xBMWx

I've had my Smile Booster (from the E60.NET Group Buy) since the end of April 2008 and loved it from day one, like so many others here in the forum. As with all mods, you get used to them after a while and just take the performance for granted.

My car is in for a Service at BMW today, so I took the Sprint Booster (S off to be on the safe side... and I WAS SHOCKED!! I really cannot believe how much slower the car reacts without the SB. I even did a throttle reset to sharpen up the response, which helped a little, but its still a long long way away from the response times I'm used to with the SB.

The biggest delay is when you are cruising and then squirt the throttle for a quick boost in speed; with the SB the car always reacts immediately, however without the SB there was about a second (?) delay before the car started reacting. This is what really shocked me, I couldn't get over that delay and how much I had to push the pedal to get a reaction and in some cases it was too late. (E.g. you want to quickly pull out at a juntion, change lane, accelerate so someone can move into your lane behind you, etc.)

I bought the SB for improved performance and driving pleasure. I'm now thinking its also a good safety aid as it allows greater and immediate control of the car's speed, especially at low / idling speeds. Needless to say, I really do recommend the SB add-on to everyone here!

BigMike

I have a 520d LCI and thought that the delayed reaction when stepping on the pedal was due to the diesel engine's slow reaction....

So with the SB you don't even have that any more?

If so, maybe it's time for me to get one!

xBMWx

The 520d struggles a little below 1800rpm because this is where the torque and power starts coming in, however I have been informed that the LCI 520d deals with this much better now. On the LCI 525d the max torque is already there with 1300rpm.

That said, the SB will none the less still provide a quicker response from the throttle and in turn the engine. You will see an improvement, especially if you have the automatic where you have less control over the revs.

Rizbel

I've taken my car to the dealer for warranty work twice without taking the SB out. They never mention anything about it.
The SmileBooster will stay on for as long as I own the car (and the wife says it's OK )

smarty156

xBMWx - I've got an E61 530D (218bhp version) and I'm getting fed up of the time lag issue.
I thought about an SB but I was worried that the slightest touch of the throttle would make it change down rather than using the torque of the diesel engine. How do you find this? I don't want it to be constantly dropping gears whenever I press the throttle. On a motorway that would be a real pain.

RJH&CO

how do you reset the throttle?
I need to do that.

xBMWx

After a day or two, you and the self-learning throttle will have adapted to the SB. After a month or so it will have become second nature.

With regards to motorway driving, you are absolutely correct; you want to use the diesel's torque and not have it dropping down a gear the whole time, which it will do with the SB. I travel about 1000km per week on the autobahn alone and get round this by putting the car into manual mode. This works just fine, because if you do want to drop down you either do a quick flick of the shifter or use the kick-down function.

As I wrote in my first post, having driven with the SB for a number of months and got totally used to it, and now having driven without it, I can't believe how slow the car responds without it -- and will not be driving it without the SB. (And this is coming from a leased company car driver, who is very risk adverse when it comes to mods!!)

xBMWx

Here you go:
(This works on all BMWs)

1) Put the key in and press the start button / turn the key so that all power is on, but the engine is not on. With the auto you do this by pressing the start button, but not putting your foot on the brake.

2) Push the throttle down past the kick-down point to the boards and hold it there for 10 seconds (- I typically hold it there for 15 or so)

3) Finished! You can start the engine and drive.

You will have now reset the throttle and it wil be more sensitive, i.e. react quicker. The "learning" process will start from that point, so I typically try to drive agressively / heavy footed for a while, so that it learns to have a quick response. Over time it will become slower, because you will not always drive foot to the floor, and it will learn to react slower. When it becomes too slow, just do a reset.

smarty156

That's what worries me. I do have the paddle shift conversion so switching to manual isn't such a hardship but sometimes you just don't want to. Having said that, if I'm cruising at 80mph in 6th it seems if I ever want to speed up it always drops to 5th anyway as it is.

I've got other issues that need resolving first (hesitancy and juddering on a light throttle) but once they're sorted I might give an SB a go. Wonder if anywhere in the UK will let me return it if I'm not happy?

xBMWx

You can buy SBs all over the place, should be able to find one in the UK via a Google or Ebay search.
I purchased mine via the E60.NET group buy because it was discounted and the crazy Euro - Dollar exchange rate -- It was the same price in Dollars as I could get it here in Germany in Euros!