slagburn
I'm trying to track down the reason my 401 isn't up to par. While tuning the EFI, I dyno'd it. 260/ 355 wheel hp/tq. It was running out of steam at 5K. So for some reason I decided to swap a 292 cam in. 240/305. After that tune, I sat scratching my head and decided to fiddle with the timing, though it was already at 36 degrees total. I must have turned the dizzy 15 additional degrees, and it ran great, no pingin and lots better power, pulled on top for the first time.
Then I swapped on an MSD 6A. Now it rattles like crazy, even set back to 36 degrees. It was a Unilite running on its own before.
briefly: 180 psi on all cylinders, at 5K feet near Denver.
292 cam, unported 291C's, Torker, forged slugs. Commander 950 EFI, 900 cfm. Air fuel ratios are verified good by my new wide band tuner.
The headers suck. They're AMC blockhuggers with a Chevy bottom half. I didn't to the best job keeping the insides smooth. All 2.5 out, 2 mufflers behind that.
Sorry for the book.. I am at a loss here. It runs good, but nowhere near what I'd expect. I'd appreciate any ideas.
jeepsr4ever
Yup sounds like hell if it isnt rear wheel power numbers. Something isnt right there
tufcj
The 291 heads are good for compression, but they aren't the best flowing AMC heads. What compression are you running? Are you running the cam at 0*, and has it been degreed in? I've found big variances between different manufacturers timing sets. What gears and tire size are you running? That can have a huge affect on a chassis dyno.
Bob
tufcj
slagburn
Cam is installed straight up. The compression is about 10.5:1, it's been a while but I did cc everything out once upon a time. The gears are 3.07 with 28" tires, which isn't great on the street but should be fine on the dyno.
I could deal with a low number if it felt strong, but it just feels soggy.
I'm missing about 100 rwhp somewhere. It sucks, I have friends with performance cars and I'm the retard w/ the slow ass AMC.
Goose
I have noticed that my AMC's all like bunches of advance.. but aside from that.. Are these hp figures at the rear wheels? and what is it in..??
slagburn
Yep wheel horsepower. I was over there some more today and fattened up the fuel in a few spots. It's up to a huge :) 262 and 350 tq again.
They threw me off before I was done tweaking because my tires were scaring people. 140 mph and 225/75 15's don't mix too well.
The vehicle is a 90 Jeep Comanche.
slagburn
stumped the experts huh?
jeepsr4ever
Heck no....pitch the torker and get yourself a airgap.
You need 10.5 compression and a bigger cam to take advantage of the torker intake
Lifted79CJ7
LOL, 401 in a commanche!! I love it!!! So where are the pics???
Jack
slagburn
A couple years later and it's a lot better. This time around I'm running some ported iron heads, not 291's, that flow 300/220 if i remember right. Flattop pistons for 12.6:1, and the same Comp Magnum 292 for now, Torker intake, E85 fuel. ~400 rwhp.
rollen dean montoya
that is way better :lo1l: sometimes ya just gotta tinker some more :razz:
slagburn
slagburn
oops
rustyfloors
