Borg Warner Question + My Build

[Chaos the Xile]

Ok for starters my S1 RB25 is getting a MASSIVE overhaul and can handle the power figures i'm looking to obtain. I am leaning hard toward the B/W S471 Turbo but I wan to know which A/R I should use(1.10 or 1.25???). This car is going to be mild street/drag car. Following Mods have been made so let me know your suggestions.Oh looking to make 700+whp.

RB25 S1Eagle RodsCP PistonsACL BearingsARP Head/Main StudsN1 Oil & Water PumpsJUN Crank CollarTomei Head GasketTomei Procams 270/10.25mmTomei Solid Lifters/ShimsSupertech Dual Valve SpringsSupertech Ti RetainersSupertech Seat LocatorsBig Port JobRB26 Plenum & ITB'sOS Giken Triple Disc ClutchOS Giken Super Lock LSD

Let me know about the turbo any other suggestions will be appreciated!

[Largekid]

why such a large turbo? You could hit 700whp w/ a S372 with your build specs. I have become a big fan of the BW series turbos as of late, they are really showing they can make serious power numbers. As far as the a/r...not to sure on the proper size there, but if you hop on over to turbomustang forums, the BW reps are always on there. you could call them and they would get you taken care of. They are very cool and extremely knowledgeable people.

[Chaos the Xile]

cool, i will look into the s372, still in the air on which a/r to go with...

[Cjmartz2k]

why such a large turbo? You could hit 700whp w/ a S372 with your build specs. I have become a big fan of the BW series turbos as of late, they are really showing they can make serious power numbers. As far as the a/r...not to sure on the proper size there, but if you hop on over to turbomustang forums, the BW reps are always on there. you could call them and they would get you taken care of. They are very cool and extremely knowledgeable people.

S471 is like a 1000rwhp turbo or something like that IIRC.

[Chaos the Xile]

man I was lurking around honda-tech last night and I bfound a older Prelude with a F20B bottom end, stock H22A head making 790whp on C16 and a little over 30psi, that's insane i'm liking the s372!

[l0nestar]

I wondered where you had snuck off to! Nice build!

[Chaos the Xile]

yeah, i'm still here just been tryiung to get the money to complete this build. next up is fuel. but hooefully it al goes as planned i'll have some nice pics soon and by summer hopefully some great dyno numbers to share!

[Booztd 3]

FWIW you dont even need a 372 to get 700rwhp...

Although I havent gotten an official dyno number....My 3600+lb Z32 was trapping 136mph on an S366 @ 29psi

The compressor will flow more, but I havent turned it up yet....750ish may be the limit on that turbo, but it would come on a hell of a lot sooner on a 66 versus a 72....

If you have a true twin-scroll manifold, get the biggest AR you can get. Lag time is basically negligible when swapping around hotsides....

[WhatsADSM]

FWIW you dont even need a 372 to get 700rwhp...

Although I havent gotten an official dyno number....My 3600+lb Z32 was trapping 136mph on an S366 @ 29psi

The compressor will flow more, but I havent turned it up yet....750ish may be the limit on that turbo, but it would come on a hell of a lot sooner on a 66 versus a 72....

If you have a true twin-scroll manifold, get the biggest AR you can get. Lag time is basically negligible when swapping around hotsides....

x2,

The 471 is retardedly oversided for what you want.

And you can probably get away with something like a 370 or 366, even.

A good powerband is always more important than a peak number anyways. Unless you just want to race dynos all day.