JB4 and launch control

[///bproden]

I'm curious to know how well launch control works with the jb4 (either stage). Anyone with experience able to chime in? Does it work just as usual? More tirespin?

[AM4ZING]

Originally Posted by ///bproden

I'm curious to know how well launch control works with the jb4 (either stage). Anyone with experience able to chime in? Does it work just as usual? More tirespin?

The JB4 wouldn't affect the launch mode setting but adding more power to the rear wheels will definitely result in more wheel spin. (unless you use boost limits by gear)

[Mike@N54Tuning.com]

Originally Posted by ///bproden

I'm curious to know how well launch control works with the jb4 (either stage). Anyone with experience able to chime in? Does it work just as usual? More tirespin?

If you're talking about the boost limit by gear, this works with the factory launch control. The JB4 cannot limit boost beyond factory targets, so basically at max setting you are turning off the JB4 in 1st and 2nd gear and running factory boost targets.

Mike

[Irishace]

I have serious issues launching now with JB4 power. I can't use LC I just now feather the gas.

[///bproden]

Originally Posted by Irishace

I have serious issues launching now with JB4 power. I can't use LC I just now feather the gas.

This was my concern. Is there so much power with JB4 (either stage) that basically makes using launch control useless? Or if possible would it be best to use the limit boost feature in 1st & 2nd, until 3rd gear or when traction is possible?

[Irishace]

Originally Posted by ///bproden

This was my concern. Is there so much power with JB4 (either stage) that basically makes using launch control useless? Or if possible would it be best to use the limit boost feature in 1st & 2nd, until 3rd gear or when traction is possible?

I tried limiting boost with minimal success. I also tried launching in 2nd and its sluggish out of the hole then the tires roast when boost comes on. It's an art to launch this car on stock rubber with the bigger power output.

[infamousdiz]

warm tires and new road pavement and i have no traction issues. everyone complains about traction here but i dont have any issues i get no wheel spin in 2nd gear just a chirp

[Mike@N54Tuning.com]

Originally Posted by Irishace

I tried limiting boost with minimal success. I also tried launching in 2nd and its sluggish out of the hole then the tires roast when boost comes on. It's an art to launch this car on stock rubber with the bigger power output.

If you limited boost then you turned the JB4 off essentially. So any launch issues would be due to stock power If on stock rubber then even stock boost makes launches and traction difficult.

Mike

[FC4]

Originally Posted by infamousdiz

warm tires and new road pavement and i have no traction issues. everyone complains about traction here but i dont have any issues i get no wheel spin in 2nd gear just a chirp

For the most part, people on forums grossly exaggerate traction issues. I've seen this for practically every car for any state of tune on any forum I've been a part of for the past 15+ years. It's nothing new.

[TurboSid]

Launching on JB4 with full power (map 2) is too much power for the stock tires. Even launching at the lowest rpm possible.

I'm not a drag racer I just have fun with the car but at the track better tires + boost by gear would work better.

[9SECDD]

Originally Posted by ///bproden

I'm curious to know how well launch control works with the jb4 (either stage). Anyone with experience able to chime in? Does it work just as usual? More tirespin?

I experimented quite a bit with launch control, and also ran a dozen 1/4 mile runs in one day a few weeks ago at Bimmerfest East. I have a BMS Stage 1 tune with stock tires.

The surface is key. Fresh, gravel-free pavement almost always hooks up fine. At the drag strip, the first two runs with launch control worked great. But after that, I had serious traction issues. Fishtailed and had to let off.

So I'm definitely upgrading the tires to extreme summer tires that are wider (Bridgestone RE-71R 265/285 19s). Hoping that helps.

All that said, the boost is worth it. In fact, just ordered full JB4 so that I can control the boost in each gear (lower/eliminate boost in 1st & crank it up in 3rd & 4th).

[///bproden]

Originally Posted by TurboSid

Launching on JB4 with full power (map 2) is too much power for the stock tires. Even launching at the lowest rpm possible.

I'm not a drag racer I just have fun with the car but at the track better tires + boost by gear would work better.

Good to know thanks!

Originally Posted by NJ-M4

I experimented quite a bit with launch control, and also ran a dozen 1/4 mile runs in one day a few weeks ago at Bimmerfest East. I have a BMS Stage 1 tune with stock tires.

The surface is key. Fresh, gravel-free pavement almost always hooks up fine. At the drag strip, the first two runs with launch control worked great. But after that, I had serious traction issues. Fishtailed and had to let off.

So I'm definitely upgrading the tires to extreme summer tires that are wider (Bridgestone RE-71R 265/285 19s). Hoping that helps.

All that said, the boost is worth it. In fact, just ordered full JB4 so that I can control the boost in each gear (lower/eliminate boost in 1st & crank it up in 3rd & 4th).

Also, good to know you think it's still worth it and enough that you're upgrading to JB4. I'd like to still be able to use this launch feature, and if boost by gear works better and still allows the feature to be somewhat used, i'd be a happy camper.

I take it you both think the tune is worth it and will continue to use even if this "crank rod issue" becomes more apparent?

[CaryTheLabelGuy]

Originally Posted by ///bproden

Good to know thanks!



Also, good to know you think it's still worth it and enough that you're upgrading to JB4. I'd like to still be able to use this launch feature, and if boost by gear works better and still allows the feature to be somewhat used, i'd be a happy camper.

I take it you both think the tune is worth it and will continue to use even if this "crank rod issue" becomes more apparent?

While the non-keyed crank hub assembly is an engineering failure on BMW's part, we still don't know how widespread the issue is or isn't.

[9SECDD]

Originally Posted by ///bproden

Good to know thanks!



Also, good to know you think it's still worth it and enough that you're upgrading to JB4. I'd like to still be able to use this launch feature, and if boost by gear works better and still allows the feature to be somewhat used, i'd be a happy camper.

I take it you both think the tune is worth it and will continue to use even if this "crank rod issue" becomes more apparent?

Definitely still worth it to me. I may buy the TPG keyed crank hub fix just to be sure since I'm adding downpipes and full JB4.

[stranger]

do you need to run meth or race gas to use the boost limiting feature?

could I use it with shell v power 99?

[Mike@N54Tuning.com]

Originally Posted by stranger

do you need to run meth or race gas to use the boost limiting feature?

could I use it with shell v power 99?

The boost limiting in 1-3 gears does not require any mods. Its global for all maps, from map1-7.

Like I mentioned above, the boost limiting feature cannot target below OEM boost, so in essence the maximum setting is to turn the JB4 off in those gears as it will prevent any added boost over stock curve.

Mike

[stranger]

Originally Posted by Mike@N54Tuning.com

The boost limiting in 1-3 gears does not require any mods. Its global for all maps, from map1-7.

Like I mentioned above, the boost limiting feature cannot target below OEM boost, so in essence the maximum setting is to turn the JB4 off in those gears as it will prevent any added boost over stock curve.

Mike

I thought it was only for map 6, would I need to connect the fuel mass and the waste gate connectors?

[Mike@N54Tuning.com]

Originally Posted by stranger

I thought it was only for map 6, would I need to connect the fuel mass and the waste gate connectors?

I usually recommend keeping the EWG connectors stock if running map1/2 and connecting the MASS Fuel. What map are you running?

Mike

[stranger]

Originally Posted by Mike@N54Tuning.com

I usually recommend keeping the EWG connectors stock if running map1/2 and connecting the MASS Fuel. What map are you running?

Mike

Map 2 at the moment as we don't get e85 in the uk

[Mike@N54Tuning.com]

Originally Posted by stranger

Map 2 at the moment as we don't get e85 in the uk

Ya connect mass fuel and leave EWG off. ITs not active on map2

Mike