kendo347

ok guys. I went to the track today and ran a13.265@115.910. 60ft 2.417. 660 8.877. This is in albuquerque, nm at 5200 ft elevation which is supposed to amount to an 18% loss at the rear tires. This mph seems a little high for the altitude. I dynoed 321 sae at the rear. Im using the nx gemini wet kit with 125 hp jets(52nitrous and 28 fuel). Is it just me or does this mph look extremely high??!!According to calculations I should be at around 107 uncorrected at this elevation. Is it possible for tracks to correct speeds?
Kenny
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sep1234

Hey guys, his dyno was 321 SAE (corrected & without nitrous). Sorry for the confusion. His actual RWHP up here in Albuquerque (5,200 ft) is about 260 HP (without nitrous). With nitrous his RWHP is about 368 with nitrous and not corrected for altitude. If his car is actually seeing 368 RWHP, it does not seem right that his trap speed is 115.9 mph; it should be around 106 mph. Either the track is correcting his speed for the altitude, or the speed is measured incorrectly.

The question is the following: do tracks at high altitudes correct the speed?

bad2000ss

iTrader: (6)

If 400rwhp is good for about 120mph trap speeds, 368rwhp should put you right around 115. Sounds about right to me.

sep1234

400 RWHP is not good for about 120 mph trap speeds. Four hundred RWHP is good for about 111 mph trap speed.

The question is the following: do tracks at high altitudes correct the speed?

sep1234

Browsing around the Internet I found that tracks do correct times and speeds for altitude. Here is an article referring to the correction of time and speed by tracks at high altitudes:

Time and speed correction

Here is the one sentence to which I refer:
This is similar to the corrected times and speeds provided by some quarter mile tracks.

bad2000ss

iTrader: (6)

I have heard in the past that VERY FEW tracks do. Your track most likely wasn't but the only way to know is to call them and ask.

As for a car not hitting 120mph with 400rwhp, I can agree with that, if it was a full weight car. But then again, I don't believe we were ever told how much the car weighs? There are cars on this board trapping in the 125 range with as little as 440rwhp.

Sounds to me like you're punching the dyno numbers into some kind horsepower/ET calculator you found on the net. Those calculators are NOT accurate. Your 18% figure could be off as well. Even though the actual altitude is 5200' the Air Density could be different. The DA could have been in the 3000' range. In Palmdale, CA the track is 2700' but in the winter time the DA can be in the 1000' range. Summer time the DA could be in the 5000' range.

What kind of dyno was it? Every dyno reads different. Dyno numbers really don't mean anything. If you were to take the car 3 blocks away to another dyno it might read 20 more or less horsepower.

Villain281H

iTrader: (5)

I'm hitting 117 mph in a brick of a car for wind-cutting (Nova) with 372 rwhp at 3500 lbs. so I wouldn't say 120 mph isn't possible with 400 rwhp.

Just my $.02

Derek

Muerte_X

iTrader: (1)

Hey, I'm from Albuquerque too. Well, first off, the abq dragway does NOT correct for elevation, I didn't think any track did, but I know ours doesn't.

Also, nitrous isn't affected by elevation, so if you're calculations are using your sae numbers it won't come out right. Our track elevation is 5320ft, and the DA from what I've seen can vary from 5500 up to 8000ft. 5320 ft alone is responsible for about a 1.1 slower ET. The best thing to do is, make a run without nitrous, then another with. Subract that difference from your corrected ET to get an estimate of what you might run at/near sea level. 107mph seems about right for an m6 with ~320sae. At least A guy i know with about ~320whp and an auto trapped at 105. While MPH is a good measurement of your hp to weight ratio, I wouldn't trust any calculation unless you really know the weight of your car.

Did you make more than one run? The track has been known to give weird ET/MPH on occasion.

That's a good mph especially for up here, work on that launch. and You'll be into the 12's easy.

kendo347

I ran a 14.42 @101 naturally aspirated. Damn I hate high elevation!! The 13.2 @ 115.910 was my first run at the track with nos. Right after I lauched I thought my rear end was on a pogo stick. Holy .... Boing, boing, boing. Correcting this will be my next project after the heads, cam, and headers.

Muerte_X

iTrader: (1)

Well, the N/a run mph is right on about that i've seen other stock/near stock m6's run. Yeah, I hate the elevation, I ran a 14.3 @ 98 with a lid. I'm getting a new converter and a cutout put in this friday, should put me into the 13's.

It takes some practice to launch an M6 car well. My friend has a C5 and he was cutting 2.0's all day, I know it's a different car, but still M6, LS1, and if anything the IRS should be harder to launch with. I'll have to ask him how he launches.

SScam68

iTrader: (20)

Also from Albuquerque....

I ran a 14.2@101 (3700 raceweight, 2.4 60')with lid and free mods on street tires.

I have quite a few mods now and ran a 13.31@106 N/A (~3700lb race weight, 2.1 60') I dumped the clutch at 6600 on that run but the tires didn't hold. The track was going away at that point.

I am expecting to hit high 12's with 107-108 trap speeds from some additional mods and dropping the weight down to 3400lbs. Shooting for a low 1.9 60' .

The track elevation is 5350ft according to the site and the DA is hovering around 6000ft right now. In the summer the DA hangs around 8000 to low 9000's .

If you clean up that 60 alone you'd be in the 12's. Drive that car and low 12's shouldn't be a problem.

Frank

edit: 400rwhp should be good for high 11X's.

GETSOMZ28

iTrader: (1)

Another from Abq. Your trap seems about right. I put down ~280hp-290hp (actual, not corrected) and I run high 12's at 107-108.

kendo347

Thanks guys. It appears my 60ft is the current problem. I was launching at aroung 2k and hitting the nitrous in 1st gear with the window switch set at 3k rpms. If i launched any higher than 2k the tires would not grab with the nitrous. Next time I will try hittin it in second gear but the next time I go I will have heads/cam as my motor is coming out next weekend.

Firehawk409

Honestly man do u know what your talking about?? I pulled a 105mph trap speed with a internally stock lt1, with a few bolt ons.Friend of mine with the exact same mods minus the electric water pump(i have one) got a 106. No weight reductions or anything. Actually my rims are a bit heavier then my stock ones. LS1s run 104/105 pretty much stock. All this done with around 280 to 300hp to the wheels.

LS1_PNYTAMR

iTrader: (1)

hell i dunno i trapped 123ish consistently on teh spray.. i say 115 sounds good for that altitude.. need to drop that 60ft to about a 1.8 atleast though

DietCoke

iTrader: (18)

I make ~365hp and trap 116 through an automatic.

PNYKILR

I'm from ABQ aswell. My old setup dyno'edd 360rwhp at our altitude. I ran 12.0@116mph. Your speed is right. I'll be at the track this weekend with the new setup. I drive a black LT1 T/A

Neal

SScam68

iTrader: (20)

You got your **** up and running Neal?

I would head out to go see if I wasn't moving

Muerte_X

iTrader: (1)

Sounds like a nice setup, I think I saw the thread on rsw too. I'll be there if the weather is nice. I'll keep an eye out for you.

PNYKILR

Heading to the track today guy's. Hope to see you all there.

Neal