For 325whp on 91+meth: GT2871, 2876, or 3071?
 

Like the title says, my plans for the next power step include a built shortblock, possibly a stroker, and at least 325whp on 91 octane and meth injection. M3s and STis are fun, but I want to mess with Vettes and 600cc bikes. ;) The car's got a big radiator, oil cooler, soon to have a 6-speed, so it should be well-sorted and able to handle the power reliably.

My initial thought was the 2871, since I still want a car that's reasonably streetable and not just a high-RPM monster, but at the same time I do have some plans to rev the car harder than stock (build will include billet oil pump gears, and after the setup is together, a built 99 head) so I am a little worried about the top-end flow of the 71. I know y8s has the 2876, which definitely peaks my curiosity, and the other option is the 3071. If I did a 3071, it would probably be with the small A/R T3 exhaust housing option.

I'm also on the fence between EWG and IWG; if I did a 2871 and kept the IWG, I could keep my current manifold and DP. If I were to do something like a 3071R, I'd have to convert my S3 manifold into an S5 and sell my downpipe.

So what do you all think? I'm not afraid of running some seriously high boost pressures to make the power with a smaller turbo, if it means more driveability when I'm just putzing around town at 10psi.

you could probably do it with all of em. It's probably 18-20 psi on my turbo though.

more for the 2871
less for the 3071

blah blah blah :)

What about the 2860? When do you think that would hit.

Don't know much about turbo's, but If I were you, I'd buy the bigger one as you'll get cooler charge temps and if later down the road you want more ( I know right who builds a setup and then upgrades???) you won't need to buy another turbo.

Bigger than a 2871 on a 1.8 liter? Damn. Sometimes I feel the 2871s on my 6.0 liter are a little too big. :bowrofl:

My vote is for the 2871, but that's just my uneducated opinion on turbo sizing. I'd want to build boost in all gears and not have a torque curve that still has positive slope at redline and that would be my fear with a bigger turbo. Don't chase after a ginormous peak power number.

we'll he's talking maybe a stroker and built to rev so i'd think a 2.0 liter revving to 8k+ would do fine. sr's easily run big turbos with 2.0 liters of displacement so does a 4g63

I'd be worried about not making my goals with a 2860RS, and Ben just said in another thread that if one is looking at the RS, they should be looking at the 71 instead.

I don't know of anyone in my area with a BIG turbo car (the biggest one I know of is a T3S60 car and I've driven it) so I don't really know how it will compare to my 2554. :( I want some semblance of spool, but I also know that if I want it to pull hard on top and make the power I want to make, I'm going to have to give some of that up.

the 2554 should spool like a damn SC on your car...

I'd imagine w/ a built motor and a 99 head and 3" exhaust you'd spool a 2871 pretty damn quick....

Ask me in a year and I'll let you know. ;) I'm planning on going with a 2871 on a worked 1.6L so we'll see.

Actually, if Brad (newbsauce) makes it to dyno day, you'll see what a 2871 will do on a 1.6 (stock head/built shortblock) so it should at least give you some idea of where you might be.

http://www.flyinmiata.com/tech/dyno_...MII_GT3071.pdf
Blue line on that plot is for a GT3071 @ 11psi on a FM stroker w/headwork for another data point.

the 2871 can support well over 325rwhp....no reason to go too big.

when your ready to upgrade keep me in mind cause your running the turbo i want. im looking for a good used gt2554r to upgrade my cheasy t25. but as for your question the gt2871r will be more than enough for you to make that power. i've ran that turbo on my old sentra se-r and at 18 psi i made 335whp and 330 wtq.

My God Andrew... why?

-Ryan

Why not :D STIs, Evos, etc. are fun, but think about how much fun Vettes and 600cc bikes would be...