Camshaft advice needed

[rob86gn]

On the dyno the hp and tq drop at 4400rpm. Prior owner told me the car has the Poston 202 duration @.50 / 430lift cam which is supposed to reach peak power at 5600. This one pulls to 4400 (320hp) then drops off hard 20hp instant then down to about 250hp at 5000rpm.

Is is the cam? 12 dyno runs made, all drop at 4400rpm no matter what fuel, timing, or boost changes were made.

Can anyone recommend a cam good to around 5500rpm that is proven for a car that should be in the 400rwhp range?

 

[BlackBandit]

Kinda sounds like it could be your valve springs.

 

[PaCemkr86]

what was the a/f ratio ?
was it getting any knock retard?

 

[vacuum 6]

Kinda sounds like it could be your valve springs.

2nd that.

 

[rob86gn]

I never thought about the valve springs being the problem. I will look into that. The a/f ratio we ended up making the best power with was 12:1. Timing was 21 deg (best power). Alcohol injection kept the knock out.

 

[PaCemkr86]

if they are the stock valve springs.. then they are prolly wore the hell out

 

[49-blues]

I have a brand new set of champion iron springs-$55. shipped.