turbo LS vette kart guy has been trading places with me all year).
Went one last time. Turned the boost up a fair amount. Got 3 passes. First pass was a 9.90 on ~9.2 PSI.
Other 2 passes were 1/8 mile only on 15 PSI. I didn't pick up anything on the 60 foot, but dropped nearly a half second off of my times.
5.89x, two passes in a row, still on the same 60 foot (probably first ~120 were about the same) as my 6.3x times I was getting from my high 9 quarter passes.
Didn't run it out the back, it was spewing like a volcano out of the radiator and the tires were getting hit too hard on the 2-3 shift.
Which leads us to a couple of months ago, when I put the complete pull-out engine/turbo/radiator/etc up for sale.
Someone bought it, to drop into their C4 vette kart. They're paying me to do the swap, and I currently have it running on a Terminator X to prepare.
This means.. I finally get to build the engine I intended to originally, but spent 3-4 years trying to blow up a 4.8 that never once had any issues (other than tossed belts).
Which brings us to today......
Last edited by AwesomeAuto; 11-23-2020 at 10:45 PM.
Nice write up. 1 of the reason I do builds on here, so I can remember what I did lol. What on earth prompted the ZX10R shocks as opposed to a car shock? Light weight?
Nice write up. 1 of the reason I do builds on here, so I can remember what I did lol. What on earth prompted the ZX10R shocks as opposed to a car shock? Light weight?
I had been scouring cheap coilovers on ebay for a long time.
When I seen the ZX10R coilovers in their complete form, they had everything I needed. Eyelet mount on the bottom, stud mount on the top.
They were roughly the length I needed also, and the spring rate was in the ballpark of 400 lbs/in, which was good for the orientation I was running them in.
I bought one, tweaked it a little and it fit. Tried it on the rear, it fit. Spent a couple of months watching Ebay until I found 3 others. In about ~4 hours, I had all 4 of them installed.
The car handles and rides significantly better. Flatter in the corners, softer over bumps.
Before, the rear leaf was completely at the top of its travel. I would have to climb on and jump on it to make it go down at all. It made the back slide out everytime I tapped the throttle.
I'm extremely happy with the cheap coilovers, but I'm also at the point of wanting to upgrade.
The front of the car sits higher than the rear, even though I have 2" worth of spacers on the rear. I'll likely wait until a deal pops up on double adjustables and put them in the front first.
Finally updated everything to get it up to current.
Unfortunately, sharing videos from Instagram isn't easy lmao, so the last bit of that 2020 post didn't get Embedded.
Obviously there is a massive amount of detail missing.
I think I left out:
-The car was started with a fingerprint at one point.
-It had functioning paddle shifters for the TH400 at one point.
-The rear wing used to work as an air brake on linear actuators, but I removed it once I realized they couldn't lift the huge wing back up at 140 mph.
-The wiring has become a major disaster, and I have $800 worth of misc wiring items to install this winter.
-The TOTAL cost of everything I own for the car right now is right around $15k, that is factoring in the original cost of the car which was technically nulled by the part-out.
What engine CID, aluminum or iron block, head choice etc. are you going with this time?
-Aluminum Gen 4 5.3 (may or may not go forged). Heads are still up in the air. I have a ported set, but I'm still considering options.
-Quad GTX3071R clones, .63 A/R T3, 3" downpipes merged into 4" dumps on each side. Bellmouth inlet on each turbo.
-Holley Split intake, 102mm elbow, China throttle body.
-Vibrant 6" intercooler, custom end tanks, Wiggins style clamps and 4" piping between intercooler and throttle body.
-Baker complete valvetrain.
-Holley 302-3 pan with baffles.
-Mounted to the car with front/mid plates so I can relocate the coils to the old mount areas.
-Accusump system.
-Upgrading the radiator to something much larger, with either a Delta PAG brushless fan, or a modified C7 brushless fan.
Aiming for an extra 1000 RPM on top of what I was seeing with the Gen 3 4.8, so 8200-8400 RPM.
Also shooting for 1200-1300 HP.
I'm hoping to run 9.0-9.2 on single digit boost this time around.
The 4.8 made 560-570 on ~9.6 PSI.
The 5.3 would make 10% more if all things were equal from the increase in displacement (+50 HP).
Add 1000 RPM, a better intake manifold, larger cam, better heads, better flowing downpipes w/o sidepipes, and 4 billet turbos, I'm hoping this all amounts to another ~120-140 HP. So the goal is 730-760 at the wheels on less than 10 PSI.
My converter was originally specced for this combo, so it'll work better than it did with the 4.8. I've also added a dump valve for launch.
I'm also trying to shed about 160 lbs off of the car.
Most ET calculators, with 2500 race weight and 730whp put me in the 8.7x territory,
but I'm giving it as much as half a second on top of that because of the gear ratio, IRS, and whatever other issues.
I'm planning on keeping track of this year's build here.
I like the idea of trading records with the other Vette cart.....so build it to take another second off 😂. That battery ground strap was a pisser!
Yeah, the guy and I run a Facebook page for Vette karts called Vette Hack.
His car was originally setup for autocross and he switched to drag racing when he removed the small block and went with a nitrous LS.
Not long after, he went turbo. He went 9.50s the night his Dana 36 let go, and has since swapped to a straight axle 8.8.
If I run better than 9.50s, I don't think anyone else will be going faster than that for a while.
The 10.97 record stood for like 11 years before a Vette Kart guy with a stock LS3, that he won in a raffle, went 10.77.
Always thought these karts looked hacked together but yours looks great. While trying to figure out why I have come up with two possible reasons in comparing it to either Leroy or the Roadkill version. In the case of Leroy you don't have the turbos hanging up so high and in both cases (which may explain the high turbo mounting w/Leroy) you don't have the cage extending high down the side of the engine bay (at least I don't see it). Do you give up any anything by not extending the cage into the engine bay and tying into the front of the car? Love the front bumper too.
Always thought these karts looked hacked together but yours looks great. While trying to figure out why I have come up with two possible reasons in comparing it to either Leroy or the Roadkill version. In the case of Leroy you don't have the turbos hanging up so high and in both cases (which may explain the high turbo mounting w/Leroy) you don't have the cage extending high down the side of the engine bay (at least I don't see it). Do you give up any anything by not extending the cage into the engine bay and tying into the front of the car? Love the front bumper too.
I didn't originally extend the cage because it wasn't required for an 8.50 cert.
The issue I had afterwards, was that with so much weight hanging off of the side of the engine, I would get really bad twisting up front when going over bad roads or train tracks.
Solid mounts didn't fix it. I'm hoping motor plates help this time around. If I have to extend the cage, it'll raise the turbos up probably 6".
I really want to keep them low. I drive the car a few thousand miles a year and its already hard to see directly in front of it on twisty roads (it handles AMAZING).
The front bumper was originally made to extend out so far because it was meant to house the intercooler. When I ordered my intercooler, it was supposed to be a top-exit.
When it showed up, it had a 90 degree outlet. I tried to make it work, but eventually gave up and decided to run it the way I have been.
So glad to see this car back on the forum.
Leroy is cool and all that but Cletus has a much bigger bank roll and to be honest what your doing takes creativity and not just ordering parts from a vendor.
I'm curious to see how this car progresses in the future.
Quad billet turbos??
Nitrous??
Big cube short block?
So glad to see this car back on the forum.
Leroy is cool and all that but Cletus has a much bigger bank roll and to be honest what your doing takes creativity and not just ordering parts from a vendor.
I'm curious to see how this car progresses in the future.
Quad billet turbos??
Nitrous??
Big cube short block?
Scroll up to post #12.
I'm hoping to go 8.99 on the Dana 36. I REALLY baby the first 300 feet to keep it alive.
I could do it on the current setup around 15-17 PSI. The 5.89 1/8th pass on 15 PSI shows that I was definitely in the ballpark if I added power on the back half.
If I get around to swapping in the IRS 9" (its a $3500 swap), it'll put my total investment in the car around $20k, and I'll set my sights on going faster than 8.50.
Nitrous has always been an option, and at one point I was actually installing it on the car. I don't think it'll get that far, at least not this year.
There is technically a 3.0 version planned for the car as a whole, but that is very very much a funds-permitting project.
I want an LSNext aluminum block, 388", quad billet 6262s, Glide /w GV overdrive, an updated cage, and a 9" solid axle rear. That's the ultimate goal. 7.99s or better. Maybe 2022.
So glad to see this car back on the forum.
Leroy is cool and all that but Cletus has a much bigger bank roll and to be honest what your doing takes creativity and not just ordering parts from a vendor.
Manuals also require some sort of skill to get down the track after you buy the parts. Having a car your grandma can drive the same times as you while eating an ice cream cone just isn't as entertaining. Look at Cleetus C6 Ruby, a dozen people have jumped in that thing and driven it to within a tenth of its personal best, many of which have never driven a 9 sec, let alone an 8 sec car before.
Manuals also require some sort of skill to get down the track after you buy the parts. Having a car your grandma can drive the same times as you while eating an ice cream cone just isn't as entertaining. Look at Cleetus C6 Ruby, a dozen people have jumped in that thing and driven it to within a tenth of its personal best, many of which have never driven a 9 sec, let alone an 8 sec car before.
I was in no way discounting Cleetus' skill behind the wheel, running any manual car into the 7's requires a great deal of skill and I thoroughly enjoy watching his videos.
I was simply acknowledging that Cleetus has the budget to do whatever he can dream up which lets be honest, many of us would love which has elevated his success but that builds like The Chupacabra also appeal to the garage mechanic car guy who is operating on a small budget while trying to have a good time and go fast.
11-23-2020, 08:30 PM
The Quadvette. Goals and upgrades. 
