Hi Guys, my Avenger runs out of puff at about 100kph, just like most old school cars. I was wondering is there any Higher ratio diffs fitted to other models of Avenger? Mine is the good old 75' 1300 super so its no rocket ship by any means, But it would be good if I could just drop the revs a bit at cruizing speed without having to do any major gearbox conversions. Any suggestions? Cheers.
Chapter 8 page 132 of Haynes manual lists about 5 different ratios from 3.54 up to 4.37
Crown wheel 35/37 and 39 teeth mated with pinion wheel 8/9/10 and 11 teeth
4.37 37/9
3.54 39/11
apart from reguritating that I have no idea wich gives better topend or acceleration - suspect the lower is Auto and give better acceleration
4.37 found in early 1250 Models
I just did a 5 speed conversion on mine which was awesome for dropping the revs. Dropped them from 3,500RPM@100KPH down to 2,800RPM@100KPH. But yeah that is a pretty expensive route to take.
Have a read of this topic, we discussed different diff and gearbox ratios.
http://www.avenger.co.nz/forum/index.php?topic=32.0
Quote from: avenga on February 01, 2011, 01:21:03 PM
Gear ratios (to chassis number R4 184358)
4th 1.000:1
3rd 1.366:1
2nd 2.029:1
1st 3.317:1
reverse 3.680:1
Gear ratios (to chassis number RH 184359)
4th 1.000:1
3rd 1.387:1
2nd 2.165:1
1st 3.538:1
reverse 3.680:1
4.37:1 35 crownwheel teeth, 8 pinion, road speed= 25KPH per 1000RPM, 4,000RPM@100KPH
4.11:1 37 crownwheel teeth, 9 pinion, road speed= 26KPH per 1000RPM, 3,846RPM@100KPH
3.89:1 35 crownwheel teeth, 9 pinion, road speed= 27KPH per 1000RPM, 3,704RPM@100KPH
3.70:1 37 crownwheel teeth, 10 pinion, road speed= 28KPH per 1000RPM, 3,571RPM@100KPH
3.54:1 39 crownwheel teeth, 11 pinion, road speed= 30KPH per 1000RPM, 3,333RPM@100KPH
And you can change the cruising speed a bit by tyre size. Read this post. Ross (Oldschool) said changing his tyre size made it better on the open road.
http://www.avenger.co.nz/forum/index.php?topic=96.0
Also have a read of my 5 speed gearbox conversion.
http://www.avenger.co.nz/forum/index.php?topic=60.0
personally I would not go to that effort, of swapping Gearbox unless it was my Daily and I was traveling long distances
plug and play /diff / tire sizes sound simple
try the below for playing with tire sizes
Quote from: JoKer on February 28, 2009, 09:34:20 AM
For all sorts of car related data and is not guaranteed 100% perfect but is capable of your general needs
(http://img.photobucket.com/albums/v427/JoKerNZ/c-calcv2.jpg) (http://dl.getdropbox.com/u/1025165/CarCalculatorV2.1_free.zip)
Please accept the ZIP file download 21KB filesize (TINY!)
Full credit to Stephen Penney [Author] and original link (I have lost) from NissanSilvia forums in AU for file origin
please report any problems with the file to me
Hey Sam. Sticking they factory wheels back on will help a bit, as the 185/60s on the car now are relatively small
Cheers guys, all great suggestions. I did stick the standard rims & tyres on for a day and it helped, but they look terrible so they promptly came off again lol. I think the 3.54:1 ratio diff would be the go. Now Ive just got to find one. Ill stick up a wanted add. Also I think its about time I throw that 1600 in ;D
Good luck finding a 3.54:1 in NZ. Most diff's are 3.89:1 or 4.11:1. I use a 4.11:1 estate diff in my race car and a 3.7:1 in my '75. I used to scrap late model Chrylser Avengers which had the 3.7:1 diff but all the hillmans are 3:89:1
Quote from: NZTiger on February 01, 2011, 08:56:46 PM
Rear axle ratio...
All NZ 1500 had 3.89.
1300 had 4.11 along with the Estate.
1600 had 3.89 until the last mk2's that changed to 3.7, so 3.89 is most common.
4.375 was never fitted to NZ built Avengers, it was standard in UK 1250 and 1300? and also 930cc Sunbeams.
I am sure that 3.54 was never used for NZ Avengers and I am not sure what it was used in.
Quote from: 1300super on May 31, 2011, 03:11:50 PM
Also I think its about time I throw that 1600 in ;D
this haha.
also, another one of my plans for it was to get some 14 or 15" steels of a citreon (same stud pattern) and get them widened. then could run a semi low profile tyre on it so it looks lush, but still retain a decent rolling diameter.
i have to pull my diff out as I am 1 wheel drive.. will count crown wheel (was welded-locked diff)
same with the spare/original in the shed
Just don't weld your diff like this.
(http://www.pirate4x4.com/forum/attachment.php?attachmentid=530018&d=1276882298)
hahha yea thats where i went wrong! awesome windup that was...
see how the 1600 goes sam before you change diffs etc my old 1500 at home would sit at 90mph flat out back home so 60mph shouldnt be that stressful on the running gear,have no idea what ratio diff was in the 1500 super will get a look later
Yeah thats not a bad idea Dave. Ill chuck it in and let you guys know how it goes.
Once I got the speedo and tacho working on my 1979 1600 GLS it told me I was doing 3000rpm @100 km/h. It has 165/80-13 tyres. It probably has the 3.70:1 diff, the lowest ratio one you can get in NZ Avengers. My other 1600 Hillman Avenger with a 3.89:1 diff and 175/80-13 tyres works out to the same 3.70:1 ratio, so you can make quite a difference to the revs by fitting bigger rims/tyres. There's lots of 3.89:1 diffs around (saw a few at Smash Palace) and it would be heaps better than the 4.11:1 one you have at the moment, whether you're running a 1300 or 1600 motor.
Your speedo must be wrong or something Ross because a 3.70:1 gives you 3,571RPM@100KPH and because the speedo picks up the speed from the gearbox it doesn't matter what tyre size you have, It won't effect what your gauges are reading unless you are using an external speed sensing device like my GPS speedo.
Even the 3.54 is only 3,333RPM@100KPH so to get 3,000RPM@100KPH indicated on the speedo you have to go down to like a 3.2:1 with a speedo cable to suit.
If you want to do some testing Ross we can go for a drive with my GPS speedo plugged in to each of your Avenger.
And the difference between 165/80/R13 and 175/80/R13 is 2.6KPH @ 100KPH and the difference between the 3.70:1 and the 3.89:1 is only 3.7KPH difference @ 100KPH so neither are going to make a huge difference. I worked out the tyre swap between those sizes will drop the engine by 107RPM and the diff swap from 3.89:1 to 3.70:1 would drop the engine speed by 133RPM so bugger all change really.
Compare this to my 5 speed conversion with 5th being 0.82:1 which with standard tyres would drop a 3:70:1 Avenger from 3,571RPM@100KPH(28KPH/1000RPM) to 2,928RPM@100KPH(34KPH/1000RPM), dropping the engine speed by 643RPM at 100KPH. In my Avenger with the combo of my tyres and 3.7:1 diff I get ~2,800RPM@100KPH going by my GPS speedo saving me ~771RPM @ 100KPH.
my spare diff is 3.89, check build thread for cool 200kph + run
I saw that. Man your new engine is quick. 0-200KPH in only a few seconds.
You should switch to a 4.11 for rally use, gives you better acceleration but kills top end a bit.
I could pull 200KPH down the back straight of Pukekohe flat out in top with my 4.11:1 diff.
Yes I thought the speed was a bit high for the RPM, as the manual says the 3.70:1 does 28 km/h per 1000 rpm = 3571 rpm @ 100 km/h on standard 155/80-13 tyres, which is 3474 RPM on my 165/80-13 tyres.
My tacho is probably accurate, so my speedo is probably reading 10 to 15% high, like Scarletts....lol
Yup, as I said. the tyre swap drops the engine revs by around 100RPM so 3474RPM@100KPH sounds right.
I was getting around 3,500RPM@100KPH on my 185/70/R13 tyres which is a 5.5mm increase in tyre diameter. 165/80/R13 are a 8mm increase so 3474RPM@100KPH would be spot on.
But the 3,000RPM@100KPH you said before is way too low for any tyre/diff combo you could get away with. They only way to get that low is a gearbox or diff conversion.
Yeah, I know when we went to Palmy, Scarlett was reading 56 km/h when those speed displays on the side of the road said I was doing 50 km/h, so that's 12% fast, even with the 175/80-13 tyres! If the GLS is similar, it will read about 15% fast with the 165/80-12 tyres, so a real speed of 86 km/h @ 3000 RPM...lol
We'll have to check it with your GPS speedo.
Yeah 3000RPM@86KPH is about right.
I will just find the cigarette lighter power adapter for my GPS speedo and we can take it for a test run. Once you know what the revs are at a certain speed then you can just use the rev counter to tell how fast you are going. I used to do that before I got my GPS speedo, I knew 3,500RPM was about 100KPH so on the motorway I would just make sure I stuck to under 3,500RPM
Intersting guys, but my GL is no way doing 3500rpm at 100k, mine is doing 3200 and that is what it was doing when a copa did me for doing 100 in a 80..and I did see his dash mounted display....and by the way them road side speed displays are full of shit...didnt you see target lol
Yours is a late model so it would probably have a 3.70:1 diff. What size tyres are you running? I could do the math to work out what the revs should be at 100KPH.
I agree those road side signs are crap. My gps speedo is really accurate and I find those road side signs are all over the show. If they even pick up my car at all.
I just put a couple of Sierra 14" x 5.5J wheels and 175/80-14 Kingstar H714 (Hankook) tyres on the back of Logan's car to improve the gearing, as Avengers rev like crazy on the highway...lol
An Avenger 1600 (3.89 diff) with standard 155/80-13 tyres does 3550 rpm at 100 km/h
With the 175/80-14 tyres that drops down to 3250 rpm, a big improvement!
Even better for a 1300 or Wagon with the 4.11 diff, revs drop from 3750 to 3400.
Speedo should still be okay as they read fast anyway.
The front is running standard 13" rims with 165/80-13 tyres.
Has a nice raked (Starsky and Hutch) look with the 13" on the front and 14" on the rear.
I have more 14" Sierra rims for $40 each if anyone one wants them?
Awesome. Love the cop rim look.
It would look pretty cool raked. I do that on most my cars. My charger is 245/60/R14 vs 215/60/R14 and my '75 Avenger will be 225/50/R15 vs 205/50/R15.
Yeah, the cops have no chance of catching Logan now...haha
An easy mod as the Sierra offset is the same +40, so the tyres tuck under the guards nicely.
175/80-14 is normally a commercial 8 ply tyre - too stiff for a car.
The 4 ply Kingstars are excellent, cost $93 each fitted and balanced.
Just done Diff swap from late Model Chrylser Avenger Sedan, no motor or dash so no idea what size it was
musta been 3.89:1 / same as what I had as the 100kph speed : revs are the same
then I saw this on Instagram
(https://igcdn-photos-d-a.akamaihd.net/hphotos-ak-xfa1/t51.2885-15/e35/13694335_329921750731555_1702145402_n.jpg)
www.instagram.com/p/BJmZq35jEpt/ (http://www.instagram.com/p/BJmZq35jEpt/)
something about a Dana 30 in an Avenger diff in Brazil
now that's something to look into I reckon
appears to be a LSD? or locker?
The chassis tag will tell you if the Chrysler was a 1300 (3.89 diff) or a 1600 (3.7 diff)
The 3rd and 4th figures are 1M for a 1300 and 7M for a 1600.
The 2nd figure is the year..
M=1977/78
N=1978/79
P=1979/80
Q=1980/81