I actually have the sprint booster in my 335 BMW coupe. The car's an automatic, and it helped immensely. I used to get so annoyed when passing in normal drive, that I found myself always using the sport mode and paddle shifters.

So in normal Automatic mode, it actually works by reducing the lag a lot. I'm not referring to the turbo lag, that's still there. It's not bad, but the two together in normal auto make the car sluggish when passing.


That's the good, the bad, is your fuel economy drops. *Not just me but a friend has it in VW GTI, and another in his 550 bmw.

Don't ask me why, but since I installed it, I lost about 2mpg. I used to get a combined 24.3 in that car. Now I get 21.8-22.2mpg. Same driving style, same shift points, same roads etc. I'm not sure what changed. All I can think of is that it revs sooner, and holds the rpms up which in turn burns more fuel??

Also, when the car's in sport mode using the paddle shifters, i can't tell a difference at all.

Which in theory leads me to believe the ecu runs a different map or something in sport mode on the BMW. Changing the pedal response and shift points.

Now with my Nismo and a 6spd, I think it would be wasted money.
But if you have a auto trans, its worth it.

YMMV....

I had the sprint booster intalled on my RX-8. It had a button that let you change how reposive you wanted the throttle to be. From normal to aggressive. It works to a degree, but it won't make the car any faster or free revving. Cuts maybe a few milliseconds off since it's already sending a signal before your foot goes down or something about the voltage. I can't remember which. I personally don't think the Z really needs it and money can be better spent elsewhere for real power gains.

I don't expect the device to increase the power, but I do want a much faster response to my right foot action. Right now, it's especially frustrating when blipping the throttle for a downshift. My Honda Element is much more responsive in this regard.

The latest version of this product offers 3 different settings. I'll probably find that the middle setting will be just fine for me.

I agree. The most aggressive setting is way too sensitive and your passangers will hate you for it. It's a pretty easy install by the way. You just remove the pedal and install the device before the harnest. Easy to take off in case you need to have warranty work done.

Sprintg Booster
 

I does what they claim I have one installed

From what I read, yes, it just makes it a hair trigger. Actual response is unchanged, you just don't have to move your foot as far to get the same response. A proper tune should eliminate these issues. $20 in parts being sold for $330 is a bit much for so little.