Exactly.
good point on the dyno run after the cleaning…have to justify that cleaning dont they ;D
Well it is funny…lots of the rs4 guys are former students of the b6/7 world where we all learned not to trust someone selling us a performance product on the basis of dyno alone…i.e. Tune, air intake, exhaust etc. check the recent unitronic threads on AZ for an example…they are getting laughed off the forum for dyno marketing.
Yet the entire rs4 community with a few exceptions is willing to believe the dyno with respect to performance gained from carbon cleanings…without actually checking performance.
An interesting development in this thread…
the two cars in question (my still bone stock RS4 and the recently carbon cleaned RS4 owned by Mistro) went back to the dragstrip this week (as seen in the Toronot (sic)_Motorsports Park thread). The temperature was near freezing, the density altitude was around -800 feet most of the day…so conditions for making power were great…and that showed up in the results.
Some interesting results from the day (all data on 94 octane pump gas).
My best elapsed time - 12.83 @ 109.2
My best trap speed - 12.85 @ 109.9
Back in April, I went 12.75 @ 108.3 MPH. Traction was WAY better that day, with me cutting 1.82-1.83 sixty foot times. This time unfortunately I was more like 1.87-1.91 all day. For reference on our quattro Audis, we gain a tenth in the full quarter mile when we shave a tenth off the first 60 feet, which really measures the time you take to get through first gear. At 60 feet we’re going around 35 MPH or so.
The other car, has had a few modifications. First, here’s what he had back when we did the original carbon clean test:
ECS Hpipe exhaust crossover in lieu of the resonator section of the stock exhaust. This is a minor help for power, mostly it’s just sound. He had this on the original before and after.
JHM intake phenolic spacers - he installed these when the manifold was out.
That was it back then. Since then he has added
KWv3 coilovers, lowering the car a good 2" (from the looks of it compared to mine)
Piggie pipes - basically he gutted the PRE-catalytic converters, up close to the end of the headers where they mate up with the downpipes.
So to recap, yesterday my best was 12.83-12.85 @ 109.2-109.9.
Yesterday Mistro’s best was 12.47-12.53 @ 113.7-113.8
!!!
Pretty huge delta. This is important for two reasons:
- the carbon clean + piggies + intake spacers + being a little lowered = around 0.4 seconds/4 MPH gained over a quarter mile…pretty significant
- the RS4, in the hands of decent drivers with decent mods, is running QUITE strong, especially when compared to other platforms that are supposedly more ‘responsive’ to mods.
As I said earlier in the thread, I remain unconvinced that carbon cleaning is drastic and transforms the car…but I certainly think it has an impact on top end. Break down that delta however you want, just thought I would share.
Also had a ‘discussion’ with MRC on a thread on RS246 about cleaning
Seems we see lots of guys getting carbon cleaned and dyno’d by the same place that did the $1000 carbon clean, so I’m not entirely sold on the results. Not that I think anyone is running a scam or something, but I just don’t care much for the dyno, let alone when it’s measuring the gains of a mod or service…and is in the hands of the guys selling the mod or service.
MRC mentioned they did an ‘independant’ carbon clean a while back, with the cleaning done by MRC and the gains measured on someone else’s dyno. They have this on their web page, advertising the service.
Gains were 24 hp at the crank (dyno is at the crank by measuring wheel + loss on the rundown).
The ‘after’ dyno included a ported/polished intake manifold, so tough to attribute the gains alone to carbon on the first ‘after’ dyno.
[quote=“MRC webpage”]The intake manifold was refitted after being returned from our flow shop ported, polished and modifed with the flaps removed, with proven results from the flow bench.
After various modifications the intake manifold was optimised for peak flow at 8000rpm with good gains from low valve lift.
[/quote]
MRC are charging between 700 and 900 dolllars for the port and polish so I would assume there is some kind of gain to be had there. So the 24 hp carbon gain is really 24hp = carbon + P&P&deflap gain.
Anyone have a guess on gains made from P&P? I think if carbon buildup + P&P = 24 hp at the crank, I can definitely think of a few better ways to spend that $700-900 the P&P costs. What do you guys think?
Spend the $700-900 on lessons from you and Mistro on how to drive the RS4.
Props to Mistro for getting his hands dirty on his car, getting out the DP’s and doing DIY piggies. Otherwise I’d spend money on that. http://jhmotorsports.com/shop/catalog/exhaust-downpipes-jhm-b7-rs4-piggies-p-566.html Looks like piggies would be about $700-900 all said and done including shipping and in the inevitable 13% Dougal and Stevie want for their cut.
I don’t know what the track roadrace superstars do but I think the spacers are a good mod. Not scientific in any way but Mistro’s mani felt noticably cooler to touch than saki’s at the strip, after hot lapping the 1/4 mile. I’m sure for the road course, there will be some beinefficientits after a couple of laps. That’s speed you can’t measure on a dyno.
I don’t think people really consider the effects of heat build up and cooling on power. They want the one time “hit” of power for a one-off street race when the reality is we don’t use the power in our cars that way! In daily driving, the time I usually want that power is when I’ve been driving for a while and need to cross a 6 lane highway to turn left!
My only other concern with the carbon clean/build up is the potential from damage from debris peeling away. How common is that? I would get CC’d for that concern alone, if it were a big deal.
Carbon cleaning is a lot of money and a lot of work (assuming not doing other work) for something that could have negligible beinefficientits, other than maybe for valve longevity.
The price in the us in some markets has been dropping lately
Elite is offering it for $650 including oil I think
A dealer in Oregon Erik do the clean for $450
JHM will do it for $550
To me, that’s a great price point for the work. There is certainly a performance gain to be had, so that’s nice, and of course the engine safety factor.
Up here it is more like $1100 -$1200. I will get it done at some point here. Should have done so two weeks ago in Detroit when JHM was in town!
Well heck, at $500 I’d do it too, if I could find that price around me. I was thinking $1000+, and at that price I would just wait until I was doing some other kind of work.
Bumping this thread up - lots of good info and discussion here.
I was making fun of the people that freak out about RS4 carbon here: http://audirevolution.net/forum/index.php?topic=2845.0
… and saki reminded me of this thread that he posted before I owned a RS4. I support the hypotheses in this thread completely, and like that there is supporting performance data.
Good stuff.
Bumping this thread up - lots of good info and discussion here.
I was making fun of the people that freak out about RS4 carbon here: http://audirevolution.net/forum/index.php?topic=2845.0
… and saki reminded me of this thread that he posted before I owned a RS4. I support the hypotheses in this thread completely, and like that there is supporting performance data.
Good stuff.
I wonder if that is running ITBs?
I wonder if that is running ITBs?
Is that the drag car form a few years ago? It had 2.2 turbo inline 5… Port injection. Old fashioned as fuck…and comfortably, the engine of choice in the fastest Audis ever.
That car went high 8 seconds. They took the power train from that thing and put it in an a5.
Not sure if this is it.
Is that the drag car form a few years ago? It had 2.2 turbo inline 5… Port injection. Old fashioned as fuck…and comfortably, the engine of choice in the fastest Audis ever.
That car went high 8 seconds. They took the power train from that thing and put it in an a5.
Not sure if this is it.