GTI transmission mod for fuel economy thread - page 2 - General - VWDiesel.net The IDI, TDI, and mTDI source.

• #15 by bhtooefr on 20 Feb, 2006 09:09
• I don't know if it's possible to swap a .681 into an 020.
  
  However, here's the .681 02J thread over at TDIClub: http://forums.tdiclub.com/showthread.php?t=119288
• #16 by bhtooefr on 20 Feb, 2006 12:10
• There appears to be a .71 5th that is in the following transmission codes:
  
  6G, 7A, 7D, FH, FJ, FN
  
  Same conditions as the previous numbers I gave, it's 2907 RPMs in 5th. This is much less agressive, but on an NA diesel, a 143 RPM drop is still a big deal, and isn't too much. Roughly 39.5 hp are available at that RPM level, as opposed to 41.5 for the stocker's RPM level, and 37.5 for the GTI's RPM level.
  
  Now, would someone with ETKA find out what the part numbers are for this gear set?
• #17 by BlackTieTD on 20 Feb, 2006 12:17
• .71 in FF code trans as well.
• #18 by vph on 25 Feb, 2006 19:30
• I have an 85 golf that was originally a NA and someone converted it.  They didn't get it running and it had set for several years... since 92.  I picked it up for $200 bucks...sweet deal.  I had a pump off of a spare NA and bingo!  Dave at Passenger Perf. shipped me a downpipe and I had the rest of the exhaust done at 2.5" out the back.  It's fun.  Sorry, I got carried away... back to the topic... It has an ACH trans...I also have an old Cabrio that I'm parting out with a FF trans.  Are there any downsides to the FF?  I'd like the longer gearing.
• #19 by bhtooefr on 26 Feb, 2006 06:37
• This tranny's ratios are:
  
  FD: 3.89
  1st: 3.45
  2nd: 1.94
  3rd: 1.29
  4th: 0.91
  5th: 0.71
  
  You'll get 2869 RPMs at 70MPH in fifth with 175/70-13s.
  
  Note that from 3rd on, the gears are taller. Also note the final drive is taller. Acceleration in all gears will be negatively affected, especially third through fifth (however, all of these gear swaps would be negatively affecting at LEAST fifth).
  
  However, I'm not going to do anything until I get a turbodiesel. I had to overtake someone on the interstate yesterday, and was watching the speedo SLOWLY climb...
  
  55............56............57............58 (so on, so on)
  
  And the guy that was tailgating was kept back by my smoke cloud
• #20 by vph on 26 Feb, 2006 06:59
• Seeing as I have the added torque of the turbo I think I might do it.  The only other thought is that I'd like to find a 3.67 final drive.  If I could get that final and install it I'd have it installed in my spare FF trans before tearing out my current trans.  
  
  Does anyone out there have a 3.67 laying around?
• #21 by bhtooefr on 26 Feb, 2006 09:03
• You'd be better off asking around on gasser forums.