I know this may have been covered, but I have done the V6 conversion and am enquiring if any one has sorted diff ratios. At 100 the tacho reads about 3k so want to lower this abit......Does anyone know what ratios I can get down to or any affordable diff conversions......any help greatly appreciated
PeterD said
01:10 PM Jun 21, 2018
More info required. What vehicle are we discussing? What V6 conversion have you installed? If you talk in code then most of us will no understand you.
Joda said
02:08 PM Jun 21, 2018
Hi mick, take it that the vehicle is a ford vg transit van? Auto or manual? Google the owners clubs first, see what options You can find there, what revs did the original motor sit on?
The v6 will have a designed rev range for the car it was originally for, this may not suit a different car due to gearbox ratios & different weights of vehicles, plently of diff rebuilders out there who could advise You.
Joda
Eaglemax said
06:40 PM Jun 21, 2018
Yes, not enough info but-
Eg. My jba tourer has a holden v6 engine, 5 speed but is mated to a cortina 4 cylinder differential that has a ratio of 3.7:1. My revs are too high. At 110kph in 5th, revs are around 2600. Means I have to tow in 5th gear which is not ideal.
Now, cortinas came out in a 2.9:1 diff ratio for its 6 cylinder car. If that was installed then revs will drop from 2600 to about 1900 rpm or 2400 in 4th, much better and 5th can be utilised when not towing on the highway, for good economy which is what an overdtive is meant to do.
So, do some research as to what diffs came out in your transit , if falcon diffs were used and what ratios are available. Work out what % reduction of revs are desired and reduce your diff ratio accordingly. Seek out a speedo specialist for speedo recalibration and away you go.
Hope that helps
Eaglemax said
07:16 PM Jun 21, 2018
Mick, further to my above post, depending on a number of factors involving clearance to the vans body and guards, you can try to fit larger tyres.
Use this site: https://tiresize.com/tyre-size-calculator/
Put in your tyre size which I believe is 215/75 r16
Then choose a tyre with larger diameter like 235/85r16 the site will calculate the differences.
Bare in mind you can only go (I think 15% or 20% larger before you are illegal in width from standard.
The above larger tyres will be 20mm wider but will be over 10% laeger circumference. That means a drop of 10% in revs...instead of 3000rpm you'll be doing 2700, a nice drop. It will raise your van 1.5" or 37mm.
You will use the same rims and diff. Just get your speedo recallibrated. Download the gps speed program and accurately find your true speed eg indicated 100kph , real speed 110kph. Hence need speedo gears altered 10%
Aus-Kiwi said
08:27 PM Jun 21, 2018
Get a diff from an E series Falcon . 3.27 or 3.45 from XR series . Disc brakes and only Require welding on leaf spring coupling . A diff from station wagon or Ute . Is leaf . So adapting is easier . XR diff would be LSD . With 3.27 ratio rpm should be around 1800 / 2000 rpm . Allows the overdrive in auto to work properly . kickdown on hills etc . keeping engines torque, economy in its sweet spot .
-- Edited by Aus-Kiwi on Thursday 21st of June 2018 09:32:09 PM
Aus-Kiwi said
08:37 PM Jun 21, 2018
Like . https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F262898441249
madaboutled said
09:36 PM Jun 23, 2018
Mick, I have a VG with V8 you might find the diff is a ford 9 inch, if so then apparently the ratio's are easy enough to change. Mine is doing about the same revs which I'm OK with cause it rarely drops down a gear to go up hills. My thinking is if I play with the ratio's to drop the revs then it will be using lower gears on just about all hills in which case would use more fuel. .... just sayin!.
Aus-Kiwi said
09:46 PM Jun 23, 2018
9â is way over engineered . Yes good diffs . But he is way under 200 kw . I have 500 kw through std Falcon 3.27 LSD , 27 Spline diff . Half the unsprung weight . You need ratio between 3.08 to 3.5 . With 4 speed auto . Transits did not come out std with 9 . If theres one fitted ! Great . Just replace centre head unit with 4.5 ratio . Should give you roughly 2200 rpm at 100 kph .
-- Edited by Aus-Kiwi on Saturday 23rd of June 2018 09:52:47 PM
Mickthesparky said
10:51 PM Jul 8, 2018
Hi mate........I will look into it for sure......
Mickthesparky said
10:58 PM Jul 8, 2018
Hi guys....Sorry about the lack of info.....It is a VG Transit with a VP Commodore V6, and has the Turbo 700 4 speed auto behind it......Current ratio is 5.14.....Aus Kiwi do you think that the E series diff will fit ok?.......I am turning it into a Lekkies van with a bit more torque, but have a supercharged V6 I will put later on.........current tyres are 225/70/R15.. So I am trying to go for economy but enough torque to drive it with all my Lekky **** on board....
I have an LS1 in the shed that would look................
-- Edited by Mickthesparky on Monday 9th of July 2018 12:09:04 AM
Jaahn said
10:15 AM Jul 9, 2018
Hi Mick
As you probably already know the GM Turbo 700 has an overdrive top gear of 0.70. So you should take this into your consideration when selecting the diff ratio.
EG existing diff is 5.14 x 0.70 give effective top gear ratio of 3.6.
I know this may have been covered, but I have done the V6 conversion and am enquiring if any one has sorted diff ratios. At 100 the tacho reads about 3k so want to lower this abit......Does anyone know what ratios I can get down to or any affordable diff conversions......any help greatly appreciated
Get a diff from an E series Falcon . 3.27 or 3.45 from XR series . Disc brakes and only Require welding on leaf spring coupling . A diff from station wagon or Ute . Is leaf . So adapting is easier . XR diff would be LSD . With 3.27 ratio rpm should be around 1800 / 2000 rpm . Allows the overdrive in auto to work properly . kickdown on hills etc . keeping engines torque, economy in its sweet spot .
-- Edited by Aus-Kiwi on Thursday 21st of June 2018 09:32:09 PM
Mick, I have a VG with V8 you might find the diff is a ford 9 inch, if so then apparently the ratio's are easy enough to change. Mine is doing about the same revs which I'm OK with cause it rarely drops down a gear to go up hills. My thinking is if I play with the ratio's to drop the revs then it will be using lower gears on just about all hills in which case would use more fuel. .... just sayin!.
9â is way over engineered . Yes good diffs . But he is way under 200 kw . I have 500 kw through std Falcon 3.27 LSD , 27 Spline diff . Half the unsprung weight . You need ratio between 3.08 to 3.5 . With 4 speed auto . Transits did not come out std with 9 . If theres one fitted ! Great . Just replace centre head unit with 4.5 ratio . Should give you roughly 2200 rpm at 100 kph .
-- Edited by Aus-Kiwi on Saturday 23rd of June 2018 09:52:47 PM
Hi mate........I will look into it for sure......
Hi guys....Sorry about the lack of info.....It is a VG Transit with a VP Commodore V6, and has the Turbo 700 4 speed auto behind it......Current ratio is 5.14.....Aus Kiwi do you think that the E series diff will fit ok?.......I am turning it into a Lekkies van with a bit more torque, but have a supercharged V6 I will put later on.........current tyres are 225/70/R15..
So I am trying to go for economy but enough torque to drive it with all my Lekky **** on board....
I have an LS1 in the shed that would look................
-- Edited by Mickthesparky on Monday 9th of July 2018 12:09:04 AM
Hi Mick
As you probably already know the GM Turbo 700 has an overdrive top gear of 0.70. So you should take this into your consideration when selecting the diff ratio.
EG existing diff is 5.14 x 0.70 give effective top gear ratio of 3.6.
Jaahn