Originally Posted by Sakib
Ish knows way more about cars than I do, but I gotta correct his math here. The crank-to-dyno calculation is correct, but the dyno-to-crank calculation is not. 20% of the dyno number is a smaller number than 20% of the crank number. So, if you were to add the 20% to whatever number the dyno gave you, you will get a smaller crank number than the real thing.
Example, for auto:
Ford says the V6 gets 305 at the crank. 305 - .20*305 = 244 at wheels/dyno.
Going reverse, if you do what Ish says: 244 + .20*244 = 293 at crank. WRONG.
What you're supposed to do: 244/0.8 = 305 at crank. RIGHT.
Simple algebra for where the 0.8 comes from:
Crank - 0.2*Crank = Wheels
0.8*Crank = Wheels, which is the same as Crank = Wheels/0.8
If you have a manual, change all the .2's to .15's, and the 0.8's to 0.85's.
Thanks for the correction Sakib. This is what I meant, I graduated from IU .. so you can't expect much.
Speaking of the drag strip, it was interesting and a lot busier than I would have expected ..
I saw a 2013/14 Shelby run a 16.7 @ 116, the guy killed it off the line. On street tires... wtf? How do you do that? Then he backed up that run with a 14.2 @ 118.... This guy seriously needed a driver mod. He would just dump the clutch and bounce of the rev limiter a few times, immediately shift into 2nd (which took forever) like 30 feet into the run doing maybe 10 mph, 2nd would damn near stall out, then he'd hold 2nd on the rev limiter for at least a second before attempting 3rd. Usually you could hear the trans grinding every time he went to shift. Poor car ... some people shouldn't have the things they do.
I saw a 100% stock Camaro run a 9.6 @ 140 while pulling the front wheels for about the first 70 feet... A new COPO Camaro that is.
Being at Muncie dragway in Indiana, the Lingenfelter guys were there in their new Reaper truck - this one actually..
550hp, supercharged 6.2 ... it ran a 14.3 @ 94 mph. Which is fast considering it's a giant *** truck with 33's on it.
One of my clients had his C6 Z06 out, he managed a 10.03 @ 141. It's supercharged, putting down around 650+ whp. It's also converted to an automatic. It's a built 4L80E with a 4k stall. Stock suspension with DRs. Pulled the front wheels for a few feet. This car is a beast.
A VW GTi ran a 14.2 @ 111, track had oil on it after a guys rear diff exploded. This car was fast.
Saw another 3.7, with an auto run a 13.8 @ 102.
A new 5.0 ran a 13.3 @ 108.
A new Z/28 ran an 11.9 @ 123, these sound really, really good.
Another 3.7 that was dressed up like a Shelby .. it ran a 14.1 @ 98.
Then I got in two passes... DA was around 1000, car had about 3/8 tank of fuel, tire pressure was 35lbs in all four and spare tire and junk were all removed from car.
My first pass was a 14.1 @ 102.4 with a 2.3 60' ...
I dumped the clutch at 3500 rpm, expecting to hook, that didn't happen. I spun really bad in first and second (surprisingly)... the guy that ran before me exploded his drive shaft and diff. So they sprayed the track down to get rid of all the crap that was on the track. Apparently they over-sprayed and never cleaned it off as the 1 - 2 shift set the car fairly sideways. Everyone was having issues getting down the track immediately after this. Also had issues with the clutch pedal on the floor when shifting to 3rd.
About 90 minutes or so later, my second pass was a 13.6 @ 105.2 with a 1.96 60'.
This run was solid, I didn't feel I could manage any better with the track conditions on stock tires and suspension.
On launch I slipped the clutch from around 3800-4000 rpm, and it took off about as fast as possible. A little wheel spin off the line, car never bogged, nailed 2nd and 3rd. It felt much faster than my first run, more than the times would indicate.
All in all ... not bad for my first time at the strip in a few years. I'm very impressed by this little 3.7.
This morning, I was having issues with the clutch pedal engaging at the very bottom of the travel, near the floor. I damn near stalled the car out a few times. Apparently it didn't like the abuse from the last run, although it was fine on the way home last night.
As much as I like this car, I still hate it.
Looks like I will be addressing the clutch issues next before any other mods. This fall I plan on long tubes with X pipe, no cats, drive shaft and nitrous