Any Et predictions?

[Fastvette94]

Good to know. BTW, your Facebook link isn't working for me, got an unavailable or no permission notice.

[ijames]

Time slip:
60ft 1.394
330ft 4.116
660ft 6.456 @104.37
1000ft 8.502
1/4 10.262 @127.14
Track is at 550ft elevation it was around 70degF on Sunday and it was good weather. No clouds and little wind, maybe a 5mph crossing to headwind.
4.56 rear gear
31" rear tire (100.25 circumference)
1.89 TCI gear set
The flash I don't 100 percent know yet it's 5200 or more. Haven't got settled in enough to watch. I moved the tach from before and I keep looking at the wrong spot at launch. (Old habits are hard to break. Run a car the same for 10 years then change it.)
Belt driven alternator pretty much 1 to 1 drive ratio with a moroso larger alternator pulley.
Standard weight eagle forged crank and H beams.
It's a 377, 4.155x3.48 in a stock 400 block with profiler 210 heads on Methanol.

Go to http://www.weather.gov/ and put in a city and click "3 day history" and you get the previous three days of weather data including temperature, humidity, and barometric pressure every hour for the nearest airport. For Hagerstown at 1:53 PM it shows 67F, RH 20%, and barometric pressure 30.14 in Hg so pretty good air. Now if they would just go ahead and show the density altitude . At Capitol it was 61F, 35%, and 30.18 in Hg so you gave up just a tiny bit, to save 150 miles of extra driving .

[cgarb]

I live about 40 mins from Hagerstown and about and hour 20 mins from Capitol. Typically​ Capitol pays better and the traction is better so it's worth the extra 40 mins to me. It's my wife's facebook, I couldn't get it to work either. I will try something else.

[Fastvette94]

So if my 20 year old excel spreadsheet is still correct:

Hagerstown was at 454 DA w/ SAE CF of 0.959 (104.3%)
Capitol was at 42 DA w/ SAE CF of 0.953 (104.95%)

[maxracesoftware]

using "power = force x velocity" equations
i get 547.1 Peak HP and 460.6 Peak TQ ( all at 600 RPM/SEC Dyno test rate )
it will be less than 547.1 HP if you removed 200 Lbs off RaceCar and if you have a Ram-Air HoodScoop ??

[John Wallace]

Fastvette94, you're using the 'corrected' Baro instead of the absolute Baro for the DA.
This will give a false DA if not accounted for.

[Fastvette94]

Fastvette94, you're using the 'corrected' Baro instead of the absolute Baro for the DA.
This will give a false DA if not accounted for.

Thanks for the feedback.

I haven't looked that deep into the DA calculation itself.

What I am using for correction for horsepower is the SAE J1349 JUN90 method (I use the Relative Humidity, Baro Pressure, and Air Temp along with vapor pressure equation as inputs into this standard).

So when the weather channel reports 29.96 in Hg (14.714 PSI), I plug that number in (I'm interpreting this as meaning absolute value). So that number is actually a corrected value? If so I will have to further process the number.

[Stan Weiss]

Well the results are in...My previous best was at Capitol raceway in Crofton MD, today I raced at Mason Dixon dragway. It is higher elevation and I went a 10.26 today at 127. It's almost identical to what it ran at capitol at all increments. I think it may be at least the same or a tenth quicker. I lost 4th round an all my runs were between a 10.26 and a 10.28. 7 total because I took a time shot after the race was over to try launching at 4k off the brake. I footbraked in the race. It ran another 28 except pulled the wheels about 6" which was horrible because that shit was fun as hell...Lol. Now I will want to run electronics just to play. I'm pretty happy. Shifted at 6800 and it went through at 6800. My vaccuum guage read zero at the finish line so I have a 950 to try on my car rather than the 750 that's there now. I'm thinking maybe it's not needed?

I do not remember ever seeing that.

Stan

[cgarb]

What do you mean by that Stan? The vacuume guage is something new I put in the car this year. I didn't know if it would be anything useful to have or not. I have a lean out valve plumbed inside my car that is connected to the intake, into the rear of the plenum. I have a tee in the line and the gauge is into that. Once warm the engine idles around 7 and as you rev it goes up which I thought was interesting.(Opposite of what I thought would happen) Once it goes to the floor on a run it drops to zero. Is my guage placement no good to get a good reading?

[John Wallace]

I plug that number in (I'm interpreting this as meaning absolute value). So that number is actually a corrected value? If so I will have to further process the number.

That is not the absolute pressure.

The numbers shown on TV weather reports are 'corrected' which is not the actual pressure.
(if you live in Denver, I'd say you never see 30.14 in/Hg, but TV will show that)

[Stan Weiss]

What do you mean by that Stan? The vacuume guage is something new I put in the car this year. I didn't know if it would be anything useful to have or not. I have a lean out valve plumbed inside my car that is connected to the intake, into the rear of the plenum. I have a tee in the line and the gauge is into that. Once warm the engine idles around 7 and as you rev it goes up which I thought was interesting.(Opposite of what I thought would happen) Once it goes to the floor on a run it drops to zero. Is my guage placement no good to get a good reading?

What I meant was I have never seen the vacuum gauge reading zero @ WOT @ the finsih line.

Stan

[cgarb]

Maybe mine is reading zero because it is not direct into the intake plenum. It's got about 18 inches of 1/2" hose between the tee and the plenum. Good to know. Maybe I can route it differently and see if it changes.

[Fastvette94]

If I had to guess I would say a small leak in your vacuum line or your gauge is suspect. I had a vacuum gauge on a 406 SBC and it would flutter between a small vacuum and zero at full throttle. The length of your line wouldn't matter much as the air is basically static at the dead ended line.

As to your surprise noticing the vacuum at idle and then going to zero, there's a vacuum there because the throttle blades are throttling the air stream into your plenum. The cylinder/pistons are still pulling the same geometric displacement so a vacuum is created. This vacuum is good for fuel evaporation/atomization and hence the primary reason why you need an accelerator pump that adds extra fuel once the vacuum suddenly drops (fuel drops to the intake floor, as I am told). At full throttle the air rushes in to fill the vacuum.

Carbs are rated (say 900 CFM) at 1.5 inches Hg (I may be off on that but I can't check at the moment). That's the pressure drop across the throttle blades required to flow the 900 CFM. Simplifying here as flow is no way constant in a motor but if your engine was demanding 900 CFM your plenum vacuum should be close to this vacuum on average.