2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

What's wrong with my 90 Turbo?

Thread Tools
 
Search this Thread
 
Old Sep 17, 2001 | 04:17 AM
  #1  
ROSHX7's Avatar
Thread Starter
Senior Member
Tenured Member 10 Years
 
Joined: Apr 2001
Posts: 455
Likes: 0
From: Surrey, B.C. CANADA
What's wrong with my 90 Turbo?

I got a 90 Turbo system on my 87 TII. Today I wanted to try running FULL BOOST, so I yanked off the line at the wastegate and left it open. I only got 11psi in 3rd gear and about 13psi in 4th gear! What's up with that?...shouldn't I be hitting full 15psi in the line is open?
Reply
Old Sep 17, 2001 | 08:35 AM
  #2  
ZachSpazz's Avatar
I wish I had a posse...
Tenured Member 10 Years
 
Joined: Feb 2001
Posts: 896
Likes: 0
From: Cincinnati, Ohio-Boycott Central
Don't come to us crying when you pop your engine.

Have you done all the fuel mods, FMIC, and exhaust mods? If you haven't, you shouldn't be running that much boost...you're looking a t detonation and large repair bills in no time flat.
Reply
Old Sep 17, 2001 | 03:15 PM
  #3  
ROSHX7's Avatar
Thread Starter
Senior Member
Tenured Member 10 Years
 
Joined: Apr 2001
Posts: 455
Likes: 0
From: Surrey, B.C. CANADA
Don't worry, after blowing up 2 engines in the past 3 months, I'm not going to let it happen again! I'm running extremely rich right now, with larger primary & secondary injectors and the Walbro fuel pump. I just wanted to make 1 run @ full boost and see what I get. Eh that's a nice Rx7!, nice front chin...where u get that from?
Reply
Old Sep 17, 2001 | 06:04 PM
  #4  
Chris Ng's Avatar
I'm with stupid -----^
Tenured Member 10 Years
 
Joined: Mar 2001
Posts: 994
Likes: 0
From: Calgary, AB, Canada
He's popped 2 motors..
Both times because of stupid "mistakes"
He comes back and says he ran with the wastegate unplugged just to see what it was like..
sigh .. I don't wanna be mean or anything.. but... hell I have $50 saying that he's gonna lose another motor before the end of the year...
Stick all the fuel mods you want.. you're still going to pop your motor.. fuel is not everything you have to account for.. timing and intake charge temps are also in the picture...
Take some time and learn about how the motor works in general.. you just got your motor rebuilt.. if it's not running right now then quit tinkering with it... 90% of the time motors run poorly because of driver wanna-be mechanic not knowing what the hell they are doing..
Reply
Old Sep 17, 2001 | 06:40 PM
  #5  
ZachSpazz's Avatar
I wish I had a posse...
Tenured Member 10 Years
 
Joined: Feb 2001
Posts: 896
Likes: 0
From: Cincinnati, Ohio-Boycott Central
Originally posted by ROSHX7
Eh that's a nice Rx7!, nice front chin...where u get that from?
Thanks! That front chin is STOCK! It's pretty rare actually, I've only seen a few TII's with 'em.

Regarding your car though...I would really drop some money on a new ECU or AVC-R, something to control the boost and fuel ratios. If you don't already have one, get a FMIC as the stock one sucks. Even a Starion or Volvo intercooler in the front will help out greatly, as the stock one just BAKES in it's position. When I gun my car, I always cruise for a bit to cool the IC off before I step on the throttle.
Reply
Old Sep 17, 2001 | 08:09 PM
  #6  
ROSHX7's Avatar
Thread Starter
Senior Member
Tenured Member 10 Years
 
Joined: Apr 2001
Posts: 455
Likes: 0
From: Surrey, B.C. CANADA
Smile

Ok, NO MORE flaming about my addiction to boost! I'll leave it alone then, just run the 12psi I'm getting max in 4th gear right now and just leave it at that...no more crazy boost! Thanks for the warnings!
Reply
Old Sep 17, 2001 | 09:23 PM
  #7  
SoloRacer's Avatar
Senior Member
Tenured Member 10 Years
 
Joined: Mar 2001
Posts: 524
Likes: 0
From: Calgary, Alberta
Rosh,

I know Chris and he's a good guy and he is right. Pulling the line off the wastegate to get maximum boost is not a smart idea - even if you have the fuel and ignition mods. You will find your inlet temps will be extremely high (ie: hot air going into your engine) and you could detonate. Another thing to think about is making more boost does not always mean making more power. Each turbo has a range where it is efficient. On our turbo's you really don't gain much when over 12 lbs and anything higher than 15 lbs all you are doing is heating the inlet air, risking detonation, shortening the lifespan of your turbo and possibly losing power at the same time. I don't know how much you understand about turbocharging but getting the most PSI of boost does not always equate to making more power. Cold dense air at lower pressure will make more power than hot thin air at higher pressure. I know of a guy with a T04B 60-1, p-trim, 0.96 A/R that was making over 300 rwhp with only 7lbs of boost. That is far more than the 15 lbs of boost you are trying to get out of the stock turbo will ever give you. Chris isn't really flaming you. He's trying to encourage you to learn more about your car. I know he's hoping that your future posts will be about what you have learned about your car and not about another popped engine. Without guys learning how their cars work we would never have info on TID mods, ACV removals or fuel pump rewiring. So keep the boost at a safe level and good luck!

Last edited by SoloRacer; Sep 17, 2001 at 09:26 PM.
Reply
Old Sep 18, 2001 | 12:12 AM
  #8  
Chris Ng's Avatar
I'm with stupid -----^
Tenured Member 10 Years
 
Joined: Mar 2001
Posts: 994
Likes: 0
From: Calgary, AB, Canada
okay okay.. I was a little harsh.. I appologize

As Eric mentioned, more boost doesn't neccesarly = more power, just as more fuel doesn't always = more safety..
The stock turbo should be good for a max of about 12 psi.. anything beyond that just makes you run closer to detonation..
even when you're pumping out 12 psi on the stock turbo you'll find alot of times that your boost will start dropping off at about 6000 rpm .. it just can't keep up..

I'm turning over a new leaf and I'll start answering your posted questions
Reply
Old Sep 18, 2001 | 07:30 AM
  #9  
Josepi's Avatar
Despise Enmity
Tenured Member 20 Years
 
Joined: May 2001
Posts: 2,420
Likes: 0
From: Richmond, VA
Originally posted by SoloRacer
Rosh,

I know Chris and he's a good guy and he is right. Pulling the line off the wastegate to get maximum boost is not a smart idea - even if you have the fuel and ignition mods. You will find your inlet temps will be extremely high (ie: hot air going into your engine) and you could detonate. Another thing to think about is making more boost does not always mean making more power. Each turbo has a range where it is efficient. On our turbo's you really don't gain much when over 12 lbs and anything higher than 15 lbs all you are doing is heating the inlet air, risking detonation, shortening the lifespan of your turbo and possibly losing power at the same time. I don't know how much you understand about turbocharging but getting the most PSI of boost does not always equate to making more power. Cold dense air at lower pressure will make more power than hot thin air at higher pressure. I know of a guy with a T04B 60-1, p-trim, 0.96 A/R that was making over 300 rwhp with only 7lbs of boost. That is far more than the 15 lbs of boost you are trying to get out of the stock turbo will ever give you. Chris isn't really flaming you. He's trying to encourage you to learn more about your car. I know he's hoping that your future posts will be about what you have learned about your car and not about another popped engine. Without guys learning how their cars work we would never have info on TID mods, ACV removals or fuel pump rewiring. So keep the boost at a safe level and good luck!
Would a FMIC be good for cooling the intake rather than stock presuming he's still using the stock IC?
Reply
Old Sep 18, 2001 | 05:48 PM
  #10  
87jap951's Avatar
Full Member
Tenured Member 10 Years
 
Joined: Mar 2001
Posts: 227
Likes: 0
From: Indy In. USA
Good advice! I now have a 88 T2 and I want to soak up all the info I can! My 87 T2 was wrecked when someone pulled out in front of me! Keep the good stuff coming guys! Happy...safe boosting!
Reply
Old Sep 18, 2001 | 06:07 PM
  #11  
13BAce's Avatar
On a long vacation
Tenured Member 10 Years
 
Joined: Feb 2001
Posts: 2,160
Likes: 0
From: Bay Area, CA, U.S.A.
Originally posted by ROSHX7
Don't worry, after blowing up 2 engines in the past 3 months, I'm not going to let it happen again! I'm running extremely rich right now, with larger primary & secondary injectors and the Walbro fuel pump. I just wanted to make 1 run @ full boost and see what I get. Eh that's a nice Rx7!, nice front chin...where u get that from?
My friend knows a guy who makes exact replicas from fiberglass. My friend has one, and it looks great. I think they're about $200.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Queppa
New Member RX-7 Technical
11
Nov 18, 2024 03:47 AM
diabolical1
2nd Generation Specific (1986-1992)
30
Jan 30, 2016 05:50 AM
fidelity101
2nd Generation Specific (1986-1992)
13
Aug 31, 2015 07:47 PM
ChrisRX8PR
Single Turbo RX-7's
18
Aug 21, 2015 01:56 PM
Frisky Arab
2nd Generation Specific (1986-1992)
13
Aug 18, 2015 05:30 PM




All times are GMT -5. The time now is 06:46 PM.