Is 1.15 a/r for turbine to big??

[fo0manchu]

I have a t4 turbo with 1.15 a/r for the turbine side and a .60 for the compressor side. I dont know what turbine wheel it is but the diameter is approx. 2 5/8 inches. Will this be to big for a Kae? Or should I swap out the turbine with a t3 with a/r of .63? When could I expect boost to come in with the t4 turbine as compared to the t3 turbine? Thanks!

[WDRacing]

I had a .81 TO4E on my RB20 and saw boost at 5000rpm. You'll have no useable powerband with that turbo at all....total lag monster. Swap it for a T4 .63 AR and you'll be way better off.

[ADAMHU]

i have a .84 ar turbine...its about as big as I would go for our 2.4l ...its very free flowing but laggy for street use...

[WDRacing]

I thought you had the T3 exhaust housing Adam???

[ADAMHU]

i do...but its still a big bugger of a turbine

[fo0manchu]

so, should do you suggest I get a t4 turbine housing with .63? Or would I be okay with a t3 housing with .63? I already have the t3 housing so it would be more feasible. But what would be the different characteristics of each housing? Im guessing the t4 would be more efficient but also more lag as compared to the t3? BTW, Im only looking to push around 12-15lbs of boost. Thanks

[j-z]

LMAO!!!!!!!!!!!!! remember that the stock ka only revs to 6500 or so...

[WDRacing]

The stock KA can rev to 7200 or so without killing the stock internals.

The .63 T4 will be fine, so will the .63 T3. It just depends on how quick you want spool.

Brian

[j-z]

i know, i was refering to the consideration of using a 1.15 a/r t4.

[WDRacing]

Yeah...not much time on boost, but it would pull your teeth out wen it kicked in...lol. Imagine the rpm climb as your driving, it takes like 4 secs to get to 5500, then you hit the rev limiter in .4 secs...lol.

Brian

[j-z]

yes, that is EXACTLY what would happen. not really good for anything but making your passengers check their pants. dont know about you but i like my clean seats .