soliari

know of a good correction factor/calculator for 8000 feet DA???

Here's the breakdown:
1.94 60'
8.56 1/8
13.02@108.7 1/4

DA=8000 feet
temp: 82.5
alt: 30.01
dew: 37.0
track altitude: 5350 feet

I am just curious as to my corrected times.

Thank you.

TheSloth

yeah this is what I use

http://www.modulardepot.com/density.php

soliari

woohoo!!! That puts my corrected numbers at 11.49@121.55 ... I hope that calculator is accurate!!!

BTW, relative humidity (calcualted frome the numbers above was 19.7)

TheSloth

yeah I hope it's correct too hehe. Gotta love high DA

gator's 99TA

iTrader: (2)

so you ran a correctly 11.49 @ 121 or so with a 1.9 60' time? that sounds odd. i wouldnt think the 60' is effected much with even that air. but that is some horrid DA. why bother racing other than for the run of it.

Tom the roofer

iTrader: (9)

I raced in +3,500 DA today. I had a blast.

soliari

Really?? I think 60' times would be affected greatly. Why?? The air conditions affect the engine at all RPM's and points on the track, not just the big end. The CF for the evening I ran was 1.239. So if I left the line with 310 RWTQ at 8000 feet DA, I would have left the line with 384 RWTQ at 0 feet DA. Is it not reasonable to expect an extra 74 RWTQ to appreciably affect the 60'?? I think it is ...

Now, could I actually run an 11.49 if I drove down to a perfect race track?? I don't know, but I doubt it ... first, my poor rear end would explode, second, I'm not sure my clutch would stand up to the extra power. I'm just happy to know the potential is there with my baby cam ... I still have more modding to do!!!

gator's 99TA

iTrader: (2)

the 60' is more about traction and how hard the chasis will allow the tire to grab the surface. i dont really think the DA and the RWTQ work in that linear fashion but oh well.

as for the rest of the driveline not taking it, you are absolutely correct and that is why corrected ET has very little weight to most racers unless we are talking records.

soliari

that could very well be true. I've never been lucky enough to take the car down to a good track so I can't really speak from experience. Have you really had opportunity to take your car up to a higher elevation??

I know that when a friend of mine comes up from Roswell (3000 ft elevation) he notices a loss of 1.5 or so on the line and about 3 on the big end.

gator's 99TA

iTrader: (2)

i have run in DA = + 4000 feet (850 feet of elevation) in kansas city. used to run 11.90s and came down to FL and ran in DA = + 500 feet (elevation of 50 feet lol) 11.70s with near identical 60' time. about 2 mph defference.

PewterZ28

iTrader: (1)

The DA greatly affects the sixty-foot, especially when you’re in 8000 DA! You will make a lot more torque in near zero DA than in 8000 DA. It’s a no brainer. I’d bet you anything he would be sixty footing high 1.5’s or low 1.6’s in near zero DA. I have raced in 3000 DA and my sixty-foot times were about .10 to .12 higher than what I pull in near zero DA. And yes, I was dead hooking. DA affects every number on your time slip, except your car number.

soliari

very interesting. As PewterZ28, I would have expected the 60's to be a little lower in the lower elevation/DA. But then again, everything is a balancing game. The more power you put down, the more suspension/chassis work you'll need. I always assume those calculators take all the ideals for granted.

I've been playing balancing act with my car for a decent performer at both the strip and road course. So far it's going ok, but my RR suspension would further stack the deck against such a low ET.

So, in your opinion what can my car run at a good prep'ed track and good air?? SAE numbers for the car are: 397/394 and race weight is 3640 (w/driver)

SScam68

iTrader: (20)

Gabe

I have plotted the correction factors from the NHRA. Its pretty much a line so all you have to do is extrapolate to the respective altitude.

Power has a lot to do with how you 60', but so do a lot of other factors. Your 60's aren't bad considering its also setup for the road course although I do think there is a 1.8 in there.

gator's 99TA

iTrader: (2)

guys, when someone is pulling 1.9 60' you arent going to pull 1.5 with sea level altitude. lol. come on! 1.9 = spinning like crazy and i am SURE he was on radials of sometype. esp after reading he has a stock driveline and didnt want to break it.

but then again if you guys want to bench race 60' times with correction factors, be my guest

soliari

Actually, I run ET Streets at the strip. Stock radials only net 2.1+ 60 foots. I know I can cut a better 60' if I left the line harder ... the car was bogging due to the ET Streets hooking so well.

BTW, I wasn't bench racing. I was curious to know what the correction would be that's all. It's hard to know how the car and mods are going when you have 8000 feet DA to overcome. Hell, the track is at 5350 feet. Even in perfect weather I would be down on time compared to most on this board just because of the altitude.

PewterZ28

iTrader: (1)

Well let’s ask him, Soliari, were you spinning?

Gator, do you know how much of a difference 8000 ft. DA makes?!? That is huge! We’re talking nearly a second and a half in ET. Assuming the car is set up to hook (i.e. slicks or DOT slicks) with a dead hook I see no reason why he couldn’t sixty foot in the low 1.6’s if it’s a 6 speed car, 1.5’s if it’s an auto car with a stall converter.

But to say DA doesn’t effect sixty-foot times…THAT is laughable! I guarantee if you take a car like mine, that dead hooks 95 out of 100 launches, it'll go from high 1.5's in zero DA to somewhere around 1.8's or even 1.9's in 8000 DA!

Soliari, get your car to hook in near zero DA and you easily have an 11 second car. Probably an 11.60 car, maybe better. Again, it all depends on your launch.

PewterZ28

iTrader: (1)

http://www.modulardepot.com/density.php

soliari

Well, the car was dead hooking. And, as I said before there's more left in the car ... I just need to launch harder.

I'm looking to get a 12.9x in this DA on my current setup and I'm looking to mid 12's in the Fall when the DA comes down.

SScam68

iTrader: (20)

Gator, your telling me 80+rwhp/80rwtq is not going to affect your 60'?

FWIW on street tires we avg about 2.2-2.3 60's, when you sea level guys can pull off 2.0's.

Do you think its traction? because I can launch at 4500 on street tires and dead hook and barely pull 2.2's.

I've got the slips to back that up! Spinning well net you 2.4's

We are typically down 50-80 rwhp from you low alt. guys. so our times aren't exactly impressive.

buffhomer

I can speak from personal experience that YES, DA and/or elevation will affect every number from 60ft to the 1/4mph. You want examples? Crack open a beer and read:

Got my camaro, A4, lid only, ran it in Houston (HRP, 10ft elevation) with a -200ftDA:

1.970 (stock tires)
13.19@104.5

Two weeks later ran it in Roswell (3600ft elevation, 3800ft DA), same setup:

2.09
13.82@101.0

Zero spin on either race day. These runs were made in February and March of '02.
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Later, after adding a ported maf, Vigilante converter, cutout and some Hoosier slicks, I ran in San Antonio (~500ft elevation), in right at 0ft DA:

1.74 (off idle)
12.45@108.0

That was made during the Clash of the Titans weekend in November of 2002. Two weeks before that I had ran in Roswell, with the same setup and 3600ft DA:

1.82
13.03@103.2

Again, zero spin. Funny thing is, the 60ft seems to be nearly on the same correction curve for altitude as the ET. Roswell's correction factor for elevation is ET x .9562 and MPH x 1.0465. **NOTE: This is the elevation correction, not DA correction to standard.**
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Another one, with the current setup in Roswell I normally ran 12.85-12.95@104.5 with 60fts from 1.81-1.84. Went up to Albuquerque (elevation 5300ft) and best ETs there were 13.27-13.35 with mph at 102.5-103.0. 60ft times were from 1.85-1.87, again, this was on Hoosiers so tirespin is not a problem.

I've raced at 10ft, 500ft, 1300ft, 3100ft, 3200ft, 3600ft, 4050ft, 4100ft, and 5300ft elevations and I'll be damned if some yokel comes on with no experience in this area and tries to plead his case. I'll put up any or all slips, you name it and consider it done.