[bradsm87]

MPPSK is the only way to get the DME to report more torque to the TCU. MPPSK + JB+ on the lowest setting would be a good combo IMO.

[Styx]

Does using the paddles and "manually" shifting the 8AT negate this problem or is the lag still noticeable?

[Antec800]

Manual shifting helps a little lifting, and lifting off the throttle just a bit when shifting helps a little also

[AlexM240i]

Engine hesitation and laggy shifting from 3rd gear with my JB+ even using octane booster and premium fuel in my 8Auto M240i. I had to turn the dial to half boost to prevent the laggy shifting. Not happy with it....

[babyboss]

Had JB+ Units tested in 2 csrs
M240i
440i F32
Both cars hated it ..
Made little mid range & lost out on higer rpm on dyno ..
Both lost smooth drivibility ..

Not worth it **

[GA/\/\/\/\A_CT]

Originally Posted by riskmaker76

One point Terry made to me personally - every car is different. Some tolerate more or less timing differently with added boost. My car super sensitive to octane... the best gas yields tiny gains in timing - but any improvement allows me to run higher boost than stock.

Costco is not "top tier gas" lol.... And yes Top Tier gas makes a big difference.

Put some VShell in there OR put 1 gallon of E85 with your "Costco Top Tier Gas".. Dont put more than 1 gallon - your trims / afr may rise without you knowing..

Timing is key to make power with added boost. If timing is retarding - all the extra boost wont make a difference - this is probably whats occuring due to your "Costco Top Tier Gas".

Of course weather plays a role but varies most by season not by day or week honestly. For example, I can now run 3 PSI additive now that the weather is cold out... but during the summer with my VShell 93 the best I could run and maintain sufficient timing was 2 PSI. (I have 440 with MPPSK which already has roughly 2 -3 PSI above stock thus the very conservative boost targets).

My suggestion is first get some good premium gas and see how it drives... If its still falls flat, back it off... keep backing it off until you see gains.

The benefit of the JB4 is you can see all the metrics needed to properly tune to the situation (ie bad gas, hot weather, etc. etc.).

PS - I have no shifting issues honestly - may or maynot be because of the JB4

Looking at your time slips, it seems that your runs are very close until the 1/8 mile mark. At the 1/8th you are within 1mph on both runs. At the 1/4 you are 3mph different. There is less shifting in the last half of the 1/4 mile, so my guess is it’s not the transmission but maybe the boost control is too high for your octane and timing is getting pulled on the longer gear ratios.

[AMG KLR]

Originally Posted by GA/\/\/\/\A_CT

Looking at your time slips, it seems that your runs are very close until the 1/8 mile mark. At the 1/8th you are within 1mph on both runs. At the 1/4 you are 3mph different. There is less shifting in the last half of the 1/4 mile, so my guess is it’s not the transmission but maybe the boost control is too high for your octane and timing is getting pulled on the longer gear ratios.

Timing pulling is a common problem with the JB+. That's why most people who regularly use it dial the boost back to what it was shipped with or slightly below. Yes it makes less power but it does become drivable.

If you want a real tune then people should get one. I am happy with my JB+ for now as it will keep my warranty safe