BUGA Community
Technical => Driveline => Diffs => Topic started by: Gordon on February 25, 2011, 09:43:53 AM
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Hi All
I've spent a good few ours going through all of the diff related posts on the forum and eventually decided to start a new post as my mechanicals differ somewhat from the more common setups. So apologies up front to all those who are sick of diff postings :-[
I'm running the factory standard 4 cylinder option - the Vauxhall Victor 2.3L slant motor behind a standard 4 speed manual Bedford gearbox. I don't have any plans to change this setup. The diff is the standard 4.1:1 factory option and I am suffering with the usual complaint. She pulls like a feight train but tops out at about 80km/h. You can push her a bit further but she is over revving at that stage. We have had a failed attempt at installing a Cresta diff centre and Murray from McQuoid Engineering is now suggesting that we look at modifying the axle to accept a Ford Falcon diff centre. This gives us plenty of spares going forward and also a great deal of choice in terms of the ratio.
So the question now is around the ultimate ratio for my setup. In terms of weight the van is factory standard with only some light carpeted wood panelling in the back and an aluminium framed double bed base. In terms of future use the van will mainly be used for cruising and camping and we also plan to tow a jet ski at some future stage. The ultimate setup would allow us to cruise happily at 100km/h on the open road and with just enough grunt to make driving around the suburbs pleasant. Improved fuel economy would be a bonus, but isn't essential.
Any advice would be greatly appreciated.
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3.45:1 i dont think youd bother going 3.89 as its not enough difference to the 4.1 to worry about. 3.45 will be the ratio you want. wouldnt want to go any taller with a 4 cyl! good for driving at 100 althou still reving a bit will be ok for towing small stuff.
i have a question for you new zealand blokes. do you guys ever get holden 6's in your vans or were they are slant 4's? i recon the holden 6's are sluggish image a slant 4!
cheers
ben
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3.23 3.23 3.23 3.23 3.23 3.23 3.23 3.23 3.23 3.23 buga i'm repeatin myself :D ;D ;) i have found this to be the best comprimise between torque & cruising speed cheers neil
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I agree with Ben, some thing around 3.4:1 or 3.5:1 would be you best option, she would still have some get up and go off of the line, but would also have a bit more top end speed.
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the ford option is the borg warner, which came out in ford and holden and others. fords mainly did the 2.xx and 4.xx while holden did the 3.xx (the xx is various numbers).
I'm changing my ratio from 3.08 to 3.45 (down at murrays tomorrow)
Give steelie gears a call, sorry forgot his name, he is really good on ratios vs rev vs speed
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Sorry guys, 3.5 is to high for a 2.3 litre 4cl, great behind a six but a 4 I'm not sure, ok Gordon just pulling your leg, maybe what you want it for it maybe ok, just keep in mind those open roads in NZ with slight hills, as I said before you only have a 4 speed and 3rd gear is not a driving gear, so you can't stay in it forever ;) David let me know how it dives when done, would be interested to find out.
Hay has anyone put a 5 speed behind a 2.3??
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welllll i dont agree with ben .....so there :P 3.5 will be to high were talking about a pizzly 4 cyl here its absolute max rpm would be 5000rpm i could sit here and work out the roadspeed/rpm but i cant be stuffed ...its been a long hot shit of a day and i need a drink!!! ;)
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have had most , best one for me was 3;23 with Holden 253 was very reliable combo
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Yes, someone thinks the way I do................... :D
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I went the Holden 3.45 Diff with a 6cyl holden & 4 speed box & its a good combo. 3rd gear up hills but 2nd in the big ones..
100k plus at 2,200rpm 80km at 1700rpm thats pulling 2.4tone (camper )
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gday what wheels are u running? hq? if your changing the diff then your probably changing the wheels ive got a normal holden banjo diff in mine but had to get my windened stock hq wheels offset on the rear to suit the narrower diff, didnt cost too much. but im sure u could find some wheels to fit. u would just have to reweld the spring and shock mounts. then u could choose whatever diff ratio u want and see whats best! changing the diff centre is a piece of piss. i run a 3.08 with a 202 and trimatic and cruise at around 2700-2800 at 100...went all around oz with a fully loaded van sweet as! ( mind u spent five grand on gas!!!) take it easy... westy
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gday what wheels are u running? hq? if your changing the diff then your probably changing the wheels ive got a normal holden banjo diff in mine but had to get my windened stock hq wheels offset on the rear to suit the narrower diff, didnt cost too much. but im sure u could find some wheels to fit.
I have a standard width banjo diff and 15x10mags with a 3 3/8 backspace and a 8mm spacer inbetween. I'll be bending the lip on the wheel well down for a tiny bit more clearance when fully loaded.
The 10"mags look great but will need flares, i also have a pair of 15x8.5"mags (maybe for sale soon) with the same backspace, and would probably fit under standard guards with a 235 or 245 tyre
But from memory, hq steel rims are scarily close to the springs and guards with a standard width diff
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Bas, changed the crown wheel and pinion to 3.45, still not 100% happy with it. The speedo is now out so is hard to gauge but keeping up with the traffic on the motorway the speedo is around 110, which cruises at about 1950rpm, at 120k's its at about 2200 rpm which is pretty much the same as the 3.08 gears. I might try find some 3.7 gears after easter
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David, slip around one day and look what device they have set up on the box to correct the speedo, it looks like factory but the boys at autolab had no idea, thought the 3.45 would of been a good match.
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David, slip around one day and look what device they have set up on the box to correct the speedo, it looks like factory but the boys at autolab had no idea, thought the 3.45 would of been a good match.
A speedo redution box? can you take some pics/ and or tell me where you get them?
I'm sure i'll need one very soon
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Hey All. Thanks for the opinions and suggestions voiced so far.
Westy I'm currently running 8 inch HQ studded jellybean style mags on the back. They are 14 inch in diameter and are fitted with 245/50/14 rubber. They are proud of the body by a good bit on each side. I like the look but the authorities may have different ideas :).
Hey Busy, sorry to hear that the 3.45 hasn't worked out the way you wanted.
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Hey Aaron
I ran a speedo adjustment type box on my CF2 which was setup for the TH350 auto box and the standard CF2 speedo guage. Unfortunately I don't have a picture of it, but it was manufactured by Keinzle (who I think also make movements for clocks). It was a rectangular aluminium casing bout 3 inches long and 1.5 inches wide and it had a nut type fitting that allowed you to screw it directly into the gearbox where the cable normally goes. Directly next to that fitting on the housing it had a similar fitting that your speedo cable now goes into. If you opened up the box it had two interchangable gears that adjusted the drive ratio. From memory I had it fitted by a crowd who repaired all types of guages. I watched them set it up and they had a measured off distance in their yard. With the cable straight into the gearbox they disconnected the other end from the back of the speedo and counted the number of cable turns over the measured distance. They used their findings to work out the ratios needed in the unit and then selected the appropriate colour coded gear from a box of gears they had. Sorry I don't have the exact details for you.
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Bas, changed the crown wheel and pinion to 3.45, still not 100% happy with it. The speedo is now out so is hard to gauge but keeping up with the traffic on the motorway the speedo is around 110, which cruises at about 1950rpm, at 120k's its at about 2200 rpm which is pretty much the same as the 3.08 gears. I might try find some 3.7 gears after easter
Jaycar have a kit that you can build to adjust electronic speedos.
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Will load a piture of the unit that is used on mine... Will post picture tomorrw as it's to dark out there now...
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Jaycar have a kit that you can build to adjust electronic speedos.
who has an electric speedo? Bedfords at least have a mechanical speedo
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TOM TOM speedo ;D
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Gordon, you want some flares like I have on my standard CF hehe not sure if I have the photo of them on here, but they are just a strip of rubber I got from para rubber and screwed to the wheel arch as I had to cover the tread for the cert.
I'm running 235/70/14 on the back
Jesus, I'm running commodore dash which is eletronic
Bas, I'm going to take the van down to Hamilton again next weekend again and see how it goes. Will get gearing right before I sort speedo out.
The van has a full tank of petrol and some "stuff" in the back so is pulling some extra weight, will be empty for the nats (can dump it all in the garage when I pull the custom van out), hopefully it will cost less than $67 to get there and back
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David have you thought about running 15's on the back...... Ok I now see your running 14x 70's so not to far off.
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Jesus, I'm running commodore dash which is eletronic
Oh, my apologies
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who has an electric speedo? Bedfords at least have a mechanical speedo
rocket has one of those jaycar ones.
http://cgi.ebay.com.au/NEW-5-GPS-Australia-2010-sat-nav-Car-navigation-system-/220670332599?pt=AU_Electronics_GPS&hash=item3360fa0eb7 (http://cgi.ebay.com.au/NEW-5-GPS-Australia-2010-sat-nav-Car-navigation-system-/220670332599?pt=AU_Electronics_GPS&hash=item3360fa0eb7) - cheaper than getting a speedo cable made up and you get a gps for free!!
But from memory, hq steel rims are scarily close to the springs and guards with a standard width diff
i have a banjo diff in a van here and the walls of the tyres are about 10mm from springs but whats wrong with that? if the tyres touching the springs there is something dramatically wrong already..
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Now these would look nice.................... 15x7 - 15x8 - 15x10
http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Wheels-tyres/Alloy-wheels/auction-356747893.htm (http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Wheels-tyres/Alloy-wheels/auction-356747893.htm)
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Busy, try a arfter market Harley shop, or punch up Zodiac on the pc, we sell a few of these, sorry to say that l refuse to do electrical stuff so not quite sure if their compatable. They come in 1 to 1 or 2 to 1, hope this helps
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Bas, I was wrong, my rears are 235/60/14 not 70 series but they aren't much smaller than the original commodore 15's
Thanks Rossie I'll look into it
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Ok, on the camper I run 275x50x15 on the rear and 205x75x14 on the front, they are close to a perfit match, considering how many rotations a wheel does it plays a major part. I guess it does not matter what the holden runs as you have proven this with the diff ratio, as if that was the case you should of been ok.
Food for thouhgt...Bas
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Hi all,
Yet another queery about diffs, :-\ i've just acquired a diff with a chev center, i've been told its a 2.92 ratio and it will be going into my van which runs a Ford 302 with a c4 trans, will this gearing be too tall ??? I'm running a standard Beddy diff at the mo and the poor thing is revving at 2500 at 80 kmh, and with the standard diff i get into 3rd gear before i even leave my driveway!! :(
I have 14"x7" rims but havent decided on what rubber to run yet, obviously this will make a difference too, anyone have any recommendations on tire size ???
Stuey.
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might be a bit tall, what do you want it for, around town, motorway, drags .... 3.3:1 is a more universal gearing
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Hey Busy,
Just want it for around town and motorway work.
If i reduced the profile size of the rear tires would this affect it much ???
Stuey.
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Hey Stuey I recon that 2.92 would be fine with that beaut little 302 FORD all the old falcons had 3.00 & they were fine but they had 14inch wheels if you go bigger wheels just make sure the overall diameter off tires are about the same Ive had lots of falcon v8s with that combo & they towed heavy caravans easy especally the autos but I had a GT 4speed & it was hopeless especially for passing 3rd too high 2nd too low But thats only my 2bobs worth others might not agree Cheers Reid
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Thanks for that Reid, :) any info is better than none at all, i'm gonna try the 2.92 and will probably go for 235/60/14 tires on the rear, unless anyone else has any better ideas ???
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yeh every ford down our local wreckers is running 2.92. i checked half of them because i was looking for a different ratio! all 6's. your v8 will handle it easily.
ben
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it will handle it but with hills and the aerodynamics of the bedford .... try is the only way
Like my standard CF, i had the 3.08:1 diff gears, running the standard commodore drive line but I had to go to 3.45:1 for motorway, round town was fine with either
235/60/14 is a good size tyre, i have them on back of my standard cf (and front of custom cf), the toyo is a nice tyre, tread and look and grip well