Information on the 5th gear mod all in one post

Swalsey

Member
Hi

I've been mulling over the facts trying to make a decision and put this together - thought I'd post it up in case others have found themself endlessly looking through pages of the main thread here http://www.a2oc.net/forum/showthread.php?t=11914 .

Table from Mike on engine speeds
mph / 0.756 / 0.700 / 0.681 / 0.650 / 0.625
70 2575 2383 2318 2180 2127
60 2205 2042 1987 1867 1822
50 1838 1703 1655 1555 1520
40 1470 1360 1325 1245 1215
30 1103 1020 995 935 912


Reduction in engine revs over standard 75hp
mph / 0.756 / 0.700 / 0.681 / 0.650 / 0.625
70 2575 192 257 395 448
60 2205 163 218 338 383
50 1838 135 183 283 318
40 1470 110 145 225 255
30 1103 83 108 168 191

Rolling road data courtesy of Will here: http://www.a2oc.net/forum/showthread.php?t=12702&page=2
rpm / torque base / torque remap / power base / power remap
1500 / 100 / 100 / 29 / 29
2000 / 160 / 200 / 61 / 76
2500 / 160 / 190 / 76 / 90
3000 / 130 / 180 / 74 / 103
3500 / 110 / 160 / 73 / 107
4000 / 110 / 140 / 69 / 107


Prices

The prices for the ratio sets have increased by 2.5%, so the new prices are:

0.622 ratio - £85.11 & £62.87 = £151.68
0.659 ratio - £86.79 & £76.11 = £166.97
0.681 ratio - £123.74 & £69.60 = £198.17

2nd hand 90hp 0.7 cogs suggested price:
(quoting Mike's posts in group buy thread, post 196)
I can suggest is that the new prices are £90.22 & £143.47, so a 50% reduction would not be unreasonable, taking the total price to £116.85.

It's really for 90PS owners to set their own rates though - I know that I'd rather keep hold of the old ratios just in case, as opposed to underselling them.

Mike's fitting costs:
I'd estimate fitting costs to be around £80 plus parts (so add on for transmission oil and possibly a new gasket - I'll advise better when I've done mine), or you can supply your own oil if you prefer (2 litres will be needed).

Power/torque curves from riverlad here:
http://www.a2oc.net/forum/showpost.php?p=94262&postcount=17

and Mike's graph here:
A2TDiRatios.gif

A2TDiRatios-35to85mph.gif


Thank to all the contributors on the topic!
 
Last edited:
Not sure - I think since the 6 speed gearbox upgrade came along, the longer 5th gear mod has fallen out of favour a little!
 
thats dissapointing, have you had yours long dan?? how do you find it has it improved mpg much??
 
thats dissapointing, have you had yours long dan?? how do you find it has it improved mpg much??

Take a look at my fuel spreadsheet (as below at 27-Mar-2010 ). Note that I had a remap at the same time.

It's difficult to compare like for like unless ones journeys are similar before and after and the driving style is the same - a remap does allow one to exercise the turbo occasionally ;) But looking at holiday fuel consumption:

Sept 2008 - 58mpg
May 2010 - 62 mpg (4,000 mile trip to Sweden) immediately after the change
Sep 2011 - 60 mpg

Not that much of a difference. I made the change for quietness on motorway driving but then had the remap to help at lower speeds (I tend to move from 3rd to 5th). However, the remap doesn't really help as it doesn't impact until about 2,000 revs.

In recent years my type of journeys has change considerably with more town and shorter journeys and more A and B roads. On B roads the longer 5th can be a pain. So the typical mpg has dropped to 55 but as shown by a recent trip Dawlish (100 miles each way) I can still get 60+ mpg with the engine (from memory) cruising at 2,200 to 2,500 rpm.

I'm thinking of removing the remap so I can get far more choice and competitive prices on insurance. If I took the remap off I would probable take the longer 5th off as well.

Hope this helps rather than confuses ;)
 
Last edited:
Yes I'd say it gave my MPG a useful tickle upwards, especially so when I was doing 60miles a day all on m-way/dual carriageway last year. Whether it's enough of an MPG boost to have actually been cost-effective though I don't know. There is a wider gap between 4th and 5th and I think because of that a remap is essential as you need more driveability from the engine to be able to cover it, but you soon get used to it. As Alan says though the biggest benefit is probably the lower cabin noise and vibration when driving at m-way speeds due to the (significantly) lower RPMs. It does make the car feel more relaxed generally. I think I've probably had mine in for at least 3 or more years and an awful lot of miles. Would no doubt find driving a normally geared TDi now a bit odd!

I'm sure the parts are still available as they're all original VAG parts from the catalogue (albeit from I think a VW commercial van gearbox!), and fitment is straightforward as the 5th gear pair is handily located on the end of the shafts, so when the gearbox cover is popped off, there are the cogs.
 
Back
Top