Dyno results - 2010 DSG S4 100 tune, 034 HFC's(junk), miltek non-res, various intakes
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IMO dynos are a less-than-ideal place to test intakes anyways, especially those like Strat's that may be a little more susceptible to heat soak if they aren't getting adequate amounts of cold air. This would make sense given Arin stating that the boost gets dumped if certain IATs are reached as a safety measure. Thus, I think the answer is the IATs, and it isn't as much of a problem in the real world.
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While I don't totally disagree, most products we see advertised are tested on... a dyno... I could be wrong but I don't remember anyone talking about lower IAT's when the intake was released, again I may have missed it... Problem is in the real world we drive our cars in traffic and are often forced to sit at stoplights and such thus causing the intake to heat up... This then has the system start with hotter air and makes the intercooler have to work harder to compensate... Also, I have done a lot of datalogging that I hadn't really talked about, nothing like what APR does but honestly, I have not seen IAT's hot enough to dump boost... My valve readings are usually 0 at WOT...
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They did step up, they pulled the sale of the LCF's for now until things can be "fixed with software."
Last time I checked you can't increase airflow with software. The elements in this cat as less dense than stock, but the diameter of the cat is also a good bit smaller, so I would be surprised if it flows the same volume of air at speed compared to stock.
CircuitTested has said that they now have data to support the flow issue claims - we'll see. I thought you said you read the threads regarding this. You asked for more proof than the drag runs, proof which was all over the 2 threads on this.
Last time I checked you can't increase airflow with software. The elements in this cat as less dense than stock, but the diameter of the cat is also a good bit smaller, so I would be surprised if it flows the same volume of air at speed compared to stock.
CircuitTested has said that they now have data to support the flow issue claims - we'll see. I thought you said you read the threads regarding this. You asked for more proof than the drag runs, proof which was all over the 2 threads on this.
Back to you...you still haven't addressed my question about how a supposedly freer flowing intake will cause a loss of torque on a before after dyno, when nothing is changed but the Audi pressurised intake being pulled out in favour of the Strat intake.
Does this mean you realised you made a mistake? Maybe time for you to step up?
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IMO dynos are a less-than-ideal place to test intakes anyways, especially those like Strat's that may be a little more susceptible to heat soak if they aren't getting adequate amounts of cold air. This would make sense given Arin stating that the boost gets dumped if certain IATs are reached as a safety measure. Thus, I think the answer is the IATs, and it isn't as much of a problem in the real world.
Again...it's low end torque that vanished, not horsepower at the top end. Are you saying the boost is dumped, but re-instated as the car approaches redline (when it's REALLY hot)?
One thing I definitely agree on...the dyno can spin all kinds of stories, not all of them true. I've seen cars that dyno 400 whp lose races to cars that dyno 310 whp...on the same dyno, and with weight equalised. I've also seen cars dyno very little change after a couple of mods, but they perform much better. This is why the 4.2 guys tried to stay as far away from the dyno as possible. Too many dyno tricks for us to all know and understand...and that's when people are being honest! Bring an element of dishonesty in, and you can have your part dyno whatever you want.
Last edited by sakimano; Jun 27, 2011 at 10:03 AM.
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Second time you've made no sense.
1. Where does the B8 S4 make peak torque? IIRC it's closer to idle than it is to redline. So why are you talking about a high rpm restriction? Engine speeds aren't going to see the 034 cat being a problem where the S4 makes peak torque (2-4k RPM).
2. The other data we have (primetime's dragracing slips) bear this out...he has no down low problems with the cat AT ALL as is evident by his good launches and first half times. The supposed restriction causes trouble at high rpms...which is again irrelevant to these dyno numbers that show a problem making peak torque at low RPMs.
3. Don't forget that in the two tests Ron had the 034 cats on for both dynos. The only change was the airbox...Audi vs. Strat...so you need to explain why a suposedly freer flowing Strat INTAKE is going to cause a loss of low end torque. The car dyno'd the same peak hp (close enough) with both airboxes in...but lost about 20 WTQ with the strat box.
Telling me to go read a thread on AZ (that I've already read) isn't going to get you out of explaining something you posted that was dead wrong. I asked you to explain so you could show the forum what you know (or don't know)...not for my own edification.
1. Where does the B8 S4 make peak torque? IIRC it's closer to idle than it is to redline. So why are you talking about a high rpm restriction? Engine speeds aren't going to see the 034 cat being a problem where the S4 makes peak torque (2-4k RPM).
2. The other data we have (primetime's dragracing slips) bear this out...he has no down low problems with the cat AT ALL as is evident by his good launches and first half times. The supposed restriction causes trouble at high rpms...which is again irrelevant to these dyno numbers that show a problem making peak torque at low RPMs.
3. Don't forget that in the two tests Ron had the 034 cats on for both dynos. The only change was the airbox...Audi vs. Strat...so you need to explain why a suposedly freer flowing Strat INTAKE is going to cause a loss of low end torque. The car dyno'd the same peak hp (close enough) with both airboxes in...but lost about 20 WTQ with the strat box.
Telling me to go read a thread on AZ (that I've already read) isn't going to get you out of explaining something you posted that was dead wrong. I asked you to explain so you could show the forum what you know (or don't know)...not for my own edification.
Bruce
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exactly...nowhere near the tune's boost limiter removal kicks in, and nowhere near an engine speed where that cat is likely to be restrictive, thus the discussion of high engine speeds and boost limiter removal etc. is irrelevant to prime's dyno numbers.
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034 posted flow bench testing showing that their cats flow more than the factory cats. So I wouldn't call them Low Flow Cats. There is definately something about their design in conjuction with this engine that's causing issues and people are losing power because of it, but I don't think it's their flow capacity.
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Bruce
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logging would work but FATS is a funny reference.
FATS is a B5 only thing. There's a very specific reason it's that exact RPM range...and that reason doesn't apply to these cars at all. It was used by a couple of tuners way back in the day who didn't have a dyno, and who realised something specific about the B5 S4 in the stock tune..and in the bad aftermarket tunes. Comparing their tune to those other tunes was useless as they'd done something in the lower RPM range that would trounce the other tunes/stock so to create a 'how is their tune compared to ours' test that would actually help them see where they stood, they used the 4200-6500 range for an apples to apples comparison.
A simple log from 2000-7000 would be great in this case, but it needs to be the exact same road and the same section of road in the same direction blah blah blah. Otherwise the data is useless.
FATS is a B5 only thing. There's a very specific reason it's that exact RPM range...and that reason doesn't apply to these cars at all. It was used by a couple of tuners way back in the day who didn't have a dyno, and who realised something specific about the B5 S4 in the stock tune..and in the bad aftermarket tunes. Comparing their tune to those other tunes was useless as they'd done something in the lower RPM range that would trounce the other tunes/stock so to create a 'how is their tune compared to ours' test that would actually help them see where they stood, they used the 4200-6500 range for an apples to apples comparison.
A simple log from 2000-7000 would be great in this case, but it needs to be the exact same road and the same section of road in the same direction blah blah blah. Otherwise the data is useless.
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I think the best way to resolve the intake question is some VAG (VCDS) instrumented road logs with the two intake systems, recording things like RPM, IAT, boost, timing, etc. Prime has a VAG. Use the same exact road section for the two logs. I would suggest running the FATS test.
Bruce
Bruce
Oh and I will log the 1/4 mile passes and can share those #'s as well...