Pro Stock John

iTrader: (34)

I made 73_rwhp with Crane 832's, and 230/236 Cam Motion Cam.... 17 psi I think thru a T400. I have had a lot of springs in my car. When I went to 236/246 cam I had to change the springs to 977's.

kp

iTrader: (34)

Nothing wrong with the cam unless its a tooth off or something.

I'm running a 232/240 115 XER with a 9.2:1 346 and making a bit more power then he is. 5 psi isnt going to get you much, I run 25 degrees + of timing at the 5psi level, goes down as the boost goes up naturally.

Valve float is a possibility, if the power just stops at a certain RPM but I'm sure you guys know about what springs to use with that size cam.

Get some more boost or add some timing..

kp

iTrader: (34)

Post up what pulleys and what blower he has on there, like ebz06 stated 550-570 on a procharged stock Z06 with headers is fairly common. If everything is correct it at least make close to the power it was making with the bigger cam on the same pullies. Putting a bigger cam in wont increase much unless you put more air in along with it. Going form a Z06 cam to the present cam I have maybe lost 3-4psi of boost along the way but naturally I had to pulley it up to take advantage of it.

I would think he would much happier with a smaler cam regardless of the peak power

BlackScreaminMachine

iTrader: (17)

I am no cam expert but seems to me that the cam was ground with alot of duration and not enough LSA to compensate, not that LSA should be used to dial back the cam, the duration should have been matched for the application more effectivly. Definitly seems to be that Boost is being bleed off. Also through I would think to see this cam in a larger cubic inch D1 or better procharger.

Tiago

iTrader: (27)

How much boost on the car in the previous dyno? incase something went wrong...


what displacement?

Got Me SOM

iTrader: (2)

slowhawk how much total timing did you add, or did you add 8-10 degrees in low and midrange? that's amazing.

I'm running a 224/230 .581/.588 on a 115. it pulls n pulls n pulls, but i'd rather have something make more midrange and low personally for a street car.

HUNTER02SS

iTrader: (24)

I agree Ron ,you will need to make more boost now that the cam is flowing more air and keeping the valve's open longer and opening higher! It is possible that it will loose power until you pulley it for more boost.Stock piston's should be good for 8-10lbs of boost on a good, safe tune!

kp

iTrader: (34)

Well thats the thing, you cant expect to stick a big cam and more power with the same pullies unless you are moving a ton of air to start with. 8-9psi isnt much so I would guess its maybe a P1SC car or a D1 really slowed down.

I wouldnt have expected to lose 70hp either but I can vary 50hp on the dynojet pretty easy with a little heat soak if I make one pull and do another right after. Plus like slowhawk mentioned a little timing here and there can a big difference.

HUNTER02SS

iTrader: (24)

I wonder if that car has a big single front mount or the 2 4inch. intercooler's,or maybe if it even has the older style,smaller intercooler's.?

kp

iTrader: (34)

Dunno, but 5psi isnt much whatever it is - the cam isnt that big

BlackScreaminMachine

iTrader: (17)

Boost is being bleed off, who know if the cams have the same exact type of lobes. the #'s are not always universal. I think he needs different pulley or just more blower backing it.