Choosing a Turbo

[Vidra]

I've been reading alot lately... and searching, but I'm still looking to hear from you guys. I'm looking into a turbo build for a KA24DE and basically I'm shooting for 300 RWHP using all stock internals except for a turbo cam, plus all the bolt on's. Additionally, this car will be a daily driver and I want to keep the bost at no more than 15 lbs (preferably lower though). I've been looking at some Garrett turbos.... specifically the GT30 family. Will this turbo fit my specifications (I will have a cooling system also)? Would you recommend the GT3071R or the GT3076R? How do I go about choosing my Trim and A/R??? Sorry for the questions.... I know to some degree how these choices will affect an engine... but since this is specifically for the KA24DE I'd like to hear your feedback. Thanks!

[Florida240sx]

My t3/t4 setup which is for sale made 274 and 265 at 10psi... with a leaking HG I had arias 8.8 and crower v2 cams on it. Enthalpy ecu tune.BTW I had this turbo at 19psi SS camaro was very much disgusted with his car... as well as the M3

[Vidra]

Got more info for me about your sale??? Anyways... I hear I should be looking for a T3/TO4E turbo with a .63 or .64 turbine A/R and 50 compressor trim.... should I go with an internal wastegate or not? What size compressor and exhaust wheel am I looking to get? And... how about compressor A/R? I know this all depends on what I want... but really, I want 300 rwhp @ 10 psi on stock internals w/ a cam. And I want this power preferrably till at least 6500 rpms (if thats possible while maintaining boosting really low) + I'm looking for quick boost which will come in as low as possible. Sorry to be so demanding... but I gotta make some decisions here as I hope to purchase parts and do my build over the christmas break (1 month for me ).

[neverlift]

if your willing to read it goes through a lot of detail on turbo choices and how to decide... I cant dig it from my recent visits but its by wdracing and its called turbo 101 on here. great read.

floridas kit sounds like its what your looking for. To say the least 15 would get you to 300whp with a good h/g and proper tuning, plus stock comp is a bit higher than 8.8:1. I like the t3/4 for higher boost all day its in its nature.

for holding boost up top go with the smallest IC that fits your build, meaning dont go with a 50x25 with 3.5 in/out lol cause its huge. plus it will hinder a fast spool. I notice lag with my stupid sr smic maybe 10x10.

[Vidra]

thanks for the feedback... and yes, I've read turbo 101 already. I'm still looking for info thou about compressor and turbine wheel sizes? Ohh, and what about compressor A/R (I hear this really doesn't affect too much thou)? Mucho gracias

[Biggamehit]

http://www.turbobygarrett.com/....html

[Vidra]

I've already read this and pretty much whatever google could give me... I guess I should re-word my question.... just as a .63 or so A/R on the turbine side is good for this setup (and supposedly a 50 trim on the compression side), what would be a good A/R for the compression side and what about turbine trim? Also, these are dependant upon the size of the wheels.... so can anyone recommend specific wheel sizes, trims, and A/R.

[guillermoe]

IIRC, area ratio variations in the compressor dont give a big difference and thats why there are no compressor housing options (at least in Garrett).

[spooled240]

well if you want a low boost application and a quick spool you'll want the turbos with maybe a 50 trim and a tighter housing. I have a 57 trim t3/t4 on 9 psi and I think it is a tad too much for such a low boost setup . Plus I have a huge fmic (11"x27") so that doesn't help much..if you're gonna keep your stock compression, then you don't need a whole lot of boost to get 300 rwhp, so I'd recommend getting the 50 trim t3/t4 with .50 A/R that should spool 10 psi under 3,000 rpm's no problem!

O yeah, idk florida240sx's enthalpy is going to work on 9.5cr since it's tuned for 8.8cr, am I wrong?

[ppctx]

i think Enthalpy charges $150 for a retune, so if you get it, order all your parts, send the ecu back in with the list of your actuall parts? I dont know but I would suspect that changes in CR would require (lower to higher) or allow (higher to lower) timing adjustments.

[spooled240]

and fuel delivery. you're gonna need more fuel in the combustion chamber with high compression as opposed to lower compression on the same boost.

[WDRacing]

The Turbo 101 article needs to be redone, all the pics are broken because the site I was using back then went tits up. Unfortunately, I don't have the pics on my PC. So I need to re download them and host them on ISERVE.

I can however say that without a doubt the best turbo you can buy is the T3/TO4E. Get the 50 trim compressor and a stg III exhaust wheel and make sure the exhaust housing has a .63 AR. There are several thread that go into the what and why of turbo's. But it's been proven by me and several other that the turbo I just suggested is the best bang for the buck.

Go external, internal waste gates are not worth it IMO. Any decent setup isn't going to use an internal wastegate anyway.

[email protected] is you need anything.

WD

[NateDogg]

There wont be any gain by retuning for 9.5:1 from 8.8:1.

I would also consider a Holset HX35 as a cheaper startup turbo still capable of 400whp+. It has good response as well. Some make 15psi before 4000rpm.

If you're looking for a kit, 240turbo.com is the leader, in my opinion.

[WDRacing]

http://stores.teamblindside.com/Detail.bok?no=149

$329 Although it is a 57 trim, it will still work just as well as the 50.

[spooled240]

I have a t3/t04e 57 trim and it spools slower, but not a whole lot than the 50 trim. I love my housing size, but is there a way to replace the turbine/compressor wheels?

[WDRacing]

It shouldn't spool any slower...

[RogueGamer]

so what does changing the compressor trim size do?? just more air per pound of boost or what??

[spooled240]

From what i've read, the higher the trim number for the compressor wheel, the more air it "scoops", i guess it's the design of the fins/blades. I get 9 psi of boost at 3,000 rpms, which is actually later than some other people running 50 trims, but then again i have a huge fmic and a exhaust header..

[WDRacing]

so what does changing the compressor trim size do?? just more air per pound of boost or what??

It's simply a different compressor wheel that moves more or less air. The 57 moves a tad bit less throughout a larger portion of the efficiency window. But both trims will work nicely with the KA.

I get 9 psi of boost at 3,000 rpms, which is actually later than some other people running 50 trims, but then again i have a huge fmic and a exhaust header..

Every car will be different since there are literally 1000's of variables to be considered. Everything from timing and AFR to FMIC piping and weather needs to be taken into account.

WD