KB1500 mild cam - worth it?
I've been doing some looking into a cam for my 5L Cougar that has a KB1500 on it that I typically run @ 6 psi. I also will run 8 psi at the track. I have been messing with Engine Analyzer Pro and it is telling me that there is little to be gained with a mild cam (XE264HR or Crane 2031). I have AFR heads and a decent exhaust and am making about 320 RWHP (108 MPH @ 3700lb). Here are the numbers...
6PSI - stock cam w/1.7's - 382 FWHP @ 5500RPM 349 avg (3500 - 6000)
6PSI - XE264HR cam - 384 FWHP @ 5500RPM 351 avg (10 HP gain @ 6000)
6PSI - Crane 2031 cam - 385 FWHP @ 6000RPM 350 avg (11 HP gain @ 6000)
6PSI - XE274HR cam - 398 FWHP @ 5500RPM 354 avg
but if I just lower the intake air temp 25 degrees (water injection) I get the following:
6PSI - stock cam w/1.7's - 396 FWHP @ 5500RPM 365 avg
6PSI - XE264HR cam - 404 FWHP @ 5500RPM 369 avg
6PSI - Crane 2031 cam - 407 FWHP @ 6000RPM 368 avg
6PSI - XE274HR cam - 416 FWHP @ 5500RPM 372 avg
And repeated upping the boost to 8 psi:
Regular heat:
8PSI - stock cam w/1.7's - 406 FWHP @ 5500RPM 374 avg
8PSI - XE264HR cam - 412 FWHP @ 5500RPM 378 avg
8PSI - Crane 2031 cam - 412 FWHP @ 6000RPM 378 avg
8PSI - XE274HR cam - 422 FWHP @ 5500RPM 381 avg
And water injection (lower intake air temp by 25 deg F) + 8 PSI:
8PSI - stock cam w/1.7's - 424 FWHP @ 5500RPM 393 avg
8PSI - XE264HR cam - 436 FWHP @ 6000RPM 400 avg
8PSI - Crane 2031 cam - 432 FWHP @ 6000RPM 398 avg
8PSI - XE274HR cam - 445 FWHP @ 5500RPM 402 avg
You can see where KB is about right with claim that you get about 10 HP with a 212 duration intake (XE264HR) and 20 HP from a 222 intake duration cam (XE274HR is 224). They would normally have good cool air when doing their dyno pulls. For us people who actually drive our cars, water injection is the only way we are going to get cooler air. When I see that you can get 42 HP by just cooling the intake charge and upping the boost 2 psi, it makes the extra 10 HP from a mild cam seem like a waste of money and time. Now the XE274HR cam seems like a winner but I don't want a cam with that much duration. BTW, the simulation shows a 49 FWHP gain going from stock unmodified E7 heads to AFR165 heads (at 8 psi - 20HP for "P" heads), so that seems like money well spent. Heck, even the Flowzilla gives 10 HP at 320 RWHP - $700 is a lot of money for 10 HP, but it's easier to install than a cam. And the Flowzilla will give 40 HP at 400 RWHP with stock drivability.
I hope this info is helpful to people here - at least it was fun playing around with the software.
Anybody have any real world experience with these or any other cams with the KB1500 to share? The simulator clearly shows the 1500 running out of steam somewhere around 480 FWHP (~400 RWHP) - and it is VERY difficult to get to that 400 RWHP mark too - it's amazing that Jeff Bellman did it - with stock cam!
Edit: I actually compared the stock cam (w/1.6's) to XE274HR at the 400 RWHP (11.5 PSI boost w/Flowzilla and good heads)) level and got only 26 FWHP! Same engine got 6 FWHP just going from 1.6 to 1.7 ratio rockers!
