MBH LT Headers_RENNtech Tune Dyno Results
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2008 A8L, 2002 996TT X50, 2009 X5
bhamg and MBH/DC, great work and thanks for sharing the info!
bhamg - if I'm understanding everything right, as it sits, the car is roughly +65-70 rwhp over the stock baseline? I'm sure that's still a handful on the street. Do you have the final chart as well (I assume there must be one, for you to know that it's down 20 rwhp with those cats in place)? Did adding in the CA-legal cats materially change the AFR?
Since the primary cat was going to be aftermarket anyway, what made you choose a "CA-legal" cat? I'd expect others likely measure as clean, and are as effective at mitigating drone... since you're not using all CARB-approved and/or -exempt parts, I guess I just don't understand the point of the CARB-approved/exempt cats... I'm probably missing something there, however. Again, great results.
![drive](https://mbworld.org/forums/images/smilies/driving.gif)
Since the primary cat was going to be aftermarket anyway, what made you choose a "CA-legal" cat? I'd expect others likely measure as clean, and are as effective at mitigating drone... since you're not using all CARB-approved and/or -exempt parts, I guess I just don't understand the point of the CARB-approved/exempt cats... I'm probably missing something there, however. Again, great results.
![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
Last edited by c32AMG-DTM; 06-22-2010 at 08:35 AM.
#56
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bhamg and MBH/DC, great work and thanks for sharing the info! ![drive](https://mbworld.org/forums/images/smilies/driving.gif)
bhamg - if I'm understanding everything right, as it sits, the car is roughly +65-70 rwhp over the stock baseline? I'm sure that's still a handful on the street. Do you have the final chart as well (I assume there must be one, for you to know that it's down 20 rwhp with those cats in place)? Did adding in the CA-legal cats materially change the AFR?
Since the primary cat was going to be aftermarket anyway, what made you choose a "CA-legal" cat? I'd expect others likely measure as clean, and are as effective at mitigating drone... since you're not using all CARB-approved and/or -exempt parts, I guess I just don't understand the point of the CARB-approved/exempt cats... I'm probably missing something there, however. Again, great results.![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
![drive](https://mbworld.org/forums/images/smilies/driving.gif)
bhamg - if I'm understanding everything right, as it sits, the car is roughly +65-70 rwhp over the stock baseline? I'm sure that's still a handful on the street. Do you have the final chart as well (I assume there must be one, for you to know that it's down 20 rwhp with those cats in place)? Did adding in the CA-legal cats materially change the AFR?
Since the primary cat was going to be aftermarket anyway, what made you choose a "CA-legal" cat? I'd expect others likely measure as clean, and are as effective at mitigating drone... since you're not using all CARB-approved and/or -exempt parts, I guess I just don't understand the point of the CARB-approved/exempt cats... I'm probably missing something there, however. Again, great results.
![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
#57
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2008 A8L, 2002 996TT X50, 2009 X5
#58
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bhamg and MBH/DC, great work and thanks for sharing the info! ![drive](https://mbworld.org/forums/images/smilies/driving.gif)
bhamg - if I'm understanding everything right, as it sits, the car is roughly +65-70 rwhp over the stock baseline? I'm sure that's still a handful on the street. Do you have the final chart as well (I assume there must be one, for you to know that it's down 20 rwhp with those cats in place)? Did adding in the CA-legal cats materially change the AFR?
![drive](https://mbworld.org/forums/images/smilies/driving.gif)
bhamg - if I'm understanding everything right, as it sits, the car is roughly +65-70 rwhp over the stock baseline? I'm sure that's still a handful on the street. Do you have the final chart as well (I assume there must be one, for you to know that it's down 20 rwhp with those cats in place)? Did adding in the CA-legal cats materially change the AFR?
Since the primary cat was going to be aftermarket anyway, what made you choose a "CA-legal" cat? I'd expect others likely measure as clean, and are as effective at mitigating drone... since you're not using all CARB-approved and/or -exempt parts, I guess I just don't understand the point of the CARB-approved/exempt cats... I'm probably missing something there, however. Again, great results. ![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
Last edited by bhamg; 06-23-2010 at 02:41 AM.
#59
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2008 A8L, 2002 996TT X50, 2009 X5
I didn't print the w/cat chart but I will be getting that and a few others too. It was a matter of my needing to hit the road and being in Las Vegas by a certain time...and I just made it with 5 minutes to spare. I will be hitting the Dynojet the Vegas guys use also but may wait until it cools down a little into the fall...it was 104° in Scottsdale when we were dynoing. No effect on AFR's no cat vs. cat.
The deal with cats is that I am told there are big differences between aftermarket cats. Many cannot meet the 8/80 OE requirement. Aftermarket CA-legal cats must meet 10/100 requirements and are independently tested and certified. Sure the substrate is more restrictive but because there is considerably more of the precious metal catalysts (Magnaflow told me X3 times more than 49-state versions to make them both more efficient and much longer lasting) in the CA-legal version, the whole point of this exercise was to use them to do it right...to CA OE or better standards. Using 49-state cats to try to gain a few more HP never even entered my mind, to tell the truth. From the headers to the cats, I fully expect this system to easily outlast OE.
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2008 A8L, 2002 996TT X50, 2009 X5
Just noticed something. Your car put down a stock baseline of ~370 rwhp, in 104 degree heat at well over 1000' elevation. For a frame of reference, another C63 on the exact same dyno (but undoubtedly better weather conditions I'd think - check the date) put down a stock number of ~330 rwhp:
https://mbworld.org/forums/c32-amg-c...55-vs-c63.html
I didn't realize C63's had so much variance in their stock output... we're talking 40 whp difference, which is huge. Apologies for the OT observation.
https://mbworld.org/forums/c32-amg-c...55-vs-c63.html
I didn't realize C63's had so much variance in their stock output... we're talking 40 whp difference, which is huge. Apologies for the OT observation.
Last edited by c32AMG-DTM; 06-23-2010 at 07:31 AM.
#61
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Actually the repeatable baseline and the figure used was 360 whp, which is still on the high end of C63's on that dyno...I'm told others have come in around 345 whp. So really, we are talking a range of around 15-20 whp for stock C63's. There's always an outlier or two or three. In my experience bone-stock E39 M5's, all well-maintained and in excellent condition usually show 35+ whp differences on the same dyno, same hour tested. There's always someone around the corner on a different dyno with a higher number...I'm interested only in the relative gain.
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2008 A8L, 2002 996TT X50, 2009 X5
IMHO, as long as one is being consistent in the reported results across all levels (i.e. best vs. best vs. best, or repeatable vs. repeatable vs. repeatable, etc. - just not repeatable vs. best vs. best) it's useful data for a relative comparison. Which I think is what's shown here, which is good.
I don't know what others have averaged on DC's dyno dynamics (or how many C63s make up that average), but the only publicly posted results I've seen commented on here have been ~330 rwhp. I'd assume those were the best results (not just repeatable) out of a handful of runs (that's how the vast majority of operators do it, AFAIK...). So it's fair, I think, to say your factory-freak was outputting nearly 40 whp more than 1 or 2 other DC-tested C63s when all were in stock trim... unless something else changed in the meantime (settings, correction factors, etc.). What's amazing though is that your headers-only and headers+tuning results were almost identical to that other C63. So the only major difference was the baseline figure (see graph in first post):
https://mbworld.org/forums/c63-amg-w...2-22-10-a.html
...I'm interested only in the relative gain.
![Smilie](https://mbworld.org/forums/images/smilies/smile.gif)
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#63
AZ weather is a nightmare when it comes to dynos... the weather changes so drastically from one season to another that its hard to compare... plus their dyno is at relatively high altitude with thin/dry (and occasionally boiling) air so it really pushes the benz ECU's to their outer limits (not to mention AZ's crappy gas). Having dynoed in AZ many times, it really is not a dyno friendly place (tucson being even worse than PHX). Couple that with the "heart breaker" Dyno dynamics dynos and it can make even the strongest of cars/motors look weak at times. AZ is one of the worst states as far as dyno results are concerned making the results even more impressive.
As C32-DTM mentioned, all that really matters is before & after variance and ensuring proper consistent testing methods are used. The actual number itself is irrelevant most of the time, the % gains are what matter most.
As C32-DTM mentioned, all that really matters is before & after variance and ensuring proper consistent testing methods are used. The actual number itself is irrelevant most of the time, the % gains are what matter most.
#65
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Sorry but it's not going to happen soon. For one I do not have my test pipes handy. Also even if I did I'll need a lift. In the late fall/early winter I'll be doing my track and VBOX performance runs and the test pipes will go on then but most likely not before.