[forza1976]

Originally Posted by timtech

Seeing this make me feel really good that I ran a 12.9 with a 335xi sedan with nothing more than a SSTT and all season tires.

Makes a huge difference being at sea level. We are so handcuffed here with the elevation.

Nice run, a 12.9 is darn good. I am anxious for the spring so JT and I can take the cars to Bandimere Speedway to see how they run. Unfortunately that track is at 6000 feet above sea level, but that's just the deal here in Colorado.

[astrobmw]

Originally Posted by purplewidow

...maybe in colorado or other mountainous regions...

You've got it. There were times that we could not get our RWD E46 up the steep grade coming out of our neighborhood while neighbors driving anything with AWD made it. Ordering AWD was cheaper than moving.

Mileage with cruise set at 80mph:

328i: 30-33 mpg
335xi: 26-29 mpg

Milt

[forza1976]

Originally Posted by astrobmw

You've got it. There were times that we could not get our RWD E46 up the steep grade coming out of our neighborhood while neighbors driving anything with AWD made it. Ordering AWD was cheaper than moving.

Mileage with cruise set at 80mph:

328i: 30-33 mpg
335xi: 26-29 mpg

Milt

I will love my xi for skiing... But this is a little off topic for the dyno discussion jtmccabe started above.

[lnferno]

Awesome work guys! Very impressive results for both cars. This is a great illustration of how much elevation impacts cars at higher elevations.

Kudos to you both for taking the time to take your cars to dyno especially on the same day.

[jpsimon]

it's nice to see that the peak torque numbers are about the same!

[S62PWR]

I'd be intersted to know if this was a roller dyno or a Dyno that bolted up to the hubs. Does the gearing affect the torque numbers? BC the gearing in the two cars is different to make up for the weight. If a roller, tires can make a traction difference as well.

Last, for those of you not using snow tires (all season, please), you're missing the time of your life, it's your chance to be a rally driver in the Winter when everyone else is avioding the roads...I've rarely if ever been stuck, and some of the best times I had are in the Winter. Of course, I have spun a FEW times... RWD and AWD WITH snows

BTW not a single Sport Ute or Chevy Subdivision has ever passed me on the way up the Mountain, I smoke 'em. And plenty of them are off the road (unintentionally) because they think they are king with four wheel drive, please. I just laugh. Operative word: Snow tires, best you can get.

I once passed 20 4 wheelers following a plow in five inches of fresh snow, see ya!!! By the time I was passed, I was doing 70 in the fresh creamy white snow... no tracks, heaven. Be warned, snows are rapidly, and I mean rapidly losing their effectiveness after the first half of tread life. Be warned! Sell 'em used and get another set.

[forza1976]

They were on rollers, this was a typical dynojet 222/248 dyno.

I believe the gearing does effect the tq numbers as you can see JT and I have different numbers with the same 3rd gear pull. I have no idea how all this stuff works but the XI does have some driveline loss as you can see.

I have some excellent fun on I-70 as well going up to the ski slopes. With my XI, there isn't many vehicles that can pass me unless the snow is just too deep. The car is a vessel!

[Dan335i]

My last two cars were evo,s.An 03 8 bought new.Kept it until the IX came out and traded the 8 for an 06Evo BR350 IX Serial#005.Those were the only awd performance cars i,ve ever owned.Lots of 4X4 vehicles ,bronco,explorer,pathfinder,grand cherokee,etc.,etc.All of my other performance cars were rear or front wheel drive.I would say 90% were rear drivers.My last before the evo,s being a bought new01 Camaro SS,black,6MT w/every availiable option.The evo,s were modded and both had the best summer tires out there.I thought i would never buy a rwd again after those awdrivers,(evo,s).But after getting use to the 335i coupe i felt like i came back to my roots.The point finally being,theres nothing like a great handling rwd car,whether it be a coupe or sedan.

[forza1976]

Originally Posted by Dan335i

My last two cars were evo,s.An 03 8 bought new.Kept it until the IX came out and traded the 8 for an 06Evo BR350 IX Serial#005.Those were the only awd performance cars i,ve ever owned.Lots of 4X4 vehicles ,bronco,explorer,pathfinder,grand cherokee,etc.,etc.All of my other performance cars were rear or front wheel drive.I would say 90% were rear drivers.My last before the evo,s being a bought new01 Camaro SS,black,6MT w/every availiable option.The evo,s were modded and both had the best summer tires out there.I thought i would never buy a rwd again after those awdrivers,(evo,s).But after getting use to the 335i coupe i felt like i came back to my roots.The point finally being,theres nothing like a great handling rwd car,whether it be a coupe or sedan.

Holy rambling on about your car resume.

[Supramano]

Just wanted to bring up the possibilities for why the xi looks lower than the i in these graphs...I just got my car dynoed on a dyno dynamics and my graphs were also very low and jumpy like this one. If you look at the graphs the i's hp and torque are much smoother than the xi's. AA told me today that dynojets and dyno dynamics dynos cannot give accurate readings for xis. The only dyno that can do it is a mustang dyno. Reason being the rollers on a mustang can be fixed to roll at the same speed so the awd system will not intervene. Regardless you have the dtc button pushed or held down for 10 seconds....i was getting the same results. During my stock run and AA chip runs the small traingle light was on, but the larger light in the center stating 4X4 underneath woud come on for a half a sec and the car would pick back up again. Ny car did this twice during the runs...1st time about 4000rpms and again at 5000 rpms/ Def. losing power, looks very similar to your graphs but my jump down was more pronounced cause i have more mods. Im going to a mustang dyno on the 23rd to get an accurate reading and post the results. XI's stay away from all dynos but mustangs....lata

[Dr_Dirt]

Originally Posted by Supramano

If you look at the graphs the i's hp and torque are much smoother than the xi's. AA told me today that dynojets and dyno dynamics dynos cannot give accurate readings for xis. The only dyno that can do it is a mustang dyno. Reason being the rollers on a mustang can be fixed to roll at the same speed so the awd system will not intervene.

Dynojets can't do this?

[Evo8MRto335I]

Obviously I am not questioning the validation of the document, thanks for sharing but as far is the results, it does not make sense at all. There is a torque difference of 80lb/tq in the upper rpm range in favor of the 335i, then the XI "mysteriously" gets better torque on the lower rpms.

Something does not look right. The results should be steady, more like the same difference all across the rpm range. It looks like the real difference occurs at 3000 rpm in which both cars completely switch roles. From 3000 rpm and up the 335i leads but bellow 3000rpm the XI has a clear advantage.

[KanosWRX]

Originally Posted by E90ice

Looks like torque is about the same for both cars...just the rwhp is about 20-30 higher for the RWD car.

Actually even thought it technically only has 1 wtq less if you look at it overall it looks like its down about 15-80 wtq less across the entire power band. Its amazing how much it drops off after 5k rpms. I didn't expect that. And WHP is also down about 25hp after 5k rpms. Guess that's drive train loss for you although it interesting that it doesn't effect it really much at all before 5k rpms.

[Supramano]

Originally Posted by Dr_Dirt

Dynojets can't do this?

Active auterwerkes told me the only dyno i can use is a mustang dyno.....dynojets and other similar awd dynos do not have the capability to lock the rollers to rotate at the same speed. This causes the front and rear tires of the car to give 50% of power to both ends. That way the DTC or DSC will not engage and limit your power.

[jpsimon]

"You have to set the dyno software to accept "clutch-type" center diff as it keeps the front and rear roller speeds equal."

-shiv

[Supramano]

Originally Posted by KanosWRX

Actually even thought it technically only has 1 wtq less if you look at it overall it looks like its down about 15-80 wtq less across the entire power band. Its amazing how much it drops off after 5k rpms. I didn't expect that. And WHP is also down about 25hp after 5k rpms. Guess that's drive train loss for you although it interesting that it doesn't effect it really much at all before 5k rpms.

Same thing was happening to me....the traction control would only start engaging around 4000rpms. Therefore the torque seems to not get affected because all the torque this car creates is before 4000rpms. If you look at my dyno sheet my torque is at 350 till about 3500rpms but my max hp was 285....all because the traction control was boggin me down atfer 4000rpms..when all the hp kicks in. The above two graphs i would bet would be within 1-2 hp of eachother if they did it on a mustang, because thats how much torque it loses due to awd...torque didnt get affected in these graphs because dtc didnt kick in till about 4000 rpms.

[Supramano]

Originally Posted by jpsimon

"You have to set the dyno software to accept "clutch-type" center diff as it keeps the front and rear roller speeds equal."

-shiv

Dyno dynamics said their dyno did not have that capability

[Supramano]

Originally Posted by Evo8MRto335I

Obviously I am not questioning the validation of the document, thanks for sharing but as far is the results, it does not make sense at all. There is a torque difference of 80lb/tq in the upper rpm range in favor of the 335i, then the XI "mysteriously" gets better torque on the lower rpms.

Something does not look right. The results should be steady, more like the same difference all across the rpm range. It looks like the real difference occurs at 3000 rpm in which both cars completely switch roles. From 3000 rpm and up the 335i leads but bellow 3000rpm the XI has a clear advantage.

Exactly it doesnt look right...xi's traction control kicked in at 3000- 4000 rppms. In my grpah i have a jump down at 3400 rpms and again at 5100...the guy who did the dyno said my tirnagle flashed in the center a few times during the run. I also watched the engine and it shaked a few times running to redline....i was like" what the hell is that" i thought there was something wrong with my car..i called AA frantically telling them the situation. Regardless you hold down the traction button to dissengage it does not disengage entirely...the dyno guys said this happens to some mercedes too. the turn of the traction control but it still engages on them.
I wouldnt be surprised if the i and xi performed exactly the same if not the xi having even more torque than the i.

[jpsimon]

I just talked to swift motorsports in Norwich, CT (860 823 1909). They have an AWD dyno that has individual rollers for every wheel and lets you set the dyno software to accept "clutch-type" center diff. This is exactly what we need.. I'm going to be going there soon

[Supramano]

Originally Posted by jpsimon

I just talked to swift motorsports in Norwich, CT (860 823 1909). They have an AWD dyno that has individual rollers for every wheel and lets you set the dyno software to accept "clutch-type" center diff. This is exactly what we need.. I'm going to be going there soon

awesome let me hear how it goes..they tell you what brand dyno it was??

[jpsimon]

Na I didn't even ask (I didn't care after he told me it would be fine)... I'll be sure to post up the dyno plot etc