Turbo reactions

[rb25drag]

Looking to buy a new turbo! Found an awesome deal on a Pt88! Its a big turbo but how will it react on the rb25? Here is a link to one identical im looking at.

http://cgi.ebay.com/ebaymotors...98796

Im looking in the 700 HP range and I know this one is good for over 1200hp.

I also have a 2 step so I should be able to spool this turbo from the line, Turbo lag should be a problem.

But I have a guy Im working a deal with on a Pt88 ball bearing turbo with low miles/HKS Manifold / 850cc top feed - low impedence rochester injectors/55mm Borg Warner Turbo Werks wastegate.

This is going to be a drag setup. Not a daily driver. So will the turbo be capable for what I need?

[Darius]

You really should plot what your air flow and pressure ratio line will be on the compressor map to see where it lands. There is no doubt the turbo will have the flow capacity, but will you be surging at part throttle or running through an area of poor efficiency=heating the charge air more? Everyone's setup is different and depends on your application. For only 700hp, a 1200hp turbo is going to laaaag unless you have an automatic transmission or you get that Gizzmo interface working to keep the revs up during your shifts.

If I was at work, I could get you a kick-a$$ link to approximate your mapping points.

[Joe]

darius is correct again

you cant oversize a turbo and run less power. it becomes incredibly inefficient and will struggle and possibly become damaged.

read up on how to size turbos. you need to get the one thats perfect for your power goals, not one that you get a deal on.

[mello88]

Hmm interesting... I was going to try to help you by finding a compressor map for ya, but according to this thread: http://www.yellowbullet.com/fo...13285

Compressor maps don't exist for the PT88 (and most garrett large frame race turbos apparently). Considering it'll flow 120lb/hr it's probably a little too large for your RB25 but then again you didn't tell us what amount of boost you wanna run...

GL

[l0nestar]

that snail is crazy big...

[Shocker]

You might be better off with a big 42r. It will spool faster, and get you to your 700hp goal. Hope you have the funds to support such a build.

[rb25drag]

Darius, When you can get me that link I would greatly appreciate it!

As for PSI Im looking to run 25-30PSI.

My gizzmo launch interface should be ok to keep the turbo spoiled up!

As for funds for this build. The only think Im lacking is PFC, Injectors and turbo to make my 700 Hp goal. Internally the motor is already built.

[Shocker]

Darius, When you can get me that link I would greatly appreciate it!

As for PSI Im looking to run 25-30PSI.

My gizzmo launch interface should be ok to keep the turbo spoiled up!

As for funds for this build. The only think Im lacking is PFC, Injectors and turbo to make my 700 Hp goal. Internally the motor is already built.

track only car? I'm not sure what you need 700hp for if not..... don't forget the drive line with that type of power as well....

[rb25drag]

Drive line is going to break, Already got plans to deal with that. I currently have a Stage IV Cusco exedy twin plate clutch on the 5 speed transmission. I have already broke the axles once, but they was 18 year old axles. I bought new axles for now. As soon as I trash the rear end and transmission Its going 9inch ford tubed out with a 350 turbo transmission.

But I need power right now.

My local 1/8 mile track has Street bounty races. Im trying to run the 6.00 index class heads up on the .400 pro tree.

So what turbo do you guys suggest?

[Darius]

I will get you the link on Monday morning when I go back to work. I am totally busy all day tomorrow otherwise I would swing in there and get it for you then.

Off the top of my head, the GT3582 with the 1.06 exhaust housing could put you in the 650hp neighborhood with decent spool. 25-30 psi of boost might run you off the top of the map though.

[rb25drag]

ok thanks Darius no hurry!

With a Gt 35 or even the 42 I think it will push more power with lower boost. I think It should be in the 600 ball park around 20-25PSI with either of those turbo's.

But ill find a good combination hopefully!

[Darius]

Here is what I used to size my turbo.

http://www.not2fast.com/turbo/...shtml