Weavsvet wrote:
Quote:

BeachBum wrote:
I think your torque curve should instead look something like one of these I filled-in with theortical curves....

Not sure which one.....but it could be the purple one that not only helps the torque where its missing, but extends the power up into the rpm range. At the very least, it is one of the other two.

[IMG]http://i526.photobucket.com/albums/cc342/tldrane/weavdyno.jpg[/IMG]

That would be great! But still, this cam is a across the board cam,1900-6200. You're saying it can deliver something like this?

BeachBum wrote:
Quote:

Weavsvet wrote:
Quote:

BeachBum wrote:
I think your torque curve should instead look something like one of these I filled-in with theortical curves....

Not sure which one.....but it could be the purple one that not only helps the torque where its missing, but extends the power up into the rpm range. At the very least, it is one of the other two.

[IMG]http://i526.photobucket.com/albums/cc342/tldrane/weavdyno.jpg[/IMG]

That would be great! But still, this cam is a across the board cam,1900-6200. You're saying it can deliver something like this?

Here is the shape your torque curve should be....

http://www.corvette-guru.com/modules/ ... id=100493#forumpost100493

Notice his Torque peak is around the 4500-4800 rpm area or thereabouts. This is Josh's motor in that old testing he did last year..... he is actually running a little more cam than you, albeit in a 383, and I believe also has the same heads as you.... with my point being, your torque peak should not be at 5500 rpm with that combination.... it should be in this same area shown in the link... you run less cubes, but also less cam and thus your torque curve should be close to a mirror image of his, except down a bit of power due to the cubic inch difference.

He has a dip down below 3000 rpm, but that probably has to do with the initial hit on the dyno and the sudden loading of the motor.... same as your 1st dip, which is fine and I think normal... (actually on yours, I think its because you're coming off the converter on your 1st small dip.)

He is a Miniram L98, you're an LT-1.... but the intakes, in general provide a very similar rpm range and torque curve in my opinion.....

You just need to fiddle with it a bit on the dyno and I'm sure you'll find the answer..... but that dip of yours is definitely a valley, when it should be a hilly peak..... and that can't be good.

dan0617 wrote:
Congrats! Nice improvements. I think your tune is closer than alot of people think, but needs a little work. I'm guessing from what I'm seeing you are going a little too lean for the amount of timing you are running in that area of the tune. It is pulling timing I'd bet.

I found through track testing that my car makes it's best power at 12.2 to 12.7 afr. Anything over 13 and I lose power, no matter where I set the timing. Anything under 12 and I also seem to lose power, but not as much as I lose when I approach 13.5 afr.

If you get the afr's dialed down to less than 13 everywhere and you think it is pulling timing due to false knock, cut the brown wire that is coming out of the knock module. I tried the LT4 knock module and now I even have the elusive 4.3 caprice knock module, and still got some false knock. I cut the brown wire so it disables the knock retard but doesn't throw any codes. I then put a male connector on one end and female on the other so I can plug it back in anytime I want. Just listen closely for pinging when making runs, it will sound like someone shaking popcorn kernels in a tin can. Keep advancing timing, and watch the afr's as every 2 or so degrees of timing you gain without detonation you will need to add more fuel. When you hear any detonation abort the run, go back, pull out 2 degrees of timing, and you found the sweet spot.


What tires are you running? I used Nitto drag radials and with a fast roll down of the throttle, after a good tire heating, it would dead hook and I'd get 1.6X 60' times every pass. I went to MT ET street radials, and I could get those times (and 1.5X 60' times when spraying just after getting my foot to the floor) with very little tire heating. The tread doesn't last as long tho. Only suspension mods are removing the front sway bar (you could disconnect yours to see if it helps, without removing it), and setting the rear alignment to +1.5 degrees camber. I run around 17 to 18 psi in the rear tires when drag racing.

Doing these things, you should be able to run with or beat my N/A times. My best so far was a 12.08 @ 113. Was consistently 12.15 to 12.20 last season, on the 3.07 gears. I'm guessing this year, since I went to 3.45 gears and a D44 so I can launch harder, and some more tuning, that I'll get an 11.90 or maybe 11.80. I'm betting you will get that, I'm guessing your car is lighter than mine. I'm sitting at 3520 with me in it.

dan0617 wrote:
Congrats! Nice improvements. I think your tune is closer than alot of people think, but needs a little work. I'm guessing from what I'm seeing you are going a little too lean for the amount of timing you are running in that area of the tune. It is pulling timing I'd bet.

I found through track testing that my car makes it's best power at 12.2 to 12.7 afr. Anything over 13 and I lose power, no matter where I set the timing. Anything under 12 and I also seem to lose power, but not as much as I lose when I approach 13.5 afr.

If you get the afr's dialed down to less than 13 everywhere and you think it is pulling timing due to false knock, cut the brown wire that is coming out of the knock module. I tried the LT4 knock module and now I even have the elusive 4.3 caprice knock module, and still got some false knock. I cut the brown wire so it disables the knock retard but doesn't throw any codes. I then put a male connector on one end and female on the other so I can plug it back in anytime I want. Just listen closely for pinging when making runs, it will sound like someone shaking popcorn kernels in a tin can. Keep advancing timing, and watch the afr's as every 2 or so degrees of timing you gain without detonation you will need to add more fuel. When you hear any detonation abort the run, go back, pull out 2 degrees of timing, and you found the sweet spot.


What tires are you running? I used Nitto drag radials and with a fast roll down of the throttle, after a good tire heating, it would dead hook and I'd get 1.6X 60' times every pass. I went to MT ET street radials, and I could get those times (and 1.5X 60' times when spraying just after getting my foot to the floor) with very little tire heating. The tread doesn't last as long tho. Only suspension mods are removing the front sway bar (you could disconnect yours to see if it helps, without removing it), and setting the rear alignment to +1.5 degrees camber. I run around 17 to 18 psi in the rear tires when drag racing.

Doing these things, you should be able to run with or beat my N/A times. My best so far was a 12.08 @ 113. Was consistently 12.15 to 12.20 last season, on the 3.07 gears. I'm guessing this year, since I went to 3.45 gears and a D44 so I can launch harder, and some more tuning, that I'll get an 11.90 or maybe 11.80. I'm betting you will get that, I'm guessing your car is lighter than mine. I'm sitting at 3520 with me in it.