Just wondered if anybody who has a 4.2 S/C has had a remap?
Who done it? How much and the big question was it worth it power & mpg - I want to know all about it !!  Cheers Laurence.

A remap on this engine doesn't bring that much, maybe 20-25 hp at the most, not something you can feel on this car. Doubt also that there will be a measurable mileage difference...

Not sure what you are looking for in terms of power, but a different exhaust might also help due to it being more auditable and thus giving you more sensation. Manufacturers claim about 10-12 hp increase, but I have never seen a creditable dyno test. RRS SDV6 HEV Dynamic
XKR 700 BHP with Twin-screw and LSD

Spoke to Overfinch, JE Engineering & Superchips who all offer no more than 15 hp increase and all suggest its a waste of money on the S/C.

Exhaust and uprated supercharger are the options but they cost a fortune.

Smaller pulley and a remap is supposed to give around 40 to 50bhp? Cayenne Turbo "S" 521bhp Standard

www.bmw535d.co.uk

Doesn't that cost circa £4,500 though?

That's a bit of a different outlay that £500 on a remap

Pulley and remap wont be costing me £4500. Pulley and remap £500 or £600 tops. After all it is an old DENSO ecu not rocket science Cayenne Turbo "S" 521bhp Standard

www.bmw535d.co.uk

Ive had both remap and pulley done with the supercharger & inlet manifold ported ... it has made a big difference. It does push the power further up the rev range so you do tend use sport mode often to keep the revs up.. but it leaves a standard s/c for dead  2006 RRS Supercharged
Hawke Saker 22" rims Nitto Tires
Larini exhaust System
ECU remap
Modified and ported supercharger with 3lb pulley

which pulley. 1.5 or 2.5psi increase? I am going to go with 2.5 psi increase and fit a larger flow intercooler pump and maybe look at flowing the inlet manifold and supercharger. Inlet temps seem really high. need to get these down to make good power. Cayenne Turbo "S" 521bhp Standard

www.bmw535d.co.uk

Hi Paul,

You might also have a good look at the intercooler piping, you will notice that there are just very small openings for the return flow from the intercoolers. Then on some vehicles the +/- cables are swapped for the intercooler pump, so they are operating already at a reduced volume because of this.

Here is a link for the bosch pump (bosch partno: 0392022002) that flows about 10% more than the stock one (their pretty cheap):
http://www.siliconeintakes.com/product_info.php?products_id=1001

Can't do that much more about the heat though, its inherent of the (h)eaton design, its just not build for high pressures, only way would be (besides swapping the heaton via alky kits or so.

Would be interesting to see before and after dynos. RRS SDV6 HEV Dynamic
XKR 700 BHP with Twin-screw and LSD

Thanks for that. I will look at the intercoolers.

how do you mean +/- changed?

Yes I have read lots re the heaton

I can do before and after. the local guy is pretty usless working with autos but I suppose it will give a base line and if i work on ATW figures only it will be good enough.

His rolling road worked out my 535d had 8% tranny losses ( BMW quote 18 to 22% losses), yeah right that is more like a motor bike  Cayenne Turbo "S" 521bhp Standard

www.bmw535d.co.uk

The plus and minus leads where switched. I noticed this as the new large pump I wanted to install didn't run properly, there is also a TSB for this with the vin range of affected cars, but can't remember the number.

Drive train losses also depend on the dyno type you use, ie the small dual drums per wheel ones have more drag, and will thus give lower whp figures/so higher losses. I know that in Germany these types are popular. If you use the (better imho) large drum per wheel dynos you get much more realistic whp figures, but of course here the losses are lower.

Which RRS do you have now? RRS SDV6 HEV Dynamic
XKR 700 BHP with Twin-screw and LSD

ciaa wrote:

you do tend use sport mode often to keep the revs up.. but it leaves a standard s/c for dead

avos wrote:

The plus and minus leads where switched. Which RRS do you have now?

Ahh I see.

Dont have one yet. BM up for sale will get one early next year

http://www.bmwland.co.uk/forums/viewtopic....55#p979855

You will have to excuse the muppet who stole my thread  Cayenne Turbo "S" 521bhp Standard

www.bmw535d.co.uk

ciaa wrote:

Ive had both remap and pulley done with the supercharger & inlet manifold ported ... it has made a big difference. It does push the power further up the rev range so you do tend use sport mode often to keep the revs up.. but it leaves a standard s/c for dead

How are you doing pulley and remap for £500 - £600 ?

Id like to know more about where i can get the bits, if its a DIY install for that price and so on, 40bhp for that cost is awesome.