www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You




Go Back   TDIClub Forums > VW TDI Discussion Areas > TDI Power Enhancements

TDI Power Enhancements Discussions about increasing the power of your TDI engine. i.e. chips, injectors, powerboxes, clutches, etc. Handling, suspensions, wheels, type discussion should be put into the "Upgrades (non TDI Engine related)" forum. Non TDI vehicle related postings will be moved or removed. Please note the Performance Disclaimer.

Reply
 
Thread Tools
Old February 13th, 2014, 16:31   #1
tom101
Newbie
 
Join Date: Jan 2014
Location: Spain
Default A5 3.0 Tdi remapped, rear diff vibration over high torque

Hello, I need help with my car, it's an A5 3.0 tdi quattro '08 with 80K milles
I've remapped it with aprox. 300hp and 700nm (515fl).

My problem is that accelerating at low revs (between 2000-3000revs) in long gears (4th, 5th & 6th) there is an intense vibration/tremble around the rear diff. I'm not sure the vibration is in the rear diff or in the drive shaft.

Over 3000revs there is no problem at all, also in short gears there is not any vibration.
I'm pretty shure it's due to the high torque. But I have limited the remap to 600n/m and the vibration remains.

I have a friend with exactly the same car and remap 60k milles, and it has exactly the same vibration as me. So the problem it that the rear diff/drive shaft/ shaft bearing of this car can not allow this torque in low revs without trembling.


I like so much torque between 2k-3k revs, had anybody similar problems?
I would like to know any mods I could do to allow the rear transmission to hold high torque

thanks you very much

Last edited by tom101; February 14th, 2014 at 18:31.
tom101 is offline   Reply With Quote
Old February 13th, 2014, 18:30   #2
aNUT
 
aNUT's Avatar
 
Join Date: Nov 2006
Location: Front Range, Colorado
Fuel Economy: Great.
Default

Any time you have excessive vibration @ peak torque, the first things to investigate are the axles, mounts, and driveline. The AWD longitudinally mounted cars often have driveshaft stabilization issues. The driveshaft is supported by a rubber diaphragm, and it's been known to get soft or tear...there may be a stiffer one that's available. In North America we didn't get your car with TDI torque until very recently, so I haven't had to directly address any such complaints as all these cars are brand new.

You might also check for lash in the joints of diff itself.
__________________
www.dieselland.net
aNUT is offline   Reply With Quote
Old February 14th, 2014, 07:41   #3
mickyTDI
Veteran Member
 
mickyTDI's Avatar
 
Join Date: Sep 2003
Location: Longford, Ireland
Default

I get this with my remapped Passat, it's only front wheel drive. At 2000 rpm in a highish gear when i floor it the whole car shudders, over 2000 it doesn't. Is your car auto? I'm wondering is it the clutch doing mini slips.
__________________
2017 VW Passat 2.0 BiTDI 288.4bhp CUAA
mickyTDI is offline   Reply With Quote
Old February 14th, 2014, 18:17   #4
tom101
Newbie
 
Join Date: Jan 2014
Location: Spain
Default

Quote:
Originally Posted by aNUT View Post
Any time you have excessive vibration @ peak torque, the first things to investigate are the axles, mounts, and driveline. The AWD longitudinally mounted cars often have driveshaft stabilization issues. The driveshaft is supported by a rubber diaphragm, and it's been known to get soft or tear...there may be a stiffer one that's available. In North America we didn't get your car with TDI torque until very recently, so I haven't had to directly address any such complaints as all these cars are brand new.
You might also check for lash in the joints of diff itself.
Thanks you, I also think this noise can be the driveshaft trembling up and down quite fast due to this soft rubber diaphragm.
Strangely the vibration is always the same, with the same frecuency. Speed does not affect it at all.And as I said before, only appears below 3000revs and long gears.


Have seek many dyno remapped tests of this model and always has a light and progresive gain until 3000 revs, so I think is a stock problem.
Mine is quite aggressive over 1900revs as I requested to the chiptuner, I always had it in 1.9pd

I actually think the real problem is that this car has not been sell so much in north america. Because I am looking for race parts like one piece driveshaft, reinforced support bearings, poliurethane silentblocks,..... and I don't find nothing at all

regards and sorry for my english
tom101 is offline   Reply With Quote
Old February 14th, 2014, 18:26   #5
tom101
Newbie
 
Join Date: Jan 2014
Location: Spain
Default

Quote:
Originally Posted by mickyTDI View Post
I get this with my remapped Passat, it's only front wheel drive. At 2000 rpm in a highish gear when i floor it the whole car shudders, over 2000 it doesn't. Is your car auto? I'm wondering is it the clutch doing mini slips.
I think that's normal, my seat 1.9pd does too due to peak torque, but it dissappears quick.

The vibration I describe is loud, is like having an helicopter attached to your real axle until you lift your foot
tom101 is offline   Reply With Quote
Old February 26th, 2014, 16:25   #6
tom101
Newbie
 
Join Date: Jan 2014
Location: Spain
Default

well, I'm still not sure of if the noise comes from the driveshaft or the diff.

I've been looking for stronger driveshaft rubber, but didn't find anything to buy.

But I've found this way to reinforce this rubber fullfilling it with poriurethane window welt or similar.
I like it because is a fast and cheap way of test if reinforcing it, the noise gets reducer or not.

http://www.audizine.com/forum/showth...-3M-Windo-Weld

also have been looking for reinforced diff mounts and found this one,
the original ones are very soft too. The problem is that buying it from america delays so much and already have to pay additional tax, also this mount is realy hard and causes other diff noises as I have read in other forums.

I'm thinking about fullfill those rear diff mounts of poriurethane too in order to test, the original ones cost only 12$

http://www.apikol.com/index.php/prod...-mount-b8.html
tom101 is offline   Reply With Quote
Old February 27th, 2014, 04:57   #7
mojogoes
Veteran Member
 
Join Date: May 2003
Location: england
TDI(s): mk3 tdi golf
Fuel Economy: not much
Default

Hi!! Did your car have any signs of this same vibration what so ever before you had it remapped.................Its seems to me that if this was a fwd car it would have the same problems as what you describe but obviously shudder from the front end / gearbox etc as my mk3 golf would do if the tune had to much fueling and not enough advanced timing between 1800rpms and 3000rpms............You may have had a little shudder before tuning / a remap on paper but nothing that would cause you any alarm!!

So am I right in thinking that a tune / remap on this car would also need to in some way bypass the built in gearbox over torque system that regulates the amount of torque that the gearbox allows / sees , As it could be this which is in conflict with your tune and fighting against it?
__________________
A3 / mk3 golf with 249Whp "Now in the hands of someone else"

Last edited by mojogoes; February 27th, 2014 at 05:00.
mojogoes is offline   Reply With Quote
Old February 27th, 2014, 05:16   #8
Jayg
Veteran Member
 
Jayg's Avatar
 
Join Date: Oct 2012
Location: Anchorage, AK
Default

This sounds like a rear differential mount in my experience.
Jayg is offline   Reply With Quote
Old February 27th, 2014, 06:29   #9
mojogoes
Veteran Member
 
Join Date: May 2003
Location: england
TDI(s): mk3 tdi golf
Fuel Economy: not much
Default

Ah ha! yes also bad maintenance will show up any parts that need fixing after power upgrades lol.
__________________
A3 / mk3 golf with 249Whp "Now in the hands of someone else"
mojogoes is offline   Reply With Quote
Old February 27th, 2014, 06:54   #10
ben0069
Member
 
ben0069's Avatar
 
Join Date: Oct 2012
Location: wales
Default

I am also getting this problem, exactly the same symptoms, last week I removed my prop shaft and have had a new centre bearing put on, I was informed that the 2 end joints were fine, car has covered 197,000 miles . I will be re- installing the prop shaft tomorrow(fri) and will post back to see if that was the cause.
Just to add, I didn't have this problem before I put a hybrid turbo on and bigger nozzles.

Last edited by ben0069; February 27th, 2014 at 07:07. Reason: more info
ben0069 is offline   Reply With Quote
Old February 27th, 2014, 07:08   #11
mojogoes
Veteran Member
 
Join Date: May 2003
Location: england
TDI(s): mk3 tdi golf
Fuel Economy: not much
Default

Hi ben how much power are you running at present.............And did you have the car remapped / live tuned.
If the turbo and injectors/nozzles are a well known quantity then who is the chip company who wrote this file for that particular combo.
__________________
A3 / mk3 golf with 249Whp "Now in the hands of someone else"

Last edited by mojogoes; February 27th, 2014 at 07:12.
mojogoes is offline   Reply With Quote
Old March 1st, 2014, 09:28   #12
ben0069
Member
 
ben0069's Avatar
 
Join Date: Oct 2012
Location: wales
Default

prop shaft worse now than before I took it off!!! I should have saved a lot of time and expense by just getting a new one in the beginning!! more expensive times coming up, and I don't think it was the cause of the original vibration issue either, prop shaft vibration is more like a helicopter rotor being under the whole car and the faster you go the worse it gets the original vibration still looms between 2000 and 3000 revs.
could the engine be fuel starved ? would that account for this extreme shuddering? but then if I change down and floor it I get no vibration.
ben0069 is offline   Reply With Quote
Old March 1st, 2014, 10:08   #13
mojogoes
Veteran Member
 
Join Date: May 2003
Location: england
TDI(s): mk3 tdi golf
Fuel Economy: not much
Default

No!! this is a sign of over fueling and not under fueling...........it was known back in the day and even accrued in cars who ve pump were a little to advanced and then after nozzle or a standard chip/map was added they would shudder exactly in the rev range you mention....................if you +hammered the pump you could also get it to do the same thing......Can you put it back to the standard tune to rule this out.
__________________
A3 / mk3 golf with 249Whp "Now in the hands of someone else"
mojogoes is offline   Reply With Quote
Old March 1st, 2014, 11:29   #14
ben0069
Member
 
ben0069's Avatar
 
Join Date: Oct 2012
Location: wales
Default

Thanks for that reply, it seems plausible, I will have to look into it.
ben0069 is offline   Reply With Quote
Old March 1st, 2014, 12:42   #15
ben0069
Member
 
ben0069's Avatar
 
Join Date: Oct 2012
Location: wales
Default

Thinking back I must amend one of my earlier comments that I didn't have the problem before the turbo and nozzles, it was actually after the re map that this problem appeared. Which was done by.... which isn't a particularly good map after all and was bloody expensive.
ben0069 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
High vibration from R5 TDI motor AntonvBosch VW Touareg TDIs 6 May 17th, 2013 15:37
2012 passat tdi vibration at high speeds monty66 VW Passat Family (NMS and B7) TDIs (2012+) 12 June 27th, 2012 21:19
A5 clutch torque rating. 06SpiceRedTDI VW MKV-A5 Golf/Jettas 7 August 1st, 2007 08:09
My A5 TDI Rear end CATDI VW MKV-A5 Golf/Jettas 4 April 14th, 2007 08:18
Torque Sensing Diff information... Gary Miyakawa Upgrades (non TDI Engine related) 1 October 14th, 2001 14:06


All times are GMT -7. The time now is 01:18.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2017, All Rights Reserved
Page generated in 0.14588 seconds with 11 queries
[Output: 128.67 Kb. compressed to 107.09 Kb. by saving 21.59 Kb. (16.78%)]