t3 with .36 or .48 housing?
16-08-2007 | 10:17 PM
#6
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Joined: Oct 2003
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From: S/E Kent, Thanet
as said, of under 230 bhp, go .36.
Have you got graph's for both? as would be good to see,
i went from rst .36 to cossie .48, and its made it breath better, but as said put the spool up 750rpm higher, 22psi @ 2500 tp 3250 rpm
Originally Posted by Oranoco
I just changed my .36 housing for a .48 and only gained a couple of bhp from it and made the car less driveable to boot. I would stick with the .36 housing personally
Have you got graph's for both? as would be good to see,
i went from rst .36 to cossie .48, and its made it breath better, but as said put the spool up 750rpm higher, 22psi @ 2500 tp 3250 rpm
17-08-2007 | 04:07 AM
#7
PassionFord Post Troll
Joined: Jun 2003
Posts: 2,866
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From: Finland
From my experience with both:
.36 (standard S1) starts boosting properly at around 3000rpm and where it creates lets say 0.5bar 1.0bar on comes a few rpm later. It took around 1.6-1.7 bar of boost to make 250hp. At this boost, the power delivery was a real sudden kick in the back. I'm sure the back pressures were monstrous and the reversion really starts to kill power already over 5000rpm, even with a standard cam.
.48 (4x4 cossie) stats boosting slightly at 3000rpm too, but it takes a lot longer to get to over 1.0 bar, like at around 4000rpm. However, tha same ~250hp is made at only 1.3-1.4 bar of boost. Downside is not only the bost building at higher up the revs, but the time it takes too. Travelling at 5th gear and 3500rpm where the turbo is capable of producing already useable boost, it just takes 1-2 seconds before the turbo spins up to speed. Another downside is actually lower power in 1st and 2nd gears. Seems to me that the engne rpm is changing too fast for the turbo rpm to keep up. This results in 1st gear in a car that is uncapable of spinnning the wheels and boosts 1000-2000rpm later. At 3rd there is plenty of wheel spin then.
These perceptions were made with a motor running a standard cam, standard C/R, Megasquirt efi, some DIY porting and a GRS IC. Needless to say, the mapping needed to be corrected for the larger exhaust housing to make use of it.
.36 (standard S1) starts boosting properly at around 3000rpm and where it creates lets say 0.5bar 1.0bar on comes a few rpm later. It took around 1.6-1.7 bar of boost to make 250hp. At this boost, the power delivery was a real sudden kick in the back. I'm sure the back pressures were monstrous and the reversion really starts to kill power already over 5000rpm, even with a standard cam.
.48 (4x4 cossie) stats boosting slightly at 3000rpm too, but it takes a lot longer to get to over 1.0 bar, like at around 4000rpm. However, tha same ~250hp is made at only 1.3-1.4 bar of boost. Downside is not only the bost building at higher up the revs, but the time it takes too. Travelling at 5th gear and 3500rpm where the turbo is capable of producing already useable boost, it just takes 1-2 seconds before the turbo spins up to speed. Another downside is actually lower power in 1st and 2nd gears. Seems to me that the engne rpm is changing too fast for the turbo rpm to keep up. This results in 1st gear in a car that is uncapable of spinnning the wheels and boosts 1000-2000rpm later. At 3rd there is plenty of wheel spin then.
These perceptions were made with a motor running a standard cam, standard C/R, Megasquirt efi, some DIY porting and a GRS IC. Needless to say, the mapping needed to be corrected for the larger exhaust housing to make use of it.
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18-08-2007 | 03:16 PM
#8
Professional Waffler
Joined: Aug 2003
Posts: 25,425
Likes: 41
From: HertFORDshire
Originally Posted by Fiecos Dan
as said, of under 230 bhp, go .36.
Have you got graph's for both? as would be good to see,
i went from rst .36 to cossie .48, and its made it breath better, but as said put the spool up 750rpm higher, 22psi @ 2500 tp 3250 rpm
Originally Posted by Oranoco
I just changed my .36 housing for a .48 and only gained a couple of bhp from it and made the car less driveable to boot. I would stick with the .36 housing personally
Have you got graph's for both? as would be good to see,
i went from rst .36 to cossie .48, and its made it breath better, but as said put the spool up 750rpm higher, 22psi @ 2500 tp 3250 rpm
