i have an Ap1 that is getting boosted soon. I get so confused when it comes to turbo's with all the differet housings and A/R, trims, etc etc. As this being the FI forum, i'
m seeking your opinions and knowledge basis, to help me make an educated choice for my turbo sizing. my goals in mind are... I'm only going for a MAX of 400hp on the stock bottom end to start, with a custom tubular log manifold. then i will save to have the block sleeved with forged pistion and rods etc etc. At that point i'm going for 600hp on E85. My initial thought was going with a Gt35R, i dont want to go with a ball bearing turbo right out of the gate(can't rebuild a ball bearing cartridge/ they are expensive to rebuild in general) So my first question is What is the closest turbo size in a journal bearing to a gt35r in a precision brand? My second question is i had someone recommend going with a gt4088, one its a twin scroll housing, which from my understanding doesn't do well on f-series motors unless its a high horse power set-up, and isnt a 40 series turbo a tad bit big for the goal im looking for?

thank you

 

Pte 5858 that's what I plan on doing when I boost a s2000. Good spoil with good top end. Can make 400+who all day.

 

Here's an article on turbo sizing in general:
http://www.motoiq.com/MagazineArticl...e-Matters.aspx

 

I'm running a Comp CT4X-5862. Makes 400 easily with fantastic spool and lays down over 600whp when pushed hard.

 

400whp will be pretty hard to make on 91/93 octane with a log manifold. I highly suggest you save and go with a tubular manifold that has a proper merge collector and not a log manifold. A log manifold will hold you back 60-80whp on straight pump gas 91/93 octane.

 

Ive seen first hand an s2k make 420hp on pump gas with a tubular log manifold. i have no worries that i can make 400 with that manifold. 600 is a whole different story yes. but the overall end goal is 600 on e85. so this beginning number is only because my current motor has a 135k on it haha. So a built bottom end is first before i go above 400.

thank you for the reply though

 

But if you want 600 later on, why set yourself up for failure? You're going to have an uphill battle to get 600 (even with E or race fuel) on a log. Build it once and get a good tubular manifold now. What "tubular" log manifold did you see make 420? The only logs that come close to being considered tubular that I can think of are the Full Blown, Pfab, and Kings performance log manifolds and these still will become a restriction log before 600hp.

 

S200sx fmw made 600whp 420tq on my ap1 with great spool!

 

What fuel? How much boost? Have a dyno plot?

 

But if you want 600 later on, why set yourself up for failure? You're going to have an uphill battle to get 600 (even with E or race fuel) on a log. Build it once and get a good tubular manifold now. What "tubular" log manifold did you see make 420? The only logs that come close to being considered tubular that I can think of are the Full Blown, Pfab, and Kings performance log manifolds and these still will become a restriction log before 600hp.
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i see how it may appear that i am setting myself up for failure with a tubular log manifold. But i am going into it with the understanding that i very well may have to have a new manifold made and re-work my downpipe to support 500-600hp in the future. Now i would love to go straight for the 600hp and be done but there is a lot of other supporting mods that need to happen before the can become a realistic HP goal. the "tubluar log manifold" that i have seen make 400-420hp is a product produced by LHT Performance in Tampa, FL. (not trying to sponsor anyone) He some really great photos of a couple turbo set-ups he has built. the "yellow S2K" is a close friend of mine and his put down 420hp with the manifold i'm speaking of.