ArcticFormula

Hi Guys,
I try to read a bit an understand, but unfortunately one aspect of cam design I just don't get at all are these ramp rates. I hear XER tossed around, but am ignorant of alternatives or other lingo. My basic understanding is that the ramp rate is controlling how fast the intake/exhaust valve opens to max lift and then closes or along those lines.
For someone who is considering a conservative custom cam because he wants excellent drivability (along the lines of 220-220 .580 .580 116lsa straight up) is the xer the right grind for me? Going to have patroit gold duals which come with the afr 205 heads. Thanks for any clarification on options.

zoophagy

XE-R lobes should have better driveability, but they sound more like a sewing machine and are harder on your springs.

FASTONE

You have the right understanding of the fast ramps,for a mild cam maybe go with the XE lobes or cams.They"ll be a lot easier on your valvetrain and quieter(is that a word?)Why didn"t you get a cam from AFR to match the heads?

Beast96Z

iTrader: (21)

The cam AFR uses in the 205cc package is a 224/228 XE-R. You have the correct aspect of the ramp rates etc. Harder lobes open the valves sooner, but tend to be harder on valvetrain parts, but with the springs that are avalible these days, the lobes aren't really a problem. Harder lobes also produce better vacum so you don't tend to have brake problems in the bigger cams. You wouldn't have to worry about that with a 224 cam though. For a nice mild set-up, I'd use the AFR 205's and the cam they reccomend, the 224/228 XE-R.

CHRISPY

With the duration and lift you are talking about the XE-R lobes would work fine with the PP doubles.

Remember springs are a wear item. If you do a lot of racing I'd replace them every season.

PREDATOR-Z

Kinda went a similar way, AFR's with MTI Stealth II 224/220, .581/.581 116+0 XE-R (Comp grind)

FASTONE

Sounds good!I didn"t know that AFR cam was made by Comp,but I"m not surprised!