MRC Magic!

[iR8V10]

Got to Surrey Rolling Road today and crashed the end of a BMW forum meet. As you can imagine with the updated results below, I wasn't popular!

504.3 BHP, 517 lbf. Torque (700Nm)

Feels great to have broken that 'illusive 500'. Charlie sprayed some water on the intercoolers for the last run, did the trick!

I'll post up the printout later, thanks again to Lucas and the boys at MRC!

[grizz]

How much more did the water make ?? I'm thinking about a water spray for the ic's

[BigMo]

think the saying goes 2bhp per degree drop in temp

[iR8V10]

1st run 485 ish, 2nd run 470 ish

Sprayed with water once....498

Sprayed once again...504.3

Made a real difference, this offset the fact that rolling road cooling won't be as good as on road, but a definate boost none the less!

[hahnmgh63]

On the street you have air flowing over the intercoolers, on the dyno, a fan helps but really only a few mph of direct airlflow compared to the street. Water makes a huge difference on the dyno but from what I've seen, unless it is a hot day and your talking slower speeds, not as big of a difference on the street on most cars. Water does conduct heat around 23 times better than air if I remember my physics correctly.

[ecain63]

Interesting. Grizz, maybe you could develop some sort of water spray system for these cars. An untapped niche possibly? Could be a little earner.

[Stuart6587]

I had a Subaru Impreza WRX about five years ago that I hill climbed which ran at about 320bhp. I noticed that the STi versions ran an intercooler spray which on the early versions was a manual version with a switch whereas on the later ones it was automatic. I decided to make a home made one and rerouted the water from the windscreen washers(which were never used when hillclimbing) via additional tubing and wiring so that I could manually spray water on to the intercooler. BHP would increase depending up the conditions by up to about 25-30 bhp, i.e. about 10%, so most definitely a worthwhile modification.

Designing and producing an after market kit would not be difficult and you can find them for sale, see here on eBay:

http://cgi.ebay.co.uk/Intercooler-Water ... 1|294%3A50

[LucasRS4]

Doug has just put water injection/water mister on his RS6.

[Daveperc]

I woulds have thought that injection would be more effective than simply spraying the intercoolers as it would take more energy (heat) out of the air, and thus create a denser charge.

I had WI on my old SAAB 99 2Dr Turbo, a factory kit that linked in with the wategate etc to raise the boost by about 1/2bar when activated. It only kicked in when the boost reached a pre-set level (just below normal full boost, and there was quite a delay when it came on (accompanied by a satisfying whine from the WI pump, and then the boost suddenly rose and the power was there. Took a bit of getting used to, especially in winter when the sudden changes in power through two wheels on snow and ice made for intersting moments, but was a good system.

Pretty sure there are some old threads on here where others have fitted kits before. Main problem I think would be finding space for the water tanks (the washer system is fairly small compared with what you really need, and the challenge of integrating it with the ECU etc - but then I guess that's where Doug's skills come in.

Could be fun though

Dave

[TIMSRS]

Did it make much improvements to Dougs 6 ????

[iR8V10]

...

[S2tuner]

I love the torque curve, nice and FLAT, yours is a really good one Dave. At least our maps don't need decats to get the BHP we claim

[Golfather]

S2tuner, How come the BHP and torque drop off after 5500?
I thought the RS6 turbos flowed a lot more volume over the K04's on the RS4, yet that peaks at the redline?

Can the value be adjusted on your custom map?

[S2tuner]

golfather, RS6s always make peak power around 5500, after that boost starts tailing off because of the turbos being too small for the 4.2l engine. On an RS4 it's different because there's a smaller engine to feed with the turbos, and you can get loads of power until the redline.

If you get a full exhaust with decats, you can get a bit more power higher up, but the RS6 engine itself is made in such a way that high RPMs flow isn't great great, so you'll rarely see peak power at 6000 RPM IMHO and IME.

HTH,

Mihnea

[Cornishmoocher]

I love the torque curve, nice and FLAT, yours is a really good one Dave. At least our maps don't need decats to get the BHP we claim

So, Who's maps do........?