TexasLT1

I just got back from the track here in Roswell, NM. After an embarrassing first run of a 16.1 at 80.5, I ended up with a best of 14.2 at 100. not too bad I guess, my 60' was a 2.3 and had an 1/8 of 9.3 @ 79. About what I expected for a 3500' altitude difference from home where I had a best of 13.1 @ 109. Sad thing was that about 50% of the cars out there were imports, I ran 2 of them, one got a 16.4, the other got a 19.4. Oh well, I might head back out there before I leave for home, but probably not, I found out how my car runs up here and thats all I really wanted to do.

Larry Dunlap

Hey man, when you get back to Texas let me know. Ive been working on my car and have been out to Lonestar a few times recently. We should go. Man that's a pretty big difference for that altitude

I wasn't born in Texas, but I got here as quick as I could, haha

TexasLT1

Larry, I'll be home from the 15-22 this month for Spring Break, then I wont be back till may. Depending on how things go with my brothers car I definitely want to go to the track. Yeah I was surprised it was that much of a difference, but I knew I would definitely run slower.

"I wasn't born in Texas, but I got here as quick as I could, haha"

MdFormula350

man that really is a huge difference in times!!

AlkyIROC

Now you know how I feel. 3500 feet altitude and most race days it's over 5000 feet density altitude. Going to a lower elevation track is so nice. The engine sounds crisper and it makes more power.

I always tell people that having a 12 second street car here is a very fast car.

five7kid

iTrader: (14)

5000'? That's not even the altitude here, and air density? I rarely see it below 8000', and have seen it over 10,000' on some hot days.

That first run at Topeka is a feeling I'll never forget...

TexasLT1

Stephen - yeah I love the lower elevations now, I never knew how much better they were. The camaro that I ran against on my last run ran a 12.9, back home it would have been in the 11's no doubt. I think if I wouldn't have thrown my belt, lowered my tire pressure a little more and probably worked on the burnout a little better I would have gotten into the 13's but oh well, I didn't want to push it too hard since I'm driving home for spring break this weekend.

five7kid - where in CO is littleton? I'm going to the AF Academy next year in Colorado Springs, and once I get my car up there I plan on racing it. Hopefully by that time though I'll either have turbos or the big-inch SB I've been checking in to.

five7kid

iTrader: (14)

Littleton is Columbine. Or, vice-versa.

Southwest Denver metro area. Actually, neither Columbine nor I is in the Littleton city limits - we just borrow their mailing address. I live about 6 miles from Bandimere Speedway, which is off C-470 and Morrison Road. A short hour from the AFA, depending on traffic accidents on I-25.

TexasLT1

Is Bandimere the one out right at the edge of the moutains? I remember seeing one when we drove through the area on the way out to Keystone. You wouldn't happen to know if there was one in the Springs area would you? Granted it'll be 2 years before I can take my car up there but I sure would like to know if there was a track near. With a full service auto shop on base I plan on getting alot of things accomplished on my car.

five7kid

iTrader: (14)

"Thunder on the Mountain", they say. Right up against the foothills.

I first raced in Colorado Springs (1/8 mile track, east of town). I made it on the track team for the regionals at Bandimere that year. The next year, I was shipped over to Germany, and when I came back 3 years later, the track was closed.

I understand the track closed in 1979. But, I'm not sure exactly, but without a doubt it was closed in 1982. Pueblo is the only other track close by. Julesburg and Douglas, WY also have tracks.

TexasLT1

Ok then that is the track I'm thinking of. I'll check around the springs area when I get up there and see if there is a track in the area. if not then I'll just be using some of my overnight passes to head up there

five7kid

iTrader: (14)

Well, you can look if you like, but I'm telling you there isn't any track in the Springs anymore.

AFA is right about mid-way between Bandimere and Pueblo. Julesburg is about a 3 hour drive from here, Douglas between 4-5 hours.

TexasLT1

my bad, I missed this statement...


I guess I'll be going to Bandimere then! I can only imagine how slow my car would be up there in its current rendition. If I was slower by a second here, it'd have to be atleast 2 seconds slower up there.

five7kid

iTrader: (14)

The conversion for ET, 5800' elevation-only, is 0.9276. Multiply your high-altitude time by that for sea level, divide your sea level time by it for your high-altitude time.

Air density-altitude - well, that's a completely different story. 8500'-9500' is much more typical.

TexasLT1

Well I guess that tells me what the density altitude was here the other night, because if I divide my sea-level time by that number I get the time I ran here. Where could I find the number for various density altitudes?

AlkyIROC

I do my conversions with dyno formulas. They're more accurate. If you do need to do an altitude conversion, it's best to know what the density altitude is and use that. If I used our local 3500 feet conversion, my car would be considered slow when I'm really racing at 5000 feet.

The NHRA conversion charts are mostly for Stock/ SuperStock racers. They get altitude corrected but only for elevation, not density altitude. That's why when someone is trying for a record, they make a run as early in the morning as they can when conditions are at their best. Since NHRA doesn't change the conversion as the day gets hotter and the density altitude rises, there's a better chance of getting a good altitude corrected run when the conditions are better and the density altitude is low.

There are some tracks like Mission BC that are at sea level (24 feet). When conditions are good, the density altitude can be below sea level. Other tracks like Boise Id are high elevation tracks. Records are set there because of the cool dry air on summer mornings. The density altitude can be below the elevation. NHRA says the track is #### feet above sea level but the density altitude is actuall less. The cars will make more power and since it's altitude corrected, they set records.

Racing at altitude takes a bit of tuning knowledge. For every 2000 feet up, you should decrease the jets about one size because of less air to burn. My car at a lower elevation track would need larger jets or else it would run too lean. Other things is stuff like gearing. At higher altitude the engine produces less HP. I use 4.56 gears here. At lower altitude I make more HP and don't need as much torque multiplication to get off the line. 4.30 gears would be better suited.

That's one of the reasons I hate suggesting parts for different cars. Would my car be faster with 3.73 gears from 3.42? It really depends on how much power the car makes and where in the country it runs. What works good for someone in Florida won't work for five7kid in Colorado.

300hpse

iTrader: (2)

lousy colorado, robbing my power

TexasLT1

lol, no kidding, hopefully by the time my car gets up there I'll have a LOT more power anyway.