Boost question?

Post by **Gmans13** » Fri Aug 08, 2003 9:04 pm

Ok I've had my sr going for a good 3 months now and about a month or 2 ago I installed a boost gauge and manual boost controller. The boost controller seemed to work find at first but now I notice that it will get pegged at 10psi then as my rpm's are still climbing it will back off to arround 7 or 8 psi . Do I have a leak? Turbo going? Anyone have any ideas. I am still running the smic at 10psi

Post by **Gmans13** » Fri Aug 08, 2003 9:04 pm

Post by **Ace** » Fri Aug 08, 2003 9:04 pm

Thats just what happens to the small T25. I boost like 11psi and it will usually hold that most of the way but whn I bump it to 13psi it starts to drop once rpms get really high. The SMIC may play a small role and with a FMIC it may hold a bit better, but its mostly the turbo.:starwars:

Website · Post by **quiksilvia** » Fri Aug 08, 2003 9:04 pm

i wouldnt push that little sidemount past 12 psi, and watch out for darth vader turbos is what ace is trying to say

Post by **GraySilvia** » Fri Aug 08, 2003 9:04 pm

Ummm, that's how MBC's work. That's why some people choose Electronic boost controllers, because MBC's do that, call 'boost spike' for obvious reasons. It's completely normal.

Post by **Ace** » Fri Aug 08, 2003 9:04 pm

quiksilvia wrote: watch out for darth vader turbos is what ace is trying to say

I just threw that in because I went through the smileys list and I hadn't seen it used before so I threw it in.

Post by **float_6969** » Fri Aug 08, 2003 9:04 pm

Damn, I was going to answer this one and you guys beat me too it. Though I thought they had a T28? Could be wrong...

Post by **Gmans13** » Fri Aug 08, 2003 9:04 pm

thanks

Website · Post by **quiksilvia** » Fri Aug 08, 2003 9:04 pm

s13's have a t25, the s14 has a bb t 25 or 28, i cant remember and the s15 has a bb t28

Post by **ride4lame** » Fri Aug 08, 2003 9:04 pm

The s14 has like journal bearings or something like that. They aren't actual ball bearing turbos. Thats why everyone goes for the s15 turbos if possible

Post by **float_6969** » Fri Aug 08, 2003 9:04 pm

doesn't the S15 have ceramic blades too? I thought I heard that somewhere? And I said T28, cuz I was thinking S14 for some reason.

Post by **hokiruu** » Fri Aug 08, 2003 9:04 pm

S14s have a garret ball bearing t28. Dunno if it's a dual ball bearing cartridge, but it is ball bearing.

Post by **BuudWeizErr** » Fri Aug 08, 2003 9:04 pm

GraySilvia wrote:Ummm, that's how MBC's work. That's why some people choose Electronic boost controllers, because MBC's do that, call 'boost spike' for obvious reasons. It's completely normal.

Hes talking about the opposite. A boost spike is when you set it for x amount of boost, but the boost controller doesn't let enough pressure reach the wastegate and the boost continues to rise past the level you just set.

He is talking about setting the boost for 13 psi, but when he gets to high RPM's, it starts falling off to 11 psi, which is common.

Run an SR with the wastegate unhooked. It will spike to ~20, then fall off to like 12 or 13 at the top end.

T25's are just too ridiculously small.

Post by **Movingviolation240** » Fri Aug 08, 2003 9:04 pm

ok, S14 and S15 are both full ballbearing, the only company that dosn't use dual in their BB applications is turbonetics. There are a few guys out there with tripple BB centersections.

The S15 has no ceramic parts in it, but the exhaust wheel is inconel. That's about the only diference between the S14 and S15. They have the exact same compressor, same compressor housing, same center section, just a better exhaust side (inconel wheel and a divided wastegate outlet).

The skyline's got ceramic turbo's in the RB20 and 25 on some applications.

Paul

Post by **float_6969** » Fri Aug 08, 2003 9:04 pm

PAUL LIVES!!! You been working a lot man? Don't see you on the boards much anymore. Did the flying industry pick back up again? And when are you going to get away from the dark side and come back to the CA forums!

Post by **GraySilvia** » Fri Aug 08, 2003 9:04 pm

BuudWeizErr wrote:Hes talking about the opposite. A boost spike is when you set it for x amount of boost, but the boost controller doesn't let enough pressure reach the wastegate and the boost continues to rise past the level you just set.

That's boost creep, not a spike, which is what I was talking about.

Post by **BuudWeizErr** » Fri Aug 08, 2003 9:04 pm

Hrm. You may be right. But creep and spike, from what I've been told are almost the same thing. Both are when your wastegate doesn't open enough and the boost starts rising.

meh it doesn't matter. We both know what we are talking about.

Post by **Movingviolation240** » Fri Aug 08, 2003 9:04 pm

boost spike is cuz the wastegate didn't open in time, boost creep is when the gate is open but not flowing enough so the boost keeps going up anyhow.

Yes I'm alive, I am up in Rhode Island now, for the next 2.5 weeks. So I had to buy a modem for my computer and settup a dialup account just to get on here and BS you guys

I'll try to make it back into the CA forums a LOT more after I get home, but till then all I can do is jump on here for a little bit each night. If anybody's in the Providence Warwick area and wants to get together for a beer let me know my cell is 260 804 2022.

Paul

Post by **Gmans13** » Fri Aug 08, 2003 9:04 pm

If the s14 and the s15 have pretty much the same turbo then why is the s14 rated at like 225hp and the s15 250hp? I thought the s13 and the s14 turbo's were similar t25's and the s15 was the only one with a t28.

Post by **float_6969** » Fri Aug 08, 2003 9:04 pm

I would imagine the S15 runs more boost. It also has an inconel exhaust wheel as Paul said, and a divided waste gate. Maybe the S15 has better head work, different ECU tuning? I'm just guessing. It's kinda hard to get info for S15's due to them not really being available. They're still too new.

Post by **hokiruu** » Fri Aug 08, 2003 9:04 pm

:rolleyes...Sigh... Yeah, I used to think the same thing about which one had which turbo. The s15 SR is easily available with a little bit of a wait, and runs the same 7psi stock as the rest of the SR family. The difference in turbo is the main difference for the increase in power. And it has variable valve timing (VTC) on both the intake and exhaust sides. Now no more on this subject on this thread!

Post by **hokiruu** » Fri Aug 08, 2003 9:04 pm

OH YEAH, GMANS13- READ THE FRIGGIN FAQ ON THE TOP OF THIS FORUM!

Post by **Gmans13** » Fri Aug 08, 2003 9:04 pm

damn sorry dude...didn't mean to make your butt wet

Website · Post by **quiksilvia** » Fri Aug 08, 2003 9:04 pm

ha ha ha...you have a wet butt....wtf does that mean...

Post by **SWIFT_DRIFT** » Fri Aug 08, 2003 9:04 pm

hokiruu wrote::rolleyes...Sigh... Yeah, I used to think the same thing about which one had which turbo. The s15 SR is easily available with a little bit of a wait, and runs the same 7psi stock as the rest of the SR family. The difference in turbo is the main difference for the increase in power. And it has variable valve timing (VTC) on both the intake and exhaust sides. Now no more on this subject on this thread!

s14 and s15 motors use the same vtc. The s15 motor uses larger injectors = the higher hp along w/ the turbo.

Post by **Samabra** » Fri Aug 08, 2003 9:04 pm

and it has mAd JDM eNgInErInG yO

Post by **hokiruu** » Fri Aug 08, 2003 9:04 pm

Yeah, I think you're right, thanks for clearing that up swift. My bad.

Boost question?

Boost question?

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