'05 A4 rev limiter
Thread Starter
Le Mans Master
Joined: Jun 2007
Posts: 7,610
Likes: 12
'05 A4 rev limiter
On my '05 A4 w/ 3.73 and 2800 stall... I am having an issue during WOT that my tuner cannot duplicate.
About 70mph I loose power and the acceleration is held back, then I release the throttle and WOT again and I break free. I am no where near 6700rpm where the rev limiter threshold is reported to be, unless it is much lower on the A4. I don't see many performance stats about the A4 so I'm judging from posts about the A6.
Is there a secondary rev limiter point that I'm hitting? Can this be tuned out?
About 70mph I loose power and the acceleration is held back, then I release the throttle and WOT again and I break free. I am no where near 6700rpm where the rev limiter threshold is reported to be, unless it is much lower on the A4. I don't see many performance stats about the A4 so I'm judging from posts about the A6.
Is there a secondary rev limiter point that I'm hitting? Can this be tuned out?
Le Mans Master
Joined: Aug 2004
Posts: 5,259
Likes: 16
From: Monroe Township New Jersey
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
St. Jude donor in memory of jpee '14
Ok I'll take a stab.
You have to match the converter to work with the gears you pick and make sure that it runs cool (add an external trans cooler).
Our cars come with lock up converters. There is a torque converter clutch solenoid TCC that controls when the convertor locks up (when the tcc is applied the converter operates on a 1 to 1 basis). Your tuner wants the convertor to lockup on WOT which will give you no slippage & a quicker ET.
In HP Tuners there is a section AUTO TCC. Your tuner has to adjust for the WOT release vs gear vs TPS. There are several tables in this section. It would seem that there may be a incorrect value in one of the tables.
I took a quick look at my stock tables:
TCC applied for WOT is 85 MPH and released at 81 for a A4 with 3.15 gears. Yours should be different to account for the lower gear ratio.
I would imagine a DTC to be set since your new gear ratio would not be within the stock range.
Then, there may also be the possibility that the shift points may be incorrect as my stock WOT Normal shift point is set at 6400 rpm & 41 MPH. The hot setting is set or 5800 RPM when I run the car it normally short shifts at WOT between 6200 & 6300...... go figure
This can be found in the auto shift speed section of HP tuners.
Once again I would expect that you would see a DTC set if there is a incorrect value.
You might want to take a ride with your tuner as he runs a scan for codes. I hope this is somewhat helpful.
Good luck
You have to match the converter to work with the gears you pick and make sure that it runs cool (add an external trans cooler).
Our cars come with lock up converters. There is a torque converter clutch solenoid TCC that controls when the convertor locks up (when the tcc is applied the converter operates on a 1 to 1 basis). Your tuner wants the convertor to lockup on WOT which will give you no slippage & a quicker ET.
In HP Tuners there is a section AUTO TCC. Your tuner has to adjust for the WOT release vs gear vs TPS. There are several tables in this section. It would seem that there may be a incorrect value in one of the tables.
I took a quick look at my stock tables:
TCC applied for WOT is 85 MPH and released at 81 for a A4 with 3.15 gears. Yours should be different to account for the lower gear ratio.
I would imagine a DTC to be set since your new gear ratio would not be within the stock range.
Then, there may also be the possibility that the shift points may be incorrect as my stock WOT Normal shift point is set at 6400 rpm & 41 MPH. The hot setting is set or 5800 RPM when I run the car it normally short shifts at WOT between 6200 & 6300...... go figure
This can be found in the auto shift speed section of HP tuners. Once again I would expect that you would see a DTC set if there is a incorrect value.
You might want to take a ride with your tuner as he runs a scan for codes. I hope this is somewhat helpful.
Good luck
Thread Starter
Le Mans Master
Joined: Jun 2007
Posts: 7,610
Likes: 12
Thanks Tommy, I appreciate the time you took to write these tips. However, we've done all this. I was hoping to hear from someone that says "there is another rev limit point that needs to be removed..."
The power loss happens at about 4800rpms. We don't know why. Installing headers and ported FAST right now, then will retune once again. Hopefully we'll discover the problem then.
The power loss happens at about 4800rpms. We don't know why. Installing headers and ported FAST right now, then will retune once again. Hopefully we'll discover the problem then.
Le Mans Master
Joined: Aug 2004
Posts: 5,259
Likes: 16
From: Monroe Township New Jersey
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
St. Jude donor in memory of jpee '14
Your welcome,
I had thought that I read about a similar issue whereas someone changed the shift rpm because he was hitting the rev limiter and even though he changed file he still hit the limiter. I did a quick seach but could not find the thread.
I would suggest that you try posting your question on the HPtuners forum. The only other suggestion I would make to to check the file cell by cell
once again good luck
I had thought that I read about a similar issue whereas someone changed the shift rpm because he was hitting the rev limiter and even though he changed file he still hit the limiter. I did a quick seach but could not find the thread.
I would suggest that you try posting your question on the HPtuners forum. The only other suggestion I would make to to check the file cell by cell
once again good luck
