[Evo8MRto335I]

Hi,

I am just contribuiting to the statistics. I took my 335I to the track to see what it would do. I did fantastic considering the altitude and heat. The track is located at 3100ft of elevation(Tucson SIR) and the temp was close to 100 degrees.

I did 5 identical passes of 13.63 with a few 103mph trap speeds. I also ran a few 13.8, 13.9 and a couple of low 14s though.

My BMW times compared to the Evos that I had is better. The 335I not only ran faster but also quicker when compared to the Evo 8 MR and Evo 9 when I ran them stock back in the day.

I am very impressed with the results. NHRA altitude conversion chart puts me at 13.15 sec and 107mph at sea level but I am not here to brag but just to share.

I am very happy with the car, quick and cosnistent. It is a coupe with Steptronic

[Evo8MRto335I]

This is another car that ran at the same track with a Eurobahn Turbo Tuner 335I sedan auto.

http://www.e90post.com/forums/showthread.php?t=56396

[CASHBY]

nice time for the factors given!!!

[Evo8MRto335I]

^^ Thanks I well appreciate it. Just for the record my other cars ran:

Evo 9 ran 14.0@101 stock same track(ended with 12.2 later on with mods)
Evo 8 MR 13.8@103 DP and air filter(but later ended with 12.2 with more mods)
Stealth R/T TT 13.8@99 stock

The BMW feels effortlessly when launching. I ran the first runs at 13.8- 13.9 launching it at 1300-1400rpm, then later I launched at around 2000-2200 and got the 13.63(5 times identical).

On the Evos and the Stealths you had to launch them above 4500rpm to get the most of out them.

I weighted the BMW and it weighted 3510lbs with less than a 1/4 tank. My car has sport package and leather so I know that adds at least 50 more lbs(bigger tires, bigger rims, electric controls on the setas, leather weight, maybe bigger sway bars?)

[Dr_Dirt]

Originally Posted by Evo8MRto335I

Hi,

I am just contribuiting to the statistics. I took my 335I to the track to see what it would do. I did fantastic considering the altitude and heat. The track is located at 3100ft of elevation(Tucson SIR) and the temp was close to 100 degrees.

I did 5 identical passes of 13.63 with a few 103mph trap speeds.

My BMW times compared to the Evos that I had is better. The 335I not only ran faster but also quicker when compared to the Evo 8 MR and Evo 9 when I ran them stock back in the day.

I am very impressed with the results. NHRA altitude conversion chart puts me at 13.15 sec and 107mph at sea level but I am not here to brag but just to share.

I am very happy with the car, quick and cosnistent. It is a coupe with Steptronic

You gotta love turbos, automatic altitude compensation. Normally aspirated cars lose 3% power for every 1000ft of elevation.

[Evo8MRto335I]

Originally Posted by Dr_Dirt

You gotta love turbos, automatic altitude compensation. Normally aspirated cars lose 3% power for every 1000ft.

I use to have a beater 1991 Honda Civic SI(hatchback) which ran consistent
16.8@82 at SIR(tucson 3100ft) and ran it at SAR(San Antonio 700ft) and ran .5sec quicker 16.3@84-85. No other mods

[musc]

Great time for the elevation! It's harder to use the NHRA correction factor because of the overboost, but great time nonetheless.

The weight is a little less than 3582 listed by BMW, but I believe there weight is fully optioned and unladen.

[Dr_Dirt]

Originally Posted by catm3

Great time for the elevation! It's harder to use the NHRA correction factor because of the overboost, but great time nonetheless.

The weight is a little less than 3582 listed by BMW, but I believe there weight is fully optioned and unladen.

Doesn't the NHRA have a seperate correction factor for turbo-charged cars?

[musc]

Originally Posted by Dr_Dirt

Doesn't the NHRA have a seperate correction factor for turbo-charged cars?

They separate for forced induction cars in general, not those that have the ability to overboost automatically to compensate for elevation. Not all cars do this.

[Evo8MRto335I]

Originally Posted by catm3

Great time for the elevation! It's harder to use the NHRA correction factor because of the overboost, but great time nonetheless.

The weight is a little less than 3582 listed by BMW, but I believe there weight is fully optioned and unladen.

I have always weighted my cars at this track. I left the car with floor mats and I was carrying maybe an additional 20lbs with the helmet and a couple of other things.

The car weighted 3510lbs with less than 1/4 tank. As far is the altitude conversion, yes you guys are correct, you have to take into consideration that it is different for the turbos than for the NA but get this, when I routinely took my Evos from SIR(Tucsn 3100ft) to Firebird Raceway(Phoenix 1248ft) I use to shave an average of .2-.3sec and increase my speed by 2mph.

That was a 1900ft altitude difference. At the end of the day it all makes sense, I did a decent time when compared to the average or even the official car magazine test. To me everything seems very normal, it would have been maybe a 13.2 to 13.4 sec run and a 103-106 mph trap somewhere else.

[musc]

Originally Posted by Evo8MRto335I

I have always weighted my cars at this track. I left the car with floor mats and I was carrying maybe an additional 20lbs with the helmet and a couple of other things.

The car weighted 3510lbs with less than 1/4 tank. As far is the altitude conversion, yes you guys are correct, you have to take into consideration that it is different for the turbos than for the NA but get this, when I routinely took my Evos from SIR(Tucsn 3100ft) to Firebird Raceway(Phoenix 1248ft) I use to shave an average of .2-.3sec and increase my speed by 2mph.

That was a 1900ft altitude difference. At the end of the day it all makes sense, I did a decent time when compared to the average or even the official car magazine test. To me everything seems very normal, it would have been maybe a 13.2 to 13.4 sec run and a 103-106 mph trap somewhere else.

It's good if these cars weigh less than BMW states. My M3 weighed in at 3370 unladen, even with smg, premium, power seats, etc.

Yes the turbo correction factor is different, but still the correction factor assumes you just have a turbo car, not a turbo car with an ECU that adds in up to 0.2 bar to compensate for elevation change. The 0.2 bar compensation still doesn't equal power at sea level, but its a lot better than NA and turbo cars without boost compensation. I feel bad for you guys that have to run at these high elevation tracks. I'm sure you'll run some quicker times closer to sea level

[Evo8MRto335I]

I feel bad for you guys that have to run at these high elevation tracks. I'm sure you'll run some quicker times closer to sea level [/QUOTE]
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Tell me about it... specially if you are a guy that goes to the track all year around like me. The only moral compensation is that all other competitors also run very slow. I am trying to download a couple of videos but it will take me some time though.

[Dr_Dirt]

Originally Posted by catm3

They separate for forced induction cars in general, not those that have the ability to overboost automatically to compensate for elevation. Not all cars do this.

I don't believe the car overboosted. It's just the fact that the turbos spool until the boost setting is achieved. It really shouldn't matter what the altitude is.
Super-charged cars should not be in the same category as Turbo cars since they use a fixed pulley to run the compressor, altitude will affect them much like normally aspirated cars.

[musc]

Originally Posted by Dr_Dirt

I don't believe the car overboosted. It's just the fact that the turbos spool until the boost setting is achieved. It really shouldn't matter what the altitude is.
Super-charged cars should not be in the same category as Turbo cars since they use a fixed pulley to run the compressor, altitude will affect them much like normally aspirated cars.

At that elevation, the car compensates for elevation by adding in more boost. Check through some old posts. Members have documented this with boost gauges. It's well known fact that the 335i can go from 0.6 bar to 0.8 bar to compensate for elevation.

[musc]

Originally Posted by Evo8MRto335I

-------------------------------------

Tell me about it... specially if you are a guy that goes to the track all year around like me. The only moral compensation is that all other competitors also run very slow. I am trying to download a couple of videos but it will take me some time though.

Two 1/4 mile tracks near me are 131 and 350 feet above sea level

[Terry335]

Originally Posted by Dr_Dirt

I don't believe the car overboosted. It's just the fact that the turbos spool until the boost setting is achieved. It really shouldn't matter what the altitude is.
Super-charged cars should not be in the same category as Turbo cars since they use a fixed pulley to run the compressor, altitude will affect them much like normally aspirated cars.

It does, around 2psi more @ 3500' in my testing.

[Evo8MRto335I]

^^^ Once I run the car in Phoenix that will clear all the speculations. If the BMW ECU really compensate for altitude differences then I shouldn't run faster in Phoenix (Firebird,1900ft lower than the track in Tucson,SIR). But then that is what also they use to say on the Subaru WRX that its ECU compensates for altitude.

Again, I rather take it to the track and find out myself. I am though inclined to say that the car will run faster in Phoenix for the simple fact that even though the ECU compensate to raise the boost you still make the engine run smoother and not that hard at lower altitudes.

my .2c

[musc]

Originally Posted by Evo8MRto335I

^^^ Once I run the car in Phoenix that will clear all the speculations. If the BMW ECU really compensate for altitude differences then I shouldn't run faster in Phoenix (Firebird,1900ft lower than the track in Tucson,SIR). But then that is what also they use to say on the Subaru WRX that its ECU compensates for altitude.

Again, I rather take it to the track and find out myself. I am though inclined to say that the car will run faster in Phoenix for the simple fact that even though the ECU compensate to raise the boost you still make the engine run smoother and not that hard at lower altitudes.

my .2c

It will run faster at lower elevation. Even with the ECUs overboost the air density is better at lower elevations, so you'll make more power. You just aren't going to lose as much elevation as the majority of people.

[Terry335]

Originally Posted by Evo8MRto335I

^^^ Once I run the car in Phoenix that will clear all the speculations. If the BMW ECU really compensate for altitude differences then I shouldn't run faster in Phoenix (Firebird,1900ft lower than the track in Tucson,SIR). But then that is what also they use to say on the Subaru WRX that its ECU compensates for altitude.

Again, I rather take it to the track and find out myself. I am though inclined to say that the car will run faster in Phoenix for the simple fact that even though the ECU compensate to raise the boost you still make the engine run smoother and not that hard at lower altitudes.

my .2c

For some reason it only compensates around 90% of the difference, so you'll run a little quicker, just not as quick as you think.

That is unless you throw a ****** on the car ahead of time.

[Evo8MRto335I]

I want to make a very strong remark guys.

First of all, so far and since I have this car I have never seen the temp gauge going over 250. My car was build in May and delivered to me at the end of June but from what I read I have the second version of temp gauge(reads up to 340)

Despite making a total of about 16 or 18 passes the car never overheated. This is simply amaizing, I basicly did hot lapping.

When comparing it to the Evos, yes the Evos wil get an extraordinary steady and consistent 1.7-1.8 60' however you could not launch the car like that that often due to the heat and stress otherwise you will face whroping the clutch /flywheel surface.

Botton line, it handled about 16-18 passes (hot lapping) and I never saw it passing 250 degrees. This car is fantastic.

[Dr_Dirt]

Originally Posted by Terry335

It does, around 2psi more @ 3500' in my testing.

Terry, I believe what you are seeing is a differential pressure effect. You probably didn't use an "absolute pressure gauge" meaning that your guage didn't reference something like an absolute vacuum. The car uses a MAP (manifold absolute pressure) sensor. Boost gauges are nothing more than a differential pressure gauge so at a higher altitude your Zero point is actually a negative #.
Yes the turbos will spin faster at higher altitudes to reach the desired boost according to a MAP sensor.
Basically your car should perform at higher altitudes close to what it would at sea level minus any additional spool time needed to reach boost.
It's not really overboosting, its just the normal boost setting according to the MAP sensor.

[Terry335]

Originally Posted by Dr_Dirt

Terry, I believe what you are seeing is a differential pressure effect. You probably didn't use an "absolute pressure gauge" meaning that your guage didn't reference something like an absolute vacuum. The car uses a MAP (manifold absolute pressure) sensor. Boost gauges are nothing more than a differential pressure gauge so at a higher altitude your Zero point is actually a negative #.
Yes the turbos will spin faster at higher altitudes to reach the desired boost according to a MAP sensor.
Basically your car should perform at higher altitudes close to what it would at sea level minus any additional spool time needed to reach boost.
It's not really overboosting, its just the normal boost setting according to the MAP sensor.

The gauge showed 0 when the engine was off. I developed my own map sensor based boost controller so I was doing a lot of testing and paying close attention. The ECU also adjusts boost targets based on IAT.