135i Launch Performance: I'm probably doing something wrong.

[BMW135pls]

Firstly, I don't think my launch performance is bad at ALL, still way faster than most cars on the road and I'm ok with that. The question I have is why hasn't my 0-60 time shortened with the mods I've put in and after learning how to launch it better?

On a complete stock car when I got it last year, I clocked 5s 0-60 time. At the time I was just putting it into DS and ogreslamming the throttle. The car had bald runflats on it at the time, and the suspension was stock so I was bucking and snaking around the whole time. Since then, I've put in a JB4 on map 5, which doubles the boost pressure to 16lbs. AA exhaust/dps which are pretty wide open (stock midpipe still installed). M RSFB bushings, which tamed the back end so that launching no longer causes the bucking/snaking. And brand new Michelin 225/255 PSS tires, which widen the contact patch and really help to put the power down. Now I am also launching in 2nd using mild brake boosting to between 1.5k-2.2k RPMs. 0-60 times are completely unchanged at 5s absolutely flat.

I know the only "performance" related mod has been the JB4 upping the boost pressure and all, but it all helps in its own way. Should I expect to see the time go below 5s with future mods, or is that figure indicative of a limitation of the frame? Am I launching wrong? Any thoughts?

[methodz]

Wow, I don't know bud but after all those goodies I'm actually pretty damn surprised that there is no difference It has to be something right? I always thought even after changing the RSFB if you raced a stock car you'd already be faster because the back end of a stock would be all over the place. And after adding all that other stuff... hard to believe. I hope you figure it out.

[ShocknAwe]

Maybe try limiting boost in 1st and 2nd.

[135ilust]

Is it an auto or manual? I believe that map 5 takes sometime to auto tune, where you have to do 3 to 5 wot pulls from 1st to 3rd all the way to redline. If not, the car will basically be untuned.

[ShocknAwe]

Originally Posted by 135ilust

Is it an auto or manual? I believe that map 5 takes sometime to auto tune, where you have to do 3 to 5 wot pulls from 1st to 3rd all the way to redline. If not, the car will basically be untuned.

False. It can actually overestimate boost your car can handle based on mods initially and end up "detuning." Typically it will start at Map 1 levels and learn up from there.

Your auto tune pull instructions are also false. Map 5 does not auto tune unless in 3rd or 4th gear at WOT and you need to continue to over 4500 rpm. 1st and 2nd gear are worthless for auto tuning.

Please make sure you are posting accurate information in the future.

[e36addict]

Why don't you take your car to the strip and see what it's actually capable of?

[BMW135pls]

Originally Posted by 135ilust

Is it an auto or manual? I believe that map 5 takes sometime to auto tune, where you have to do 3 to 5 wot pulls from 1st to 3rd all the way to redline. If not, the car will basically be untuned.

Actually this may have SOMETHING to do with it. During the RSFB install, I had an oil change also, and the tech told me he wasn't able to reset the oil timer like normal due to the controls to get into that being the same as the controls to get into the JB4. When I got the car back, the JB4 was in map 4 setting instead of 5. (This was remedied on the day I picked it up, so it has nothing to do with the 0-60 testing I spoke of) I've been driving with the JB4 since last October about, but maybe the JB4 needs to "relearn" everything all over again from the map switching or whatever he did when he was in there. TBH I haven't really looked at the boost meter to make sure that it's hitting 16psi on pulls, but just by the butt dyno, the car at least feels like it's as fast as it's ever been. Is there a way to master reset the JB4 programming so that I can just be absolutely sure that he didn't accidentally mess anything up when he was messing around?

[MuNkY6913]

There is a default settings page in the other forums. You have to go into the user settings tab and match all of the numbers in the picture. You should always log. Put it on map 4. drive it around for a little while(5-10 mins).go back to map 5 and do 3 wot pulls in 3rd or 4th gear, on a closed course obviously, from 2k rpm to 6500 rpm. Do a couple more for good measure and get a log. See what's going on with your car. You should always log before and after mods. If your going to change things you need to make sure your watching those changes and verify the changes are happening and your car is ok with it. Definitely get to the track and get a real number. Not sure what you used to get your time but I have also used gps and obd2 reader to get a time but I trust the 1/4 mile slips more.

[BMW135pls]

Ok, I have an update

Tried launching a few more times today, best run was 4.59. Did a few things differently this time. This time instead of shifting at around 6k to save the engine, I let it rev out to redline and autoshift, that means that the entire launch to 60 is in one gear, so we can rule out shift times. Also hit the gas a little harder after letting off the brake, though the traction loss if you over-torque it still raised our time on a run or two, I'll have to get a feel for the right amount of power to apply. There was also a hundred or a hundred fifty less weight in the vehicle (discarded the body when I realized I no longer needed it to weigh down the back end after the RSFB upgrade). I bet I could get even lower times if I throttled it perfectly. All in all I'd say I'm very satisfied with what the car is doing now, I'm probably the major limiting factor, need to learn the proper technique to maximize times and all that