[MiniFr34k]

Hi Folks

Another n00by question from me

Just wondering if there are any serious/long term ill effects with running a 15% pulley on 'stock' software. Will this lean it out too much?

By 'stock' software, i mean that it is a MTH tuner file, tuned specifically for all my other mods EXCEPT the pulley.

Since the pulley addition, performance is fantastic (wheel spin of first and second lol), but more importanly, fuel consumption has improved significantly.

Iam now clearing 450kms a tank, where as i was struggling to meet 400kms a tank previously.

Cheers.

[Eds]

That's the same question that has been bothering me for a month now since I had my pulley done (stock software with 15% reduction pulley) that is why I have decided to order the 93+ Shark Injector.

Although Mini of Richmond, Canada said that it should be fine as long as I use 93+ octane and after checking the spark plugs for signs of running too lean (hot spots) which is not, I'd rather protect my investment and enjoy the extra HP & Torque that the upgraded ECU will provide.

[obehave]

There were hundreds of folks, myself included, running a 15% before there were ever remaps available.
No lean conditions and no problems even on track cars.
Probably hundreds of thousands of miles done collectively .

[MiniFr34k]

cool thanks for that

[Capsaisin]

Be careful, stock software DOES NOT MEAN MTH TUNER FILE!!!
People may assume you have stock software, meaning standard BMW file. This is OK to run with a 15% pulley with stock BMW software, but it is not clear that this is what you actually mean .
I would not be so sure that running a 15% pulley with standard MTH tuner file would be OK as the MTH removes some of the "safety" margins built into the BMW software in order to extract more power.
Adding a 15% pulley to a standard MTH tuner file could push the engine outside of safe limits. I would certainly not risk running this combination without professional advice.
You should get further advice from MTH, they can upgrade your tuner file for free if you bought it within the last 12 months.
Alternatively you should have a word with Roland at GTT, they use MTH tuner files and will be able to advise on any problems with your combination and also advise you on any further minor modifications you might require to ensure you engine is correctly set-up.

[greyghost2004]

15% wil eb no issue with the stock software. Ive seen guys run up to 17% without any issues. It could perform better with new software but it is not a safety issue.

Mark

[MiniFr34k]

Thanmks for the feedback.. ive since uploaded new software and loving it

[TallAndy]

I thought you could end up with a cracked cylinder head running a 15% pully only with no other mods

[Capsaisin]

I believe there was some confusion over what MiniFr34k was actually asking. But I think I have at last discovered the answer to both possibilities.

You can run a 15% reduction pulley with stock BMW software - no problem, especially if you use colder plugs to be safe.

You CANNOT add a 15% reduction pulley to a stock MCS running stock MTH tuner file. You MUST get your MTH tuner file updated.
I now believe this is because on a stock MCS, MTH use a lot of timing advance to get the extra power. If you now add a 15% pulley, the timing with the stock MTH tuner file will be TOO advanced and you risk engine damage.
So you have to get a new map for your pulley, presumably with a less agressive timing profile.

[roland2003]

Well explained Capsian. Yes the extra advance on the mth map for stock size pulley will be too much with the smaller SC pulley. Its often tempting to run too much advance, as with a little stab of the gas in second gear may not get it to pink, and will give more 'snappy' performance than a map with less advance ,in these 'undemanding conditions'.
Nailing it in fifth or sixth with the sustained high loads that comes with it though is very different. You need to test every car at WOT to near max revs in at least 4th gear at least 3 times in close succession listening very carefully for pinking or worse.
Stock (ie bmw) is fine with -15% pulley but use 98 Ron.
Best Regards Roland GT Tuning

[Perm]

Roland,
If this is not a commercially sensitive question.......
Who do you trust for mapping your cars?

Perm

[Capsaisin]

Quote: Originally Posted by roland2003

Well explained Capsian.

Well credit where credit's due Roland. I sort of knew the first bit, but I admit you put me on to the reason you can't run the standard MTH tuner file with a 15% pulley.

[minigolf]

Pete, I'm a bit slow off the mark buddy, what pulley are you running and so on?

[MiniFr34k]

Liam - you';re alot quicker off the mark than iam, trust me lol

Running 15% right now. 2% yet to be installed, so its a paperweight for the moment.

[St00ge]

a very light paperweight

I ran my 17% on my car with the "stock tuner" MTH file for a couple days, and my car seems to have survived ok. Now that i think about it though, i shouldn't have done. But i wasn't really thinking.