Real altitude vs sea level test results here

[biglady112]

Well all this talk I have seen recently about how turbo cars don't lose that much from sea level to up here like in colorado. Well, I have the answer first hand.

I know a gentleman who loses 1.4 seconds off the bottle between here(denver) and Las Vegas. On nitrous he looses 1 second flat.

Now, my 1990 eagle talon I had was just over .9 seconds slower from here to racing in maryland. This was without changing anything, just tuning the best that I could for the 5000ft difference in elevation. I would run 12.1@115 at bandimere speedway here in denver. In texas the best time I ever ran was a 11.2@124.

Now if that isn't proof enough I don't know what is. I was stationed in maryland for over a year. So I had plenty of time to dial the car in.

I was also stationed in west texas and saw a .7 second difference racing at Wall dragway compared to bandimere.

I will say it time and time again, we have to take in the same kind of air that the N/A guys have to. Stock Evo's and Sti's run in the low 14's here, the fastest stock C5 corvette I have ever seen run was a 14.7. Other LS1 powered cars are in the 15's all day here. My friends 2G stock ran a 15.3@89 here. And most normal dsm's here run 1.9 sixty footers or slower. If you run a 1.8 or faster you are doing really good up here. Its just a way of life. Cars literally die out up here. My friend with his 2G saw the same .9 seconds when he moved to seattle from denver. He said his car was a whole different animal there. It even sounded different there he said. He was running mid to low 12's on pump gas there with a small 16g.

Just a added note, the PRO RWD guys that run here in NHRA, well the fastest pass ever by one this year was a 6.9@198. If the guys with 1500+hp are losing upwards of a half second, think of more normal powered cars.

So there it is. I am sure there will be some nay sayers on this, but I have been all over the country and raced in two different states with similar results. I even have a friend thatt moved away for a little while and had the same results. I know you all won't believe me as there have been some other posts that people haven't agreed with. But you know, this is first hand experience. I have been there and done that. I can't say it any other way. My car physically was slower no matter what I tried at elevation before I sold it.

Steven

 

[99gst_racer]

Just a added note, the PRO RWD guys that run here in NHRA, well the fastest pass ever by one this year was a 6.9@198. If the guys with 1500+hp are losing upwards of a half second, think of more normal powered cars.

I once read an article about Brent Rau and his car. It stated that as they travel and see different elevations, they have to have many accommodating engine tunes for each elevation. When he was in the Rocky's, he has to low his boost pressure and make up for it with increased timing advance. I think he looses somewhere around 400-500 HP.

I would personally hate living in a high elevation, thin-aired state. Has Chris taken his car to the track yet to compare his CA times with CO times?

 

[biglady112]

No, it sat for like two months, when we finally tuned it, it was closed. They close the first week of october here. So he will have to wait until spring. But I imagine he will put it on the dyno before to long. He is working on registering it here. He is just lazy right now. The plates are california plates and have been expired for some time.

Colorado will make a grown man cry. Very humbling on the track and dyno here.

Steven

 

[4G63 For Me]

I've read at ~6000 feet you subtract a second and add about 10MPH to your trap speed and you'll have an idea of what you'd do at sea level.

There is a calculator out there for altitude and other adjustments as well, if you really want to get into exact numbers.

I don't think I've ever seen anybody disagree with the fact that altitude slows people down. It wouldn't surprise me if they are out there, but that's just silly.

 

[biglady112]

This is to show whar a turbo car loses at altitude. I hear people say all the time turbo cars ddon't lose much and correction factors don't apply to the.

Steven

 

[toutsuu]

So now my 15.4 at 87mph 1/4 mile time is looking pretty good if I subtract a second and make it 14.4 at 97 mph

 

[xveganxcowboyx]

I'll preface this by saying my car is not running great, but I think that makes changes in air density even more pronounced. I just took my car up north and back again through several high passes. At my home elevation of 4000ft it runs pretty well. The higher I get in the passes the weaker it gets. Obviously weaker. It's almost pethetic.

Another comparison. I drove my mom's Golf TDI from MN to western Montana. In MN I could set the cruise at 80-85 with no problems. As the elevation increased the top speed for cruise decreased finally setteling at just over 70 above 4000ft. That's a pretty big difference.