[Brett530]

Sprint Booster V3 Review

I’ve been driving with the new Sprint Booster V3 for about 3 weeks now and I have to say I love it. I was hesitant to buy it, because I really didn’t need more driving modes in my 2012 F30 335i Auto, but the throttle performance was driving me crazy with inconsistent behavior. The unpredictability of the engine-transmission interaction is at the heart of my dissatisfaction with the F30. I added a Burger Stage 1 a year ago, so there is plenty of low end grunt, but it did nothing to improve the slow decision making of the transmission at low speeds.

How It Works:
This device remaps the throttle signal with a range of more aggressive settings. It does not add any power, but it does make the car feel more powerful. It delivers power exactly when you want it, which in my book, for a daily driver, is more valuable than adding more power to the N55. It has Sport mode with 9 settings and Race mode with 9 settings. Despite the names, it is just a gradual increase in response. Less pedal travel is needed to produce more throttle. So why not just skip this gimmick and push the pedal harder? I think the difference is time of travel. It isn’t just pedal position that matters, but the time to travel to that position. The Sprint Booster seems to send a clearer (i.e. faster/harder) signal to the computer, so you avoid the “hmmm, what gear would provide the optimum balance of economy and power?” delayed response that seems to happen at slow speed. Now it is a clear “go fast!” signal being sent. I’m not pushing the pedal further or faster, but the transmission immediately grabs the right gear now.

Expectations:
Coming from an E39 530i, I expect precision and predictability. The more telepathic the experience, the better. Less physical movement, with exactly repeatable input/output results is a more telepathic experience. The stock F30 was not providing that for me. I expect to feel a direct connection between my foot muscles and rear wheel torque, with nothing in between. The same foot movement should produce the exact same acceleration every time; no hesitation, no delays.

What Sprint Booster Solved:
I started to dislike this F30 because of initial hesitation when accelerating from a stop. There is a bit of acceleration and then a pause, maybe less than half a second, like it is rethinking what gear you really want, then an abrupt surge once it finds the gear. Clearing the car’s adaptations seemed to help some, but was not a lasting solution. BMW drivers who can identify with my complaint will be happy to hear that the Sprint Booster has solved this completely. I use Race setting 2 in Comfort Mode and the acceleration from a stop or slow roll is precise and responsive without tip-in delay. That alone is worth the price of entry for me.

Some might say, "Why not just keep it in Sport Mode all the time?". A problem with early F30s is that in Sport Mode, the transmission will not shift up to 8th gear (someone said it would above 100+MPH, but I have not verified that). While I tend to have a heavy foot, I still make an effort to save gas when I can. I use Comfort Mode most of the time for commuting and anytime speeds are above 45 MPH. I don’t mind the shift points in Comfort Mode, and find the car has better manners overall. Sprint Booster allows me to have aggressive, precise throttle control in Comfort Mode, use all 8 gears, and save a bit of gas by upshifting more conservatively. At 4300 Ft., the N55 doesn’t have much high RPM pull, so holding gears is mostly noise anyway.

Drivability
I find drivability is improved in all regards. It does not make the car twitchy at all. In Sport mode at about 5, there is a very slight hesitation for gear selection, but still way better than stock. I keep mine at Race 2. It is crisp and precise. When I want more, I use the Sport Mode switch on the console. With that combination the car requires more driver attention if you don’t have much room in front of you. It almost feels like you are in a lower gear – it will jump forward with very little throttle pressure. Just for fun, I tried Race setting in Eco Mode, and it was like Comfort Mode with more aggressive upshifting. Seemed useless, but some might have need for such a combination. I have not tried Sport+ since I assume I’ll just spin the tires more (I still have the Blizzaks on), and I have not felt the need for quicker throttle response than Sport Mode with Race setting.

My average gas mileage dropped from 24.3 MPG to 23.9 MPG with mostly the same driving patterns (very little freeway driving), but I have been having a lot more fun with the car now, so it probably isn’t the Sprint Booster itself that is causing the decrease.

Installation was pretty simple. I used a Torx (star) bit at the base of the pedal and then slid the pedal up and forward (toward the engine) to get it free. I routed the cable by tucking it up under the edge of the console and mounted it by the shifter by pulling up the aluminum console piece that holds the iDrive control. It just pops off (but it takes some force).

Overall, I could not be happier with what it has done for my F30. The car should have come this way from BMW.

[otay]

Originally Posted by Brett530

Sprint Booster V3 Review

... but the throttle performance was driving me crazy with inconsistent behavior. The unpredictability of the engine-transmission interaction is at the heart of my dissatisfaction with the F30.

I expect to feel a direct connection between my foot muscles and rear wheel torque, with nothing in between. The same foot movement should produce the exact same acceleration every time; no hesitation, no delays.

There is a bit of acceleration and then a pause, maybe less than half a second, like it is rethinking what gear you really want, then an abrupt surge once it finds the gear.

Overall, I could not be happier with what it has done for my F30. The car should have come this way from BMW.

Thanks for the review, everything in your quotes above is SPOT ON.

This is my number 1 complaint with with my 8AT 335i: Hesitation when pulling away from a stop, or at very low speeds. For me, it's somewhat inconsistent, in that it happens more often when engine/tranny is cold; rarely happens after driving for 15-20 minutes or so. This is why I've just learned to live with it, and be careful with foot pressure for the first bit of pedal travel. If it happened all the time, I'd be more interested in this $250-$300 mod (plus, I've only got 3 more months of lease payments on this one )

It's also interesting that you mention the interaction with the tranny. "...the transmission immediately grabs the right gear now." I've been trying to pay attention to RPMs/engine sound when this delay happens, and it seems the engine speed is actually increasing, but the car doesn't move much. Very annoying.

I'd do this if I was not going to 340i 6MT soon.

[uncleruckus]

awesome review, well written

[gpchamp]

I have a similar product, Remus Responder, and like you, love it! Made daily driving my 428i much more enjoyable.

[mike@x-ph.com]

Thank you for the review

[aacocella1]

The Sprint Booster V3 has had many good reviews for BMWs. SprintBoosterSales.com has the cheapest price and a 3 month money back guarantee.

[BEAR-AvHistory]

Why not just skip the whole thing & push the pedal down a little further?

[Korvo]

Originally Posted by BEAR-AvHistory

Why not just skip the whole thing & push the pedal down a little further?

Do you even understand what this does? Pushing the petal down further doesn't increase throttle response.

Read before you reply.

[jjhebigscreen]

I have had the sprint booster for about a month. For you doubting thomases that think it is snake oil or are saying just push the pedal down further I say you have not tried the product. I have mppk and mpe which I thought made a nice difference in power and throttle response. I wish I went with another exhaust but that another thread. I can honestly say the sprint booster made a far bigger difference in my throttle response. It is so much more enjoyable. Revs build way quicker and the car feels significantly faster even though I know the sprint booster does not add power. This upgrade was the best thing I have done to the car. I have a smile on my face every time I drive the car. Im not a stop light racer as Iam 55 an those days are behind me but I must say I have kept two or three annoying cars from getting in my lane. I live in the city and these annoying drivers pull up to the stop light in a lane that is not truly a long term driving lane as there are parked cars ahead and you need to merge immediately. My other car is a 2017 mazda cx5. About 1 week ago I installed the pedal commander which is a similar product. Sprint booster did not make a v3 for my Mazda. The difference in throttle response and drive-ability is gigantic. I never really enjoyed driving the Mazda due to its sluggish throttle response. I now truly enjoy driving this great little suv. One thing I will say is since Im using higher revs more frequently I am able to enjoy the engine sound and exhaust a little more. On the downside my mpg have dropped about .2mpg but I consider this a worthy trade off. I also would think I a putting more stress on my over all car but again a worthy trade off.

[Sportstick]

Originally Posted by pdegene

Do you even understand what this does? Pushing the petal down further doesn't increase throttle response.

Read before you reply.

Excellent advice! This was from a Mercedes group, but the principles are the same.

http://www.crosslake.net/~dbipes/spr...intBooster.pdf

It has been widely referenced as shown in a Google search.


(P.S. Cars have pedals. Flowers have petals.)

[tsm007]

Thanks for the review. Well written and precise. I wonder if this will void my warrenty...

[Sportstick]

Originally Posted by tsm007

Thanks for the review. Well written and precise. I wonder if this will void my warrenty...

Search and read the Magnuson Moss Warranty Act. Anything aftermarket you do can void a warranty claim if your action/equipment can be shown to be causally related to the failure. Adding an engine mod probably cannot void a warranty claim if your radio stops working, for example.

[RobG_M340]

I bought a Sprint Booster v2 off someone on Craigslist and it's made a huge difference on my '18 440i. Anyone know if there's any major reason to warrant getting the v3?

[Brett530]

I have moved to a '17 340i since writing the above review and the engine-transmission matching is quite a bit better (nearly perfect). So while I moved the sprint booster to the new car, I find I keep the setting pretty low since it just doesn't need as much help as the 335. The JB4 may also have something to do with it, but wheel spin starts to become a problem if I crank up the Sprint Booster too much.

rgilkes: I doubt an upgrade would change things much.

[BEAR-AvHistory]

Originally Posted by pdegene

Do you even understand what this does? Pushing the petal down further doesn't increase throttle response.

Read before you reply.

What it does is front load the throttle input by taking it out of of the back end. There is no increase in power it just redistributes where it come in vs throttle position.

JB4 has the same feature built into it. Many of us dialed it back instead of forward because it was to easy to overcome the tries it the power hit to soon.

The booster functions the same way the JB4 does. It intercepts the throttle transducer signal input & tricks the ECU into seeing more pedal movement then is actually taking place.

Do the same thing in the COBRA with its FORD racing tune-able throttle/ECU package. Only thing is I soften the input to get more throttle control in a 550HP 2200lb car.

[Sportstick]

Originally Posted by BEAR-AvHistory

What it does is front load the throttle input by taking out out of the back end. There is no increase in power it just redistributes where it come in vs throttle position.

Correct. In short, it addresses the human perception phenomenon that more response in reaction to small input is more satisfying. A 0-60 time with versus without Sprint is the same. It just feels better because you get more reaction for less initial input. "It jumps off the line!" (...which it would also do if you felt comfortable flooring it.) If you like that feeling, by all means, enjoy, but there is no actual difference in performance. And, be ready for a diminution of response at the last portion of the throttle travel as compared to the as-delivered condition in your car. The trade-off has to occur somewhere!

[jjhebigscreen]

Hi Sportstick,
Have you ever installed a sprint booster in a newer BMW?

[Sportstick]

Originally Posted by jjhebigscreen

Hi Sportstick,
Have you ever installed a sprint booster in a newer BMW?

No, never felt the desire but I can understand why others might enjoy the experience. I had a Subaru which behaved like this by design. There is something to be said about small pedal motion resulting in more of the available acceleration sooner. Just doesn’t hold the appeal for me.

[BEAR-AvHistory]

Originally Posted by Sportstick

No, never felt the desire but I can understand why others might enjoy the experience. I had a Subaru which behaved like this by design. There is something to be said about small pedal motion resulting in more of the available acceleration sooner. Just doesn’t hold the appeal for me.

This was common even in the bad old days of push-rod controlled carburetors. Small engined two barrel cars got different geometry in the linkage bell cranks to initially open the throttle blades quicker than the big engine four barrels, made the little engined cars "peppy".

There ain't no free lunch.

[Brett530]

There is another effect that is being ignored (mostly by the critics). When you press the throttle slowly it does not prompt the same downshift as pushing it quickly. It tries to hold the gear slightly longer until it realizes it needs to downshift. The problem I had with my 2012 335 is that the transmission was hesitating not wanting to downshift for an aggressive enough acceleration. With the sprint booster the quicker signal caused a faster 1 or 2 gear downshift and the car responded as expected. And like I said above, my 340 behaves as expected so there isn't much need for the sprint booster, except when adaptations start making the car lazy.

[Sportstick]

Originally Posted by Brett530

There is another effect that is being ignored (mostly by the critics). When you press the throttle slowly it does not prompt the same downshift as pushing it quickly. I

That is true if you have an automatic trans, but, if you like the effect Sprint creates electronically, why would one push the throttle slowly in the absence of a Sprint?

[Brett530]

Originally Posted by Sportstick

That is true if you have an automatic trans, but, if you like the effect Sprint creates electronically, why would one push the throttle slowly in the absence of a Sprint?

That is really the essence of its value. Try pressing the throttle very quickly and stopping at 1/3 travel. Maybe with 100% focus you can do it, but it is very difficult to not overshoot how far you want to press it. Foot/ankle muscles are just not that precise (and I used to be a drummer). With the S.B. you don't have to press it fast and it is much easier to get the desired effect with a slow gentle push. It isn't that you can't replicate the SB with your foot, it is just far more effortless to do with the SB in place.