Poorvette
#61
Team Owner
Pro Mechanic
I powershifted a T5 behind a SBC 400 in a Trans Am for years and years. I broke a $12 shift for at one point. It's all about traction, and shift technique. They CAN last. And like wise...there are people who can break an anvil.
#62
Racer
Thread Starter
I centered the motor mounts...
Apparently C4 vetts should have the motor offset 2"
So I seem to have some cutting to do.
AC compressor won't fit, need a delete pulley. Since I habe $0 I guess I better work on other things....
Apparently C4 vetts should have the motor offset 2"
So I seem to have some cutting to do.
AC compressor won't fit, need a delete pulley. Since I habe $0 I guess I better work on other things....
Last edited by rbates74; 05-21-2019 at 08:21 PM.
#63
Team Owner
Pro Mechanic
Any word on that T5??
I used the brackets out of an '88-'95 truck...minus the AC part....
I used the brackets out of an '88-'95 truck...minus the AC part....
#64
Do you know your rear gear?
EDIT: Just noticed Tom said the same thing. That makes at least 2 of us with experience saying get a T5 and let that that car rip.
Last edited by pologreen1; 05-22-2019 at 01:00 PM.
#65
Racer
Thread Starter
The AC on a 3800 is verry low and very wide hits both the frame and the steering...
Good news is everything else is working out. Though im still looking at options of moving things around.
#66
Team Owner
Pro Mechanic
Cool....thanks!
Whoops Yes, I forgot the 3800. Duh! I was thinking SBC.
Whoops Yes, I forgot the 3800. Duh! I was thinking SBC.
#67
So you will use the pontiac trans? Man if you make this all work successfully in a c4, you are an amazing engineer.
Starting to think a fiero would have been the item, but this is interesting.
Starting to think a fiero would have been the item, but this is interesting.
#69
Racer
Thread Starter
Jeggs rollcage sucks in a vette. I will have to lower my seat 4 inches to have enough room with that bar.
Jeggs rollcage for c4 sucks a little. Will have to drop my seat four inches to clear this.
Managed to secure a Holden Commadore supercharger case and TB. Will still need sone firewall modification but I think I will be able to keep my Wipers now.
Also got a Holden thermostat housing. It almost clocks the right way. Will still require some backyard engineering to conect.
Used ebay intercooler $50
60 and 80k mile units off a Ford Focus ST $70 each. They are good for around 290 HP each on a 2.0 should make a bit over 500 HP on the 3.8 internal waste gate and BOV, so its a real bargain.
It feels really good to make some more progress on this. Wish I could afford a custom cage. It works with a racing seat, but I was hoping to use stock seats.
#70
Racer
Thread Starter
Still need to build the turbo pipe but holding off till we get the front downbars in
Ditched the twins. Picked up an ebay gt45 on the cheap. Plumbing is just way easier.
Some more progress.
A few mockup pics. A few completed tasks.
The hotside pipes are a bit cobbled, may have to revisit later but they should function.
Totally ripped out the motor mounts and started over. The FWD motor mounts were going to work, but they got in the way in a couple spots.
Last edited by rbates74; 08-11-2020 at 01:15 AM.
#73
Having owned 2 grand nationals in the past, if it is a budget build, a single turbo is absolutely the way to go. I love the 3.8 and the 3800 was a step up from that. I believe a few people swapped out the 3.8 for the 3800 and had very encouraging results.
You are probably aware that a turbo is a much more efficient power adder as it has no parasitic drag. I do know that twin turbos usually include a smaller one to help with the spool up time. You can also help that lag with one of the great converters they have for that combo. My turbo supported 650 hp (TE44) and spooled up pretty quickly with a transcrafters orange crush converter. I didn’t have real high goals with my setup. I never wanted to run real high amounts of boost, I only would go to about 20lbs.
I finally went back to V8’s. I know I will not have the power of the Buick V6 but I have this need for the V8 rumble. I had a Z06 and that was the coolest car I ever had. The reason I say that is that (for me) I usually went to the track and came back frustrated with the Buick. It rarely ran as good as it should have. Tuning issues, octane issues, chip issues, transmission issues, you name it. The Z06 was completely simple, put gas in it and it ran incredibly strong. Now I have a 89 Z51 6spd and it’s is a pretty fun car to drive. I’m older and do not race anymore so I’m happy with the L98.
Sorry for the long winded reply but I certainly have interest in this style of project, I just like turbos better than superchargers.
Good luck and keep posting.
#74
Racer
Thread Starter
I'm building this on an ultra low budget. A better turbo more closely matched to the set up would be a lot more money.
New this turbo costs $150 and I got it secondhand but unused for about $50. The supercharger cost $277 the intercooler and piping was also second hand and unused for $75 or so.
We built the hotside from scrap besides 1 $50 stainless doughnut and a wastegate.
Maybe $550 in the whole shot.
With a 2.55 pulley its going to have boost at Idle and the turbo should be at full spool by 3500 RPM.
It should come out of corners like a rocketship.
A simple large cube V8 has a lot less potential for gremlins for sure but hey... Im too far in to change now!
New this turbo costs $150 and I got it secondhand but unused for about $50. The supercharger cost $277 the intercooler and piping was also second hand and unused for $75 or so.
We built the hotside from scrap besides 1 $50 stainless doughnut and a wastegate.
Maybe $550 in the whole shot.
With a 2.55 pulley its going to have boost at Idle and the turbo should be at full spool by 3500 RPM.
It should come out of corners like a rocketship.
A simple large cube V8 has a lot less potential for gremlins for sure but hey... Im too far in to change now!
#75
Racer
Thread Starter
A freezer panel gave up this aluminum sheet to become my new dash.
We still have to build the gauge/cluster pod. But I think its coming along well.
#77
Team Owner
Member Since: Oct 2004
Location: altered state
Posts: 81,242
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St. Jude Donor '05
Hot rodding is all about doing something different...wgaf if it isnt all corvette my god lol
Those 3800s have strong potential, more than most would think. Ought to haul azz at least
Those 3800s have strong potential, more than most would think. Ought to haul azz at least
#78
Racer
Thread Starter
Its been a lot of work, and I mean a stupid amount, of work and thought and research getting this far.
#79
Racer
Thread Starter
So, this is my Buddy John's build. He runs mid 9s in a full bodied frontwheel drive Grand Prix.
His is one of the guys I've met since I decided to twin charge and is helping to guide me.
The car has a heavily home modified stock m90 supercharger and an s475 turbo.
That is the massively hogged out bypass valve he uses to sidestep the rotors of the m90 when the monster turbo is spooled.
His dyno numbers are insane for a mostly stock V6
i am working out a plan to modify an under supercharger intercooler core to mimick his massive bypass.
His is one of the guys I've met since I decided to twin charge and is helping to guide me.
The car has a heavily home modified stock m90 supercharger and an s475 turbo.
That is the massively hogged out bypass valve he uses to sidestep the rotors of the m90 when the monster turbo is spooled.
His dyno numbers are insane for a mostly stock V6
i am working out a plan to modify an under supercharger intercooler core to mimick his massive bypass.
Last edited by rbates74; 09-18-2020 at 07:24 PM.