NEW STOCK RS4 1/4 MILE RECORD - 12.75 @ 108.36

[sakimano]

Originally Posted by gibsonl Hey Arthur, how can you be back to assuming that carbon is a myth? I posted my pre and post dyno runs which were a 30whp+ difference. The dyno was by an independent shop who had nothing to do with the cc. I don't think anyone who actually owns an RS4 still contests the existence of carbon. And to say that a lw clutch and flywheel is insignificant ... Are you kidding me?! I'm guessing you've never driven a stock car vs one with a lw setup. Arthur didn't say carbon doesn't exist. He just thinks that it isn't as big a negative as many others do. I agree with him to a certain extent. I think it's robbing the cars of some top end, and I think it's a dangerous hard substance to have so near the combustion chamber (scored walls on these alusil engines = new engine). However I don't think it's a massive negative that kills performance of the car. The biggest negatives when it comes to RS4 performance are 1. conditions - driving in terrible DA your car just flat makes less power. End of discussion. BaddriverRS4 went to Atlanta Raceway in 80 degrees of heat, at some elevation and wondered why his times and MPH were so ****...then went on a rampage accusing guys with faster quarter mile times of being liars. SHows us two things . First, he doesn't understand the effects of conditions on an NA motor. Second, he shoots before aiming. Both mean we ought not to listen to him. 2. driver - there are a few things you can do to **** up your RS4's ability to accelerate. The first is launching it poorly. BaddriverRS4 was launching at 2000 rpm. Bang. That causes bog, and that ensures he will never launch the car well. You need to be up around 3000 rpm, then try various levels to launch well, but below 3000 is going to see you bog. 2000 will see you nearly stall. Once you get the car moving, your dyno, thrust curve, g plots all tell us that we need to shift to the next gear at around 7500 or so. Holding the gear to 8250 might sound cool, but it makes you slower. What do almost ALL RS4 owners do at the strip? Shift at 8250. So you now know why baddriverRS4 ran high 13s in his car, and why I ran 12.75. You notice I didn't mention carbon buildup in there? If my theory that carbon is most impactful at the top end of each gear is correct, it's 500-750 RPMs that I don't use at the dragstrip (and not many of us should be frankly) so I don't think it's such a big deal (7501-8250 RPM...before which I've already shifted to the next gear). Go compare your before after dyno curves. Area under the curve for the whole pull, especially top end, will show a gap but the peak vs. peak dyno number difference is pretty dramatic. Area under the curve from 5000-7500 is not so dramatic (and that's where you need to be during the quarter mile). When guys say 'I gained 30 whp'....they aren't gaining 30whp at 4000 RPm. They might be gaining it at 7800 RPM..where they shouldn't be at the dragstrip anyway.

[gibsonl]

Then I guess we'll just have to disagree. I did about

[gibsonl]

about 5-10 0-100s with BADRS4 before my carbon clean, we even swapped cars, and it was always the same result. My car got murdered from start to finish pretty thoroughly. After my clean it was the complete opposite. Once again we even swapped cars to eliminate driver variances. But unless you actually lineup a cc car vs a non-cc car yourself all of your theories are just theories.

[sakimano]

Originally Posted by gibsonl

about 5-10 0-100s with BADRS4 before my carbon clean, we even swapped cars, and it was always the same result. My car got murdered from start to finish pretty thoroughly. After my clean it was the complete opposite. Once again we even swapped cars to eliminate driver variances. But unless you actually lineup a cc car vs a non-cc car yourself all of your theories are just theories.

That's certainly interesting information. I think there has to be an inhibiting factor, performance wise from carbon. I just don't think it's as big as everyone makes it out.

Go to audizine or quattrofail and what's right at the top of theRS4 forum? A stickied thread about carbon buildup. Ask an RS4 owner about their car and what's the first thing out of their mouth? "I think I have carbon buildup" or "I need a carbon clean".

It's just a bit suffocating all the negative whinging about carbon. It's not that big of a deal in my experience, after running my RS4 at the dragstrip about 35 passes in total. I haven't seen anyone do before/after 1/4 mile results or pbox pulls. Just dynos for the most part.

I met a guy with a high mileage RS4 whose first comment was 'my car has carbon'. So we raced from 2000 to 8000 RPM. A very anticlimactic race...but we were dead even for the most part. I pulled maybe 2 feet on him over the entire gear. Weight was equal in the two cars. Afterwards he was in love with his car again because he didn't have to worry he wasn't getting the full monty. When we made a video of him launching and me launching...well you can see he'd probably run 13.4 vs. my 12.7. Cars were equal though.

http://www.youtube.com/watch?v=nHC_npkINrg

[gibsonl]

Well I guess to give you even further clarification, my car even had the Milltek and he'd put a full car length+ on me in slightly under 1/4 mile. (Switching cars gave the same result) I do agree that the carbon issue is overblown in the sense that most people don't really need the full power of the car for their use. But for me, having put cars side by side, felt the power difference from the seat, and done dyno's there's really no quesitoning the facts I've gained from my experimenting. And the dyno isn't just about comparing peak numbers. My graphs showed a clear dropped in power from my second peak on the curve whereas without carbon the second peak essentially matches the first. So far I've only seen theories and claims by Audi that carbon doesn't cause a significant power impact. I've never personally experience otherwise. We even had a 3rd RS4 come with us for a dyno, and just as I had prior to my cleaning he pu tdown 293 whp. If all these things are miraculous coincidences, then so be it.

[sakimano]

Originally Posted by gibsonl

Well I guess to give you even further clarification, my car even had the Milltek and he'd put a full car length+ on me in slightly under 1/4 mile. (Switching cars gave the same result) I do agree that the carbon issue is overblown in the sense that most people don't really need the full power of the car for their use. But for me, having put cars side by side, felt the power difference from the seat, and done dyno's there's really no quesitoning the facts I've gained from my experimenting. And the dyno isn't just about comparing peak numbers. My graphs showed a clear dropped in power from my second peak on the curve whereas without carbon the second peak essentially matches the first. So far I've only seen theories and claims by Audi that carbon doesn't cause a significant power impact. I've never personally experience otherwise. We even had a 3rd RS4 come with us for a dyno, and just as I had prior to my cleaning he pu tdown 293 whp. If all these things are miraculous coincidences, then so be it.

Well, what's significant? As I said I think it's probably 10-15 whp of usable power. Your dyno my differ. Some cars show a 30 whp gain. Some even 40.

I don't know if it's responsible to take car that might have vac problems or need new sparkplugs....dyno it...clean it...replace the sparkplugs and change the oil (as you are supposed to do)...then re-dyno it, and claim the delta as 'carbon'.

If my car runs 12.75 @ 108.3 in good conditions with decent driving...and I have 35,000 miles and no carbon cleaning has been done...and I get it done...what do you think I would run? Knowing that about 10whp = 1 tenth and just about 1 mph of trap speed. You think I'm going to pick up 20-30 whp, thus I should run 12.50 @ 110+?

[gibsonl]

You aren't the original owner so how would you know if a cleaning has been done or not. I highly doubt you have high levels of carbon and trapping that high. And no, I didn't do all those maintenance things you suggested between dynos. Just cc, gutted precats and lw crank pulley and picked up 50whp to 343. If you are claiming that the dp's and pulley made up a majority of that then clearly everyone needs to do those basic mods. I had the Milltek on both times. My numbers pre work were 293 whp and 255wtq. The other RS4 we tested was 293whp and 251wtq vs BADRS4 who ONLY has a cc and K&N filter which put down 320whp and 255wtq. After doing my plugs last week I would say based on feel alone that I picked up another 10whp and significantly improved idle roughness. I had 48k when I opened my manifold and my valves were so covered you couldn't even make out the round shape.

[sakimano]

Originally Posted by gibsonl

1. You aren't the original owner so how would you know if a cleaning has been done or not.

2. I highly doubt you have high levels of carbon and trapping that high.

3. Just cc, gutted precats and lw crank pulley and picked up 50whp to 343. If you are claiming that the dp's and pulley made up a majority of that then clearly everyone needs to do those basic mods. I had the Milltek on both times.

1. the previous owner included a summary of everything ever done to the car. No carbon clean (I was hoping it had when I bought it, but alas). I also called the originating dealership to confirm the history (just in case it had some problems that weren't being disclosed etc.) and the entire history lined up. No carbon clean.

2. 'high'? I trapped frigging 108.3. My B7 S4 with tune piggies and a catback trapped 107.3. That car might have made 290whp/280 wtq. elevens trapped 110.3 and all he had was a GIAC tune which is only good for maybe 10-15 whp (or 1-1.5 mph trap speed). 108 is not a big deal. R&T trapped 108 a couple of times, as did other mags.

3. You said your carbon clean gain was 30 whp above when replying to arthur. Now you're saying it's 50 whp? And now you have piggies in there?

Anyway how about apologizing for the accusatory tone of your first post in this thread, where you WRONGLY accused me of concealing mods? You misread the thread on audirevolution and screwed up. Maybe correct yourself and admit your error.

[gibsonl]

My initial dyno was 293 and post dyno was 343 as I posted with my graphs. I said the gain from the cc was about 30-40whp by my estimate considering the other 2 mods don't make a world of difference. The intake spacers I added give some tq but they don't really add hp. Everything else with the car was the same aside from the 3 things I just mentioned. You can't compare traps of a NA car vs turbo. A turbo charged car accelerates out the whole slower but will have more peak speed depending on the boost. A perfect example is my friends 335is. Basically runs the same quarter mile but his trap is 114 at 12.6 whereas we would be around 110-112 trap at a 12.6.

[ELEVENS]

Here's what mine looked like with 33,000 miles. These don't look like they flow very well. We spend thousands for such things as performance heads, 5-angle valve jobs, and titanium valves with undercut necks to increase flow. Maybe someday, someone will publish flow bench graphs of a carboned head vs.an uncarboned head. That would be interesting!