difference between us and jap spec turbos?

Whizbang · 10-29-2009, 09:03 PM

was there any difference between the us and the Japanese FDs in regards to the turbocharger unit?

proz07 · 10-30-2009, 01:21 AM

not till 99' i do believe.

z

Brent · 10-30-2009, 07:18 AM

In 96-98, there are suppose to be some differences, but I have never seen any hard evidence of that. I know alot of the Australian guys seem to prefer the 96-98 over the 99+.

kyleaudio · 10-30-2009, 10:07 PM

not sure what the differences were on the 96-98 turbos, the waste gate actuators are gold instead of green, but that doesn't really matter. but that is what is in my car right now, when i pull then to port the waste gate (they're over boosting) i'll compare them to a set of us turbos and let you guys know then!
kyle.

joff · 10-31-2009, 10:38 AM

I think I remember hearing the newer models used some sort of coating on the inside of the compressor housing that was designed to be eroded away by the compressor blades during breakin. Supposedly would make for really tight clearances that were part of the secret to acheiving 80+% peak adiabatic efficiency.

GorillaRE · 10-31-2009, 11:45 AM

Quote:

Originally Posted by joff

I think I remember hearing the newer models used some sort of coating on the inside of the compressor housing that was designed to be eroded away by the compressor blades during breakin. Supposedly would make for really tight clearances that were part of the secret to acheiving 80+% peak adiabatic efficiency.

The units you're speaking of are the '99s.

The 96-98 twins were rated at 265hp instead of the 255hp US spec S6. The '99s were rated at 285hp. The only real visual difference besides the already stated waste gates color, is the compressor inlet. The compressor inlet on the '96-98s have a "step" or mechined "restrictor" of sorts, if you can even call it that, about 5mm before the compressor inducer. Now, to me, that means the inlet flow wouldn't be as efficient as the US spec S6s but they say that they're 10hp higher

. I remove and reshape the step any way...

Trout2 · 11-01-2009, 01:09 AM

I believe part of that 10hp increase would come from the efini y-pipe that was introduced in 96.

Jack

Cp1 · 11-02-2009, 11:20 AM

there are zero differences in them until you get into the later years (after 95) ive worked on a few rhds here and have measured the hell out of them. the reason people prefer them over lhd turbos is usually wear most of the rhd cars have lower miles thus so do the turbos.

kyleaudio · 11-03-2009, 12:36 PM

i think i also read somewhere that on the 96-98 turbos they changed something about the casting on the exhaust housing to help prevent cracks. cant say for sure tho.

10-29-2009, 09:03 PM	#1
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp Posts: 3,190 Rep Power: 21	difference between us and jap spec turbos? was there any difference between the us and the Japanese FDs in regards to the turbocharger unit? __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

10-30-2009, 07:18 AM	#3
Brent Sua Sponte Join Date: Feb 2008 Location: Killeen, TX Posts: 839 Rep Power: 18	In 96-98, there are suppose to be some differences, but I have never seen any hard evidence of that. I know alot of the Australian guys seem to prefer the 96-98 over the 99+. __________________ Road Atlanta August 2011 NASA TT 1:33 http://www.youtube.com/watch?v=IFY00PAK_Ps Traqmate's video of my car from the 2011 UTCC at VIR http://www.youtube.com/watch?v=2Zcn6...layer_embedded Video of Yellow LS1 FD at NASA TT at VIR http://www.youtube.com/watch?v=e6k0lJkcwrM

10-30-2009, 01:21 AM	#2
proz07 Needing a new tow rig. Join Date: Mar 2008 Location: AR Posts: 245 Rep Power: 18	not till 99' i do believe. z

10-30-2009, 10:07 PM	#4
kyleaudio The Newbie Join Date: Oct 2009 Location: Coatesville, PA, San Diego, CA Posts: 11 Rep Power: 0	not sure what the differences were on the 96-98 turbos, the waste gate actuators are gold instead of green, but that doesn't really matter. but that is what is in my car right now, when i pull then to port the waste gate (they're over boosting) i'll compare them to a set of us turbos and let you guys know then! kyle.

10-31-2009, 10:38 AM	#5
joff Rotary Fanatic Join Date: Dec 2008 Location: Mesa, Arizona Posts: 114 Rep Power: 17	I think I remember hearing the newer models used some sort of coating on the inside of the compressor housing that was designed to be eroded away by the compressor blades during breakin. Supposedly would make for really tight clearances that were part of the secret to acheiving 80+% peak adiabatic efficiency.

11-01-2009, 01:09 AM	#7
Trout2 Rotary Fanatic Join Date: Mar 2008 Posts: 104 Rep Power: 18	I believe part of that 10hp increase would come from the efini y-pipe that was introduced in 96. Jack

11-03-2009, 12:36 PM	#9
kyleaudio The Newbie Join Date: Oct 2009 Location: Coatesville, PA, San Diego, CA Posts: 11 Rep Power: 0	i think i also read somewhere that on the 96-98 turbos they changed something about the casting on the exhaust housing to help prevent cracks. cant say for sure tho.