I hate the hesitation of the engine starting from full-stop (zero mph). I get very little power before the engine revs and spools up boost. Short of revving high from a dead stop, which is too much boost (and hard on the clutch), what mod can I do? In a N/A car this phenomenon would feel like the fuel was cutting out or an engine miss (neither of which is my problem).

I currently have the stock pulley and will probably make a 15% or 17% change soon, but will that really help the low-end get started boosting sooner? And if so, how much? In another post of someone's upgrades, he listed some gizmo that cured his throttle lag-time - but it was around $300!!!!!! BMWs have always had a slight throttle lag, but I'm not sure if this is my main problem.

I've changed my driving habits a bit to adjust to this delay, but is there something else I can do?

 

I have no crazy data-log to prove this point, but I felt my car lagged off the line too, and while I did many upgrade, I felt that freeing up the exhaust (one-ball) made the biggest notice-able difference in off-the-line-lag.

This was measured on my highly inaccurate butt-dyno :-)

just FWIW...

 

My car isn't that fast off the line when being nice to the clutch...pick a mod, it won't help at 1500 rpm. Our little engines just don't make power there and aren't supposed to. With AC on, it is really noticable, but then again, so was it in my 7.7 litre pontiac. Whatever you do, it may help, but really, you are never going to feel it is enough without RPMs IMO.

 

Went ahead and did the one-ball mod today. Cost too much, but I was there and didn't want to screw around with trying to find $30 cheaper. $115 out the door.

I won't know of any performance gains until I burn through a tank of gas. Doesn't sound particularly louder from inside the car.

 

Congrats. I found that throttle response was much improved. Which includes off the line.

 

Sprint Booster is well worth the money and made a big improvement in both my cars.

 

If it worked for you that's great, but it is basically a faulty bandaid to cover up the real issue. I do not want to start a war here about it, but for hard driving (track, autox, etc) also, longevity. I'd avoid the sprint booster

 

You have to also consider the fact lag is partially due to our engines producing very low torque numbers at idle. Takes a bit more RPM to get them moving, whether you do it quickly and hit boost or not.

 

I've drove many manual transmission cars in my life and none of them has had a stall as bad as my 02 Mini S 6 speed from the start. I installed a sprint booster and that problem went away. It will def. bring a smile to your face. It's like the half throttle on my Hayabusa now. Takes getting used to but well worth it in the end!!!

 

Your review of it, as well as others', makes me believe that it works. But, it's most likely nothing more than some $.99 circuitry, and paying $300 for something like that just goes against everything American in me. I'm always happy to pay a fair price for something; to pay a fair amount for some other person's expertise or talent. But this "Sprint Booster" thing can't cost them more than $5.00 in parts. I don't feel the "technology" is worth $295.00 (or even $95.00) no matter what it does.

 

I agree with you 100% I got mine from a salvaged car for $60.00 Lucky me!!! They are out there and on Minis in junk yards and most junk yard owners don't have any idea what they are nor what they are worth.

 

Read the article on their own site: http://www.sprintboostersales.com/whyitworks.cfm

again glad it works for you, but you can get the same effect by simply putting in more throttle.

So what they are saying is when you have (for example) 10% throttle input, it makes the engine behave like it's at 15% or 20%...

 

dont waste the money on the sprint booster. get yourself a 15% pulley and intake to go with if you dont have one already. everyone is going to have their own thoughts about it. buuut f you really want to get rid of this "lag" find out a way to get rid of the drive by wire and use a traditional throttle cable.