Dyno numbers, not too impressive
 

I have a 79 SC with a 3.0, upgrades include Bursch headers( no cat), Bursch muffler, MegaSquirt EFI, and a 3.2 intake.
On the Dyno I hit 104 H.P. and 100 FP of torque at the rear wheels at 5500 RPM, I was a little disappointed. I am using a narrow band EGO so I am not sure if tuning is at its peak.
Between 3200 and 4200 theres a flat spot then it climbs steadily.
Any suggestions?
Mike

Mike,

I posted in the other thread you replied, but let's keep this one going.

My car is very similar to yours 78SC, 3.0L, backdated exhaust. The only difference is the intake. I got the chopped up CIS box and runners. Compared to my car you are short by about 80HP to the wheels. Something is seriously wrong.

Find a nice long road and do a couple of WOT datalogs in 2nd or 3rd gear. Send me a datalog and I'll have a look to see if there is anything obviously wrong.

Cheers,

What does your a/f ratio curve look like?
For HP numbers that low I would suspect either an ignition system that is way out of whack or your mixture is way off.
Have you pulled the plugs to have a look see?
Without more information I can't really help except to venture a WAG that it is way too rich.

A bore stock SC, with CAT, should give you 155-160 rear wheel hp. so all that work and 104 should say a big problem

A compression check and leak down would tell you if the pumping side is OK. A/F ratio sould tell you your are way too rich (or lean).

I agree with tbitz, you are about 80-100 Hp off. for the work that was done.

How did it feel? Uneven? Bucking, or smooth? Sounds asthough the ignition isn't firing on all cylinders, or the Megasquirt is off.

Check the A/F numbers...very important that it's not lean.

My stock 78 SC last year was 161 RWHP. Something wrong with your car, or the test.

I ran my carbed 3.0 SC with back dated exhaust on the dyno today, it was so lean we shut it off at 5500 on the first run. On the second run I upped the idle jets but didn't have any mains with me, still the A/F was close to 15 at full throttle. I only got 152HP and 168 ft/lbs. Knowing the car should be 155-16 stock, and more like 180 with the mods I have I was disappointed at first but between the A/F being far too lean and having not checked the timing in over a year I'm pretty confident I can get it up where it belongs.

That flat spot sounds like it's too rich to me. My buddy was there today with a his Ford and it was too rich between 3000 and 3600 rpm and the HP dropped of signifigantly. I've always found the sweet spot to be 12.5-13 at WOT with around 36 degrees total timing for naturally aspirated cars.

Well it turns out the dyno is having issues, It should be recalibrated by the time I return from the USGP. With the help of Tony Bitz and the folks at MS I have got it tuned where I want it. Presensly I have the O2gas running in the low 5's, averaging 22-24 MPG. It is my driver so this suits me fine. When it goes back on the dyno I can put the fuel to it and see what kind of HP she puts out. I have not played with timing, I know I'm not at 36 degrees. Is that number close to where I should be?
Mike