At this point all I seem to be able to gather from this ben guy and his exhaust is.
Lots of talk, lots of big words that are ment to be technical yet there is 0 data. IF all this work was done and these flow specs gone threw where is it?
I agree with the 5 or 6 people who are calling this ben guy and his exhaust a side show act. Getting this mick charicture to come post was just as bad as claiming he did all kinds of tests before making the kit.
While its great to see another option for the RS4 guys it would be great if honesty would be part of that policy. Apparently that seems to be too much to ask nowadays
Roll eyes…
As for EPL. I know this much about EPL. Nice guys not the best at what they do. IMHO JHM having a RS4 in house speeks volumes for what parts have been tested and what tune is going to IMHO be the best. Seems the JHM tune is already the best there is. It would be nice to see them get whats needed to bring it to market
If mick is really selling his JHM exhaust jump on it. IMHO its the best system out there. While there is lots of excitment I think thats the attempts of a few memebers to try and get something off the ground that seems to be grounded.
This is a very good post and should be read IMHO before taking anything that mick and ben say seriously
Add one more to the smart guy list. Good to see this act isn’t getting bought by the smarter guys.knowing first hand what goes into the same tests as ben mentioned. It became obvious that he did none of what he was talking about. The MickF28 thing just pushed it over the edge. Seems like there is a much larger scam type of attempt here then actual testing and data.
the PES guys all said PES were good. Now elevens is FASTER ET AND MPH at the quarter mile than the fastest PES car…and elevens had just a tune and h pipe!
As for working on serious cars that doesn’t qualify you to do jack shit. Ask mick about Futile Performance. Sorry…Futrell. They work on Porsches and have a shop with a shiny floor…and couldn’t install his short shifter (but still charged him $1000).
Do whatever you like Swesna. Just make sure if you make a bad decision, you tell everyone. Way too many people who make a bad decision hide from the fact out of shame or something…then tell the forum when it’s too late for the others who followed them into the trap.
Saki, yes if I end up getting the EPL tune and it is not good then I will be honest about it. I know what you mean about the PES situation. It is like they spent big dollars and did not want to admit they made a big mistake.
Elevens 1/4 mile was sweet with only a giac tune and h-pipe. He obviously knows how to drive the car. I on the other hand would probably screw up my 2nd to 3rd shift. I do not like the RS4 shifter at all or am just not use to it yet.
Like you have said…learning how to drive the car and the carbon clean are the best performance gains.
Don’t know if I have said that about carbon cleans. Have a look at my time vs elevens
He - 12.56@110.3
Giac tune
Hpipe
4025 lbs incl driver
Power shifted every gear change
No carbon (just cleaned)
Me - 12.94@107.3
Stock
4100 lbs incl driver
No power shifting
33k miles of carbon (never cleaned)
Difference was 0.37 seconds and 3.0 mph. Not that much really for tune and carbon clean and power shifting. That’s indicative of the gap that about 30 hp would generate, once you even out the car weight. 30 hp is about 23-24 whp…and that’s not a ton for tune+carbon. If I was brave enough to powershift a stock rs4 clutch I wonder what I’d run? Then we could really estimate the power gap of a clean + giac tune.
It’s a just a good time, which is great to see. Too many people run mid 13s then blame everything they can.
God I sure hope he didn’t say anything about velocity drop, and I’m an atheist. I’m too lazy to go back and read it all over again, but Ben/Mick, if you mentioned a velocity drop anywhere, I hope you never post again. Flow and velocity cannot change along the length of the exhaust; only energy, temperature, pressure, density, enthalpy, etc. Locally, velocity and pressure can change, yes, but not from one end to the other.
Anyway, the post I saw on QuattroWorld there was utterly useless. I took one look at the pretty picture, didn’t read even one word on the whole page, and I can tell you that you wasted your time, even if you actually took precise measurements of the exhaust (which is surprisingly difficult to do with any real precision). Sorry. Just calling it like I see it. Please just forget the modeling gig and just build something decent out of quality materials, test it, and offer it for sale if that’s your aim. Compare it against the competition, back to back, and show that it’s at least most of as good, and cheaper (or more available) than the competition, or show that it’s better and more expensive. After either of those outcomes, you can probably sell it without too much effort.
[quote]It is modeled with a constant pressure, or more accuratly, a mass flow value.
Posted by: BenSTi (12091) on 2012-03-18 15:57:05
I don’t have the software to model with a pulsed input. I wish I did, but for right now I am working on design optimization of my exhaust path using a constant pressure. I figure if it has a smooth even flow with relatively constant velocity, it will perform well when simulated with pulsed input (ie, actual conditions).
I have also been toying with the idea that stepped exhaust diameters may be the best choice. On a NA motor, my understanding is that you want to keep a constant exhaust velocity throughout the entire system. If this is the case, as the exhaust gasses cool, they shrink, and thus slow down. Using a stepped setup would help reduce this. I don’t know how hot the exhaust gasses are along the length of the tubing, I guess this can be found out with some creative measurements, but then I don’t have the software to properly simulate this loss of heat.
There are so many variables to consider when modeling an exhaust system like this properly and many of them have to be worked down to sort of a best guess situation where you just make an assumption based off information that is known for other applications.
[/quote]
and some comments from the guy who designed the TiAl 605/650/770 turbos (iirc):
[quote]you don’t have enough data to be be so conclusively critical.
Posted by: Jonathan C (487) on 2012-03-20 14:44:47
Don’t take my criticism as discouraging.
I doubt the OEM system has the compound bends in the rear section as you drew them.
You are simplifying the effects of the resonators and mufflers.
Minimizing velocity delta is not the design goal.
case in point i can make a 1.5" tube with the largest radii have less delta over its length than a proper 2.75" to 3" system. Head loss is your design goal. Design for that. ( you don’t have much room to really change anything in the tune path. its down to the mufflers )
nothing from flow-express will give you what you need.
from what you presented, you are not approaching this scientifically.
[/quote]
I agree fully with the head loss comment from my education/professional experience.
To be honest. Ive found most of quattroworld to be usless.
I really think its great there are so many acatual smart members here. I trully believe ben/Mick know SHIT about exhausts and they have no clue what there talking about. Reading there posts you can see more and more they don’t know much at all. Its trully apparent to me that ben is hopeing some fancy computer drawings was going to be enough to fool the quattroworld goldfish that know less then ben and mick.
Whats trully sad is that people have bought into this and would enen entertain the notion to by something from people like this.
I would for one like to say thanks to the members on here that have said something and have spoken up and shared actual knowledge
nothing sad…those quattroworld guys will i’m sure enjoy their ben exhausts. No harm there at all…they’ll never test it to see what the car is doing. They’ll just be like the guys with the capristo and the Milltek and the giac and epl guys (correction…they ARE the capriisto/milltek/giac/epl guys)…placebo’d into happiness. There isn’t a shred of pbox data or quarte rmile data on that site for them to evaluate the acceleration of a performance part. The one guiy who logs is mick, and he’s so out of touch with performance, he thinks his 175 lbs of weight reduction is what shaved almost a full second off his 3000 to 8000 rpm log time.
quattroworld is a very different forum. Trying to talk to them about performance is exasperating. The gigantic egos the RS4 owners on the site have get in the way of any progress…so they end up buying ‘exclusive’ things just to say 'i have so - and - so exclusive exhaust/tune/part. They’d much rather talk about how fast their cars are than actually show anyone. It’s an easy way to placate yourself into thinking your exclusive stuff works. Taking the car to the dragstrip will, in their minds, demean the car or devalue it somehow (even though everytime I go, I’m surrounded by cars worth double and triple ANY RS4 on earth. Last time there was a Ford GT, a Gallardo, a ZR1, 2 Z06, 1 997 turbo and his friend in a C4s as well as me, a few other Euros etc. Anyway, they avoid the strip because it’s also a real quick way to show that
a) you suck at driving (and that’s not good for the ego…their instructors at track days blow them the whole way around the track telling them how they’re smoothe and awesome)
b) your parts suck at making you faster (and that’s far too hard to admit
They’re the chief carbon buildup complain-session source on the web…mainly because they overstate its effects and use it to explain away their shitty driving skills and parts.
[/quote]
Nope, that’s just as retarded as it sounds. With a non-pulsed input, you have to have constant velocity along the whole length, otherwise your exhaust is collecting mass. I won’t explain, but that’s a sad goal statement; one of the worst I’ve ever heard to be honest.
[/quote]
Yup, beaten with his own stick. If you’re going to assume that a model completely unlike the real world is a worthwhile model, and that smooth bends will make it good, then just build an exhaust with smooth bends and forget the modeling. The big tuning of the exhaust isn’t in the bends anyway. If your bends are tight enough to show measurable performance losses, either your piping is way too small or your bends have an impossibly tiny radius. So many things matter more, including cutting and jigging the pipes up for smooth transitions between welded segments.
Ugh, I think I’m done with this thing here. It’s bothering me.
that picture is the stock exhaust. Not sure if that’s clear. Not that it matters…the theory/philosophy etc. comments are still damning. Just thought I’d clear it up in case anyone didn’t know.
Just to update this, I have since gone 12.75 @ 108.36…thus the gap is only 0.19 and 2 mph…and the difference between my run and elevens and his 12.56 @ 110.3 is:
-75 lbs of weight savings for Elevens
-power-shifting every gear for Elevens, vs. power shifting none for me
-GIAC tune for elevens vs. stock for me
-ECS h-pipe for elevens vs. stock for me
-carbon clean for elevens vs. 35,000 miles of carbon for me.
Either GIAC is doing just about nothing, or the carbon clean is doing just about nothing, or both…because the powershifting alone is good for 1mph and 0.2 seconds.
