[PsychoSlug]

Originally Posted by Smitty1

Sold my jb+ today.

And sent off a check to Cobb to get my AP. Cannot wait.

Now all I need is a car to put it on.

[Christian.]

Originally Posted by cwg

To me the more interesting difference is the shape of the power curves. The 135i curve shows it is gaining power up to 6500 rpm while the 335i peaks at 5500. All the other tune dyno curves I have seen for this motor have the power peak around the 5500 mark. To me this is a significant difference/improvement in the tune as we usually see the power taper off above 5500. Can you comment on this?

This is a common occurrence on load-based chassis dynamometers. They employ vehicle loading techniques that more closely represent real-world loading conditions and impose additional loads as vehicle speed increases.

As a vehicle increases in speed, an increased aerodynamic force is imposed. A engine's output must exponentially increase in order to push through this increased aerodynamic resistance, and increase top speeds. I say exponential because you would need to increase power output exponentially to increase a vehicle's top speed once you hit the aerodynamic top speed barrier (no gearing limitations). A simple example: to increase top speed by 1 MPH it may take 1 HP, 2 MPH = 4 HP, 3 MPH = 9 HP...and so on.

On a load-based chassis dyno (as apposed to an inertial dyno), the dyno will continue to put additional load on the vehicle through the PAU (Power Absorption Unit) as vehicle speed increases. This is the most accurate means of putting a vehicle under real world street driving conditions where aerodynamic loads increase as vehicle speeds increase.

This is why you will see more of a taper on power output on load-based chassis dyno graphs. These dynos are more closely simulating real-world conditions.

Christian.

[E60orBust]

Originally Posted by Smitty1

Sold my jb+ today.

And sent off a check to Cobb to get my AP. Cannot wait.

Now all I need is a car to put it on.

Cart before the horse...I mean tune before the car?

[cwg]

Originally Posted by Christian.

This is a common occurrence on load-based chassis dynamometers. They employ vehicle loading techniques that more closely represent real-world loading conditions and impose additional loads as vehicle speed increases.

As a vehicle increases in speed, an increased aerodynamic force is imposed. A engine's output must exponentially increase in order to push through this increased aerodynamic resistance, and increase top speeds. I say exponential because you would need to increase power output exponentially to increase a vehicle's top speed once you hit the aerodynamic top speed barrier (no gearing limitations). A simple example: to increase top speed by 1 MPH it may take 1 HP, 2 MPH = 4 HP, 3 MPH = 9 HP...and so on.

On a load-based chassis dyno (as apposed to an inertial dyno), the dyno will continue to put additional load on the vehicle through the PAU (Power Absorption Unit) as vehicle speed increases. This is the most accurate means of putting a vehicle under real world street driving conditions where aerodynamic loads increase as vehicle speeds increase.

This is why you will see more of a taper on power output on load-based chassis dyno graphs. These dynos are more closely simulating real-world conditions.

Christian.

Ok that all makes sense, but I understood that both the new 135i dyno graphs posted yesterday and the 335i graphs were generated on the same type of load based (Mustang) dyno - If that is the case, then I still have a question as to why the 135i has that great power curve holding or increasing power up to the 6500 rpm range as opposed to all the other power curves we see on this motor. If my undestanding is correct and the 135i was dynoed on a load based dyno, then the graphs show a power curve the opposite of what you are describing.

[Clap135]

Do you guys alter water pump programing at all?

[Pathy01]

Originally Posted by Smitty1

Sold my jb+ today.

And sent off a check to Cobb to get my AP. Cannot wait.

Now all I need is a car to put it on.

People still write checks???

[BQTuning]

Originally Posted by Rob@Cobb

The AccessPORT has a recovery mode in the case a cable is kicked out or some other random failure occurs, meaning your ECU is nice and safe.

Cheers,
Rob

I am going to print and frame this over my computer This is my only car atm, and I sure dont want to be stuck like chuck

[COBB Tuning]

Originally Posted by cwg

Ok that all makes sense, but I understood that both the new 135i dyno graphs posted yesterday and the 335i graphs were generated on the same type of load based (Mustang) dyno - If that is the case, then I still have a question as to why the 135i has that great power curve holding or increasing power up to the 6500 rpm range as opposed to all the other power curves we see on this motor. If my undestanding is correct and the 135i was dynoed on a load based dyno, then the graphs show a power curve the opposite of what you are describing.

We are thinking that this is a function of the parasitic loss calibration files on the different dynos. Once we get a 135i on the Austin dyno and a 335i on the Surgeline dyno we'll see exactly what the behavior characteristics are. The gearing of these cars has us running the dynos at higher speeds than we typically see on other vehicles, so we're getting into areas of the parasitic loss calibration that may need some additional fine tuning in order to more closely match.

Gary

[BQTuning]

Originally Posted by Clap135

Do you guys alter water pump programing at all?

+1 on this question above also

Cobb Team - Would I be able to dump the ROM on my Dinan S2 so I can reload it later if I want ? The Dinan S2 is key locked to my VIN.

The dealer has on my account that I have S2, coming back to them with stock will throw a red flag for sure.

[tscdennab]

Originally Posted by COBB Tuning

We are thinking that this is a function of the parasitic loss calibration files on the different dynos. Once we get a 135i on the Austin dyno and a 335i on the Surgeline dyno we'll see exactly what the behavior characteristics are. The gearing of these cars has us running the dynos at higher speeds than we typically see on other vehicles, so we're getting into areas of the parasitic loss calibration that may need some additional fine tuning in order to more closely match.

Gary

I ran my 335i on a Mustang in 4th gear and some smoke begun to show up from the dyno's electromagnetic brake

Since then I dyno in 3rd gear and there are absolutely no differences compared to 4th (I have tested).

[BQTuning]

Originally Posted by tscdennab

I ran my 335i on a Mustang in 4th gear and some smoke begun to show up from the dyno's electromagnetic brake

Since then I dyno in 3rd gear and there are absolutely no differences compared to 4th (I have tested).

I have a 07 E92 335i AMT and I ran 3rd and 4th gears on a mustange dyno. 3rd gear had lower results than 4th gear which produced significant greater results especially with the torque

Edit: I never saw any smoke being in any gear

[Clap135]

Originally Posted by tscdennab

I ran my 335i on a Mustang in 4th gear and some smoke begun to show up from the dyno's electromagnetic brake

Since then I dyno in 3rd gear and there are absolutely no differences compared to 4th (I have tested).

you sure it wasnt your tranny? I smoked the stock clutch after 10 or so baseline pulls on cpes dyno on a stock car. I then went to 3rd gear.

[ttuner]

Originally Posted by Rob@Cobb

I was able to talk to a 335is last night to grab a ROM. (Thanks J!). Over the next few I will be ripping into the ROM to look at the tuning. However, we need to find a alpha tester with either 'is' car here in Austin to allow us to complete tuning on the car for the stage maps.

Cheers,
Rob

Rob, does that mean the current tune will work on the Z4 35i DME? (not 35is)
or does that need to be tested as well?

[ROBD314]

got a '11 535i..whenever you bring it out for the n55 be sure not to forget the 5ers !!

[new2the3]

Can you please answer my question about this tune and high altitude? I live at 7500ft and travel anywhere from 5200 to 12000 ft above sea level.

[COBB Tuning]

Originally Posted by BuraQ

+1 on this question above also

Cobb Team - Would I be able to dump the ROM on my Dinan S2 so I can reload it later if I want ? The Dinan S2 is key locked to my VIN.

The dealer has on my account that I have S2, coming back to them with stock will throw a red flag for sure.

I will check with the engineering team on this. The GIAC flash for sure get's overwritten. I will confirm if this is the same for the Dinan flash.

Originally Posted by ROBD314

got a '11 535i..whenever you bring it out for the n55 be sure not to forget the 5ers !!

We will continue to support the 135,335,535 N55 cars for 2011 as well. However, we are still working on adding this support.

Originally Posted by new2the3

Can you please answer my question about this tune and high altitude? I live at 7500ft and travel anywhere from 5200 to 12000 ft above sea level.

Elevation can effect a tune and you may see less power at your elevation than another user at lower elevations. The ECU should be able to compensate for elevation changes and air density changes for proper fueling etc, however, boost targets may be reduced as you climb.

Originally Posted by ttuner

Rob, does that mean the current tune will work on the Z4 35i DME? (not 35is)
or does that need to be tested as well?

We will need to explore this a little more and report back to the community. It may be that these use a whole new ROM that will need to be added to support these vehicles.

I will get more information for you guys as soon as I can! Our boys in Texas have wondered home for the weekend. If I can't update you tonight I will do it first thing Monday morning!

Travis
COBB Tuning

[TLO03]

Personally the biggest advantage for me is not having to open the ecu compartment..

[ttuner]

Originally Posted by TLO03

Personally the biggest advantage for me is not having to open the ecu compartment..

ESS also makes a direct flash product, but it is 100$ more, and appears to make a little less power. i am looking at purchasing something come spring so hopefully Cobb has a file for my car by then.

[Enicinitas]

Originally Posted by ttuner

ESS also makes a direct flash product, but it is 100$ more, and appears to make a little less power. i am looking at purchasing something come spring so hopefully Cobb has a file for my car by then.

just go Cobb vs giac. There are quite a few flashes (giac, Cobb, oe, dinan, ess) to choose from if you don't like to pop your hood.

[Alan l.]

What separates this one from the rest is that this is 100% DIY which is HUGE!

[roninsoldier83]

Originally Posted by Rob@Cobb

We've got a couple of people with 335xi's that we're working with, but it's going to take a little time to make sure we get everything right. I'm excited to get the 'xi'ers up and running.

Cheers,
Rob

Hope you guys can get the "xi's" cracked soon, and when you're done, hopefully an '07 release shortly after!

[Rob@Cobb]

Originally Posted by Clap135

Do you guys alter water pump programing at all?

We do not on the stage 1 map. I have not seen a need for change on these power levels as of yet.

Cheers,
Rob