1995GrandprixRED2dr Posted November 17, 2003 Report Posted November 17, 2003 Hey guys, I am wondering if i were to have my upper and lower intake manifolds ported and polished and then my heads machines what would the horsepower gain be? What octane gas would i have to run?would i have to do anything else to it to make it run right? how much would it cost? and has anyone else ever tried it or done it? thx rob Quote
Redfox340 Posted November 17, 2003 Report Posted November 17, 2003 First off, the gains are hard to esimate, but on a N/A motor, perhaps around 10 - 20hp at most. That's a pretty good guess, because you'll only increased airflow on a non-boosted / blown motor. And, no, you won't need to upgrade to a higher octane; you're increasing air flow not compression ratios. Also, you may want to cross-referance on what other have asked: Port + Polishing / Matching Heads - Erik Quote
1995GrandprixRED2dr Posted November 18, 2003 Author Report Posted November 18, 2003 Well if i am going to be raising the compression ratio wouldnt it be good to run a higher octane? right now i run mid grade on my stock motor. Would i need to get a bigger throttle body and exhaust probably? jw. If i were to do this would it cause more problems or what?jw, i would guess more but thats me? thx rob Quote
Robby1870 Posted November 18, 2003 Report Posted November 18, 2003 Well if i am going to be raising the compression ratio wouldnt it be good to run a higher octane? right now i run mid grade on my stock motor. Would i need to get a bigger throttle body and exhaust probably? jw.If i were to do this would it cause more problems or what?jw, i would guess more but thats me? thx rob How are you gonna raise compression by porting you intakes? Quote
1995GrandprixRED2dr Posted November 18, 2003 Author Report Posted November 18, 2003 well from what i know, when u shave your heads, it raises the compression ratio. correct me if i am wrong. i might be but i am not sure. thx rob Quote
Robby1870 Posted November 18, 2003 Report Posted November 18, 2003 oh yeah, I see that in the original post, but shaving the heads just a hair wont make your CR high enough to warrant Premium. Quote
Jon89le Posted November 18, 2003 Report Posted November 18, 2003 Just as a FYI, i have 9.5 dished pistons and decked (shaved) heads and im fine on just 89. So you will be just fine Power increases will probably be around 10-15 i would say. But, your power band will be altered so you may only gain 10hp lets say, but that 10hp might be at a higher RPM than stock making the car feel as if its got more power. I hope that makes sense. As for the price, there are a few companies out there that actually do sell ported 3100/3400 intakes. They are also very reasonablly priced. I cant get recommendations on them because these intakes have bad bends in them and none of the companies tell me if they hand port them or what. Here are a couple companies for ya buddy: http://www.rsmracing.com http://www.doctorspeed.com/ http://www1.ecxmall.com/stores/americanperformance/StoreFront.bok For more information on the intakes, try going over to the GrandAmGT.com forum. Quote
Vegeta Posted November 18, 2003 Report Posted November 18, 2003 I do port work, what do you need to know about it? Hand porting? Quote
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