I thought I would start a thread about my build. I have built N/A, N2O, Roots blown and ATI procharged motors but this is my first turbo build.

Car is a 1979 Trans Am. 10pt cage, 8.50 Cert. mini tubs with 315/60-15 MT radials on 12x15 Weld Wheels. Strange S60 rear with Detroit locker, 3.54 gears, and 35 spline axles. Ladder bars with Afco coil-overs. All steal body with factory glass except for a Glasstek shaker hood. Weight will be about 3700 with me in it when done.

Reverse pattern T400 with a t-brake. Custom convertor by PTC

The motor. Traditional old school Pontiac. 476 CID.
IAII aftermarket block. 3' mains 4.350 bore
Scat 4340 4' steel crank
Scat 6.8 4340 rods
Solid Roller lifters from Bullet
Comp Cam Solid Roller
Lift with 1.65 rockers .571/.565
Duration @ .015 279/273
Duration @ .050 242/236
Lobe separation 112
SD performance CNC Edelbrock heads with 90 CC chambers. 350 CFM@ .700 lift
8.0:1 CR
Port matched North Wind intake
HP Ultra 950 carb that CSU rebuilt to Blow through
CSU bonnet
Garrett GT4718 88 mm turbo. .96 AR exhaust housing
66mm Precision WG
Snow meth/water injection with dual 650ml/hr injectors and 2.5 gal tank
Custom headers. 1 ¾ tubes 2.5 collectors, 2.25 crossover
Msd 6AL-2 6530 ignition. MSD Dizzy
Turbosmart Dual stage manual boost controller
Turbosmart 50mm BOV
Magna fuel 500 GPH pump with Boost reference regulator
Star vac pump

Goal is pump gas (93 octane) track car that can handle some street use. About 75% track 25% street. 1000 HP and the ability to go higher. Will be driven in 100 plus degree temps.

Any thoughts on what I have so far?

 

Always loved Pontiacs, in on this. Reminds me of my first car at 16 years old was a 1978 trans am with a 462" poncho motor with ported d ports Ram air lv cam. Definitely a handful for a 16 yr old lol. Everything looks good but that turbine is going to choke that motor the gt5018 would be better suited and up that ar to 1.25

 

I'm a Pontiac guy myself ( although mine is chevy powered ). That sounds like it should haul, pretty impressive list of parts you've got. I'm with weezer on the turbine though.

 

Thx for the feedback guys. I've been concerned about the exhaust side of this turbo and was curious if anyone would agree. What's a good place to source a new exhaust housing and potentially a better turbo for this build?

 

in agreement on the turbine restriction

and in for the Poncho build

 

Neat to see you're sticking with traditional Pontiac power. They're a great engine in terms of serviceability, and were way ahead of their time in that regard. I love mine because it's just so easy to do day to day service stuff on like plugs. I'd love to see your header design when you get it in too.

 

Thx. I had so many parts for the Pontiac that it was a cheaper build then starting over with an LS. I agree that the ease of servicing it nice.

I bought a set of Headers from a guy on the PontiacZone forums. Aronhk_MD. These pics were sent to me when he was having them built.

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Cool old school Pontiac build! Nice!

 

Figured I would post a few pics.
I really wanted to keep the shaker on the car. Had to modify the CSU carb hat significantly. but it all fits.

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Hot side fabrication and down pipe

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Looking good! Shakers were the coolest factory scoop
Ever IMO, glad to see it stay.

 

Thx. trying hard to keep it looking kind of like a stock TransAm.

Cold side done.

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Kudos on keeping the shaker - that radius seems pretty tight.

 

Thx. Ya its a very tight turn. I used a cast Alum elbow. It keeps the diameter through the turn. Some day I might leave the hood off, borrow a carb hat and try a straight shot and see if I see any gains. But for now I hope this works well enough.

 

Cool project! How much did the poncho headers set you back? I know a guy looking for a set.

 

I think they were $700 shipped. Not the most economical but they fit very well. The only thing I don't like is they are about 1/16th inch from the rag joint. I am going to replace it with a universal.

 

Nice build. I love those old pontiac's. Subscribed.

 

Nice work!

 

Went to a buddies shop today to use his lift. I had to modify the ladder bar cross member to allow the exhaust pipes to pass through it. I used two Summit racing drive shaft loops. I'm pretty happy with how it came out. Now to figure out how to get over the rearend.

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making progress