People with lag should be madder Cure Sprintbooster

[baduncadonk]

Installed Sprintbooster "auto" model today. Here are observations:

1. No instructions came with the package. (I purchased from MiniMania.com). The lack of easy, graphic instructions for a consumer hop-up part costing $330 is irritating and reflects poorly on the manufacturer and its U.S. distributor.

2. The install was conceptually easy, but I had difficulty finding enough space behind the carpeting to comfortably hide the SB unit. I managed to push it down far enough to just barely reattach the the gas pedal unit, but it was not easy and I have lingering concerns that I may be over-stressing the SB unit with pressure from the reattached gas pedal box. If my car conks out unexpectedly in the future, I will definitely pull the SB first.

As for the performance of the SB, the resulting throttle behavior is interesting:

1. The pedal is indeed a bit more sensitive at low speeds, although you quickly get used to it.

2. The throttle behavior under spirited driving does appear to negate the frustrating lag that was present before. The throttle curve seems to be nicely linear from 25% to 100% pressure on the pedal.

Finally, I had a friend, who drives an '07 M5, take my car out before the SB install today. He was frustrated by the throttle lag and wouldn't shut up about it. I will have him retry the car tomorrow, with the SB added, to see whether his impression has changed.

Originally Posted by baduncadonk

Okay, so. . .

I ordered a SprintBooster yesterday--to much abuse and laughter from my business partner, who thinks the SB is a complete scam.

I am also inclined to not believe the hype, but I will install it this weekend and try to give an unvarnished review here. I do have noticeable throttle lag in my April-build 135i automatic.

[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.

[Wraith]

hmmm, very interesting info there, but the sprintbooster provided graph does appear to be very similar to that independant test graph as far as I can see :iono:

Also with the increased/earlier throttle response, it's easy to see/understand why people would feel it's eliminated at least some of the lag :iono:

I suppose it comes down to whether the individual thinks it's worth the money or not for what it delivers - most who've installed it seem to think it's a plus to have...

[holo777]

It looks like it is actually doing exactly what it claims to do.

Now can we get the guy that wrote the whitepaper to look into v29.2 lag?

[mdynamics]

Originally Posted by Wraith

hmmm, very interesting info there, but the sprintbooster provided graph does appear to be very similar to that independant test graph as far as I can see :iono:

Not really, based on the conclusion that all Sprint Booster does is add a 30% or 50% increase the actual results will be as follows:

Attachment 10914

Which is not linear as they claim. They could make it linear by varrying the increase based on the base curve but they didnt.

[All4One]

Wow, thank you for that study. So, all lead footed fellows get to save some then by not buying the SB. It was interesting to note where it says:

"This data makes me suspect that drivers of electronic throttle response vehicles who are noting throttle lag or poor throttle response are experiencing some behavior other than true throttle lag."

Hmmm..which lag is it...turbo!?

[AdDicTed135i]

:thumbup: I got my sprintbooster installed went for a test drive,WOW its feel like a faster car more aggressive, two thumbs up for that product!!!!!!

[miro2296]

Which part# did you end up using? I found two different part#'s (BMW1900 & NME1900). The NME1900 was found on the minimania.com and found the BMW1900 on bmw-mania.com. I am sure there is a difference, can someone help me out? :iono:

NEVERMIND I FOUND MY ANSWER :biggrin: