I'm trying to make some additional runs with my drag race model to compare model results with those reported here https://www.ford-trucks.com/forums/634460-drag-race-analysis-an-interesting-story.html#post4952627 , and I'm not sure if "reaction time" is included in the typical ET's for the 60-ft, 1/8-mi, and 1/4-mi marks being reported. I'm assuming a timer starts when the light turns green, and a photo cell detects when the truck crosses the start line, and this gives the "reaction time"? Then other detectors tell when the truck passes by the other distance marks, but are the ET,s to those marks measured from t=0 being the light turns green or is t=0 when the truck crosses the start line? In other words, assume the light turns green and the truck just sits there and doesn't move for 1 sec, and then gets an 11 sec ET for the 1/8 mi. Does this mean that the truck went from the start line to the 1/8 mi line in 11 sec or in 10 sec? In either case, I assume his reaction time is 1 sec?

Also, if anyone has some 1/4 mi ET's, where they can give me both the 1/8 mi ET and the 1/4 mi ET for the same run, I can run my model from the 1/8 mi to 1/4 mi marks to match those #'s and get a much better estimate of the HP being applied to the track during the last 1/8 mile of the run, because tire slippage won't be a factor, and the rpm will be at a more constant value. Also any 1/8 mi runs with a 60-ft time would eliminate tire slippage as a factor, as I could run the model from the 60-ft mark to the 1/8 mi mark. If anyone has these types of times, you can let me know here or on the other thread, along with any other details that would help estimate the actual HP being applied to the track.

 

the et on a time slip is from when the tire trips teh start light to when it trips the finish light. reaction time is from when the light turns green to when the truck trips the start light. you can actually have a faster et adn still lose a race real easy do to this.
Hope that helps

 

That helps, but I want to make sure I know what I'm doing before I do my spreadsheet work because I have to mess with the calculations one row (every 0.25 sec) at a time for the entire run. So based on what you just said, I'm assuming the ET you gave on the other thread is your slip time from start line to finish line, and DOESN'T include the reaction time you also gave. I noticed your 60 ft time was better than the one in my table, and I'm going to do a run with NO tire slippage & 300 HP to see what the best 60 ft time is for that, and then continue the rest of the run to get the 1/8 mi and 1/4 mi times for a perfect start, but even if you could find tires sticky enough for this "perfect start" it would probably leave your drive shaft lying on the ground at the start line.

When I watch drags on TV and see the ET posted on the finish lights, is that also slip time, or is that total time from the light turning green? As you said, it's total time that determines the race winner, and I guess they give you a slip time separately so you can estimate engine performance independent of reaction time.

 

the et you see posted is like I said from when you trip the lights and has nothing to do with the tree itself only the timing lights marking out the distance. reaction time adds to that for total time. example here looked at one of my time slips from a couple weeks ago I show up as having the win by 0.436 elapsed times though were he had a 9.628 et to my 9.854 but his reaction time was a 0.970 to my 0.308 so you can see what the reaction time did in that race he was faster mph, and quicker et yet still lost, the et is based soley on the start and finish line lights but the winner is based on who passes the finish line first so your total time includes the reaction time but for your calculation I don't believe you want to add reaction as it is not figured into the time slip eta.
Now as far as tire slip myself and several others on here are doing 4wd launches so there really isn't any tire spin off the line (thus really good 60ft times)
basically the only way your going to find total et from green light to finish line is add the reaction time to the et listed on teh time slip together.

 

Reaction time is not counted in the 1/8 or 1/4 mile time.
Like said above...Your time starts when you break the timing beam at the start line.
60' = 1.681
330' = 4.859
1/8 = 7.514 @ 92.31 MPH
1000' = 9.816
1/4 = 11.762 @ 116.17 MPH
I was running street slicks so there was no tire spin! I have pulled a 1.55 60' before.

Hope this helps with your calculations.

 

Correct, ET does not include reaction time.

That is the same ET and MPH as what is on the time slip, and again does not include reaction time.

I have a timeslip pic in my sig. Click and go to the very bottom of the page. Notice underneath the 1/4 MPH it says "Left 1st 1.2833". This is the difference in the winner's time vs. losers which includes ET and reaction time. So for example, if Dzacc fell asleep at the starting line and added an additional 1.3 seconds to his reaction time, I would have won, even though his 1/4 mile ET would still be well over a second faster than mine.

 

Ok, thanks for the above, now I know how to do my runs, but the wife says no more computing until we get to Duluth, we've got to go shopping, hook up, and get ready for a towing day tomorrow. I'll do some more runs and report back in a few days.

In the meantime, if anyone wants to report a complete data set like phil6608 did, I'll try to match it and estimate HP from it using my model.

 

If you are trying to make a hp calculator from et there are lots of them on the internet. I will try and find one when I get home.

 

Since you gave me such a complete data set, I put together a new model, but the wife is after me to go to bed so I don't fall asleep towing tomorrow, so I don't have time to write up the details. I put your #'s along side my results.

If you can post more details like your GCW, diff ratio, and tranny type, etc.. I can use those in a refined analysis.

EDIT It was screwed up so I removed the pics!

 

As rusty asked in post number 8, just above your past response, are you trying to make a HP calculator? Because as he said, there are quite a few available on the 'net.

If you have something else in mind, I can try and find a bunch of my time slips for my Lightning and send you the info.

Stewart

 

Auto tranny 3 speed with OD, with OD off/ 6000 pounds GVW with driver/4.10 gears.
It's no longer a 4X4.I took out the T case/front diff and Axel shafts.

 

Here are a few that I found.
http://www.wallaceracing.com/Calculators.htm
http://www.wallaceracing.com/8th-quarter.php
http://www.tciauto.com/Products/Tech...culators.asp#3
http://www.f-body.org/gears/

Maybe these will help.

Rusty

 

Cool links, Genes gonna have an anuerism disecting the formulas that were used to make these calculators.
Gene, be careful traveling to Duluth, I know you will be, but I say this cause last week while towing the 5er through ATL, I was brake checked by the same guy 4 times in 2 miles. He was a drunk and thought he was being funny. I ended up flat patching my trailer tires and had to replace them when we got home due to his arrogance/ignorance. Had I not had my wife and 2 kids in the truck, I probably would have just run over him after the second time, but their saftey comes first. I did get a trooper on channel 9, and he did respond, but could not get to the guy before he got off the interstate.
I think some people see a person towing a large fiver as a target to mess with.

 

Thanks for taking the time to find these. I've looked at each one, and none of them will give a very accurate prediction of the drag race performance for an F 250/350 truck! The reason is that one needs to have an accurate model for the HP required to overcome rolling resistance and aerodynamic drag as the truck speeds down the track. Without knowing these #'s from one instant to the next, you won't know how much of the engine HP is actually available to accelerate the truck at each instant of time. My model calculates rolling resistance and aerodynamic drag for each fraction of a second, to see how much HP is left over to accelerate the truck. Look for my post on my new improved drag race model, and my post requesting inputs on coast down time and distance to help calibrate my aerodynamic drag model.

BTW, rustydailey, Age=?, etc..., I couldn't find you in the FTE 7.3L age database! If you want to be included in the next update post here on the thread, how old is everyone? https://www.ford-trucks.com/forums/showthread.php?t=631720&goto=newpost

 

Well, that answers my question! The timeslips for my Lightning would be useless for your equations.

Stewart