Desktop dyno.............

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Tarr

Tarr

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I know several of you have the desktop dyno programs so I want to ask a question. Which would be faster, a 450hp 2800 lb car or a 550 hp 3600 lb car? Everyone knows that a lighter car has an advantage but big HP engines have the advantage on top end, such as the HEMI.
 
450 would run 10.70-10.75
550 = 10.85-10.90

Lighter is better and easier on parts
 
i definatly agree with crackedback. a lighter car would definatly run a fasteer time on the track. on a good day the lighter car might even run a 10.40-10.30. thats just going by good weather and track conditions.:snakeman:
 
My opinion, which maybe wrong, is that the 2800 lb. car would have .16 lbs./horsepower and the 3600 lb. car would have .15 lbs./hp making the heavier car slightly faster in the 1/4 but maybe losing in the 1/8th. or at least for the first 3/4 of the 1/8th., not figuring in gearing etc. ???
 
Carl, I have Dyno 2000. If you want to call me during the evening (after 6:00 p.m. our time), I can get all of your specs and give you exact numbers. There are a lot of variables involved.
 
My engine is pretty mild but I keep wondering, what if I change the heads and cam. I have the J heads on a 340 + .030 with SS 2.02/1.60's with stock ports but 5 angle valve job. It has 9.7 comp. with the Racer Brown SSH-25 cam. That is .485 lift, 108 lobe separation with intake at 105 and exhaust at 111. Haven't weighed the car but it's a 69 Dart and I'm hoping for 3300lbs.
As you can see, this is not a race engine and I would like to upgrade heads and cam. I'm going to run the LD-340 intake and Hookers. Also using an 800 Thermoquad from DemonSizzler.
After talking to Billy, CudaChick's other half, I may forgo the power brakes due to worries about vacuum.
 
Actual head flow numbers are wonderful in any dyno program. The generic settings they have are a middle of the road kind of thing.
 
I subtracted 20% to get RWHP then ran it through a ET Calculator.

The 3600lb 550hp was 440rwhp and ran a 11.7 at 114
The 2800lb 450hp was 360rwhp and ran a 11.5 at 116

Bench racing is fun.:-D
 
What would you estimate my 68 Dart running in the 1/4? It weighs approx. 3100 lbs, 440,727, 4.88 Dana and it runs a best of 6.89 @ 99.3 mph? Thanks. I have yet to take it to Indianapolis.
 
superbird6bbl said:
What would you estimate my 68 Dart running in the 1/4? It weighs approx. 3100 lbs, 440,727, 4.88 Dana and it runs a best of 6.89 @ 99.3 mph? Thanks. I have yet to take it to Indianapolis.
Click to expand...

About 420 RWHP.

Should go about 11.20's to 11.40's at around 118 in the 1/4.
 
There are a number of variables that should be addressed also.

Stock suspension? Why does the other car weigh so much more? 800 pounds on the front of the car is going to more adversely effect ET than the same weight distributed evenly. Gearing?

Additonally, peak numbers mean jack. Under-the-curve horsepower is what gets you to the stripe quicker. Which is quicker through the quarter? A stock 225 hp Camry, or a stock 225hp Mustang?

My guess would be, given two real world cars, that the lighter car would be quicker.
 
superbird6bbl said:
What would you estimate my 68 Dart running in the 1/4? It weighs approx. 3100 lbs, 440,727, 4.88 Dana and it runs a best of 6.89 @ 99.3 mph? Thanks. I have yet to take it to Indianapolis.
Click to expand...


Should be 10.90's or high 10.80's. My Cuda was running 11.12 @ 122 in the 1/4, and 7.06 @ 97 in the 1/8.
 
I agree with Flyfish. My car runs 6:80's @ 98mph 1/8 mile and 10:80's @ 121:00 mph 1/4 mile. It is a 3500 lb slug with me in there and a small block. The best I have been able to get is 10:70 @ 124 mph on a good day.
 
Tarr said:
I know several of you have the desktop dyno programs so I want to ask a question. Which would be faster, a 450hp 2800 lb car or a 550 hp 3600 lb car? Everyone knows that a lighter car has an advantage but big HP engines have the advantage on top end, such as the HEMI.
Click to expand...
If you use horse power to weight ratio the 450hp 2800lb car would be faster. You need 580hp in the 3600 pound car to equal this ratio of the lighter car, but this is just one factor and I would bet on it. jysnflem
 
It is so not cut and dried. The engine dyno programs are very basic, and tyring to do an entire car is much worse...lol. In two purposely built and designed drag cars, with optimized setups for that, the car with the higher horsepower to weight ratio will win. Every time. If either car is not maximized, it's anyones guess.
 
jysnflem said:
If you use horse power to weight ratio the 450hp 2800lb car would be faster. You need 580hp in the 3600 pound car to equal this ratio of the lighter car, but this is just one factor and I would bet on it. jysnflem
Click to expand...
Woops I met to write "would'nt bet on it" jysnflem
 
Thanks for the input. If I get it to Indy, I will post the 1/4 mi times on here.

Thanks for the input. SHARP car and an excellent runner.
 
Your welcome Superbird6bbl. Let me know how close my et guess was. I hope I can race at Indy some day too. Some of my friends from Waterloo Ia. have been out there to race and like it.
 
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