its not a dumb question it helped me out alot but i was going to ask the same thing i have a rex with a soon to be fully built ls turbo lookin @11s or 12s

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SHOCKER RACING CRX CREW &raquo;</TD></TR><TR><TD CLASS="quote">its not a dumb question it helped me out alot but i was going to ask the same thing i have a rex with a soon to be fully built ls turbo lookin @11s or 12s</TD></TR></TABLE>

Realistically building an 11 second CRX and being a 17 year old "looking" for 11's are 2 totally different things.

 

great discussion!

 

This was almost 1 year old. But i learned alot from it.

 

I personally think that turbine wheel and housing a/r are much more important than compressor sizing (speaking say of all the T4E compressors 50, 54, 57, 60trim) , for the overall performance of a motor

myself i choose to run a 76 trim T4 turbine with a small a/r T4 housing

about the same spool time as a .63 a/r stage 3 T3 turbine

 

Hmm...I love the posts!

Anywho, it's a pretty simple concept yet I'm just not grasping:

With the cash limitations excluded, wouldn't the better choice always be a bigger turbo (eg T68 ) running....say 10psi versus a small turbo (T25) since it would be less strain? Yeah these are on the extremes, but I'm just trying to understand.

Thanks,
J

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by legendboy &raquo;</TD></TR><TR><TD CLASS="quote">I personally think that turbine wheel and housing a/r are much more important than compressor sizing (speaking say of all the T4E compressors 50, 54, 57, 60trim) , for the overall performance of a motor

myself i choose to run a 76 trim T4 turbine with a small a/r T4 housing

about the same spool time as a .63 a/r stage 3 T3 turbine </TD></TR></TABLE>

IMO, knowing how your compressor trim is just as important as the turbine side. Compressor trim sizes tell us whether the cold side will be more efficient at higher or lower pressure ratios. There ae also a few other things such as knowing how inducer and exducer sizes effect spool time. Check out the link below and read the RacerXtreme7's post.

http://www.rx7club.com/printthread.php?t=345518

 

Ok I know this is an old post but I'd like to see if my turbo is ok to use with my setup. I have a b18c1 motor with aebs intake manifold, log style turbo manifold, TiAL 38mm wastegate(8psi spring), 450cc injectors and a Holset H1C turbo. i only have a street tune but I'm hoping to get to a dyno soon and run 10-12 psi. I'm not sure on the A/R or trim. can anyone help me out. I'll mainly use it as a drag car but i'm keeping full interior to be comfortable driving on the street. Any help is appreciated. Thanks

P.S. I've raced the car before on the track and ran a 13.02 at 107mph. I'd like to get into the low 12's

 

The AR should be stamped inside of the outlet of the compressor and exhaust housings. For trim you will have to measure the wheels.

 

you have a very large problem there with that setup; the log manifold. they flow like absolute garbage. the higher the rpm, the worse it flows. if you want something for straight line, you NEED a tubular manifold.

and, big turbos and log manifolds straight up do not work worth a crap, because the big turbo needs high exhaust flow to spool and maintain smooth consistent pressure, and the log mani simply can't support the amount of flow a big turbo requires

log manifolds are useless except for little spurts of boost like in autocross, and only when used with a small turbo like a t25, t28, t3, 14g, and sometimes 16g's

 

I normally wouldn't post on a thread that is this old but sir your post is so far off from the truth is terribly wrong. Every manifold Type and style has it's advantages and disadvantages. A cast log manifold will support 400-450 and the inline pro t4 cast log has supported up to 900hp. It depends what the car is being built for and if the person wants to upgrade in the future. Cast log will spool quicker and still support good power. Bone stock gsr with cast top mount we put down low 11's and about 130mph with an extremely simple setup on a completely bone stock motor with head studs as the only upgrade. Before you post some non sense learn the truth about the information your going to spu out.

The Holset h1c is like an hx35 just older version and so long as he doesn't have one with the big 14cm turbine housings the turbo will work well on a cast log manifold. Actually holsets come on diesels that ALL utilize cast log manifolds.