1/4 mile time slip evaluation test...

[gbvetracer]

Hey guys, im curious if anyone can help with a guess or conversion of a time slip to approx. rwhp. In other words, since we all know each dyno and tuner can vary drastically in results for numerous reasons, maybe the times the car ran are a better way to look at power. My BIG question IS since most of us just do a "roll-on baby it out of the hole" launch since we dont want to light up the tires, CAN WE LOOK AT HE 2nd 1/8 Mile time and come up with any conclusions? Wow, I sure made a simple question look long and complicated! Maybe if you guys have your time slips handy we could compare numbers.. thanks!

 

[dbk]

Wait, what? :lol

What is it you want to compare?

With 592rwhp my car went 132.94mph in the 1/4 and, I can't remember exactly, but I think it went something just over 100 in the 1/8th.

 

[gbvetracer]

1/4 mile times

My car ran 11.95 at 133mph. I know the first 1/8 mile was horribe due to the start, so I was wondering if we could calculate the 2nd half quarter to figure out how it compared. My 1/8th mile was 8.17 at 99.58mph. We had a LOT of questions during our tuning and mod's, so Im curious how these numbers compare to other guys... thanks for your help...

 

[dbk]

..so I was wondering if we could calculate the 2nd half quarter to figure out how it compared...

I'm not sure I follow. You had a bad 1/8th so you want to know if the mph you picked up on the back half was good? If so, I'd say yes. What was your 60ft?

 

[gbvetracer]

back half..

Yes... I read somewhere here, but cant find the posts after numerous searches... about guys looking at the 2nd half of the run to get a feel for power and what the run "could" have been if the 1st half was good. As I said, my launch was a joke, 60' was 2.21. I dont think my top speed was even close to accurate since I came out of the hole so slow.

 

[dbk]

Yes... I read somewhere here, but cant find the posts after numerous searches... about guys looking at the 2nd half of the run to get a feel for power and what the run "could" have been if the 1st half was good. As I said, my launch was a joke, 60' was 2.21. I dont think my top speed was even close to accurate since I came out of the hole so slow.

Well, the 2.2 isn't great, but spinning a bit won't take much off your big end. Bogging would be worse, but you won't bog a stock-tired big-power GT anywhere but magic tracks like Englishtown or Norwalk. But assuming you feel you could pull a much hotter 1/8th speed, it sounds like you could probably go 137-138. I want to say back in the high 600rwhp days Piko6's car went 139mph through the traps. Only one way to find out!

p.s, pm "Jamie" to see what his 1/8th times were. I think he went 10.8x@132 a couple weeks ago.

 

[dgussin1]

My car ran 11.95 at 133mph. I know the first 1/8 mile was horribe due to the start, so I was wondering if we could calculate the 2nd half quarter to figure out how it compared. My 1/8th mile was 8.17 at 99.58mph. We had a LOT of questions during our tuning and mod's, so Im curious how these numbers compare to other guys... thanks for your help...

picking up 34mph in the second 1/8th is AMAZING. Granted a 133 1/4 should be 105 in the 1/8th, but your second 1/8 is blazing fast mph wise.

 

[jamie]

You ran identical mph as DBK so I would say you have the same HP.

 

[tpraceman]

where were you? elevation, temp and humidity?

 

[ThatPhilBrettGuy]

Best thing to do is get a PerformanceBox or VBOX from RaceLogic and look at the logs. It tracks speed etc at 1/10sec intervals and it's really easy to pick out parts of runs and compare them.

 

[gbvetracer]

thanks for the comments...

I need to run it again and launch it normally. That only run was doggin out of the hole... didnt hammer it at all from fear of spinning tires... then didnt hammer it in 2nd either feeling like it would also spin...so I granny shifted it to 3rd and held it down al the way... obviously didnt hit 4th.... I hope to be closer to 140mph with a normal run.... thanks guys..

 

[John B]

I went to a "Test and Tune" night at Raceway Park in Englishtown, NJ last Wednesday night. I dont really know what I'm doing but in 3 runs I got down to an 11.22 et / 133 mph, w/ 0.24 reaction time. It was 41 degrees and I was still using too much throttle comming out. This is with a Whipple, exhaust & tune dyno'ed at 709 RWHP. I think with a little more practice and a warmer track maybe high 10's.

I think a decent approximation form there for RWHP & ET's for a Ford GT would be

ET = 11.22*(709/HP)^(1/3)

For example
stock: 11.22*(709/529)^(1/3)= 12.37
1000 HP: 11.22*(709/1000)^(1/3)= 10.00

Or to estimate horsepower
HP = 709 / (ET/11.22)^3

eg 709 / (11.95/11.22)^3 = 586 RWHP

This of course is just an approximation and assumes a lot of things are constant that actually would not be, such as barometric pressure, temperature, traction, traction, reaction time etc...

 

[kumar]

^ with a whipple, u really really need stickier tires. with good traction, u should be trapping near 140mph easy.