Airbox mod

[mavada]

http://www.youtube.com/watch?v=8ab098jYH_Y

[Hedgehog Dodger]

I have got a sharp stanely knife and some K&N filters lying about in my garage if someone wants me to have a go at their bonnet and shove on the filters on.

Seriously though heat soak cant be that bad but I am no expert.

Subaru mount IC's above a flat 4 turbo and exhuast manifold. There are plenty of V6's and V8's which use induction kits/filters etc.

[Mr Footlong]

'cough' having owned 3 Imprezas in various states of tune, I can tell you that the intercoolers heatsoak like a total bitch if you sit for any period of time and you have to be doing a nice speed constantly to keep them running half decently. Did both FMIC and Hyperflow monster top mounts on mine. The amount of heat that the boxer engines kick out pales in comparison to these and with the 2L boxer engines at least to me, there is a tad more beathing room in the bay. There is simply nowhere for the heat to go on these IMO. Fit an engine in that fills up the entire bay then cover it with an undertray and you get the idea.

Mav, like the filtration setup but not liking the placement of that top fmic at all in that vid. If they are running those in normal single intercooler to turbo setup then it will be virtually impossible to get equal airflow/cooling to the top rad. The difference may not be enough to warrant concern but I wouldn't be sleeping at night knowing that had been set up that way on mine.

[JCviggen]

edit nvm..no point replying to something written in feb

[Hedgehog Dodger]

'cough' having owned 3 Imprezas in various states of tune, I can tell you that the intercoolers heatsoak like a total bitch if you sit for any period of time and you have to be doing a nice speed constantly to keep them running half decently. Did both FMIC and Hyperflow monster top mounts on mine. The amount of heat that the boxer engines kick out pales in comparison to these and with the 2L boxer engines at least to me, there is a tad more beathing room in the bay. There is simply nowhere for the heat to go on these IMO. Fit an engine in that fills up the entire bay then cover it with an undertray and you get the idea.

Mav, like the filtration setup but not liking the placement of that top fmic at all in that vid. If they are running those in normal single intercooler to turbo setup then it will be virtually impossible to get equal airflow/cooling to the top rad. The difference may not be enough to warrant concern but I wouldn't be sleeping at night knowing that had been set up that way on mine.

Yeah I see what you mean. There is no space at all in these bays. Even with the new GTR there is still room to put a blade of grass in somewhere granted they're a V6.

Boxers are incredibally hot. I remember Andy Forrest running his Impy with a huge GT40 turbo and no IC. Top mounted running straight into the inlet. Immense!!!!!

[Mr Footlong]

Andy makes some niiiice turbos, have bought 1 or 2 from him over the years

[perthwaRS6]

From my experience, the C5 RS6 does suffer from significant heat soak and loss of power when standing still or in slow traffic.

I found on a chassis dyno that on runs 10 minutes apart, the whp dropped by 20 whp on second run due to increased intake air temperature. This was due to the dyno fan being centrally mounted keeping the main front radiator relatively cooled, but not the intercoolers as not blowing enough air through the intercooler vents to the side mounted Wagner intercoolers (no fog lights).

Audi have found the solution to the C5 RS6 heat soak and incorporated this into the C6 RS6. If you look at the front of a C6 the intake vents are larger than for the C5. I believe the intercoolers may also be a little larger in area.

More importantly, I believe the solution to preventing heat soak at times of no or very little airflow (idling or in slow moving trafffic)- is the very large circular intake fan mounted on the front of each intercooler. These run on start up and give the C6 its characteristic 747 whine. On the same chassis dyno as the C5, multiple runs of the C6 showed no loss of rwhp.

It would appear logical to prevent heat soak from starting as then gets harder to remove it.

Same on the drag strip with the C6. No heat soak and same quarter mile times, even with ambient temp of 39C on consecutive runs 10 minutes apart.

If there is room in the C5, then kenlowe or similar type fans mounted in similar way in front of the C5 intercoolers as per the C6 could be a better solution than modified air boxes for no or slow air speed movement.A bit more power drain for the electrics- needs to be checked.

Once you are moving, then assume sufficent air flow to reduce/remove heat soak. Water-meth injection is obvious alternative solution, but you need to keep filling up fluids. Extra fans would appear to be less intrusive to manifolds, etc.

water- meth injection is another soultion but need to mess with manifolds and fluid fill up. Extra fans should be less intrusive.

Just my two cents worth.

john

AUDI RS6 C6 SANS ENGINE SHOWING INTERCOOLERS AND FANS

[perthwaRS6]

yeah the jubilee is too thight...ive had similar when i bought it, got them replaced by new ones...can be fixed with hairdryer...just to prevent (if so) leaks...

I had same problem.

My indie got it back into shape with hair dryer, thanks to mavada post.

As the inlet plastic duct is very soft, especially with the high underbonnet temps, to prevent future collapse, he installed ~1cm wide thin metal tube sleeve inside the plastic tube at location of collapse point, so as to maintain shape. Now can tighten the clip and no collapse or leak.

john

[Hedgehog Dodger]

I found on a chassis dyno that on runs 10 minutes apart, the whp dropped by 20 whp on second run due to increased intake air temperature. This was due to the dyno fan being centrally mounted keeping the main front radiator relatively cooled.....................water- meth injection is another soultion but need to mess with manifolds and fluid fill up. Extra fans should be less intrusive.

Just my two cents worth.

john

AUDI C6 RS6 INTERCOOLER FANS.JPG

Makes sense but I think dyno runs dont give the same results are real time driving. A car moving at 20mph+ will surely create a stream of air that will remove the hot air from the engine bay, and cool the intake temps in the process. Going back to the engine fans, When I was Modding my MR2's engine fans were used to remove air from engine.




I wonder if there is anyway of adapting these to fit under the bonnet of an RS6. (never seen under a bonnet of an RS6 before I get shot down in flames.)



Many old muscle cars had open carbs above the V8 or filters



I know the above photo is not running any forced induction but surely still suffer from heat soak.

Edit due to me being a.....

[chunky79]

Fan's covering the intercoolers? Sulrely they will block as much air as they will produce when you are travelling at speed, no? I understand that at staionary or very slow speeds they will be great but looking at the C6 above the actual motor covers upto 30% of the coolers!

Love the above motor Jammy dogger

[Hedgehog Dodger]

Love the above motor Jammy dogger

MGV8...best motor ever built. apart from the RB26

[Shoppinit]

Looks like the one in my Rangey. Except for the carbs, of course

[mavada]

[mavada]

The RS 6's four-wheel drive gives it a healthy advantage at every start. We tested the acceleration of all the cars to 60 mph. The other rear-wheel-drive cars got there in about four seconds, but the RS 6 was in another league—the best time achieved by hired shoe Michael Galati was a stunning 2.7 seconds. As a result, during races the RS 6 usually leads the first lap.

But the Audi guys are quick to point out that that advantage also comes with a major Achilles' heel: poor weight distribution. To make room for the four-wheel-drive components, the RS 6's twin-turbocharged engine must sit far forward, so the car has a greater percent of weight in the front than the other cars, which hurts braking and cornering performance.

Audi has created something of a legacy in World Challenge, winning the 2001 and 2002 drivers' championships with Galati driving an S4 and the 2003 drivers' title with Randy Pobst in the RS 6. It's an impressive record considering the series tries to make sure one car doesn't dominate. So the paddock is filled with speculation: Are the competition adjustments skewed to favor the Audi? That, of course, depends on whom you ask. We don't think there's any favoritism, but there isn't a clear answer and the record does make one wonder.

The RS 6s were built by Champion Racing, a race shop and car dealership in Pompano Beach, Florida. Although Champion would sell an RS 6 to another competitor, so far, no one's asked, and the two Audi-sponsored cars are the only ones in the series. Each costs about $210,000, much of it the result of preparing the car's unit body. To make the body stiffer, the areas where two metal panels meet are carefully seam-welded. The engines are built by Cosworth and make 525 horsepower, just 75 more than you'll find in a standard RS 6. Champion's RS 6s use larger intercoolers and radiators, but the turbos are stock, as are most of the engine internals.

The RS 6 found at Audi dealerships has an automatic transmission, so the race version has to make do with the six-speed manual from the Audi S4. Even though that transmission was not designed to handle 525 horsepower, it has been surprisingly reliable. The same can't be said of the ball joints, which wither under cornering forces and must be replaced every weekend—at $1000 a pop. That's a pitfall of racing based on production cars: Parts are used that were not meant to handle high levels of stress.

The carbon-fiber body has fender flares that jut out 1.5 inches beyond the stock fenders at every corner, to make room for wider tires. Those flares increase aero drag, so the team has tried to compensate by experimenting with different front fascia designs. "What you see today is revision No. 45," laments crew chief Louis Milone. There's not much a front fascia can do to change the fact that the RS 6 punches a huge hole in the air.

And it felt big and burly on the track. Whereas the rear-drive cars required precise driving and careful throttle inputs, the RS 6 felt a little more relaxed and compliant. The steering, the brakes, and the clutch all had a light feel, and with the traction of four-wheel drive, we could just stand on the gas and rocket out of corners.

If we punched the gas too early in the corners and before the car had straightened out, the rush of power would cause the car to dramatically move off the intended line. We've never been in a car that slid so easily into perfect four-wheel drifts. Rather than carve through a curve, the RS 6 preferred a more aggressive approach. It was more like throwing it into a drift and jumping on the gas as soon as it straightened. "Fun" doesn't begin to describe how it felt.

But sliding will eat up lap times, so Galati had to resist the car's natural tendency and keep it more locked to the pavement. We'd be happy to struggle with the assignment.

[Mr V10]

Cool, decent read. There is no way they are the standard brakes I spy there though, are they?