rjw

iTrader: (3)

I am looking for the parameters to enter into Dynomation advanced.

I thought that I would start with a stock LS1, so I am trying to nter all of the parameters that I can.

Has anyone played with this software or does anyone have some info?

TIA

moregrip

iTrader: (8)

I have DynoSim Advanced w/Pro Tools. Lots of fun

sorry, no LS1 build out.

MadBill

I've done some DM work on a 7 Liter LS2-based engine for road racing, but didn't bother with many of the stock specs (e.g. cam) that I knew I wouldn't be using. I've always been too busy/lazy to figure how to e-mail actual files, but if there are some specific numbers you need, PM me and I'll see what I can do.

rjw

iTrader: (3)

I figure that in order to know if the software is accurate and that the base assumptions are correct, I would start with a bone stock engine. If hp and torque and rpm's were somewhat accurate, then it could be a good base to build off of.

I need cam specs, LS1 vette or other
Head flow numbers 241 casting
intake dimensions, exhaust manny dimensions, etc.

This could be a good group project, in that if we get stuff close enough, we could then try different combos of cams, heads, etc to see if they come even close to real world results.

Another sort of bench/dyno racing without the cost or time involved.

Anyone interested, please contribute .

AdioSS

iTrader: (2)

What do you folks think of that program compared to DynoSim?

MadBill

Dynomation is an order of magnitude more detailed than DynoSim (written by the same guy, BTW) and gives you real insight into why something works (or doesn't), not just a reasonable guess at how well. For example, when you shorten the collector 2", you don't just note a power gain, you actually see the exhaust negative pressure pulse arriving at the correct time at 6,000 RPM, instead of 20 degrees too late to help pull down the cylinder pressure.

That said, it does take a lot more inputs to give DM what it needs. Airflow data for example, especially at low lifts, 0.050" to 0.200", which somehow none of the shops seem to realize is important enough to publish (Or maybe it's just that LL flow is mostly the valve/valve job in action, no port effect to speak of, and therefore fails to demonstrate their expertise!) Another one you often have to measure for yourself is the minimum inlet cross section area, which has a big influence on velocity and the strength of the pressure waves. Also, it's not always possible to find accurate SAE seat to seat valve timing as required (at least for my ancient DOS version, I think there are measurement options in the new Windows-based system)

It has been pointed out on another forum that DM isn't always correct in its predictions, and this is certainly true, perhaps more from a power projection standpoint than from accurate specification recommendations. Even if accepted by the program, few of us would have the ability to accurately input sufficient data to model port swirl or tumble, combustion chamber/piston shape, spark plug location, the innumerable factors that affect engine friction and windage, etc. Even so, it's usually the GIGO effect that is responsible for significant inaccuracies, as good data is sometimes hard to find. (e.g., erroneously extrapolating low lift flow, because the manufacturer didn't have the data and you didn't have the head to flow, or wrongly estimating the minimum cross section by 0.3 sq. in. (which can gain or lose you an easy 40 HP..)

As far as getting by with less, I recently helped out on a half day of chassis dyno work on a moderately strong 350 Corvette road racer. I had done some simulations for it with a lot of S.W.A.G. inputs, as exact flow numbers, etc. were not available. Based on the results though, I was able to suggest that the tailpipes be shortened from 36" to 14" and that this should net ~20 HP, with no losses in the normally used RPM range, and that using an available 950 CFM carb vs. the current 750 should also gain 20 HP. Twenty pulls later, the tailpipe change had netted exactly 20 HP, but the big carb picked it up 28 HP! Maybe it was the annular discharge boosters, or perhaps the final jetting was just a tad closer to optimum. Anyways, no one was complaining...

To summarize, no computer simulation can take the place of hard work, common sense and experience, but even a 'simple' program like DynoSim has a ton of advanced number-crunching going on inside, and the results are going to be sooo much better than if you just go with the cam your brother-in-law's pal says to use...

For more info: http://www.proracingsim.com/index.html
OK, off the soapbox. Now where's my commission check?

rjw

iTrader: (3)

It's in the mail...

Can you point me to some sites where DM is discussed?

I played with DM a bit last night and I it is pretty cool.

Unfortunately, the wave action model does not work with forced induction...

MadBill

I Googled 'Dynomation', and there are lots of hits (two on this site!), but not much solid new info. Give them a scan though, JIC.

BlackHawk T/A

iTrader: (3)

I've been using Desktop Dyno for years and was always wondering if there was something better...

Anyway I have some info that may be of use...hope this helps

Cam specs are:

Stock 98-00 LS1 cam

Duration @ .050 198.86 intake 209.25 exhaust
Lift .498 intake .497 exhaust
LSA 119.45

Stock 01-02 LS1 cam

Duration @ .050 196.37 intake 208.72 exhaust
Lift .464 intake .479 exhaust
LSA 115.92

Stock LS1 Head Flow:

5550racing

I think this is an awesome idea. I just got desktop dyno 2000 for free and im enjoying the hell out of playing with everything. So far I've tried to make a stock ls1 and It's dead nuts on the RPM and HP. The torque curve looks a little out of wack but its not way off. I've found quite a few cam profiles but its purty tough to find good head flow numbers.

rjw

iTrader: (3)

I punched in the numbers and power is way down from what an 01 vette ls1 should be making at the fly

BlackHawk T/A

iTrader: (3)

You really can't get it right unless you have the cam card since it wants all the values at .006, except for the lift @ .050. It took me a long time to figure this out but once I did the power curve corrected itself and it peaked right where it should.

rjw

iTrader: (3)

Do you have a cam card for LS1 2001 vette cam? If so, please email

Thanks

BlackHawk T/A

iTrader: (3)

Sorry I don't. I can only get the file just right if I use an aftermarket cam. I used the TR230 and it came out near perfect.

Steve - Race Eng

iTrader: (1)

You need actual measured Cam Doctor C1 files for camshaft input. As Mad Bill stated, you need flow numbers from .050" to max. lift flowed through the intake manifold and preferably the header. Port minimum cross sectional area is extremely critical as is the entrance area of the runner and length of the runner from the entrance to back side of the intake valve.

I have attached two C1 files. Change the extension from txt back to C1 for input into Dynomation. LS121 is a GM Hot Cam. LS126 is a stock LS1 cam year unknown. Use .006" as your lash spec.

I do not have flow data for a set of bone stock heads flowed through the intake. Following is data for a set of Patriot heads flowed though a Fast intake @ 28"

Intake valve 2.055" Exhaust 1.600"

.050" 31.2 24.3
.100 65.6 49.4
.150 103 78.5
.200 134.8 106
.300 186.5 153.5
.400 228 184
.450 244 196.5
.500 256.5 214
.550 267.5 222.5
.600 275 230.5

Intake min. cross section 2.38 sq. in Ex. 1.38 sq. in.
Intake runner length 16.5" inlet area 3 sq. in.

Remember the header primary length is from the valve, not from the surface of the head. Use the inside diameter not the outside diameter of the header tube.

Dynomation is very accurate in predicting what works and what doesn't. Low rpm torque figures are high. Peak power numbers and torque are very close however.

Have fun,

Steve

rjw

iTrader: (3)

Thanks

I wish that DYnomation allowed me to run the wave stuff with FI

speedracerz

iTrader: (8)

let me know if you get this figured out. i am going to get dynomation advanced coming, i am still debating on the pro tools version just because i want the fuel and timing tables, how nice would it be to play with a tune with a digital engine and not take any risk on a $10,000+ engine

RedWS6 00

Did anyone generate a dynomation file for the stock LS1, I want to get a good base line. I want the Wave Action model to be simular to the Filling/Emptying model.

I know I got the right number for bore and stroke.
Have got the correct cam data.

Also does anyone have figures for the exhaust?

Whats the CFM@1.5inHg for the stock LS1 intake?