rdking

Those out there with aftermarket exhausts for the allroad... did you notice any improvement in HP, pickup, torque, and lag... in theory if the turbos can breath better there will be less lag... any those of you who have modded your exhaust any difference

markcincinnati

. . .on this very subject and his response was that anything that helps the breathing will help the power (torque and HP). However, his most notable comment led me to believe that he felt that the biggest single improvement would be the "chip" -- but added that the chip+airfilter+exhaust would be very noticable.

The exhaust added 10 -15 hp and "some" torque improvement. I think he said the least potent MTM chip he offered added 56HP and 124 pound feet of torque (but the added torque came on at a higher RPM than the stock engine's 258 torque number.)

I read to this indicate nothing with respect to the tip-lag and actually the possibility that there would be some lag with the chipped version (relative) -- since the factory 2.7T engine is rated at it's full torque below 2,000RPM's and that the chipped (MTM) version was rated at significantly higher torque (good thing) but that it would "come on" later (above 2,000RPM's) thereby making the car perhaps be very strong from idle but have a specific point at which there was a step up in torque (giving a rush of acceleration to be sure) but that the progression would be a little bit notchy --

I ended up buying the MTM chip for my 1.8T TT quattro coupe and the increase in acceleration was tremendous -- but in first gear it hit red line so quickly I had to learn how to overcome the slight bit of added turbo lag.


Take this for what it is worth -- even the newbies on this board are already noting (some complaining some not) the so-called tip lag. Raising the HP and torque and raising the RPM where the torque comes on at full boil may have no effect on the tranny but the impression could very well be that there is even a greater lag --

Those who have chipped and/or put aftermarket pipes on their allroads (w/Tip) are far more likely to give you the real deal -- since my experience is chipping a manual trans car.

Also there is supposed to be a tip chip that MAY reduce the "intended delayed acceleration."

Ask around people here are quite willing to tell you the bad, the ugly and THE GOOD!

itacud

They are different. =)

I'm very skeptical at any claims (by dealerships) that less restrictive exhaust systems stress turbos more than do more restrictive exhaust systems. Specifically, reduced pressure in the exhaust pipe does not guarantee more efficient evacuation of the cylinder, during the exhaust stroke. It's that evacuation that is required for the turbine to spool. If exhaust evacuation does improve, and the turbine does spool faster, max pressure on the charge side is still restricted. But, the <i>lag</i> may be reduced. So, if designed properly, I think it's possible for an exhaust system to reduce turbo lag.

Regardless, exhaust changes can do nothing to change the "Tip Lag" that people complain of. That's a programming/configuration issue with the engine management system.

markcincinnati

. . .systems. But Mike Hoppen's comment to me made me conclude that I would like the sound of the MTM exhaust; but, I should not expect a huge rush of acceleration from this $1,700+ installation expenditure alone. The "active" change made by the chip (which generally costs between $500 - $700) is far more noticable. But even then, it would be my conclusion that the so called tip lag (which I had in my 3 4.2L V8 equipped Audis) would not change and may even FEEL worse even if the 0-100kph times were better (with the engine chip).

There are discussions on this forum and others here about the effects of the tip chip -- some say it is worthwhile.

The best tip I have ever driven is in an S6 -- I can only assume the RS 6 too has rid itself of the dreaded "tip lag."

If you have gotten this far into reading this and you are shopping for a new 03 allroad -- please take a long long test drive in both a 6spd and a tip before you buy one -- and begin posting your disatisfaction (as do some) with the lag inherent in the tip transmission (to say nothing of the final drive ratio which makes it even less quick.)

moto-one

a free breathing exhaust should let the turbo spool up faster if the heat/pressure coming in is up. I thinking that the fuel program keep the temp low then brings it up. More fuel=more heat= spool up of the Turbos,This is done to keep the tork with in the range of the componets of the transmission. the bypass valve/wastgate control by ether machanical or program in the ecu could bleed off boost for the same reason.

Rally_nutcase_1982

The statements listed here about turbo lag should lead you to the logical conclusion.
If you look at a simplified Air/Gas intake and Engine-Turbo-Exhaust workflow diagram everything here makes absolute sense. Most guys, and girls here understand the principles how this thing really works, and some go the extra mile.

So, that means if you want to improve your system you'll have to find the bottleneck first.
It all depends on your wallet and what you want to accomplish.
If you exchange the entire exhaust system from the downpipes to the end-muffler than you'll hear and feel the improvement. But if you chose to replace only the resonator and end-muffler than you may get some improvement, but not really favor the Turbo lag.
Finally, sort of a recommendation, we've used for most turbo charged engines for racing straight through pipes all the way for each Cylinder, no mufflers or other blocking devices. But unfortunately, it is not quit legal.
;-)