importance of flow on intake side of heads?
importance of flow on intake side of heads? all last year i ran some very nice LS6 heads that flow 325+ on the intake side. they are off the car and for sale, i want to bump compression down for this year for a variety of reasons. car made great power and trapped a nice MPH on only 10 PSI of boost with these heads.
looking at maybe trading my buddy for his 71CC heads he has. just had them rebuilt and flowed and they don't even flow 300 on the intake side, like 295. but they did great on the exhaust side so thats good.
from your experience, how important is the intakje side with boost? my assumption is i won't hurt myself at all going to these heads over my current ones, but looking for opinions here. couple of folks last year even suggested to me that a high flowing intake side like i have with these ls6 heads was maybe even hurting me a bit with boost, interesting theory as well.
thanks!
looking at maybe trading my buddy for his 71CC heads he has. just had them rebuilt and flowed and they don't even flow 300 on the intake side, like 295. but they did great on the exhaust side so thats good.
from your experience, how important is the intakje side with boost? my assumption is i won't hurt myself at all going to these heads over my current ones, but looking for opinions here. couple of folks last year even suggested to me that a high flowing intake side like i have with these ls6 heads was maybe even hurting me a bit with boost, interesting theory as well.
thanks!
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The more power you make NA, the more you will make on boost. However, it's been shown that cylinder head flow numbers aren't nearly as important as people think, so depending on the other aspects of the port shape, they may be just as good or better.
Mike
Mike
They arent no where near as important as a N/A app. 1 psi increase will negate a set of ported heads. The only advantage a set of ported heads have it less friction on the intake side leading to less heat and an ability to make the same power with less boost.
Originally Posted by Country Boy
They arent no where near as important as a N/A app. 1 psi increase will negate a set of ported heads. The only advantage a set of ported heads have it less friction on the intake side leading to less heat and an ability to make the same power with less boost.
1 psi won't negate a set of ported heads. You will have more power per PSI with better heads than without them. The whole "just turn up the boost" logic is BS. How about comparing apples to apples: 8 psi with stock heads......or 8 psi with ported heads. Which makes more power?
Look Heads are important, but not nearly the effect of an N/A motor. The new ported heads aren't going to make a difference with the little difference in flow for sure. Conparing stock to ported is not really an issue here since both have been ported the 30cfm difference will be no issue and depending on how much they lower your CR they may help you run more boost on 93 if that is a concern if you are running race fuel all the time then the CR isn't going to mean **** and the higher CR wouldn't be an issue any way IMO. Patato Patoto???
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You guys are crazy if you think that good flowing heads don't help an FI car.
If a set of heads picks you up 40 rwhp on an NA car, then they will gain you 80 rwhp at 15 psi boost.
ninetres is right on this one. If you have better heads, you'll gain more hp/psi with boost.
Mike
If a set of heads picks you up 40 rwhp on an NA car, then they will gain you 80 rwhp at 15 psi boost.
ninetres is right on this one. If you have better heads, you'll gain more hp/psi with boost.
Mike
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Originally Posted by engineermike
You guys are crazy if you think that good flowing heads don't help an FI car.
If a set of heads picks you up 40 rwhp on an NA car, then they will gain you 80 rwhp at 15 psi boost.
ninetres is right on this one. If you have better heads, you'll gain more hp/psi with boost.
Mike
If a set of heads picks you up 40 rwhp on an NA car, then they will gain you 80 rwhp at 15 psi boost.
ninetres is right on this one. If you have better heads, you'll gain more hp/psi with boost.
Mike
If you mean 'good' as two sets of heads, both with 230cc ports and 2.08 valves and one flows 20cfm more @ .600 then the other I disagree that it will make a huge difference on a FI app.
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Originally Posted by kp
If you mean 'good' as being being large ports/valves as opposed to stock then I would agree.
If you mean 'good' as two sets of heads, both with 230cc ports and 2.08 valves and one flows 20cfm more @ .600 then the other I disagree that it will make a huge difference on a FI app.
If you mean 'good' as two sets of heads, both with 230cc ports and 2.08 valves and one flows 20cfm more @ .600 then the other I disagree that it will make a huge difference on a FI app.
I think we can go back to the age old simplification of a combustion engine.....its a big *** air pump. Better flowing heads will move more air. Period, boost or not.
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Originally Posted by kp
If you mean 'good' as two sets of heads, both with 230cc ports and 2.08 valves and one flows 20cfm more @ .600 then the other I disagree that it will make a huge difference on a FI app.
Originally Posted by ninetres
Some of us get so caught up in the big FI numbers.....I am even happy with a decent improvement. Who couldn't use 10 or 15 whp on the same psi????
I think we can go back to the age old simplification of a combustion engine.....its a big *** air pump. Better flowing heads will move more air. Period, boost or not.
I think we can go back to the age old simplification of a combustion engine.....its a big *** air pump. Better flowing heads will move more air. Period, boost or not.
Same reason a fast 90/90 will pick up a NA car and it doesnt do much of anything of a FI car.
Not worth agrguing about it really, yes the better heads should make more power but a stock set of heads can make 1000hp on a 346 with enough boost and that will never happen N/A so there is a little more to it..
Originally Posted by ninetres
Huh?
1 psi won't negate a set of ported heads. You will have more power per PSI with better heads than without them. The whole "just turn up the boost" logic is BS. How about comparing apples to apples: 8 psi with stock heads......or 8 psi with ported heads. Which makes more power?
1 psi won't negate a set of ported heads. You will have more power per PSI with better heads than without them. The whole "just turn up the boost" logic is BS. How about comparing apples to apples: 8 psi with stock heads......or 8 psi with ported heads. Which makes more power?
Yes, ported heads will help, thats a no brainer, but are they a necessity like a N/A app, no. There are better places to spend the money. Like KP said, stock heads are more than proven.
You can spend the $1300++ on a set of ported heads and make 700 hp at 12 psi or save the money and spend it on better parts (rear, meth, etc..) and make 700 hp on 13-14 psi. I would pick the latter.
Originally Posted by ninetres
Huh?
1 psi won't negate a set of ported heads. You will have more power per PSI with better heads than without them. The whole "just turn up the boost" logic is BS. How about comparing apples to apples: 8 psi with stock heads......or 8 psi with ported heads. Which makes more power?
1 psi won't negate a set of ported heads. You will have more power per PSI with better heads than without them. The whole "just turn up the boost" logic is BS. How about comparing apples to apples: 8 psi with stock heads......or 8 psi with ported heads. Which makes more power?
Overall, I think the answer is a definite yes. The lower compression will easily allow him to turn up the boost more than enough to compensate for the lower flow numbers, assuming the rest of the engine is up to the task.
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if i where you then i would look for heads with good flow all around, this way you will get better off boost performance. but then if it a drag applications not a DD then you want outright flow!
you only have to look at the best of the best engine builder out there. you put the best stuff in there and it will make the power you want!
thanks Chris.
you only have to look at the best of the best engine builder out there. you put the best stuff in there and it will make the power you want!
thanks Chris.