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View Full Version : s15 turbo (91F00) better or GT28R?


loveless
05-23-2005, 09:41 PM
both are around 750 to 800 brand new

just wondering which one is better?

... too general? I want to run 15psi off of it, bottom mount, no internal work, no head gasket, goal is around 300rwhp. Car will be daily driven so I guess quick spool/making more power at low spool is a plus

loveless
05-23-2005, 11:33 PM
no comments?

RSP13-Sideways
05-24-2005, 12:02 AM
S15 cause it's OEM Nissan.....and it's done right.

loveless
05-24-2005, 12:33 AM
it's not realyl oem though... it's made by garrett as well, both are identical visually and price

atom
05-24-2005, 01:06 AM
You might want to double check this since I'm not 100% sure but I remember someone saying the S15 turbo has the cast in divider wall between the wastegate and turbine discharge while the GT28R doesn't. That would be the only reason I'd look for a S15 turbo over a regular GT28R, if that's true.

sideview_180sx
05-24-2005, 01:25 AM
research more before asking for opinion based decisions. especially when it comes to turbo choice. still even tho both are made by Garrett. One is made to nissan specs while the other is made to manufacturer specs. Similar design doesn't mean they are the same. Most people in the past on this forum have gone to the s15 turbo then later on went up to the GT28/rs and beyond. 300 flywheel HP or 300whp that is another determining factor also.

loveless
05-24-2005, 02:05 AM
You might want to double check this since I'm not 100% sure but I remember someone saying the S15 turbo has the cast in divider wall between the wastegate and turbine discharge while the GT28R doesn't. That would be the only reason I'd look for a S15 turbo over a regular GT28R, if that's true.

http://splparts.com/images/s15_turbo_2.jpg
this is a s15 turbo, what advantage does the divider have? it doesn't look like it's completely sealed

does it have to work with sometrhing like this?
http://www.stockreco.com/Mvc-ELBOW3f.jpg

atom
05-24-2005, 02:58 AM
It's actually one or the other. If you have an O2 pipe like the one you linked to or the greddy O2 it won't work on the S15 turbo without modification because the cast-in divider will interfere with the divider on the O2 pipe. You're right when you say the S15 divider isn't completely sealed, it looks to me it's only meant to seperate airflow directly at the mouth of the turbine and wastegate discharge. That's where the turbulence would have the biggest effect anyways.

Cliff notes:

If you have or want to upgrade to divided O2 pipe (like greddy) = get turbo without built in divider.

If you have or want O2 pipe that isn't divided (like megan racing or stock) = get turbo with built in divider.

wootwoot
05-24-2005, 05:16 PM
From what I have seen 300whp will not come from 15psi. You will need cams/intake manifold and about 18-20 psi to reach those numbers. I would honestly step up to a gt28rs, you are going to be pushing that turbo awfully hard

93 240sxfastback
05-25-2005, 01:35 AM
If you're getting into gt28rs price range I'd rather have a gt2871r.