3.2SS with MS EFI dyno results

[camgrinder]

Originally Posted by juicersr

and as John pointed out, an AFR on the slightly rich side, !

Actually, 14-1 is on the lean side. Getting the AFR closer to 12.5-1 will net you more HP.

JP, nice dyno sheet. Hard to read all the numbers, but it looks like you are over 180 ft lbs from 3700 to 5300 rpm? 180 being 10 down from the peak number.
Looking at Justins curve, he peaks at 181 and comparing 10 down from the peak would be 171 ft lbs from 3600 to 6100 rpm. (as close as I can get from pictures) I'm not trying to compare ft lbs numbers from yours to his, just the shape of the curve.
If you could move your torque curve up another 500 rpm, you could make 175 ft lbs at 6200 and have 206 HP.

I looked, but could not find a dyno sheets on the DC30 cams. My 102 lobe center version of the solex grind. Would be fun to compare to JP's sheet.

[juicersr]

Originally Posted by camgrinder

Actually, 14-1 is on the lean side. Getting the AFR closer to 12.5-1 will net you more HP.

.

My goof, i gotta get more sleep...

Gonna fatten things up when over there.

BTW, Jamie, didn't you say you were running your AFR's a little on the lean side?

[jpnovak]

I do run lean but only at the cruise states, part throttle. Anything over 90 kPa (near to and WOT) is pinned rich. I go about 13.1:1 up to peak torque and then drop to 12.8:1 from there to redline.

btw, I do not have dyno numbers on my motor yet. However, I can tell you that my peak torque is about 5500-5800 rpm based upon the fuel delivery curves at WOT. The curve follows closely the effciency of the engine where peak torque requires the greatest amount of fuel. I can't wait to get it on the rollers to see how close the tune actually is. This should happen in the next month or so. The heat is finally starting to break. Yesterday was the first non-triple-digit day in about 2 months. I really don't drive the car at all during the summer and don't feel comfortable stressing the motor in a static position on the dyno in the heat. Cooling fans help, but only so much without full dynamic air-flow from a moving car.

[jpnovak]

One thing interesting to me is that from 4-5K you are running below 13:1 (red dotted line) then from 5-6K you are running near 14:1. If you look at the torque curve shape you will see there is a dip between 4-5K and a slight rise from 5-6K. This says that you either have very good cylinder mixing to burn all the air near stoichiometric 14.7:1 or something else is up. I don't have an answer for that one.

Either way. I certainly thought the car was a lot of fun. It was much improved compared to a stock CIS 3.0. And it certainly doesn't fall flat above 5500 rpm like stock.

[J P Stein]

John:
Thanks for the complements. Sorry about the bad reproduction. It does make for a challenging read.

A couple things to ad. It is an autocross motor and I did what I felt I could to get the torque down low. The pulls were done after only 30 minutes of dyno break in time on the NOS 10.4:1 P/Cs & without benefit of anything but my basic tune......the engine "woke up" after 4 or 5 AX passes a week later. A switch to leaded 110 (vs the unleaded 99) this season made the fuel burn much better (single plug).....no more gouts of black smoke when clearing its throat & better throttle response along with more pull per my butt dyno. I agree that the numbers comparison of the 2 engines is truly apples to oranges as another poster wrote.
The cams are Solex....one NOS in the wrapper and the other "touched up" by Web Cams. They are center oilers, of course. I was in a bit of a quandary about what to do with that feature, but finally plugged them at the drive end ( this was 7-8 years back). Home builders do a lot of , me thinks.

It would neat to see another chart using your 102 lobe center cams.