T4 Too BIG ??????

[Driftin_240sx]

like the title said... is a straight T4 too big for a ka-t ? now im sure i wontt find a manifold to fit that, but will it spool?

david

[AceInHole]

i didn't like it, but the one i drove was really a "big" T4 anyways.

it still spools, but kicks in suddenly later in the rev range than i prefer. It'd probably be better for more than the 8psi i drove it at.

then again... i'm used to a turbo that spools at idle...

[DuffMan]

Engines our size usually like a smaller turbine, so a straight T4 (which covers a WIDE range of sizes without being more specific) won't have much advantage over a T3/T4.

[andrave]

actually a manifold is easy to find- revhard, (which IMO is probably the best manifold for street driven ka anyway) will accomodate a T3 or T4.
Anyway you need a little more specific info. First off, a to4B is a pretty common turbo for a ka24de with pistons and fuel mods. there are several that exploit them on stock engines. A far more common choice is the T3/T4, primarily for its faster spool up, but be aware that the smaller turbine may reduce volumteric efficiency later if you want to upgrade.
A to4E on the other hand is a big turbo and is best left to a built engine, especially the larger ones, as they can generate maybe 600 hp.

[kapower]

when you say a t3/t4 would decrease volumetric efficiency later on if you want to upgrade, how much of an upgrade are you talking about. I'am planning on running 15 psi or around 325hp,and hopefully with good spool up (I'll sacrifice hp for throttle response but 300hp is a minimium requirement for me considering the money I'am spending to build the block and cylinder head). would a t3/t4 be ok, for the ball park that range that I'am looking for. Or are my goals of 15 psi & 325hp to vauge to figure out what turbine to use?

[russian]

one word: laag

[andrave]

mild t3/t4 would be plenty for your goals.

and as for one word: lag... well that depends entirely on the a/r of the turbine. I'm sure you could whip up a t3/t4 that would suck a lot more ass than a properly matched T4.