How much power per cylinder?

[John S]

A few weeks ago I had the F.A.S.T system tuned on the Dyno. The HP numbers came in a lot lower then I was expecting. While driving the car the past couple of weeks (70 miles) I've noticed that it has a tendancy to backfire and pop during decel and coast, I originally thought that there may be too much enrichment but future tuning once the engine was broke in would correct that. The other day I opened the car up for a short burst and noticed a haze of smoke in the rear view and thought that I may have an oil leak spraying onto the exhaust.
I put the car up on the lift when I got home to check things out and found that the #5 plug wire was barely on. The boot was hung on the tip of the plug and prevented from falling off due to the wire laying against the header.
I pulled the wire off to inspect it and found that the silicone lube on the boot had cooked and asshen over pretty well, but the wire was not burned thanks to the insulator sleeve.
I cleaned the boot and termial and took the car out. What an immediate difference! It's like the engine completely woke up. The smoke haze which I think was just the unburned fuel going through the exhaust is gone as well as the backfiring and I am a much happier camper.

My question is this, in general terms does each cylinder contribute about the same amount of HP for the engines total? In my case the engine made 444.7hp and 531.8 ft-lbs torque running on 7 cylinders. Thats about 63hp per cylinder. Would I be close in estimating that getting the 8th cylinder to fire would add clost to 63Hp to the total bringing the potential hp up to close to 500HP? And how would torque be affected?

Sorry for the long post and thanks for the help.

[XcYZ]

That's an interesting question. I'll make a guess but will be interested in what others think. I'd guess that it would be a bit more power than you estimated because of pumping loss of the dead cylinder.

[70gotboost]

For the most part Scott is on the $$$ yet once again. There are NUMEROUS factors (more than just pumping losses) to weigh in on this theory, but in general 'studies have shown' your losses will be more than single cyl HP and TQ. On 'special' applications some in the 'industry' have actually shown GAINS when running down a cylinder, but that is way over and above the norm for most of our applications.

My .02, take 'er to the dyno again and LET 'ER EAT for some actual power numbers on all 8.

[John S]

Thanks Guys, I am a bit confused about something though and hopefully someone will chime in.
I spoke to the dyno tech today and he said that the engine was not missing when they ran it. I'm wondering, how would they know? Unless you were looking for it they would not normally monitor individual cylinder EGT. Would there be any other way? Monitoring the ignition would only let you know if the ignition was working correctly.
Am I wrong in thinking that monitoring individual cylinder EGT is the reliable way to know for certain whether a cylinder is firing or not?
Anyway the shop that did the tune is 2.5 hours away so I called a local shop that has a dyno and I'll bring it there to make a few pulls.

[XcYZ]

Kevin, regarding 'special' applications some in the 'industry' have actually shown GAINS when running down a cylinder, wouldn't have anything to do with a couple of measurements, such as 57/64" and 7/8", would it?

[70gotboost]

Originally Posted by XcYZ

Kevin, regarding 'special' applications some in the 'industry' have actually shown GAINS when running down a cylinder, wouldn't have anything to do with a couple of measurements, such as 57/64" and 7/8", would it?

nope, nothing to do with 57/64" and 7/8"... more like 31/32", 63/64"!!!

[69 L88 Camaro]

Were you monitoring the O2 on the side the plug wire was loose ? If so it would have showed that something was wrong with the engine. I would belive the dyno tech if he said it was on during the test/cal.