A Valid Reason NOT to Chip Your allroad...
02-11-2003, 10:10 AM
#1
AudiWorld Member
Thread Starter
Join Date: Dec 2002
Posts: 217
Likes: 0
Received 0 Likes
on
0 Posts
A Valid Reason NOT to Chip Your allroad...
Accidentally found the following information in old S4 forum post about the 2.7tt engine when it was just introduced. It was taken from the Audi technician turbo repair manual.
- US version only 250 bhp/258 lbft vs euro with 265 bhp/295 lbft.
This comes from the fact that turbo and exhaust temperatures must not exceed 1000C (beyond that the heat destroys them) The traditional way to keep turbo and exhaust temperatures manageable is to richen the fuel mixture. It appears that the ever-tightening emission laws in the US would cause the car to fail emissions under this scenario. Thus the American 2.7tt will no longer richen the mixture to keep a handle on exhaust/turbo temperatures but rather cut back on power and boost.
Other parts of the world have less restrictive emission laws and thus continue to have mixture enrichment for exhaust/turbo cooling and thus higher output.
Chipping the car causes higher boost but does not enrich the fuel mixture. Result - overheating of the turbo and premature failure...
- US version only 250 bhp/258 lbft vs euro with 265 bhp/295 lbft.
This comes from the fact that turbo and exhaust temperatures must not exceed 1000C (beyond that the heat destroys them) The traditional way to keep turbo and exhaust temperatures manageable is to richen the fuel mixture. It appears that the ever-tightening emission laws in the US would cause the car to fail emissions under this scenario. Thus the American 2.7tt will no longer richen the mixture to keep a handle on exhaust/turbo temperatures but rather cut back on power and boost.
Other parts of the world have less restrictive emission laws and thus continue to have mixture enrichment for exhaust/turbo cooling and thus higher output.
Chipping the car causes higher boost but does not enrich the fuel mixture. Result - overheating of the turbo and premature failure...
02-11-2003, 10:38 AM
#2
There are some smart people tuning turbo cars
I'm pretty sure that they have thought of this. Go browse the S4 forum for a while. They have daily discussions about EGT and a whole crap load of other variables as they attempt to maximize boost and performance.
Does emmissions suffer at all? Can't say for sure, but plenty of people chip their cars and pass state emmissions.
Does emmissions suffer at all? Can't say for sure, but plenty of people chip their cars and pass state emmissions.
02-11-2003, 10:50 AM
#3
Member
Join Date: May 2001
Posts: 3,703
Likes: 0
Received 0 Likes
on
0 Posts
This is taken care of by the Tuners.
They make the A/F very rich under high boost to keep you out of trouble. Mine blows a black smoke screen at WOT. I intend to ask AWE if it can be leaned out slightly.
02-11-2003, 11:40 AM
#4
AudiWorld Super User
Join Date: Nov 2001
Posts: 2,689
Likes: 0
Received 0 Likes
on
0 Posts
I used to have the same problem. A black puff of smoke @ wot with a slight hesitation.
Turns out one of my egt sensors was slowly dying. Wouldn't even throw a cel until my bad O2 sensors triggered it. The point is: I used to blame the chip for running rich. It was my car. Have you checked for any dtc?
02-11-2003, 12:13 PM
#7
AudiWorld Super User
Join Date: Nov 2001
Posts: 2,689
Likes: 0
Received 0 Likes
on
0 Posts
There's been countless number of testing on the S4 forum regarding this.
The consensus is that the fuel injectors don't max out until about 350hp. PES-tuning actually toyed with offering bigger injectors for the Giac x-chip. They never came out with the kit because it just wasn't necessary; also it did not make more power.
The chip makers are very good at what they do. You don't hear anybody going to limp mode from the software.
The chip makers are very good at what they do. You don't hear anybody going to limp mode from the software.
Trending Topics
Thread
Thread Starter
Forum
Replies
Last Post
snwguy
A4 (B6 Platform) Discussion
1
12-19-2002 08:14 PM