I've combed through a lot of forums and decided to run flat top pistons with my centri build; my car is a 97 cobra. I think my compression will be around 10.9:1; what kind of boost would you guys recommend for pump gas? I was thinking about 12 pounds but that may be too much for pump gas I'm not sure; I get a lot of mixed opinions reading forums. I also get mixed opinions on whether I should use 42lb injectors or 60s. I have 42s now but if you think I should get 60s I will upgrade. It won't be a daily driver but will be driven mostly on the street with the occasional trip to test and tune night. Also I need a good tuner if you have any suggestions. I'm from the Huntington, wv area so something less than a 5 hour drive would be nice; thanks in advance for the help!
Boost question for a 4 valve
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I'd personally run around 15 psi of boost with 10.9:1 CR.
42lbers are good till like 500rwhp.
42lbers are good till like 500rwhp.
Id say 8-10psi with that compression on pump gas. If you can run e85 you can run whatever you want with the right fuel system.
Really, 15lbs on a 11:1 engine on pump gas???
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OP, I'm assuming you're engine will be a fully forged motor. With your compression I would run 6-8lbs on pump gas but I would try to go with e85 and up the boost by a few more lbs.
I have an 8lb pulley I can run. I would rather not have to put race fuel in it every time I fill up; that would suck. I think if I ran the 8lb pulley I can run the 42lb injectors safely am I right? I am also going to run an air to water intercooler will that make much difference on the boost I can run on 93 with my compression?
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I would run e85 but there are no stations around me that carry it.
It depends on quality of fuel, how the motor runs, and heat transfer. There are variations to all of this. I wouldn't be surprised if you can run 12-15psi with proper fuel and timing tables.
It's all in the TUNE. keep the AFR around 11.5-11.8 . Don't go wild with the timing. It's not the boost that kills the motor.....it's the HEAT and the detonation (caused by advanced timing). Get a good IC. Also, a meth kit is a great idea to keep IATs under control.
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