Turbo Guys I need your help ASAP

[au03z71]

Here's what I have... 385 ci roller stroker with Vortec heads, originally built for natural aspiration but I've caught the forced induction bug. The more research I do the more I want to go turbo. I'm going to upgrade to forged h-beam rods, forged dish pistons, and possibly a new forged crank... but I have found a set of T3/T4 hybrids (1.32 A/R hot side, .42 compressor side) that I can pick up for $300. My question is, are these too small? I am afraid that they'll spool too quickly and choke out on the top end. The motor is in a 72' SWB c-10. I'm looking to get 600hp + at the wheels just to have fun on the street and occasionally take to the 1/8th mile. It will live in the 3500-4500 rpm range on the street and seldom see over 5500 rpm... Help me out, I need to move quickly if I want these turbos... thanks!

[Irish's_79_Step]

well i'm planning on doing the same thing with my 73 stepside. 383 twin turbo. from everything i've read and found with only one t3/t4 you'd choke out on top, but with two you should be ok. From what i remember. i'm all for someone correcting me if i'm wrong. I believe the t3/t4 should be able to get you around 600 hp with out to much of a problem. Also from what i've found. all forged internals are a must.

[shortbed70]

Well youll get to 5500 pretty quick with turbos or anything. You should be fine with them just mount them close to the motor,intercool them for sure to make the power and forged internals about 8-1 comp and specific cam then your heads will be the limiting factor cause they are only going to flow so much air and when they run out no more power.

[69trk]

id say go ahead and buy them, it's only $300, and if you don't like them or they don't perform like they should, then your engine is already set up for upgrades

[au03z71]

Good point(s)... I may have to jump on them.

[Wild83C10]

They seem a bit too big for twins on a 385 for the low rpm and hp you are looking for. You have anymore specs on them?

The proper way to size a turbo is figure out your hp goals then determine how much air you need to reach that goal then look through some compressor maps.

Check out Master Power turbos for some cheap twins or a single T76 should do the trick. If you plan to turn it up later a Borg Warner S475 maybe the best bang for the buck.

[au03z71]

Originally Posted by Wild83C10

They seem a bit too big for twins on a 385 for the low rpm and hp you are looking for. You have anymore specs on them?

The proper way to size a turbo is figure out your hp goals then determine how much air you need to reach that goal then look through some compressor maps.

Check out Master Power turbos for some cheap twins or a single T76 should do the trick. If you plan to turn it up later a Borg Warner S475 maybe the best bang for the buck.

Yeah, I've really been leaning toward the S475... I think that's what I'm going to end up buying. I'm glad I've got room under the hood though, those things are quite massive.

[Alex1]

TWIN 1.32's will never spool. the BWs475 is good stuff. Good luck!

[Wild83C10]

Also checkout the Master Power T76. Based on what you are looking for (hp and rpm range) that may suit you better. The S475 may not spool until 3500+.

So you thought the turbos you specified in your original post might choke your engine yet you are leaning torwards the S475? Do you know the differences between the two?

Aren't you asking the same question over on theturboforums.com?