I will hopefuly have my car done by mid season next year. I just picked up a garrett 91mm turbo, it should be here mid next week. Then within the next couple months I'm going to start on the headers and hot side. I will update with pictures as I make progress. I have had enough seasons of nitrous, now time to try the FI. BTW, this will be a blow through carb setup on a ~383 lt1. I'm only going to shoot for ~9.50's this upcomming season while I finish the chassis and odds and ends. I do have a couple questions to start off with though. Who make a good 1/2" header flange? Has anyone succesfuly used a set of off the shelf shorties like the mustang boys do? What size wastegate should I be using with a turbo that big?

 

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I got the turbo today. It has a 1.32 a/r so I'm not sure if that housing is going to work for me. It will be a 383 and not worried about street use. Do you guys think I will be able to spool it?

 

Seems large to me...maybe to big. As long as you can build boost at the line...then it should be good. Be prepared to have peak tq/boost above 6k rpm though.

 

That is way huge, you probably wont be able to get it spooled until your way down the track. Search for posts by wingnut, he had a 91 mm with I think a 1.00 ar housing on his 383 and was having trouble getting it to spool.

 

Here is an what he said about the 91 mm with a 1.00 ar.

"If my converter was not so loose, lag would be unbarable. However, with a 4000 rpm stall, you get off of the line and watch the bike go ahead of you for about a sec then everything gets blury and you just hang on. A little soft on takeoff. I thought about using NOS and have my DFI 7 turn it on until positive map pressure is present then all turbo after that.

I changed and went with a tb-91 big frame turbo and now have the 1.00 a/r turbine housing. I am going to order a .96 and try that too - housings are cheep!"

 

Cool. I will give the housing a try and if it doesn't work I will pick up a new one. I plan on spinning the motor to ~7600 leaving off a trans brake. Do you think the 1.00 would start to choke in the higher rpms? Thanks for the help guys. I also think I'm stuck buying a 60mm wastegate which sucks cause they are expensive as heck.

 

Looks like you and I are going to be doing the same kind of build. I'm going to run a 383 with 91MM with a 1.0 AR housing. I don't think a small cube 383 even at 9000 will choke these turbos. If it does..which I highly doubt I have a 1.32 sitting here looking at me I can go to. I plan on going alittle higher in the rpm range than you do and I'm going to "try" it on the 6 speed at first. Hopefully with a 2 step and the boost builder part of my DFI gen 7 I can leave halfway descent. What can I say..I'm a glutten for punishment.

 

Can you run twin 38 or 40mm gates instead of a single 60mm? Its probably cheaper.

 

Yes, I probralby can run 2 wastegates. How much is a new housing so I can have both the 1.00 and the 1.32 sitting around? I guess I could just call precision and find out.

 

I bet it would be pretty hard to outgrow that turbo with any size small block. Even though wingnut mentioned that it seemed like a soft launch, that would be desirable if you were going to run in a street tire class. However it wouldn't be much fun for a car that you are going to drive on a regular basis. That setup would be perfect if drag racing is your primary goal, however if you want to build something like an all around performance car a smaller turbo would be better for you. It all depends on your personal goals for the car. I try to imagine what Enzo Ferrari would do if he went broke and the only car he could afford was a Camaro. Basically I want an exotic supercar, but since they don't pay firefighters very much I'll have to get as close as I can with my Camaro.

 

Yea, it's main purpose in life is to go down the track. I might drive it for the once a month cruise nite and that's about it. I've got some pics of the turbo I will try and get uploaded today. I orderd most of the flanges and tubing so I can start on the headers when that gets here. Does anyone have a good way to make the round pipe d-shaped to fit the header flange?