Cam Choices

[DynastyLCD]

finally, its put up or shut up time, the price was right and i started a 2.0 forged engine build.
.040 freshly machined block
22mm pin Manley 6 bolt H beam rods
Arias 8.8:1 pistons

the valvetrain is setup to rev to 9k safely, and i plan on using an FP3052 or FP3065. the fuel is there too. the car's on V3. 80% of it is overkill for the turbo selection.

everything is ready for more power than i would make with either turbo. however, i have two sets of really awesome cams. a set of HKS 272's, and a set of Kelford 280's. i will also be running adjustable cam gears, whether or not i go crazy adjusting them im not sure.

two years ago, i tested both cams back to back, but on a much different combo. the setup, was a freshly rebuilt 6 bolt stock bottom end, BSEK, MLS/ARP's, stock IM, 2g manifold, FP3052, 27 psi. nothing crazy. running VPC on 680s, i was limited to 7500 rev limit without a custom burnt chip. the HKS 272's made 27 psi by 4000 on the dot, and pulled all the way through the powerband. the Kelford 280's made the same 27 psi by 4700, but after 5500, progressively made more power.

my question is, to anyone who has been in a similar situation, will the top end pull trump the few hundred RPM's of spool time lost? im sure with the added point of compression that it will spool a little faster than the stock bottom end's 7.8:1, but at the same time, if its not a big enough gain to make up for the 500-700 RPM's difference, then there is no point. im a firm believer in the old school HKS 272's, for the most part you just can't beat em. but if i could make a big gain up top, enough to make up for the lag and then some, it would be worth it. wondering if anyone here has been in this situation, and the results and/or comparisons.

 

[4thStroke]

It really depends on what you want out of the car. If its most for daily driving, the earlier powerband will be nice, but the Kelfords will puller harder, just later, and will keep pulling.

The HKS 272s are a pretty mild cam and there are more aggressive 272s that will make more power with similar spool times.

A buddy of mine had stock cams with his 16g E85 DSM. When he swapped in the FP4Rs, the car was a lot faster and made a ton more power under the curve and peaked at 430awhp and still kept the torque at 415 at the wheels. The car was a lot more fun with the big cams.

I suspect you won't be doing much daily driving above 4000 RPM, and when you want to rip on the car, you want all you can safely get. Go with the Kelfords. It will stretch out the powerband of the 30R. I'm only saying this because you already have the 280s, otherwise I wouldn't recommend them for a 30R build. I would also spend some time on the dyno with the Kelfords as I've heard that they don't always perform the best when installed straight up.

 

[Brianawd]

Its just all depends on where you want your power band. Remember shep went 9s on hks 272s So with the right set up they will make power. If running a big intake manifold then I would say kelford280s if running a stock or smaller plenum intake manifold I would run the hks 272s. But that just me. I like a car to have a nice fat hp and torque curve.