A Dyno2000 shot of some AFR190 heads and a CompCams 276 XtremeRPM roller cam.
This is with H.P. exhaust manifolds and mufflers (comparable to a stock Vettes).

I'm really leaning towards the Internet Racer's Supply LT-1 (Stage II)top end package with this cam. Looks decent to me. With a rebuild (waterpump, Opti, basic rebuild, etc.) I'm looking about the $3000 range. LT-1 Edit is coming beforehand (gotta baseline).

Just looking for thoughts on a fairly powerful, yet streetable package. This one seems reasonable to me.

Your thoughts please.

https://www.corvetteforum.net/c4/dan...lilcomp276.jpg

how about sending me a copy of dyno 2000?

Dude, it's $40 bucks!? If you plan on owning a 'Vette... get used to throwing hundies in the gutter http://www.corvetteforum.cc/ubb/smile.gif

I have been playing with DD 2000 and can not find any way to make it's torque curve (using stock parameters) look like the actual Stock curve.

Have you been able to create something resembling the stock curves? If so would you email me your .dyn file.

The point being that if DD can't properly calculate the stock parameters, how accurate will it be when you start adding stuff?

I think the curve displayed is awfully peaky looking - would expect a much flatter curve.

So you have a peaky cam/head setup (which I doubt) or DD needs some more work to accurately reflect what is going on. The key is to have an accurate stock setup to base your mod analysis on.

EDIT: It's also predicting a HP peak at 5500. I don't think this is correct. Need more work on DD before you can trust the numbers

[This message has been edited by olephart (edited 07-19-2001).]

I know you guys get sick of seeing my dyno graph, but this is what a stock curve should look like.

http://24.17.202.123/graphics/corvette/dyno.jpg

I have to agree, if it can't reproduce the baseline, how can it predict anything with any accuracy?

Nathan, I have seen road kill with more curves in it than you torque curve. That sucker is flat.

I try to model to the one published by GM. I ain't quite as flat as yours. It crosses the 300 lb level at around 1400 and 5300 rpm,
the middle is smooth and rises to 330 from about 3800 to 4800. Pretty flat, but not like yours.

I think the predictions in DD 2000 are based on carbed gen I engines. Works amazingly well on them if you set up the base engine correctly. The LT1 and later engines are a totally different animal. Gen. I math just isn't going to predict a torque curve like yours.

I think if you lie to it you can get close - I get closer results telling it I have a single plane manifold.

One day I'm going to gather up all of the dyno results you guys publish and test against your mods to see if I can get good results with the DD 2000.

In the meantime I'll just ask Mackey.

Hey C4Fetish, turn your reserve gas light off. http://www.corvetteforum.cc/ubb/biggrin.gif

Yes, gentlemen, I too had a difficult time reproducing the flat torque curve of the original setup.

Using the stock cam specs and stock LT-1 flow rates for the head, the curve was still
a bit peaky.

I did manage to get a graph fairly close.
Once I did I then proceeded to leave everything the same and just switch cams.

The most powerful with this stock setup was Comps Extreme 276HR. Then I tossed on the AirFlow 190 heads to approximate some well ported LT-1 heads.

After dickin' around with higher cam lifts and centerlines, more intake flow, bigger valves,etc., etc. I found that the curve didn't vary much, especially in shape.

I'm sure the torque values have got to be a bit high and the overall package will probably be closer to about 360hp rather than the 390hp the graph predicts.

But this was the smoothest graph with the most power under 6000rpm I could get.

Still, anyone with DD2000, I'm more that willing to trade files with 'ya (cams, heads, setups, etc.) so drop me an e-mail.

Dan, I have Dyno2000 and it's companion Drag2000. Both of these had write ups in CF this year. Once traction was tweaked to simulate current 1/4 mi data the optimizer led to increased performance that matched track results. Of course I started in Dyno2000 with a curve to resemble a stock L98 profile. Then I added pocket ported 113 heads with 1.6:1 rockers and some exhaust work.

Did you use the "Optimizer" on your build up? Do some playing with exhaust setups and watch your low end torque come up.

You might find Drag2000 quite interesting. You can import the torque curve from Dyno2000 and then optimize shift points, gears, TC stall, etc to get 1/4 mi times. I suspect you could also change the input torque curve to get optimum performance which would guide you with engine setup.

I've tweaked this one and then used it to determine my optimum shift points with my current and possible future torque profiles.

Dan, please send me your "stock" Lt1 dyn file.

I have excellent results with drag 2000. It will let you manually enter torque and HP curves. So, if you know what you are actually producing, you can get really accurate results.