Max boost for 03/04 cobra in so-cal with 91 octane?

Hawwk11

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Hey guys. I am just curious as whats the most lbs. of boost an 03/04 cobra can run in so-cal with our 91 octane?
Thanks,
 

RussZTT

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Hey guys. I am just curious as whats the most lbs. of boost an 03/04 cobra can run in so-cal with our 91 octane?
Thanks,
There are many factors. Also depends which power adder you're using however, generally its 18psi for 93 oct so in your case I would say 16ish.
 

Hawwk11

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There are many factors. Also depends which power adder you're using however, generally its 18psi for 93 oct so in your case I would say 16ish.
Thanks alot bro. This is good info. I was wondering about the adder also, im really glad you mentioned it. So basicly if i were using lets say ported eaton as opposed to kb the boost levels would be different? Is this correct?
 

RussZTT

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Thanks alot bro. This is good info. I was wondering about the adder also, im really glad you mentioned it. So basicly if i were using lets say ported eaton as opposed to kb the boost levels would be different? Is this correct?
Well, the bigger blower will provide more cfm than say over an eaton. Really you will need to get it tuned for 91 as every car is different. That way you and your tuner can see how far you can go with your A/F along with timing. :beer:
 

Hawwk11

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Well, the bigger blower will provide more cfm than say over an eaton. Really you will need to get it tuned for 91 as every car is different. That way you and your tuner can see how far you can go with your A/F along with timing. :beer:
Gotcha. Thanks alot.
 

04cobra13

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Most id do on 91 is 15lbs MAX! Especially on a ported or twinscrew set up... I learned the hard way and now i need a new motor.. Thing lots of tuners around here think 17lbs is ok on 91 which it is not cuz our 91 sucks... If u plan on running more boost do a 91/100 octane or staight 100 octane if you dont want to go through a motor..GL!
 

Hawwk11

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Most id do on 91 is 15lbs MAX! Especially on a ported or twinscrew set up... I learned the hard way and now i need a new motor.. Thing lots of tuners around here think 17lbs is ok on 91 which it is not cuz our 91 sucks... If u plan on running more boost do a 91/100 octane or staight 100 octane if you dont want to go through a motor..GL!
Ok, yeh bro thanks alot. I deffinately dont wanna screw up the engine. And 15 sounds closer to what i was thinking because when i had my 300zxTT the most safely on 91 was 14. I just asked because i wasnt sure if it varied by car.

Thanks,
 

68gtscode

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Talk to a reputable tuner and go with their recommendation. I've read lots of posts of people running tons of boost on low octane fuel, but I wouldn't do it! My shop (AED in Sacramento) installed a 3.5" upper (stock lower) on my Whipple for 91... I don't remember exactly, but I think it is somewhere around 13 or 14 pounds. Hopefully my engine will last a while and I don't have to worry about getting a bad tank of gas.

I use a 2.75" upper for 104 octane, which I believe is around 18 pounds. I also would not recommend using 100 octane from a pump- it sits down there a long time so there's a high risk of it going bad.
 
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BUMPSTICKS

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Oh god, I have no idea
Well I'll throw this out. IT'S ALL IN THE TUNE!!!!! It's great that people want to blame thier motor blowing on 91 octane. Fact is there are quite a few people running 18lbs on 91 with no problems. I even know a guy out here that runs 21lbs on straight 91 octane. I believe his SN is NITROSCOBRA. Talk to him, I personally wouldn't run more than 18 but he has a ton of miles on his setup running 21lbs on 91 octane with a 3.4 whipple. There's no doubt that the motor is on the edge now, but he runs 91 just fine right now.

Just my .02
 

04cobra13

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Well I'll throw this out. IT'S ALL IN THE TUNE!!!!! It's great that people want to blame thier motor blowing on 91 octane. Fact is there are quite a few people running 18lbs on 91 with no problems. I even know a guy out here that runs 21lbs on straight 91 octane. I believe his SN is NITROSCOBRA. Talk to him, I personally wouldn't run more than 18 but he has a ton of miles on his setup running 21lbs on 91 octane with a 3.4 whipple. There's no doubt that the motor is on the edge now, but he runs 91 just fine right now.

Just my .02

Well i had the best in So cal tuning mine... I bet running on 21+lbs on cali 91 that that car wont last too long.. All im saying is if you dont wanna go through a new motor (cuz we all know they are not cheap) then its always better to be safe than sorry..
 

BUMPSTICKS

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Oh god, I have no idea
I agree that it's better to be safe than sorry. I'm just throwing it out there that running over 16lbs is absolutely possible. BTW, I believe NITROSCOBRA has been running this setup for over 10k miles.
 

68gtscode

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Well i had the best in So cal tuning mine... I bet running on 21+lbs on cali 91 that that car wont last too long.. All im saying is if you dont wanna go through a new motor (cuz we all know they are not cheap) then its always better to be safe than sorry..

I have the best tuner in Northern CA (IMO), and he recommended I limit boost levels to those I mentioned earlier. Again, I have read lots of posts regarding people running a lot of boost on 91, but I wouldn't do it. The risk of a $10K repair bill warrants some restraint, at least for me.

I agree that it's better to be safe than sorry. I'm just throwing it out there that running over 16lbs is absolutely possible. BTW, I believe NITROSCOBRA has been running this setup for over 10k miles.

Was he using meth (I mean for his engine and not himself)?
 
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98 Saleen Cobra

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I seriously wouldn't go higher than 15lbs of boost on 91 oct for sure. I've seen a lot of cars blow up on more than 15 with 91 oct..
 

BUMPSTICKS

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Oh god, I have no idea
I have the best tuner in Northern CA (IMO), and he recommended I limit boost levels to those I mentioned earlier. Again, I have read lots of posts regarding people running a lot of boost on 91, but I wouldn't do it. The risk of a $10K repair bill warrants some restraint, at least for me.



Was he using meth (I mean for his engine and not himself)?

NO. Straight 91. BTW, WAS is the wrong word, IS would be better. I still see the car every friday at the local car shows. He is not easy on his car either.
 

Hawwk11

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WOW! Lots of great info guys. Thanks alot for all the replys, i really appreciate it. After reading everything here i will look for a good tuner shop which i already have looked in some other threads and have seen a few great shops.

Thnaks agin guys.
 

Jomo1994z71

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Don't live in Cali, but I see some people running 17#s on 91...IMHO, that's too much...better safe than sorry...I run 17#s on 93 here in Florida...
 

RussZTT

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Bottom line, every car is different. Put it on the dyno, that will show what is safe on YOUR car. We can sit here and tell you all day not to go over 15- 17psi. You're car may like less or more.
 

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