like the title says, i need to upgrade the snail.
Right now, .81 a/r o-trim
Making I'd guess 350-375whp @ 10-11psi on a street ported 13b. The to4e is very responsive. So I'd rather not lose too much of my bottom end. I really don't want or need much more then 425-450whp. So maybe a to4s? How laggy are we talking compared to the to4e?
Any other good suggestions?

 

The next step up would be a 60-1/To4S, but you are much better off with our TD61( GT35R - P trim) for your goals. It will still take between 16 and 18psi for 425/450rwhp assuming everything else is good. It would probably take 2/3+ more psi with a To4S/60-1. You're currently probably a lot lower rwhp than you think, I've dyno'ed that exact setup in an FC and it was about 300rwhp @ 10psi.

Difference in lag is probably around 600 rpms if moving up to the P trim( which you should).

P.S. Is this Kevin?

 

No, but I have kevin's old 10ae up at my cabin. He's my cousin. That ***** needs another fc!

 

I've looked into 35r's. Garrett makes some expensive turbos. If I could find one for under $1000 in good shape, I'd consider it.

 

Is your turbo an HKS sports? I had almost the exact same setup, divided O-trim T4, .84 A/R (if I remember...), T04E 57 trim compressor and a streetport. What I did was made my own hybrid, I purchased a used precision 6152E, which is precision turbo that uses the 35R-sized compressor wheel (I think it might actually be a garrett wheel...), and used the compressor wheel, housing and backplate for the cold side on my o-trim and CHRA. Got the wheels balanced by a local turbo shop, and had a very nice responsive turbo, good for ~400-450 whp. The plus side is I combined the old T04E bits with the 6152E hotside and sold the turbo on ebay to break even, lol. Wish I still had that turbo...

As I'm sure you know, the o-trim is marginally smaller than a p-trim, so you would end up with a turbo very close to a TD61, but with slightly better response, and less maximum flow on the exhaust side. If you don't feel up to doing all that, go with a TD61/GT3574 or whatever anyone else calls a p-trim with 35R. It's the next most responsive turbo that's properly sized for a rotary.