Autoblog Night Watch: Audi RS4 Hillclimb
This ground level POV video comes courtesy of the German Car Blog, after discovering that the AudiBMW.com Audi RS4 had set a new ITE class record during the Duryea Hillclimb in Reading, PA.
The massaged, 2.7-liter twin-turbo V6 provides a delicious aural soundtrack, particularly when the driver lifts off the throttle and the blow-off valve expels unnecessary exhaust gases.
Click the 'read' link for the full account of the record breaking run, as told by the S4's driver.
Reader Comments (Page 1 of 1)
Ford Mustang 1:47AM (9/11/2006)
That's pretty good. Reminds me of Gran Turismo. Too bad it wasn't in car.
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Nathan Sweeney 2:03AM (9/11/2006)
That is one sweet sounding engine.
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Fabulo 3:18AM (9/11/2006)
This is pretty amazing. The whole thing sounds smooth and effortless. The course layout lends itself to that.
For comparison (and a totally different beast) take a look at this R8 hill climb, all jerky and scary. As much as the RS4 was smooth and soothing, the R8 is jerky and ennerving:
http://video.google.com/videoplay?docid=6184680728064832823&hl=en
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Peter 3:30AM (9/11/2006)
Cool. A BOV sits on the intake side BTW, to relieve the pressure that would otherwise slow down the turbo when the throttle closes.
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Peter 3:38AM (9/11/2006)
"For comparison (and a totally different beast) take a look at this R8 hill climb"
Great drive. However that's no R8, but this guy in a Norma M20 (3l BMW engine):
http://perso.orange.fr/castellanacompetition/
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Cameron 3:40AM (9/11/2006)
#3:
For sure the R8's going to be less composed than the RS4. Most likely it rides much lower, has much stiffer suspension and has far less suspension travel.
Was the R8 fitted with a different engine? That sounded a lot like a V6 or V12. R8s normally run a flat-plane crank V8 that sounds like a hyperactive 4-cylinder.
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Cameron 3:41AM (9/11/2006)
Thanks for clearing that up, Peter.
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DPC car videos 4:14AM (9/11/2006)
Great video, I got nervous just watching that.
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Jimbo 5:07AM (9/11/2006)
When the throttle body slams shut the BOV works to relieve the pressure which would otherwise return to the turbine, slowing or stopping it. This is good for performance but equally as important, the returning pressure wave, if not released, will significantly shorten the life of the turbo bearings. Plus it sounds cool.
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Cactus Jack 5:18AM (9/11/2006)
#3, #6
It's no wonder a real racecar behaves that way. After a certain point fast laptimes come from aerodynamics creating downforce, which allows greater corner speeds. In the beginning of that "R8" video there are couple of fast turns, and the driver just yanks the wheel without lifting the throttle. The car just turns sharply, and that's something you can't do on a station wagon, even if it was RS4 Audi. As long as the racecar has speed, it sticks to the road like lane markers. In those slow hairpins he just loses the downforce as he has to slow down and with a light car, stiff suspension and no downforce the tires don't have much grip. In slow speeds it's not very dangerous or scary to have a little slides, however it will hurt the time. Those two cars are just very different and their behavior reflects the way they have to be driven.
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AndyH 7:11AM (9/11/2006)
If you follow the "read" link and look at the car's spec sheet, the car started life as an Audi S4, not an Audi RS4. Granted, it's one highly-tuned S4...but still. Anyway, great video and congrats to the driver for breaking the 2:00 mark!
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Craig Thomas 7:13AM (9/11/2006)
Great video - fantastic sound. So I feel almost churlish in pointing out that it's an S4, not and RS4.
The new RS4 has a 4.2-litre V8 and is an absolute beast of a car (are they on sale in the US?), so I wonder what it would do on the same hillclimb...
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epilonious 7:49AM (9/11/2006)
"particularly when the driver lifts off the throttle and the blow-off valve expels unnecessary exhaust gases."
Correct me if I'm wrong... but I'm pretty sure blow-off valves and bypass valves on conventional turbocharged systems deal with overpressure in the INTAKE system... venting raw exhaust (especially in lots of sports cars that work on cut-spark-not-fuel type speed control systems) into an engine compartment seems rather silly and dangerous.
I'm not saying they are the best source, but wikipedia agrees with me: http://en.wikipedia.org/wiki/Blowoff_valve
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Matthew Fortner 10:38AM (9/11/2006)
Correct, the BOV vents excess intake pressure. A wastegate controls the exhaust gas flow that spins the turbo. A properly plumbed wastegate is routed back to the downpipe of the exhaust.
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Big Al 11:37AM (9/11/2006)
Excellent video. The driver was very smooth and controlled, unlike the "stab 'n stomp" jackass from that Ferarri vdeo last week.
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MikeW 6:45PM (9/11/2006)
http://en.wikipedia.org/wiki/Audi_RS4
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John 5:20AM (9/13/2006)
That's one awesome video and driver; and an overall clean run. I love doing this sort of stuff on my M3. Too bad the roads, around my area, are a whole lot narrower than those on this video. It's still a lot of fun to do some quick hillclimb and downhill driving.
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Bob 1:01AM (9/19/2006)
The BOV prevents overboost in the intake from reaching the engine and is probably not making any noise or even functioning in a well designed turbo system. That's because there are better ways to prevent overboost and a BOV is usually the last resort safety valve. The wastegate prevents damage to the compressor wheel on the intake side/cold side that could occur when the throttle plate closes and causes a reversion pulse in the column of air between the throttle plate and the compressor wheel. When the wastegate opens, it diverts exhaust gases that would otherwise pass through the turbine (hot side) and maintain the force on the compressor wheel. This relief of pressure on the turbine wheel is what saves the compressor wheel from the reversion pulse. The rushing of exhaust through the wastegate is the sound you hear. The wastegate ideally is vented to the atmosphere to make max power, but in a street car must be routed back to the exhaust system so it passes through the emissions devices.
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Bill III 9:11AM (9/20/2006)
Believe it or not I just found this Blog today for the first time. I am the owner and driver of the 2000 World Challenge Spec S4 in the video. Just to clear a few things up. Yes, the car started life as a US model S4. The car had 0 street miles when it was built to its current configuration. It does have full real European RS4 body panels and bumper covers.
As for the BOV they are from Turbo X/S and they do vent to the atmosphere. Some of you that have already written have said better than I can, but I will say we did dyno testing and we choose this setup.
As far as the suspension it is very stiff, in fact for hills probably to stiff. We run 2000lb springs in the front and 1800lb in the rear. "Cactus Jack" said it pretty well when he talked about the difference in aerodynamics. An S4 is not a down force car and an R8 though an incredible purpose built machine was not built for hill climbs. Not to say it is not an amazing video that is just not what the car was designed to do. Remember also that Turbo charging and AWD is the ultimate Hill Climb setup. I do not mean to get into a huge argument with others who have very fast and capable Hill Climbs cars but the advantage of AWD and Boost has been proven many times since the early 80's. The video you just watched was of a 3150lb 4 door that went up the hill 5th quickest of the weekend, only behind 3 formula cars and 1 tube frame 1900lb 600HP Sunbeam Tiger. Remember also, in the rain I always have FTD.
I hope this helps, if you have any more questions just ask. Now that I found this site I will check it often. Quattro has always ruled the Hills and always will.
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