atl4love

hi..i just finish my single setup with cold side a/r .60 and hot side a/r 1.15 ,3 inch all the way to the back and big fmic ...when i first test drive it ,it kinda slower than my stock twin from the start but after 4000rpm it hit really hard....is it the hot side was to big compare to cold side??? or i am missing something??? help ...please..

Kaiser

iTrader: (1)

1.15 AR on the hot side? That's pretty large. I have a bb TO4S and I run a .70. The cold side on my TO4S is .70 also I believe.

atl4love

i think it the problem too...but i'm not really sure so i'm asking you that. oh..well another lesson for me.....thank kaiser

aariz82

what kinda cams are you running?

zazzn

you wont get any real boost till after 4k on a t04 with a ptrim espeically with 1.15

atl4love

i'm running stock cam , can i just swap out the exhaust housing to smaller side ??

Kaiser

iTrader: (1)

Yes you can change the exhaust housing. The smallest Garrett makes is a .58.

atl4love

i want quick spool up so which a/r for exhaust side are best ??

Kaiser

iTrader: (1)

Depends on your top hp goal. If you go too small on the hot side it will restrict your top end flow.

atl4love

my goal 500 max ...what are the best...

aariz82

get better cams

also BB turbo gt35 or bigger your choice

Kaiser

iTrader: (1)

Bigger turbo is not necessary. TO4S is 61lbs per minute turbo. .70 AR will be about 500wheels before it becomes restrictive. You will need a better fuel system for sure. 425 is about the most you can make out of the JDM system. A built trans would be advisable as well. Stock A340E's don't like much over 450. Bigger cams are not really necessary either. The exhaust cam on the JDM is identical to the US Supra. The US intake cam however is 9 degrees more duration and .040 lift over JDM. You gain about 10 wheels hp 4500rpm and up with this cam. A lot of Supras have made 500 wheels on stock cams.

atl4love

how about turbine housing a/r .81 ?? does it spool like stock twin ??? i'm stuck at this...

Kaiser

iTrader: (1)

I've got a .70 AR and I would not go any larger for a quick spool unless you have a looser converter, like a 3400 stall.

zazzn

You have to realize something here, even by changing the housings it doesn't make it really spool faster... It's an illusion.. yes you get in to boost faster, but the turbo threshold is still the same... Meaning if you where to mat the gas at 4000 and have instant boost it will still be the same with virutally any housing.

The smaller housings get you into boost faster but if you have 18-20 psi boost settings then you'll be hard pressed to get more then 10 PSI with a .58 @ 3000 RPM vs 3-7 PSI on a 1.15 ex housing. The real diffrence is the .58 ramps up faster... The 1.15 will prob say about about 7-10 psi until about 4000 where it hits like a ton of bricks... the .58 will be more smooth and ramp up gaining boost right up until 4000 RPM where it hits max boost.

I ran a .84, .58 and .70.... the only probelm with smaller housings is that you may get surging.