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I have this posted over on LS1Tech, so I've decided that I might as well post it here.
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.
https://www.facebook.com/100002169792801/videos/1814032318679077/
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.
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......
Now I just need to wait on the guy to come get this, and I can start on the new setup with full force.
I've started mocking up the motor plates. The rear one doesn't come close to fitting.
The pedal box on the driver's side sticks out a lot, so I'll have to do some major trimming on the motor plate on that side, and move the engine/trans forward about 1".
I'll compensate for the weight offset by moving as much as I can towards the rear.
I'm putting the master cylinder on the inside of the firewall and deleting the brake booster to allow me to move the back turbos inward/rearward.
I'll likely also relocate the line lock under the dash, but haven't decided yet. It definitely can't stay where it is.
I'm also looking for a way to lessen the footprint taken up by the wiper motor. It took up a tremendous amount of room before.
I don't want to remove it completely. I would really like to have wipers for emergency situations (and also Drag Week / Power Tour).
Now I just need to wait on the guy to come get this, and I can start on the new setup with full force.
I've started mocking up the motor plates. The rear one doesn't come close to fitting.
The pedal box on the driver's side sticks out a lot, so I'll have to do some major trimming on the motor plate on that side, and move the engine/trans forward about 1".
I'll compensate for the weight offset by moving as much as I can towards the rear.
I'm putting the master cylinder on the inside of the firewall and deleting the brake booster to allow me to move the back turbos inward/rearward.
I'll likely also relocate the line lock under the dash, but haven't decided yet. It definitely can't stay where it is.
I'm also looking for a way to lessen the footprint taken up by the wiper motor. It took up a tremendous amount of room before.
I don't want to remove it completely. I would really like to have wipers for emergency situations (and also Drag Week / Power Tour).
IIRC there was a guy who used a smaller wiper motor. It had no pulse function, just on and off but the footprint was relatively small by comparison. I have no clue what vehicle it came out of however and do not remember where I read it but it does exist here somewhere..
IIRC there was a guy who used a smaller wiper motor. It had no pulse function, just on and off but the footprint was relatively small by comparison. I have no clue what vehicle it came out of however and do not remember where I read it but it does exist here somewhere..
In this picture, you can see the inconvenience of the wiper motor.
It was <1/4" from the fuel rail which made pulling the engine in/out with the intake still on a nightmare.
My fuel lines were routed through there, as well as the 10 AN line for the catch can, the grounding wires for the driver's side coils, a couple of turbo oil lines, and the booster line was right there. I also needed to get my hand back there to remove the 2 upper bellhousing bolts on the driver's side and it was a disaster. This time, before pulling the engine, I removed the wiper motor and was blown away but just how much easier it made everything. I've decided I want to either relocate it, or replace with a smaller motor. I'll mount the motor down inside of the cowl if I have to, I have lots of space down there.
I love all the custom work! And it almost makes me want to build one. On my track car I tossed the wipers and motor awhile back. I suppose you want them for road legal issues? I would think you could even mount the motor inside the cabin with the shaft through the firewall. Just a thought. If it would mine I would lose the stock parts for something smaller and modern.
I love all the custom work! And it almost makes me want to build one. On my track car I tossed the wipers and motor awhile back. I suppose you want them for road legal issues? I would think you could even mount the motor inside the cabin with the shaft through the firewall. Just a thought. If it would mine I would lose the stock parts for something smaller and modern.
Yes, I want to keep it as road legal as I can, and useable.
I put 6000 miles on the car this year between March and October when my 2013 Dodge Dart decided to break down. This became the new daily.
I've been caught in the rain a few times in it. One time the rain was so heavy that there was standing water in the car that would rush up the firewall when I would hit the brakes and splash back at me. I removed the rubber caps on the holes in the floor and they are now drains.
Was it tough removing the cross member by the rack? I'll be doing a cam swap on mine soon and I might want to remove that as well.
I think a Sawzall with a carbide Diablo blade took it off in <10 seconds. I used an angle grinder with a cutoff wheel to clean up the stubs.
The LS engine fit in there just fine, even with the longer truck accessories.
I removed the bar because of the sheer amount of times I had the engine/trans in/out of the car in the first couple of months and was tired of having to raise the front of the car several feet off of the ground to be able to pull the engine with the transmission still attached.
Just a heads up, for any of you considering installing a mid-plate between your engine and trans in a C4.
It sucks.
On another note, if you cut off all of the tabs/ears on the driver's side of the bellhousing on your trans, you can center the trans in the tunnel and the engine in the engine compartment.
Doesn't the brake fluid get a bit warm next to the Turbo? I would try and keep the extra heat out of the brake lines.
That is a great Cart you have built there! They look like a lot of fun to drive.
How do you get to drive on the roads without a body?
Doesn't the brake fluid get a bit warm next to the Turbo? I would try and keep the extra heat out of the brake lines.
That is a great Cart you have built there! They look like a lot of fun to drive.
How do you get to drive on the roads without a body?
No issues with hot brake fluid. I'm moving the master cylinder inside of the firewall soon so it'll be even less of an issue.
There aren't any laws that say the car needs a body. Bodyless buggies have been legal for decades. Jeeps can drive without doors.
Convertibles are... well convertible. I just combine them all.
-Aluminum 5.3 (Stock long block)
-Quad Billet GT3071 turbos
-3" Downpipes into 4" merge dumps.
-Holley split 4150 intake with a 105mm Elbow
-Custom intercooler using a Vibrant 6" thick core.
-Baker cam/valvetrain
-Ran on pump E85 and controlled by MS3Pro.
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The Quadvette. Backstory, Upgrade Path, Goals.
