[forza1976]

So fellow forum members are gonna head to our track which is a short distance above sea level. Bout 6000' above.

See how we run.

raceyBMW bringing his supercharged E92 M3
tnd720 bringing his tuned M235 xDrive
Lemongrease bringing his X3MC
And I'll have my X3MC as well.
Got my dad to bring his c43amg too

Update:
We hit up the drag strip last night. Was great weather so was hoping for some good times for all of us. It was however busy.

Track stats:
- Track elevation ~6000 ft above sea level
- DA ranged from ~7600 - ~8000 (very typical)
- Temps ranged from 69F - 73F

Observations.
- The X3MC does not like to sit at altitude. We had to wait between 30-45 minutes between runs and best I could tell the IAT's were 114 degrees and climbing.
- Launch control simply does not work as well with high IAT's and not much airflow before runs. Sitting in the staging lanes too long because 200+ cars just doesn't bode well.
- Dragy, I was skeptical but damn that tool is spot on. Within hundredths of the slips.
- Dragy DA here in Colorado is bonkers and not accurate.

So, those are my excuses. Some will probably say we are still not doing it right, but Lemongrease and I both had the same issues. The car just won't launch above 2300-2400. So 60's are horrible, and the ET's show it.

That said, I was very curious to see what the darn thing could actually do with an open road and proper airflow. You'll see my Dragy runs from this morning confirming what I knew the car could do even at altitude. DA where I was this morning was 6800 approximately.

We are hopeful that the fall running, temps will be better and can have more time to cool down and not have such high IAT's. I believe the car just does not want to build enough boost when particularly warm at our altitude.

[tnd720]

Nothing like getting gapped by a new x3.... going to be fun to see an 11 second x3 at bandimere

[forza1976]

Originally Posted by tnd720

Nothing like getting gapped by a new x3.... going to be fun to see an 11 second x3 at bandimere

That might be a bit optimistic, considering the likely horrible DA.

[Max Well]

Originally Posted by forza1976

So fellow forum members are gonna head to our track which is a short distance above sea level. Bout 6000' above.

See how we run.

raceyBMW bringing his supercharged E92 M3
tnd720 bringing his tuned M235 xDrive
Lemongrease bringing his X3MC
And I'll have my X3MC as well.

Will report back if anyone is interested.

Hoping for lots of slips and pics.

[forza1976]

Originally Posted by Max Well

Hoping for lots of slips and pics.

Definitely, will do our best to track with dragy too.

[GT500R]

Originally Posted by forza1976

That might be a bit optimistic, considering the likely horrible DA.

DA around 7000+? Stock X3M will be lucky to hit 11’s

[forza1976]

Originally Posted by GT500R

DA around 7000+? Stock X3M will be lucky to hit 11’s

Agreed, not holding my breath.

[tnd720]

Originally Posted by GT500R

DA around 7000+? Stock X3M will be lucky to hit 11's

Don't worry, if he's close to 11, we will start removing seats (;

[forza1976]

Originally Posted by tnd720

Don't worry, if he's close to 11, we will start removing seats (;

The hell you will 🤣

[2020X3MCDG]

Awesome! Very curious to hear how it goes. Did not know they were opened back up. I hope you crack 11s but I would be happy with mid 12s.

Good Luck!

[forza1976]

Updated first post with my results.

[EvilEmpirE]

Congrats. Well done. DA matters so much in these things. There is that much less O2 at 7500-8k feet DA...added with the Heat. Those are easily hi to mid 11s at Sea Level with those Trap Speeds (which would also go up). The consistent 116-117 MPH Traps is impressive. That’s what I reallly like to look at more than your time down the strip. Shows that the car is making PLENTY of POWER. 4700 plus lbs and 116-117 Trap equates to about 570-585 Horsepower give or take. Good stuff....

[forza1976]

Originally Posted by EvilEmpirE

Congrats. Well done. DA matters so much in these things. There is that much less O2 at 7500-8k feet DA...added with the Heat. Those are easily hi to mid 11s at Sea Level with those Trap Speeds (which would also go up). The consistent 116-117 MPH Traps is impressive. That’s what I reallly like to look at more than your time down the strip. Shows that the car is making PLENTY of POWER. 4700 plus lbs and 116-117 Trap equates to about 570-585 Horsepower give or take. Good stuff....

Agreed,
And put the car on the scale (even though no SUV's were allowed ). With me (201#'s), 1/4 tank of gas, no spare or tools. Car was exactly 4700#'s.

[onfireX5]

Your mph is much better than I expected at that DA. The 60ft is killing your ET for that mph. Are you holding LC for 3 seconds ?

[forza1976]

Originally Posted by onfireX5

Your mph is much better than I expected at that DA. The 60ft is killing your ET for that mph. Are you holding LC for 3 seconds ?

I covered that in my reply above. I know how to use LC in this car.

[AlexFL]

Originally Posted by onfireX5

Your mph is much better than I expected at that DA. The 60ft is killing your ET for that mph. Are you holding LC for 3 seconds ?

I agree with onfire. The 1/4 mile trap speed is unusually high for a stock car (usually 115-116 mph) for this altitude. Did you use regular 93 octane gas or race gas or ethanol mixture?

Great results btw!

[forza1976]

Originally Posted by AlexFL

I agree with onfire. The 1/4 mile trap speed is unusually high for a stock car (usually 115-116 mph) for this attitude. Did you use regular 93 octane gas or race gas or ethanol mixture?

Great results btw!

Ah, good call out. Totally forgot about that. I had a 50/50 mix of 91 and 100. So probably effective 95 octane. But otherwise stock, I'm not tuned.

[AlexFL]

Originally Posted by forza1976

Ah, good call out. Totally forgot about that. I had a 50/50 mix of 91 and 100. So probably effective 95 octane. But otherwise stock, I'm not tuned.

Awesome! Yes, it makes sense now.

[GT500R]

With no tune and that high altitude, the MPH is quite impressive actually. The IATs being high didn't appear to be impacting the car that much if your MPH is 115 +

[Max Well]

Originally Posted by forza1976

Updated first post with my results.

Thanks for sharing, forza - always enjoy looking at slips and performance numbers under different conditions.

I entered your formal slips into the spreadsheet. To zero in on the DAs I went to Denver's past weather for yesterday and obtained the temps, % humidity and Barometric pressure to calculate the DAs as provided by Dragtimes.

Do you have the moon roof and/or spare?
Do you recall your tire psi front and rear? Not sure if it changed during the night and/or if you adjusted before each run?

Using Dragtimes DA adjustment calculator it estimates your 'corrected' ET and MPH at 11.783s @ 122.20 MPH. I don't know if that has been rigorously tested or generally approved in the field but at least it's something.

I can add your fastest time to our formal X3MC Stock spreadsheet with Nate's and mine once I know your moon roof, spare, and psi (if you know it).

Thanks again - Summer is here!

[forza1976]

Originally Posted by Max Well

Thanks for sharing, forza - always enjoy looking at slips and performance numbers under different conditions.

I entered your formal slips into the spreadsheet. To zero in on the DAs I went to Denver's past weather for yesterday and obtained the temps, % humidity and Barometric pressure to calculate the DAs as provided by Dragtimes.

Do you have the moon roof and/or spare?
Do you recall your tire psi front and rear? Not sure if it changed during the night and/or if you adjusted before each run?

Using Dragtimes DA adjustment calculator it estimates your 'corrected' ET and MPH at 11.783s @ 122.20 MPH. I don't know if that has been rigorously tested or generally approved in the field but at least it's something.

I can add your fastest time to our formal X3MC Stock spreadsheet with Nate's and mine once I know your moon roof, spare, and psi (if you know it).

Thanks again - Summer is here!

Nice Thanks Max.

I do have the moon roof, I took the spare out along with the tools, and the PSI in the tires was unchanged. Cold they are set to spec, but with temp in them yesterday, I really can't say what they were.

So not sure if you also saw my Dragy result in the first post as well from this morning. Frankly, if I could have launched like I did this morning at the track yesterday, it would be in the 11's officially at the strip. I was so bummed it wouldn't cooperate, but I'm determined to get another shot at it.

[Max Well]

Originally Posted by forza1976

Nice Thanks Max.

I do have the moon roof, I took the spare out along with the tools, and the PSI in the tires was unchanged. Cold they are set to spec, but with temp in them yesterday, I really can't say what they were.

So not sure if you also saw my Dragy result in the first post as well from this morning. Frankly, if I could have launched like I did this morning at the track yesterday, it would be in the 11's officially at the strip. I was so bummed it wouldn't cooperate, but I'm determined to get another shot at it.

I'll edit the spreadsheet for your entry in the formal 1/4 mile SC page for this info.

I read about Bandimere - they have a really well-prepared surface and as I noted at my Nov 2019 runs at GNV Raceway, I couldn't grip at spec tire PSIs. It doesn't make sense that you would run so much better this morning with your Dragy with just the modestly improved DA as you are still at 5800', regardless of temp, % humidity and Barometric pressure.

I suspect if you go back to Bandimere and set your psi at 32F/32R you'll see improvement in your 0-60' times. Just a hunch, and others may disagree, but those times are similar to what I had in Nov '19 and my tires weren't grabbing at rec psi settings. At 32F/35R I improved, but next time out I'm def setting at 32F/32R, and may need to adjust even lower for our track. Your settings will no doubt differ from what I need at my track, but may be worth trying.

Usual roads that Dragy is often tested on by Members have widely different coefficients of friction than a well-prepared track with tires designed for such, so oftentimes you can get by without carefully analyzing psi vs performance in those settings on regular roads. And it makes it difficult to compare Dragy on a road in NY state vs a backroad in FL or CA, ...

Just my thoughts, FWIW.