I receintly purchased a 94 Z/28, 6 spd that the previous owner put alot of money into. It has a fresh Eagle, 383 rotating assembly, Comp cam(.495/.503lift, 218/224duration@.050), 30 lb accel injectors, 52mm BBK throttle body, MSD ignition, Zoom Kevlar clutch, BBK shorty headers, mild port work and a reprogram from PCM For Less. I want to turbocharge it but I'm not sure on the exact size. I plan on doing the install and fabrication myself(not a big deal for me). I've been on LT1Boost.net and will probably fab a similar system. The car will be a every other day driver, pump gas, with no more than 8 psi due to the compression. Maybe water injection also. I've had turbo cars in the past, mainly Talons, and I love how a turbo pulls! Can anyone help me with sizing, to the point of giving me a part number to order that would work with my engine and usage? Any suggestions?

 

You can't really go wrong with a T76GTS (1100 hp). If you want to save some money, then you can step down to a TC76 (1000 hp). Or, if you have a few extra dollars and the room for it, step up to an ST80 (1300 hp). There are also several low cost BWA units available that will support around 1000 hp, but they are physically very large and spool slowly.

Mike

 

Who makes these turbos and where is a good place to purchase them? With the setup I'm talking about, I probably wont be making more than 550 hp on 8 psi of boost. Do i really need a turbo capable of 1000 hp?

 

Percision makes the T76Gts

Turbonetics makes the Tc76

Bog Warner makes the budget turbos. They come off big diesels like in the semi's. Spool slow. Big power. Cheap.


I bought a Tc76 because the cost was the same as smaller T-netic units, and I wanted scalability (room to grow). A 67mm would easily meet your goals (even go past them a bit)

 

no, decide how much power you want? but you will proll want more. then go form there!

 

Well, I dont want to tear into the motor again, so I'm thinking I cant go over 8 psi with the internals I have now. 550 hp? The big rig turbo doesnt sound too bad, as long as there are no durability issues. I just want to have some fun with the car so I'm not too concerned with spool up, as long as I'm not waiting forever for it. I am on sort of a budget. Now with purchasing a turbo, do I have to choose an A/R ratio and trim for a specific turbo or do I get what i get? Any specific suggestions for a turbo?

 

I think your best method of targeting the 'correct' turbo(always an elusive goal because of the thirst to go "just a bit quicker") is to contact one of our Supporting Turbo Vendors. I wrote down every aspect of my car's configuration, transmission type, differential gear, driving style(street only/strip only/proportion of the two), car weight, fuel system, head flows, will it be intercooled or not, exhaust type(headers, log style, stock manifolds), camshaft specs, your cost constraints and most importantly, a realistic HP goal(600 rwhp in my case). With all that in hand, I looked on the list and saw a particular vendor that seemed to be responding to a lot of questions, wasn't villified by board members and seemed not to be condescending in his replies. I sent him private msgs and, after plugging the figures into his sizing calculator, he recommended the TC76 with MPS wheel. For this quote, he did not charge one penny. It's free, yet very valuable!

 

You go with turbo's capable of 1000+ hp in order to keep the exhaust pressure down. The little turbo's capable of only 600 hp, like the T61, will run inefficiently, causing high IAT's and high exhaust backpressure, leading to other reliability problems. Even though the T76's will support 1000+, you don't have to run them there and they will be more efficient at ~600 hp.

Keep in mind that the BWA budget turbo's are physically very large and most people can't fit them.