Restrictive A6 exhaust

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Aug 22, 2000 | 09:57 AM

blk 2.7Tpsk

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Restrictive A6 exhaust

I just got an E-mail back from Hoppen motorsports explaining why they have a 295 hp rating for their A6 chip, and a 315 rating for the S4 chip. They say the A6 exhaust is more restrictive, hurts top-end, and the a6 actually runs a higher boost pressure than the S4 to make the 250 HP. This is news to me. Anybody hear anything about this??

Aaaaaargh - I don't need to be thinking about an entire aftermarket exhaust system!!!

Aug 22, 2000 | 11:33 AM

cmos9

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I have heard the same from GIAC (garret) and I also have an aftermarket exhaust

I had a local shop do a custom exhaust for me. 2.5" stainless pipe with a 2.5" Borla turbo mufflers. (One system per side for a true dual setup like stock) 630 or so totall for the system. I have a GIAC stage 1 chip as well. My impressions are as follows. Sound is very good but the biggest improvment seems to be above 4k rpm. The motor just seems smother up here now with much more power than before above 4k rpm. The stock exhaust felt like I was forcing the motor to redline etc. Anyhow this is my 2cents.
-peter

Aug 22, 2000 | 11:51 AM

Ming 2.7T

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What shop is it, I work in Irvine? Looking for a decent exhaust at resonable price

<p>2000 A6 2.7T Tiptronic
Ming Blue/Melange
Conv Pkg,Xenon,Curtain airbags,Leather
Ronal Wheels LZ 18x8.5
235/40ZR18 S-02 Pole Positions
Audi/Eibach Springs
Stongard
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Tint 5-5-20 Metalizied

Aug 22, 2000 | 11:52 AM

Bollinger

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same people who want to sell you the exhaust

They say they are experts on exhaust, then go look at the S4 chip results, where the car with an aftermarket exhaust didn't do any better (slightly worse) than stock, even with a high-powered chip installed.

I don't know about the relative boost pressures between the two cars.

It does kind of stretch things a little to say the cars are different. I believe the whole reason AoA changed the outputs from the S4 and A6 2.7T engines to be the same was so they only had to qualify a single engine (actually, two including TIP and stick) for US emissions.

That's my two cents.

Aug 23, 2000 | 04:44 AM

blk 2.7Tpsk

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More info from Hoppen

I asked them about aftermarket systems for the 2.7T, and they didn't know of any! I also asked about where the restriction was, and they didn't know - hey I have to give them credit for being honest. I also spoke to UUC, and they are prototyping a system now that will be available sometine this fall. I think I'm going to have to get it, along with a stage 1 chip of some type. Both UUC and Hoppen say the restrictive exhaust really holds the car back at the higher RPM's. Hoppen and others have said that no chip reprogramming is necessary with a freer flowing exhaust, it can only help. Well, there goes another $1500.

Aug 23, 2000 | 12:09 PM

Richard Solomon

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Higher *boost* pressure or higher *back* pressure?

I thought the ECU was the same for both 2.7T platforms (A6 2.7T and S4), but it sounds like this might not be? I'd be a bit surprised if the *boost* pressure were different, but not if the *back* pressure were...

I'm not an engine tuner, nor do I play one on TV.<p>Richard
'00 A6 2.7TQM
"Turbos make torque, and torque makes fun." -Corky Bell