yellowturbo

Hi guys !

Im helping a friend to build his SOCH...

After analysing his needs and his budget we choosed the GT28RS for his efficience and durability.

I just need to know which A/R would be the best if he plan to keep his redline to 7500rpm since he doesnt want to have to play on the head...

ATP have the following choice... .86 .64 .63 and .82 ??

Which A/R would be the best for him ? I have an idea but I would like to be sure...

Also, is it okay if his goal is +-280 whp using the internal WG ?? I dont see anyproblem but I want to be sure...

Thanks a lot I will keep you on for his project...

yellowturbo

Sonny

The .86 and .64 sound like T25 housings.

The .82 and .63 sound like T3 housings.

The recent work the Jeff (boosted hybrid) showed was using a T3 housing. Manifolds for that style of flange are far easier to come by.

I would pick the .63 a/r T3 housing.

Sonny

yellowturbo

sweet thanks... I was not sure about the T25 or the T3 housing... anymore opinion ?

eddyboy

I went with .63 myself. I believe the small t25 housing contributes to the GT28rs lightning fast response. Since the t3 housing is larger than the t25 I choose the smallest a/r they had available. Hopefully the larger T3 housing will not adversly affect spool time too much.

I guess i'll find out soon

GL

yellowturbo

For the response... I dunno... Im affraid of a too fast response on a almost 300whp street car... maybe in the case of a street car a T3 housing .63 ar would be better but in the case of a rally car the T25 .64ar would be better.... I have to search for more info... but in general I know that we choosed the best platform for his project... If I had to change my SC50 .63 ar it would be my pick !

Spoolin time is another story... my friend want want the best useable power band...

RyanEJ8

I wouldn't go any bigger than the .63A/R.

yellowturbo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanCivic2000 &raquo;</TD></TR><TR><TD CLASS="quote">I wouldn't go any bigger than the .63A/R.</TD></TR></TABLE>

yeah thats what I tought... now I have to choose between the T3 and the T25 housing.... but I think that each one have his own advantage...

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yellowturbo &raquo;</TD></TR><TR><TD CLASS="quote">For the response... I dunno... Im affraid of a too fast response on a almost 300whp street car... </TD></TR></TABLE>

Huh?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yellowturbo &raquo;</TD></TR><TR><TD CLASS="quote">
Spoolin time is another story... my friend want want the best useable power band...
</TD></TR></TABLE>

A friend upgraded from Greddy 15G to GT28RS with .63 AR T3 housing. It spools a lot faster than the 15G did, and makes better power all around.

TurboJesse

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">

Huh?

A friend upgraded from Greddy 15G to GT28RS with .63 AR T3 housing. It spools a lot faster than the 15G did, and makes better power all around.</TD></TR></TABLE>

hmm really?

Ive been in a few 220whp sohc's with 15g's and it almost feels like an all motor car on steriods(atleast to me..), the 28rs spools noticably faster?

Joseph Davis

Yes sir, it does. I forget what Rob said, but I think it was in the 900 rpm range.

BTW, I tuned an all motor Honda recently that made the last ~220 whp SOHC I rode in feel neurasthenic.

eddyboy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Yes sir, it does. I forget what Rob said, but I think it was in the 900 rpm range.

BTW, I tuned an all motor Honda recently that made the last ~220 whp SOHC I rode in feel neurasthenic. </TD></TR></TABLE>

I had to look "neruasthenic" up
For those who also don't understank wtf J.D. is saying.


Main Entry: neur·as·the·nia
Pronunciation: "nur-&s-'thE-nE-&, "nyur-
Function: noun
Etymology: New Latin
: an emotional and psychic disorder that is characterized especially by easy fatigability and often by lack of motivation, feelings of inadequacy, and psychosomatic symptoms
- neur·as·then·ic /-'the-nik, -'thE-/ adjective or noun
- neur·as·then·i·cal·ly /-ni-k(&-)lE/ adverb

JalopySiR

Sonny is right. Depends on your manifold. If it's T3, go with the .63 a/r
If it is a T25, go with the .86 a/r
BTW, I ran a non-BB T28 w/ a .86 a/r T25 turbine housing w/ 76 trim wheel. The spool was awesome. I wish there were as many T25 flanged turbocharger options back when I did my project, as there are now.
Oh, and T3 is infinately easier than T25...