should i be disappointed?
#18
#19
Your 60 foot is killing you. You need to experiment because getting a lower 2.2 60' is pretty easy once you figure it out. Mid to high 2.1 60 foots aren't out of the question. Shedding .2 seconds from you 60 will result in a .35 second drop in ET. The altitude of Vegas is doing you no favors.
#20
Dayum people! Altitude here has little to no bearing. We're at 1870 above sea level. That's a bit over a quarter mile. You don't see problems until 3500-4000 above. The ECU on this car can adapt to such a small change in altitude with ease. We're probably more affected by the heavy *** in this car than the altitude.
#21
Dayum people! Altitude here has little to no bearing. We're at 1870 above sea level. That's a bit over a quarter mile. You don't see problems until 3500-4000 above. The ECU on this car can adapt to such a small change in altitude with ease. We're probably more affected by the heavy *** in this car than the altitude.
You will most definitely see significant changes in performance between density altitudes. Here's a great example:
1) My G ran a 14.49@97mph with a 2.20 60' in 1,800' DA conditions.
2) No changes to the car or launch technique, it did 14.32@98mph with a 2.18 60' in 200' DA conditions.
Just a difference of 1,600' made a .17 second and 1mph difference in performance. Then take a gander at the cars that significantly quicker ET/MPHs compared to the average and you'll see that many are running in negative DA conditions. There are some tracks in the northeast that run almost year round and sometimes the DA is on average of -2,000. That means the car is making 110% of it's normal power and will be running at least .3 and 2mph than in sea level conditions. It's very significant.
Last edited by DaveB; 02-14-2010 at 11:37 AM.
#22
i have raced on this track before quite a few times, but this is the first time with the g. my car has stock wheels, my scanner is not working so i just punched in my times, thanks for your help and input.
FIRST PASS
R/T ... .184
60' ... 2.382
330 ... 6.618
1/8 ... 9.998
MPH... 72.45
1000... 12.924
ET ... 15.373
MPH ... 93.71
SECOND PASS
R/T ... .243
60' ... 2.398
330 ... 6.649
1/8 ... 10.026
MPH ... 72.78
1000... 12.937
ET ... 15.369
MPH ... 94.34
FIRST PASS
R/T ... .184
60' ... 2.382
330 ... 6.618
1/8 ... 9.998
MPH... 72.45
1000... 12.924
ET ... 15.373
MPH ... 93.71
SECOND PASS
R/T ... .243
60' ... 2.398
330 ... 6.649
1/8 ... 10.026
MPH ... 72.78
1000... 12.937
ET ... 15.369
MPH ... 94.34
Here's a slip from my run in a bone stock AWD for comparison. I had a full tank of gas and 50 pounds of tools in the trunk too (wasn't planning on racing that day). I could prob bang out a 14.5 or 14.6 if i shedded unneccessary weight
R/T ... .040 (no stranger to drag racing)
60' ... 2.172
330 ... 6.197
1/8 ... 9.493
MPH... 74.35
1000... 12.334
ET ... 14.717
MPH ... 94.61
You should be capable of a 2.1 with your car as well.
#23
#24
The ECU cannot adjust power for air density. The more dense the air (ie more oxygen), the more power that will be available. The ECU will add more fuel when the air density is more oxygen rich and vice versa. It cannot magically add more oxygen
You will most definitely see significant changes in performance between density altitudes. Here's a great example:
1) My G ran a 14.49@97mph with a 2.20 60' in 1,800' DA conditions.
2) No changes to the car or launch technique, it did 14.32@98mph with a 2.18 60' in 200' DA conditions.
Just a difference of 1,600' made a .17 second and 1mph difference in performance. Then take a gander at the cars that significantly quicker ET/MPHs compared to the average and you'll see that many are running in negative DA conditions. There are some tracks in the northeast that run almost year round and sometimes the DA is on average of -2,000. That means the car is making 110% of it's normal power and will be running at least .3 and 2mph than in sea level conditions. It's very significant.
You will most definitely see significant changes in performance between density altitudes. Here's a great example:
1) My G ran a 14.49@97mph with a 2.20 60' in 1,800' DA conditions.
2) No changes to the car or launch technique, it did 14.32@98mph with a 2.18 60' in 200' DA conditions.
Just a difference of 1,600' made a .17 second and 1mph difference in performance. Then take a gander at the cars that significantly quicker ET/MPHs compared to the average and you'll see that many are running in negative DA conditions. There are some tracks in the northeast that run almost year round and sometimes the DA is on average of -2,000. That means the car is making 110% of it's normal power and will be running at least .3 and 2mph than in sea level conditions. It's very significant.
#25
I need to know how you launched, did you leave it in automatic or did you manually shift, what was your 60 foot, do you have aftermarket rims, and what's your drag experience level?
Las Vegas sits at around 2,600' above sea level. Conditions last night were in the low 50s, 30ish baro pressure, and mild humidity. Calculated density altitude was around 2,600'. The engine was making 94% of it's available HP. In sea level conditions, with no changes, the car would have run 14.8@96.7mph. The MPH looks right, but the ET is still a little slow. My guess is your 60 foot was in the low to mid 2.3 range. A 2.1 60' would have netted you a 14.5@97mph in sea level conditions which is about right.
Las Vegas sits at around 2,600' above sea level. Conditions last night were in the low 50s, 30ish baro pressure, and mild humidity. Calculated density altitude was around 2,600'. The engine was making 94% of it's available HP. In sea level conditions, with no changes, the car would have run 14.8@96.7mph. The MPH looks right, but the ET is still a little slow. My guess is your 60 foot was in the low to mid 2.3 range. A 2.1 60' would have netted you a 14.5@97mph in sea level conditions which is about right.
#26
I never said anything about the oxygen. If the air is less dense, the fuel charge will be less dense and vice versa. We're talking about an 1800 ft change, not 3500 ft change. Top fuel funny cars might be affected by an altitude change of 1800 ft but a DD won't see that much of a change. Top fuel can lose as much as 500 hp with an altitude change. We might lose .... 5hp..... That is negligible to me. Being off by a tenth of a sec could easily be the driver's error. OP asked what to do better. Altitude isn't his issue. Traction could be his issue; weight could be his issue; driver mod could be his issue. Altitude certainly isn't it. Geez people. This isn't a race car.
I guess it's up to you whether you want to believe it or not that small changes in air density can affect a car's performance (especially a naturally aspirated one), but what I saying is the cold hard truth. I've been drag racing for over 15 years now and have ran a handful of cars down the strip with probably 500 runs under my belt. Without understanding DA and correcting for it, it's hard to make a legit comparison between runs on different days. I also full understand the impact of driving, 60', ideal shift points, etc. Drag racing far more complicated than people give you credit for.
Why is calculating DA so important? Because so many make the incorrect claim that mod "X" allowed their car to go "X" tenths of a second quicker when the Da may have been largely responsible for the improvement.
And finally, it's been my personal experience that some tracks are simply faster/slower than others for no real reason and I've never heard of Firebird being a very fast track. Go to Cecil, HRP, The Rock, Maryland, or E-town in the fall/winter and you can be assured you'll be running some of the fastest times in the country.
#27
#28
#29
Not to veer off the quarter mile topic, but this post involves "racing."
I raced my buddy's 2006 is350 with an intake and exhaust. He had one passenger. he has 18 inch rims with 255 width rear tires (not sure how much tire width affects acceleration).
From zero he pulls 1.5-2 cars by third gear and quite frankly im disappointed. Im launching at ~2200 rpms with kuhmo summer tires with half tread. All I have is a z-tube.
On the highway he doesnt pull away as fast, but hes still good for pulling 1-1.5 cars.
Has anyone else experienced such destruction from a lexus? And does this indicate that I'm an inexperienced/bad driver?
I raced my buddy's 2006 is350 with an intake and exhaust. He had one passenger. he has 18 inch rims with 255 width rear tires (not sure how much tire width affects acceleration).
From zero he pulls 1.5-2 cars by third gear and quite frankly im disappointed. Im launching at ~2200 rpms with kuhmo summer tires with half tread. All I have is a z-tube.
On the highway he doesnt pull away as fast, but hes still good for pulling 1-1.5 cars.
Has anyone else experienced such destruction from a lexus? And does this indicate that I'm an inexperienced/bad driver?
#30
Not to veer off the quarter mile topic, but this post involves "racing."
I raced my buddy's 2006 is350 with an intake and exhaust. He had one passenger. he has 18 inch rims with 255 width rear tires (not sure how much tire width affects acceleration).
From zero he pulls 1.5-2 cars by third gear and quite frankly im disappointed. Im launching at ~2200 rpms with kuhmo summer tires with half tread. All I have is a z-tube.
On the highway he doesnt pull away as fast, but hes still good for pulling 1-1.5 cars.
Has anyone else experienced such destruction from a lexus? And does this indicate that I'm an inexperienced/bad driver?
I raced my buddy's 2006 is350 with an intake and exhaust. He had one passenger. he has 18 inch rims with 255 width rear tires (not sure how much tire width affects acceleration).
From zero he pulls 1.5-2 cars by third gear and quite frankly im disappointed. Im launching at ~2200 rpms with kuhmo summer tires with half tread. All I have is a z-tube.
On the highway he doesnt pull away as fast, but hes still good for pulling 1-1.5 cars.
Has anyone else experienced such destruction from a lexus? And does this indicate that I'm an inexperienced/bad driver?