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Discussion Starter · #1 ·
These cams have me and my tuner confused on the N/A tunes. I am running the ModMax 25102 cams. Intake 226/.525 Exhaust 235/.575 with 111 centerlines. The heads are Fox Lake stage II's with Modmax springs/valves and flow pretty close to their stage II specs. I am also running a port matched Bullitt intake. Now these cams should start making great power at or above 5k. The motor is running 10.8 compression which these cams are supposed to like.

From the graph the cams are making power past 5k, but it just bottom's out and go's flat all the way to 6200 range. We found that these cams like timing, but it seems there's some threashold hit with them and I have no idea why? Seems like airflow issue? Any insight?

N/A run
http://www.midwestfords.org/vrtical/dyno/dynoNA03.jpg
 

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You should contact john edwards.He is having the EXACT same problem with his.Personally i think its the cams and their profiles.
He has changed heads,intakes,and a different grind mod max cam i beleive and still does the same thing.
 

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Discussion Starter · #3 ·
white99gt said:
You should contact john edwards.He is having the EXACT same problem with his.Personally i think its the cams and their profiles.
He has changed heads,intakes,and a different grind mod max cam i beleive and still does the same thing.
yes, I sent John an email. I believe the cams are suspect.
 

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vrtical said:
yes, I sent John an email. I believe the cams are suspect.
Cool,
If you decide to change cams down the road.Let me know ,ill give you my contact at comp cams and he can hook you up.
Yours would work great with a nice custom n\a set :evil
 

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jimfitzgerald said:
You can still get in on the group purchase on The Corral. I ordered my Comp Cams last week.
Don't see anything posted about a group purchase:confused: (on the corral)
 

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found it....:D
 

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Talk to Edwards before you do anything about any other cams.
 

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93Cobra4V said:
Talk to Edwards before you do anything about any other cams.
Who?
 

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John Edwards. He had the same problem last year. It wasn't the cams. It was the intake I believe....
 

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93Cobra4V said:
John Edwards. He had the same problem last year. It wasn't the cams. It was the intake I believe....
Well unless he has fixed it since two months ago he is still having the problem.I spoke with him at my dyno tune .
He changed from a svo to a ported bullit intake ,and from svo heads to ported pi heads.Both times reusing the same cams.With no change in power.He and the tuner was dumb founded also.
 

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Well as of Gainsville the past 2 weeks the car hasn't ever been faster...And was with the ModMax cams... Just because a cam is made by Comp doesn't mean it's going to do any better. I have seen any results on their cams.
 

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Hey Doug !

'Might want to look elsewhere for the problem. When you run out of cam or airflow the power nosedives post peak. Your engine does not. How long is the runner on a bullit intake ? It would seem that that intake is tuned to make a wide flat torque curve ( Just what a stock bullit does) You are making good torque very early,If you shift the torque peak up 800-1000 rpm i think you would be suprised at the results. You may have a good combination and a intake manifold tuned to make power to early for your combination. IMHO...AL
 

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Discussion Starter · #13 ·
Mrs.Boss330 said:
Hey Doug !

'Might want to look elsewhere for the problem. When you run out of cam or airflow the power nosedives post peak. Your engine does not. How long is the runner on a bullit intake ? It would seem that that intake is tuned to make a wide flat torque curve ( Just what a stock bullit does) You are making good torque very early,If you shift the torque peak up 800-1000 rpm i think you would be suprised at the results. You may have a good combination and a intake manifold tuned to make power to early for your combination. IMHO...AL
ok, how would you affect the torque peak by rpm? does that mean longer or shorter runners? The Bullitt intake has pretty long runners thats for sure, I don't have the measurements would have to find them. My intake is only port matched and minor clean up so no runner porting has been done.

Also I believe the stock cfm specs on the intake are like 230 range.

Doug...
 

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ok, how would you affect the torque peak by rpm? does that mean longer or shorter runners? The Bullitt intake has pretty long runners thats for sure, I don't
(Disclaimer... I have been accused of being incapable of relating to anything that turns less than 8000 rpm... So be forewarned..

Here goes... Every change you made (Except the manifold) should have moved up the powerband. To shift the torque peak up the runner would be shortened. How much...? First you need a starting point and determine if it is possible to modify the bullit piece.
I have not seen one up close so i can't comment on that. Pull the intake off and measure from the valve on the short side of the port to the gasket surface. Then use a piece of hose in the manifold to get a length there , Add the two up. There's your runner length. You now have some idea of what your dealing with. If there's a removable plate on the bottom , Take it off and look around.If there are long horns inside it may be possible to shorten a few inches off the casting..
 

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She's the brains of this outfit...
 

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Discussion Starter · #17 · (Edited)
Mrs.Boss330 said:
(Disclaimer... I have been accused of being incapable of relating to anything that turns less than 8000 rpm... So be forewarned..

Here goes... Every change you made (Except the manifold) should have moved up the powerband. To shift the torque peak up the runner would be shortened. How much...? First you need a starting point and determine if it is possible to modify the bullit piece.
I have not seen one up close so i can't comment on that. Pull the intake off and measure from the valve on the short side of the port to the gasket surface. Then use a piece of hose in the manifold to get a length there , Add the two up. There's your runner length. You now have some idea of what your dealing with. If there's a removable plate on the bottom , Take it off and look around.If there are long horns inside it may be possible to shorten a few inches off the casting..
Ok, I looked at the intake while I was building the motor and shortening the runners, you would have to cut the upper in 1/2 and maybe take out 1 - 1 1/2 inches off the runners. There isnt much on the lower where the runners end. Maybe 1/2 inch at best. Either way, you have to totaly custom cut it to shorten anything. I don't know what I will do. I may try to borrow a different intake and see what I find.
 

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Mrs.Boss330 said:
(Disclaimer... I have been accused of being incapable of relating to anything that turns less than 8000 rpm... So be forewarned..
Was a simple comment really that big of a deal to you that you drag it into completely unrelated threads? Thats sad...

I think its a matter of too much runner length in the intake manifold. Cams biased towards the intake in lift and duration would likely carry the torque band out to higher rpm, but nobody that I've seen offers a reverse grind without going custom.
 
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