1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Optimum boost PSI...

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Old Feb 18, 2003 | 11:28 PM
  #1  
unreality's Avatar
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Optimum boost PSI...

Turbocharged 13b motor with EFI. Stock rotors, moderate street-port. What PSI do you guys think this could safely run to still be durable?

I've been lookin at some high PSI turbos...
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Old Feb 19, 2003 | 03:20 AM
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REVHED's Avatar
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There's too many variables to say. It depends on what turbo you're running, whether you have some sort of charge cooling, grade of fuel, port timing etc. It's something that's best determined on a dyno equipped with a wide-band o2 sensor and egt.
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Old Feb 19, 2003 | 03:57 AM
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28 psi is the magical # to me!
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Old Feb 19, 2003 | 03:55 PM
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From: Trying to convince some clown not to put a Holley 600 on his 12a.
Yep- That's what they say! Right, 680? I mean everyone knows that 28 psi is the magic threshold number, right?

...Or are you just bragging.
Again.

Ya see, my problem here is not you. It's the fact that you have proven yourself very knowledgeable, yet seem to want more to let the board know (over and over) of your achievements more than helping people out by giving them useful information.
Now I could presume that "Unreality" does'nt have the means to boost his car up to 28 psi between now and the time that he inadvertantly happens across some more research data, but did you also presume as such?

Or would it be fine by you for someone to actually try cranking up their boost to 28 psi?

Think, man!
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Old Feb 19, 2003 | 04:19 PM
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You have to take into account that the guy's trying to sell stuff, not help people
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Old Feb 19, 2003 | 07:45 PM
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Jeez Guys, relax. I have seen 680 trying to help a few people here and there as well. There's nothing wrong with being enterprising either.

Back on topic. Try no more than stock boost levels for that particular year engine. I believe it's 7 PSI on the TII's and 10 on the 3rd Gens.

My tuner has told me that a good healthy engine can usually go to 15-17 PSI with a healthy tune and a good AFR.

Anything after 17PSI start looking for Race Gas and extremely good fuel and spark management.

Good Luck.
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Old Feb 19, 2003 | 07:51 PM
  #7  
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From: Trying to convince some clown not to put a Holley 600 on his 12a.
Originally posted by Directfreak
My tuner has told me that a good healthy engine can usually go to 15-17 PSI with a healthy tune and a good AFR.

Anything after 17PSI start looking for Race Gas and extremely good fuel and spark management.

Sorry, Directfreak, but 680 could'nt just say that?
Robert and I on are great terms, exchanging Emails, ect.
This has nothing to do with previous clashes between him and me on this board. We've since made 'nice-nice'.
But I have told him about this before.
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Old Feb 19, 2003 | 07:56 PM
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From: 3OH5
Originally posted by Sterling
him and me on this board. We've since made 'nice-nice'.
Really? I didn't think you'd get along with Ghandi or Mother Teresa. I guess anything is possible now.

Just yankin' on ya Sterling. BTW, I have a Supercharger now. It's weird having over 100ft-lbs more torque than HP.

I guess I am a double agent know. , You know as a Turbo / Super guy.
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Old Feb 19, 2003 | 08:32 PM
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Are you using that turbo in the pic? Talk about lag!
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Old Feb 19, 2003 | 08:52 PM
  #10  
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From: Trying to convince some clown not to put a Holley 600 on his 12a.
Originally posted by Directfreak
BTW, I have a Supercharger now. It's weird having over 100ft-lbs more torque than HP.
2002 Supercharged Harley Davidson Supercrew

"Ooooooowhhhaaaaaaaa...Papa like?


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Old Feb 19, 2003 | 08:54 PM
  #11  
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From: 3OH5
Originally posted by Sterling
2002 Supercharged Harley Davidson Supercrew

"Ooooooowhhhaaaaaaaa...Papa like?
No. Papa LOVE! (at first boost.)
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Old Feb 19, 2003 | 08:56 PM
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From: Trying to convince some clown not to put a Holley 600 on his 12a.
...and BTW.....

Here's yet another brag by 680
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Old Feb 19, 2003 | 08:59 PM
  #13  
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While we're on the 680 topic, here's where I lost my cool earlier today... maybe I went a little too far, quite unusual for me

https://www.rx7club.com/forum/showth...hreadid=159427
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Old Feb 19, 2003 | 09:46 PM
  #14  
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ill give it to him.. 720 out of a 12a is impressive.. but.. i agree.. too much bragging.. but then, if MY 12a made that much all my posts would say is

"720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! 720! "

all good though.. when i see bragging, i just skip down to the next post..


to the topic of this.. i have nothing to say.. because i dont know.. but yea, if you take a stock motor, and boost up to 28 psi.. BAM... bad advise 680
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Old Feb 19, 2003 | 09:49 PM
  #15  
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Haha, good point... mine might too
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Old Feb 19, 2003 | 11:10 PM
  #16  
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yeah, 680 has given me a lot of helpful info on my 12a turbo.Im right there with him, same as onepointone, id be bragging all day long if i was pushing over 400.
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Old Feb 19, 2003 | 11:23 PM
  #17  
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I just read about the new Mitsu Evo coming out - the thing has 19 frikkin' psi from the factory and has a driver controlled water injector in the hugenormous air/air intercooler for low speed/high load (read:autocross) applications...
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Old Feb 20, 2003 | 01:55 AM
  #18  
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Re: ...and BTW.....

Originally posted by Sterling
Here's yet another brag by 680

yah, here is the dyno run,,, racing this weekend @IDRC


www.rotaryshack.com/movies

mexico 720

exhaust as too much for the mic. ..... sorry
720 @28psi i love to brag!!!!!!STERLING

i still love ya!!!
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Old Feb 20, 2003 | 01:08 PM
  #19  
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Got Boost?
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The optimum boost ..... is always 2psi more than you are currently running

Seriously though, optimum for what? power.... the more you can the better; reliablity.... 0 psi; stock ports.... depends on tunning fuel, and even then there is a good amount of randomness, but I suppose a built rotor still has the same issues.

Like DF said, running stock boost is where you'll find a happy medium of relablity and power. If you want more, get a boost controller, and only turn it on when you need to.
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Old Feb 20, 2003 | 01:44 PM
  #20  
Eville140's Avatar
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Just keep cranking it up till something breaks. Then back it off a little bit

Later
Randy
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