[mdynamics]

I posted a thread about the throttle response problem in the 135i, and it was basically a deal breaker for me on buying a 135i. However, some recommended Sprint Booster and ever since I have been reading about it hoping to use it to fix the throttle problem. It turns out according to their fake drawn plot it will fix the lag.

Attachment 10909

But that is not true based on this white paper done by Dick Bipes:
http://frontiernet.net/~dbipes/sprintbooster/SprintBooster.pdf

He basically shows that Sprint Booster is not doing the work its supposed to do, it is just simply adding 30% increase over the amount that you press on the gas pedal which contradicts their own plot!!!


Here is a plot he shows when you press on the gas pedal in a stock car. The pedal is shown in blue and the throttle is in gray.

Attachment 10910

The lag is clearly shown at the early stage of the throttle, as he says “The pedal is in effect less sensitive at the low end, probably what most people want for finer control under low-speed conditions.” Which is true from BMWs perspective but not from a driver stand point.

Now here is the gas pedal vs the Sprint Booster output, you could clearly see that all Sprint Booster is doing is amplifying an output signal and especially at the ¼ and about pedal press which is needed the less.

Attachment 10911

I was seriously considering sprint booster as a must have but after I know the fact of what it does, I just came to the conclusion it isn’t worth the dough (especially the part where the pedal is dead above ¾ of press). If they really wanted to fix this lag and create a more linear response they should amplify the signal like they did but make it variable and the opposite of the throttle curve and that will fix things. But then again it’s like these companies that are taking the cheapest route about things and selling them for big $$$. Like SSTT it’s a great plug and play like sprint booster but what it really does is just alter the pressure and temperature reading to make the ECU use the maximum manufacturing allowed boost by the ECU. Although it’s really simple I think the SSTT is okay since they did their homework in finding out the max temp and low pres to not trigger the ECU, but the Sprint Booster is a disappointment.

Correct me if I am wrong but I believe all this is ture.