This has been a subject of debate amongst me and a few of my friends lately.. Which would better suit my setup/future plans? The Kelford 272 or the 280s?!

I dont drag race really at all, I've maybe launched my car 5-6 times in the past 2-3 years Ive owned it. If I race, its a roll race on the highway. Usually from at least a 40mph roll.

Mods are as follows...
- 2.0 Long Rod Motor. (Wiseco 1400HD Pistons 10:1cr, Manley Turbotuff 156mm rods, stock crank, AcL bearings, ARP studs).
- Gt35r .82ar
- stock ahead (aside from some beehive springs im installing).
- AEM EMS
- 1600cc Injectors
- walbro intank and a walbro inline
- E85
- stock intake mani and TB.

Now my future plans are Magnus IM and a bigger throttle body and then probably swapping out to an HTA86 but Ill probably never go bigger than that.

I want something with good topend power since Ill be revving to 9k rpms. I dont want a cam thats gonna cause me to lose a ton of power after like 7k.. And I dont want to have to swap cams ever again...

Any other info you guys may have on these two cams would be awesome and one thing Ive always wondered is what exactly does lift mean?! I always thought more lift meant more topend power but apparently that's not quite right...

 

if you upgrading the springs go with 280 for better top end, but i would chooe GSC S2 over the kelfords if i was you.

 

Yah ill definitely be upgrading springs when I swap out the cams. Ive already bought a set of GSC beehive springs.

 

I was going to suggest the 280 but after reading a couple of stories about snapping cams, it made me want to do more research on it.

 

what kind of rpm are you going to be turning on those beehive springs? you might want to consider the supertech.

 

Personally i would go with S2's and super tech springs ...

 

Lift means how far the cam lifts the valve off its seat. Generally speaking, more lift means more airflow, but that isn't always the case. Given two cams that are otherwise identical but one gives more lift favors greater power from that cam.

The ports in the factory head begin to choke around 10.5mm lift, which means once that figure is met, greater lift cannot flow more air. Both of these Kelford cam sets give 11+mm lift, which means your stock head won't be able to exploit the fullest potential of either.

In your case, the benefit of the Kelford 280 is the longer effective duration, which favors hp in the end of the rpm range. Of course, the tradeoff is weaker low speed and midrange performance with slightly slower spool.

 

So do u think the 11.5mm lift on the Kelford 280 will cause me to lose power over the 272s because of the amount of air choking or will they basically plateau? As in no matter how much lift a cam has beyond the 10.5mm, it wont make any more or less power because both cams will only be able to get a certain amount of air through my ports. Do you think I will still see power increases over the 272 on the top end regardless? Spool doesnt really bother me since all I have to do on the street is downshift and brake boost. I will be revving to 9k rpms, which is within the "safe/reliable" range of the Long Rod 2.0. Anything higher than 9k and you start to reduce longevity of the motor and my valvetrain. I already have a set of beehive springs ready to install, I'm sure theyll do just fine at 9k.

 

Anything over 10.5mm represents a plateau in airflow for a stock head.

The longer duration cam should help upstairs, but that is contingent upon other factors.

 

What other factors would my topend gains depend on? If it was your car, what would you do first I guess to help maximize topend? Ive always kinda thought my next step would be an aftermarket intake manifold. Ive seen those help out quite a bit up top. Perhaps porting my head this winter would be a good idea..

 

Is this a street car? Seems like you're after all top end power....which is fine for a drag car, but can be tedious to drive on the street. "Other Factors" as was mentioned by ted, would mean just that.....head flow characteristics part choice...all this play a factor, there is really no cut any dry answer...

 

Well I just figured as a guy who does mostly roll racing top end would be what I would want especially since as Im going through the gears I spend most of my time in the 6,500-9k rpm range. I suppose a 272 would be best. Im just unsure at what point a 280 cam is necessary I guess and if it wouldnt hurt performance to go with a 280 cam, then why not do it right off the bat? Only reason I could see someone wanting midrange with a turbo like mine is if you road race or autoX. When it comes to drag racing and roll racing it sounds like topend power is all youll need.

 

Hello Whitepwr,
I have the same hesitation, i want to know, in the end what cams you decided and why?

Im my case, i have FP Black turbo.
Thanks a lot.