1st Gear and Dynamic Traction Control

[racer_x]

Hi Guys,

I've only had my 2009 135i (6SP Manual) for a couple of days. It's completely stock and I was wondering....

What do you do about the lack of boost in 1st gear?

It seems to me that the ECU is not running much/any boost in 1st gear (compared to all other gears).

Is this just the traction control trying to keep things in check?

Is there a way of disabling the traction control by default? Or do you need to disable it every time your start the engine?

Sorry if my questions sound silly. I've not owned any BMWs before and I am traveling for work so I don't have the car or its manual at hand to look for the answers.

Thanks in advance.

[SteveAZ]

Not sure about the other tunes, but I know on the JB4 this is an option although it doesn't totally disable it, You have to hold the button down for a few seconds to do that. Don't believe there is an option when you are stock unless you're able to code it, but haven't heard of anyone doing it.

[racer_x]

Does anyone know what sort of boost the stock tune runs in 1st gear compared to the other gears?

[RimasRS]

there is no limit on boost in 1st gear on stock car

[racer_x]

Originally Posted by RimasRS

there is no limit on boost in 1st gear on stock car

I don't know about the rest of the stock cars here but mine feels down on power in 1st gear.. How does the ECU do that?

[luv135i]

WHat you feel is probably the traction control kicking in which limits the power when it happens. The only time i felt it on a stock car was in first gear WOT.

[mryakanisachoad]

6 speed STEP, +3psi, BMS dual cones, 265mm rears, 93 pump gas...that's it.



What should be the approximate 0 to 60 and 1/4 mile times?

Should that car really feel faster than a bone stock e60 M5??

[racer_x]

Originally Posted by luv135i

WHat you feel is probably the traction control kicking in which limits the power when it happens. The only time i felt it on a stock car was in first gear WOT.

Does the traction control system give any indication when it kicks in? I see nothing on the dash when this is happening.

[08LMB135i]

First gear is nutty in my car especially with a tune, I don't think boost is limited from the factory.

[luv135i]

Originally Posted by racer_x

Does the traction control system give any indication when it kicks in? I see nothing on the dash when this is happening.

Just the little icon on the dash blinks for a sec.

[Tommeh]

Yeah I just got my car back with new turbos, no tune but supporting mods.. I get wheel spin from 4k through first on nitto nt01s with a normal low rpm rolling launch. Also my boost stays at 7-9.


As for traction control jb4 has a way to link it to a steering wheel button push instead of holding the reaction control for x seconds

[BEAR-AvHistory]

Couple of things all BMW turbos have boost limits from factory. Its about 8.8psi for stock N54 motors & 10psi for the N55. The boost is also limited by rpm with the full 8.8/10psi in the mid ranges & less boost at low & top end rpms. The 335is is 11.6psi normal & 14.5psi on overboost. My 135is is still on the boat so I have not looked into it yet but it will be getting a JB4 anyway A guess would be 12/12.5psi with no overboost.

The JB4 has a setting that simulates the first button push when you start the car disabling the traction control but not the stability control.

[makrop]

Probably a dumb question bur I've never had a car with turbos before 5 days ago, but how do you tell how much boost you're at? Does that require a special gauge

[BEAR-AvHistory]

Yes & No. With a JB4 tune you can hijack one of your factory gauges to show the boost real time. You can also run a log to see what the boost was over a run or whatever you want to measure. I use my oil temp gauge for boost & my fuel gauge for coolant temperature when over 50% throttle. Below 50% they function as oil & fuel gauges.

Without a tune you need to buy a boost gauge, there are some that are integrated with the upper air vents but cost almost as much as a basic tune.

[awns729]

Originally Posted by BEAR-AvHistory

Yes & No. With a JB4 tune you can hijack one of your factory gauges to show the boost real time. You can also run a log to see what the boost was over a run or whatever you want to measure. I use my oil temp gauge for boost & my fuel gauge for coolant temperature when over 50% throttle. Below 50% they function as oil & fuel gauges.

Without a tune you need to buy a boost gauge, there are some that are integrated with the upper air vents but cost almost as much as a basic tune.

I had no idea JB4s could do that. So cool.