Sirnixalot

iTrader: (7)

Before my ring lands went I was running a set of HKS 272* 10.3mm lift intake and 264* 10.3mm lift exhaust cams on an otherwise stock 7 bolt long block, Evo 3 big 16g, ebay intercooler kit, blitz filter on a custom intake, Megan O2 housing & downpipe and a 3" exhaust on an evo 8 ecu.

I have since acquired an Evo X turbo, made an unequal length manifold to use it, Probe racing stroker pistons and an OEM 4G64 crank.

Cam timing and crank timing have always been something that i end up frustrated at trying to wrap my head around.

Would there be significant gains if i were to swap out the exhaust cam to a 272* duration?

dastallion951

yes there will be more gains in top end because the cams are open more duration that will allow you to make better midrange and topend, the 264 duration will actually hurt topend but help low end torque and some midrange, compared to 264 intake 272 exhaust which would be better

mcm308

iTrader: (13)

Yes.. get that 264 out of there..lol If anything, you would want to run the bigger cam on the exhaust side. It's a pressurized engine...

Sirnixalot

iTrader: (7)

The car's main use is for auto x so i am not after ultimate top end power. I guess the 2.3 will make up for any loss in low end going to the 272's all around.

Thanks

dastallion951

well since your gonna have added displacement with a 2.3 it would only make since to go a 272/280 cam combo, therefore midrange and top end will be increased, with out any low end losses...

TommiM

iTrader: (19)

Since you have a 2.3, and you autox, you obviously want the low end power. With a 2.3 you probably dont want to rev it as high so why not stick with the 272/264 combo for max low end without having to rev up the 2.3 uneedlessly?
If you wanted the power band of a 280 cam wouldnt you want it on a block setup to rev higher since thats where those cams wake up? Im just asking, so any more info would be great.

Sirnixalot

iTrader: (7)

I doubt i would go with the 280* cam as i will most likely be keeping the rev limit at 7500rpm.

I honestly did not get to run the cams on my stock turbo setup long enough to quantify the difference (or even get to retune for them). I was thinking if i added to the 272 exhaust cam any torque i would have sacrificed in the low/mid range would be negated by the increased displacement.

Hopefully FFWD can sort me out with a single exhaust cam from my stock cores.