441 cid dyno results

[kcl98]

Originally Posted by Paul Workman

For easier viewing...

IMMMMMMMpressive!!

Excluding inertia and drivetrain losses, that would put it comfortably north of 660 hp at the crank...an enviable figure for any NA, street driven Corvette!

I couldn't help but notice, there is quite a bump in torque between the two runs - or so it seems ( a little hard to see the graph), resulting in a pretty good lift in HP across the spectrum. Can you shed some light on what made the difference in the runs? Were they done on the same day, or is one an overlay from a previous test?

P.

Paul - Al is correct - the difference in the two runs is simply cool down time - amazing. Also a testament to how vulnerable the cars are to heat soak - at least the big inch ones. I think this helps explain why the car was able to "pop" a 10.44 @ 133 after running a pair of 10.5-10.6 @ 131.5 - the cool down really does matter that much - and these dyno results prove it.

Kev

[kcl98]

Originally Posted by LGAFF

705-710 Crank?

Yes - could be anywhere between 650 and 710 depending on whether you believe that a given drive train costs you a fixed amount of horsepower, regardless of how much the motor makes, or if you believe the drive train is a percentage loss, where motors with more power lose more between the crank and the wheels. If you use 20% loss for an automatic - it comes out at 710 - which makes me very happy... Not sure if I believe it, but I'm not going to take the motor out and engine dyno it to burst my own bubble.

[kcl98]

Originally Posted by sammy

if i can ask what is the total timing on the car,also what airfuel did you shoot for . graph looks good ,like there were no knock events .

I was aiming for 12.5-13.0 AFRs - looks like we got them. I'm not super aggressive on timing. I think I'm either 27 or 28 all in at the higher rpm ranges. I changed it back in the fall by 1 degree, so I'd have to double check. I backed it off to 23ish or so near the torque peak, considering it's a stroker. It's possible we might get a smidge more power by adjusting the timing a little bit. Could try to get slightly more aggressive.

KC

[kcl98]

Thanks Frank.

[ZRapid-1]

Very, very impressive.

Increase in displacement = 441 – 350 = 91 cubic inches
Crank Horsepower = 568/0.80 = 710 max. HP
Increase in horsepower = 710 - 405 =305 HP

That’s an increase in displacement of ((441-350)/350) of 26% and an increase in horsepower of ((710-405)/405) of 75%.

Would have been pretty good to get a horsepower increase in percentage equal to the displacement increase in percentage.

Give your engine builder a nice bonus!

[kcl98]

It's all in the 60ft - thanks to the automatic. There are a number of big inch motors that can run with or beat mine on the top end, but I don't think anyone is getting sub 1.5 60 ft times at the track. I think a Lingenfelter 415 went 10.40 @ 135 once, but I think it also had front runners on it. I'm hoping to get a 10.30 or better next year. Considering the Density Altitude was +350 feet when I ran the 10.44, I think it's doable under the right weather and track conditions. Thanks. Kevin

[kcl98]

Yes true - although I also have a friend with a stock displacement 350 who makes 474 @ the tire (about 570-580 @ crank) for an increase of 43% more power over stock with no displacement increase. His top end and mine are essentially carbon copies, with a couple of exceptions, so I know a bunch of my power is coming from the top end - cams, heads, etc. Thanks.

[sammy]

thanx for the info. i think its allways safer to err on the conservative where tuning is concerned

[Polo-1]

Originally Posted by kcl98

Yes true - although I also have a friend with a stock displacement 350 who makes 474 @ the tire (about 570-580 @ crank) for an increase of 43% more power over stock with no displacement increase. His top end and mine are essentially carbon copies, with a couple of exceptions, so I know a bunch of my power is coming from the top end - cams, heads, etc. Thanks.

My stock 94 (headers,corsa) made over 500 rwtq. with help from a blue bottle

[LGAFF]

Originally Posted by Polo-1

My stock 94 (headers,corsa) made over 500 rwtq. with help from a blue bottle

Blue Botttle........Viagra?