Turbo Choice and bottle necks?

[85daytona]

Current Mods:
-1989 common block TII
-.20 over JE forged pistons
-fully forged TII bottom end (fully balanced, rods magnafluxed)
-FM Stage II big valve head
-1988 Roller Cam
-ported 2 piece intake/exhaust manifolds
-FM stage 1 turbo (ported polished stock garret)
-braided turbo hose kit from FWD
-Spearco 1100 CFM front mount intercooler
-DSM BOV
-FWD full 3" exhaust (89 swing valve/down pipe)
-FWD 16 psi cal 3 BAR MAP
-Walbro 255/LPH fuel pump
-A568/Quaife LSD w/RPS clutch (2000 miles on tranny clutch)
-1989 K-frame/one piece cast A-arms w/full polyurethane bushings
-Koni Struts/shocks
-Front and Rear strut bars (tied into shock plates in rear)

Basically story is the car blew the HG so now the heads coming off and turbo is an obvious bottle neck but I don't know what to switch to and what the next bottle neck maybe.

Car supposedly made 271whp @ ~20psi everyone finds it hard to believe because of the tiny turbo but that's what Cindy told me. She suggest a 50 trim in a T04B cover with stage 2 wheel. I don't want to get it on there and then have the turbo still holding the car back. Any experience with that turbo anyone?

Car will use pump gas and may add methanol if I feel like it needs it. I really am shooting for some 12's race weight of ~2960lbs

[tryingbe]

You should bookmark this

http://www.squirrelpf.com/turbocalc/index.php

[turbovanman²]

271 whp on a stock garrett? If so, I think thats a record.

Anyhow, what are you goals?

A 50 trim in a E cover is what you should get, so a T3T4 with a TO4E comp cover, stage II and a .63 housing is a wicked combo and will give great street manners and also be a track animal. You should be able to get 350 whp out of it with the right head.

[85daytona]

Not completely stock. its an E1 so its got a different/modified wheel in it I think...and its been polished at the least. Ya I really need to read up on how exactly to read those damn maps just been lazy

Just how hard is it to install an E vs a B cover everyone seems to have differing opinions on it. Say I shelled out the money for a Hybrid header would this honestly make it a bolt up affair?

My overall goal would be to have the car pushing over 300whp on pump I think this is good for some 12's with good driving in a nearly 3000lb car. If I can take an ls1 vette/ws6 T/A from a roll I'd be happy

Best E.T. for this car at 16psi was 13.5's so I think a new turbo will definitely get me where I want.

[turbovanman²]

B covers have the outlet angled and are a mismatch for our cars, I believe there a high pressure design. E covers have a straight back outlet so you need to make a couple elbows or modify the outlet, not a big deal. They are better suited our engines.

Yes, TU's header will have that clear the head.

[85daytona]

Hrm so is that it just welding an elbow onto the compressor outlet? I know the E cover is really the right way to do things just don't know if the cost justifies the outcome. Does TU not sell the cast hybrid header anymore? I know I can't afford the SS one.

[turbovanman²]

Hrm so is that it just welding an elbow onto the compressor outlet? I know the E cover is really the right way to do things just don't know if the cost justifies the outcome. Does TU not sell the cast hybrid header anymore? I know I can't afford the SS one.

You just buy some silicone elbows. All I did was use 2 90 deg RX7 turbo rubber bends with a bit of pipe, problem solved.

[85daytona]

Talk about revolutionary Simon why the hell is the T04B for sale still? I'll run it by Cindy I would be much happier knowing I'm getting basically the best turbo for the engine

[shadow88]

271 whp through a stock garrett doesn't sound like too much of a stretch with the other mods listed, I got 262 and 337 tq but with a worse flowing head and pretty much the same boost pressure.

But back to the turbo choice - I have the same turbo that Simon suggested and it's good for the track, but it's laggier than I like. I'm getting used to it, but at that car's weight, you may want to consider a different exhaust housing. Maybe a stage 1 ? I don't know for sure, maybe the difference is negledgeable.

[GLHNSLHT2]

at least a true S60 turbo, If you can swing it I'd get the T3/T4 simon was talking about with a Super50 compressor wheel

[turbovanman²]

at least a true S60 turbo, If you can swing it I'd get the T3/T4 simon was talking about with a Super50 compressor wheel

Wow, twice in one night, yep, if you can afford it, upgrade to the super50 wheel,

[85daytona]

Simons on a roll!!! Ok so best case scenario would probably be the T04E cover Super 50 trim wheel and Stage 2 exhaust wheel. This turbo can support gobs of power to say the least? I'll need 2 90 degree bends to make it fit and that is all?

I have a feeling the next weakness for this car will be the clutch Dunno how much the old RPS will handle I figure worst case scenario I can lower the boost a little eh?

[tryingbe]

T04E housing can be kinda big...

T04B .60 housing vs T04E .70 housing

[85daytona]

Wow that is quite a big difference never seen the two side by side Lag isn't too much of an issue for me. I went from my nearly stock 85 TI to this beast so I think I'll be impressed by it no matter what. Car is not DD and I don't plan on street racing only thing I might ever do is some deserted highway runs

[tryingbe]

I suppose I can put a stock T3 .42 housing in the picture tomorrow too.

TU header makes routing turbo much easier.

[Ondonti]

T04E housing can be kinda big...

T04B .60 housing vs T04E .70 housing

Neither of those looks to be what you say they are.

[Ondonti]

B covers have the outlet angled and are a mismatch for our cars, I believe there a high pressure design. E covers have a straight back outlet so you need to make a couple elbows or modify the outlet, not a big deal. They are better suited our engines.

Yes, TU's header will have that clear the head.

Im guessing you got that backwards..you meant high flow right?


That said, I would never purposely mismatch wheels and housings from different series of garrett turbos. When you do that you dont really know what the compressor map really looks like.

[turbovanman²]

Simons on a roll!!! Ok so best case scenario would probably be the T04E cover Super 50 trim wheel and Stage 2 exhaust wheel. This turbo can support gobs of power to say the least? I'll need 2 90 degree bends to make it fit and that is all?

I have a feeling the next weakness for this car will be the clutch Dunno how much the old RPS will handle I figure worst case scenario I can lower the boost a little eh?

I'll take a pic of what I did to show how easy it is.

Im guessing you got that backwards..you meant high flow right?


That said, I would never purposely mismatch wheels and housings from different series of garrett turbos. When you do that you dont really know what the compressor map really looks like.

Thats why I said I get them mixed up,

Agreed,

[85daytona]

Sounds good Simon Thanks a lot I can't wait to be able to drive the car again!!!

[Chris W]

Hrm so is that it just welding an elbow onto the compressor outlet? I know the E cover is really the right way to do things just don't know if the cost justifies the outcome. Does TU not sell the cast hybrid header anymore? I know I can't afford the SS one.

Our cast iron header is still available and on sale for $375. at Carlisle next month. We replaced our more expensive SS version with the higher flowing cast iron one in order to provide a better product at a lower price.

Chris-TU