441 cid dyno results
 

Dyno sheet from 441 cid automatic ZR1 today:

Re: 441 cid dyno results
 

is that with a Hogans?

Re: 441 cid dyno results
 

705-710 Crank?

Re: 441 cid dyno results
 

WOW...

Now that's a ZR-1!!!!!!!

Will we see it at BG this year??????

:happy1:

David

Re: 441 cid dyno results
 

Lee,

No - that was with the ported stock plenum and injector housings - currently on the car - exactly the way it was when it ran the 10.44 back in October. I surmise the dyno backs up the track performance. I'd think 580-585 would be possible with the Hogan from my prior experience, but I'd probably lose about 15 ft-lbs on the torque. I think that's a better match for a traditional 6-spd, but with my auto & the wide ratio gears, I think the tradeoff might be a push at the track. It probably would trap out a little higher with the Hogan, but I'm not sure the ET would change much.

I do expect to be at BG - knock on wood, nothing goes wrong!

Kevin

Re: 441 cid dyno results
 

think it would be easy to imprive the low end with the Hogans by modifying it alittle

Re: 441 cid dyno results
 

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 .

Re: 441 cid dyno results
 

Might be talking outta my arse but what about adding velocity stacks to increase runner length some...also improves flow, etc..

http://i134.photobucket.com/albums/q...f/sany0471.jpg

Re: 441 cid dyno results
 

Nice Kevin.
Now those are some real numbers and backs it with ET/MPH.

Pete

Re: 441 cid dyno results
 

Wow Kevin. That's the fastest 1/4 mile time I've ever heard of a street legal ZR-1 putting down. The only other one was Paul Smiths at 10.6. That must be an incredible thing to feel and experience. The cost involved in getting a ZR-1 to that level is also incredible.

Re: 441 cid dyno results
 

Ya', nice job...

Re: 441 cid dyno results
 

wow!! , Great results.. This has to be on my to do list ( getting a 441 ) ..

Re: 441 cid dyno results
 

For easier viewing...

http://i185.photobucket.com/albums/x...-6-12Large.jpg

IMMMMMMMpressive!! :thumbsup:

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.

Re: 441 cid dyno results
 

Paul the torque/HP difference between the two runs is the cool down time I would think.
Wow Kevin very impressive out of An automatic N/A Z.
Good Job Pete,you know those 247 are starting to look really good.



AL.

Re: 441 cid dyno results
 

:cheers: Nice Kevin . And with an automatic too !

Re: 441 cid dyno results
 

Al,

I'm assuming the 247 is the intake cam duration?

Re: 441 cid dyno results
 

Yes Sir.
Back to Kevin good job.
AL.

Re: 441 cid dyno results
 

Thanks Al
For the non believers exhaust cams are basicly Stage I.
This car starts and drives like grandmas Oldsmobile :)
Kevin drives this car to and from work 30 miles each way in traffic.

Pete

Re: 441 cid dyno results
 

In support of your post, or more correctly, your point that a big inch LT5 making huge power does NOT suffer for street manners and low end torque or drivability...Excellent job, Pete.

See link

P.

Re: 441 cid dyno results
 

Pete,

I think we have gotten a number of data points lately that suggest exhaust isn't the issue. In fact, on a stock block, intake cam may not be the constraint. We've got some pretty good numbers for stock cam stock displacement motors putting out between 430-450rwhp. I had a converstaion with FU at BG and he stated that the LT-5 was actually overcammed. I'm beginning to believe that's pretty accurate. The motor appears to have been "throttled" from the factory. Just look at the performance bump you get by simply porting the top end. This baby just needs to breathe more. :-D:dancing

Re: 441 cid dyno results
 

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

Re: 441 cid dyno results
 

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...:-D 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.:cheers:

Re: 441 cid dyno results
 

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

Re: 441 cid dyno results
 

Thanks Frank.

Re: 441 cid dyno results
 

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!

Re: 441 cid dyno results
 

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

Re: 441 cid dyno results
 

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.

Re: 441 cid dyno results
 

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

Re: 441 cid dyno results
 

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

Re: 441 cid dyno results
 

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

Re: 441 cid dyno results
 

The LT5's love the N20:-D

Re: 441 cid dyno results
 

NOS had a kit they worked with gm to develop for the LT5 i think it was a 125 shot.

Re: 441 cid dyno results
 

Yes, they did. Thats what I had. The pills that were in mine were more then 125 shot :p

Now back to that 441.. nice torque even with a auto...