Changing final drive ratios seems to be unpopular... Why?

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El_Freddo
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Post by El_Freddo » Tue Mar 20, 2012 8:06 pm

2nd Hand Yank wrote:Thinking about how my L Series works with the stock gearing and current tyre size, both how hard the EA82 has to work up hills or in soft sand, as well as what my "crawl speed" is in 1st and FWD/4Hi and 4Lo, even now, I think I could benefit from deeper gearing like 4.11-to-1 :?
For the L series gearbox - the Part Time 4wd 5spd, you'd need to split the box and have a cut and shut 4.11 pinion shaft made up as it's longer than the EJ pinion shaft. Then you'd need to shave the crown wheel (mentioned by other members) so that it doesn't interfere with the L series 1.59:1 low range gearing. Phiz did his differently - he shaved the selector ring of the L low range so it fitted in the EJ selector fork - This also happens to clear the crown wheel.
2nd Hand Yank wrote:I might like to swap in some bigger tyres somewhere down the track. That will place more load on the engine (an EJ22 would help) but also increase my crawl speed which could be undesireable under certain conditions.
If you're going to swap in bigger tyres down the track you'd be better off leaving the diff mods until that time - otherwise you'll be cruising around at high revs and even higher revs at cruising speed due to the diff changes.
2nd Hand Yank wrote:I had a look at the EJ22 specs (on wikipedia) and it seems even earlier models had torque peaks above 4000rpm. So this engine likes to rev? If so, wouldn't it be better to be driving in the EJ's powerband?
Ok, first off. PEAK torque is exactly that - the point where the engine will no longer produce any more torque, which is marked by the number of revs it's doing at the time. Even though 4000rpm is it's PEAK torque, the torque level from down low could well be double that of the EA82. I'm sorry if I'm going off the deep end here but the peak level thing really grinds with me when comparing engines...
2nd Hand Yank wrote:I've never heard of anyone swapping out the final drive gearing on a Subaru. Is it very difficult?
It is if you don't know what you're doing. To do it you need to split the gearbox and swap the ring (diff) and pinion (gearbox drive to diff) shaft. In the EA boxes it's not worth the effort unless you're really into it and know what you're doing! The easiest option for you would be to go with the EJ22 conversion and Forester 4.11 AWD gearbox at the same time. If you're really keen you could drop the L series low range into the foz box while it's on the bench - that'd be an even better "crawl" ratio.
2nd Hand Yank wrote:I suspect I would find the crawl speed on 27" tyres behind a powerful motor might be annoying. Hmm...
Unfortunately subaru's don't really have a true crawl ratio. What they don't have in the crawl ratio department they do make up for in the weight department. We're probably about two thirds lighter than the average big 4wd cruising around out there when fully kitted out...
B00sting wrote:It is my understanding that it is possible to have another gearset (joey box) for your low range with whatever gears you choose. I don't see why you couldn't have low gearing like a landcruiser does in low range, it might cost you an arm and a leg though.
That's near impossible to do with a Subaru gearbox if you stick with the factory drivetrain layout - or without completely re-designing the subaru gearbox (which I've thought about, not hard, just need the cash for the engineering which = much much more than I'm ever going to see in my lifetime!).
But it's possible to do if you go with the divorced transfer case method, Andrew T has done it with his monster wagon but has never really finished it off. Plus he needed/wanted a 6 inch lift kit in it - looking at it I'd personally be worried about COG issues!
B00sting wrote:That's one thing that annoys me about subarus, the lack of lower gearing and aftermarket parts for 4Wding.
Welcome to a minority offroading group that the companies such as ARB don't want to deal with because they don't see the profits in it...
B00sting wrote:It's just like the locker debate, i've read the threads that go on for 20 pages but end up nowhere... It is my understanding that ARB have released an R180 locker, no reason why that couldn't be adapted to fit our subarus if we fit r180 diffs.
True, but that debate was about an auto locker behind an AWD gearbox - which I think the conclusion was that it would do funny things in corners that wasn't worth the change in driving style for the offroad advantage when you'd use it. The auto locker was sold and it didn't go any further than this once that conclusion was met.
RSR 555 wrote:You could use the 4.11 from an EJ D/R AWD box but you'll need to use this in a EJ D/R AWD casing. Not a lot of changes to make them fit, especially if you're going to fit the EJ22

I would use the D/R gearset from the old L box though.
Personally I'd hold off until you did the EJ conversion, do both the gearbox and the EJ conversion at once - A LOT LESS stuffing around to make it all work out properly with the EA engine to the EJ gearbox, the other way around is easier! Doing both at once is less down time on your vehicle and ultimately less labour in the long run.
ScubyRoo wrote:Just buy an sf5 forester box - 4.11 with 1.4 (maybe?) low range requires no internal mods... You'll just need an adapter place to fit to your EA and as RSR said, different crossmembers. Then when if you go EJ the gearbox side of things is already done. You do loose your locked centre diff though :(... unless you get someone to build you a box like Venom's :mrgreen:
Close ScubyRoo - EA gearboxes don't have a centre diff - they're part time gearboxes so the centre is just a dog clutch. Similar in a very rough way to Venom's centre diff lock but it's missing the centre diff part (not that you can add the centre diff to the dog clutch in the EA gearbox - you MUST have the L AWD gearbox in the first place! Bummer, I know right?)
d_generate wrote:Advantage of 4.44 apart from lowering your gearing is that it puts less strain on the box because it's turning over while the engine is revving higher so not as much torque needed to do the same thing at lower rev's, someone else can probably explain it better than me.
I'd say it like this. The 4.44 diff puts less strain on the gearbox and engine because the gearbox internals are doing more rotations per wheel rotation (eg 27 inch diametre) than that of a 4.11, 3.9 or 3.7 diff. The 3.7 with 27's will put the most strain on the gearbox out of all the diff ratios mentioned, this is because the gearbox internals are doing less rotations per wheel rotation...

Hope this helps you out!

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Post by NachaLuva » Tue Mar 20, 2012 8:20 pm

El_Freddo wrote: Ok, first off. PEAK torque is exactly that - the point where the engine will no longer produce any more torque, which is marked by the number of revs it's doing at the time. Even though 4000rpm is it's PEAK torque, the torque level from down low could well be double that of the EA82. I'm sorry if I'm going off the deep end here but the peak level thing really grinds with me when comparing engines...
From memory the EJ20 gets about 80% of its torque from about 2500rpm, very little below that. But from 2500rpm on the torque curve is a nice shape, no big dips
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Post by taza » Tue Mar 20, 2012 8:57 pm

nachaluva wrote:From memory the EJ20 gets about 80% of its torque from about 2500rpm, very little below that. But from 2500rpm on the torque curve is a nice shape, no big dips
Yeah its somthing similar to that. I have seen one on a dyno from a 2000 Forester. It was really low until abuot 2300 then shot up and the torque peaked at around 3600rpm but was only about 180Nm.

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Post by Gannon » Wed Mar 21, 2012 5:26 am

Peak torque only applies at wide open throttle and has nothing to do with cruising speed.

All cars have their cruising speed designed to match their 'brake specific fuel consumption' which is the point at which horsepower is at its greatest, for the lowest amount of fuel used per hp. This is then calculated for the required speed to be cruising at, which is usually 100km/h, and the final drive ratios are chosen to place the revs in this 'sweet spot' of efficiency.
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Post by 2nd Hand Yank » Wed Mar 21, 2012 8:24 pm

taza wrote:Yeah its somthing similar to that. I have seen one on a dyno from a 2000 Forester. It was really low until abuot 2300 then shot up and the torque peaked at around 3600rpm but was only about 180Nm.
My L Series embarrased your Foz for the first half-second off the line. :mrgreen:
Foot to the floor, it takes about 2-4 seconds before your EJ20 starts to put me in my place.

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Post by 2nd Hand Yank » Wed Mar 21, 2012 8:26 pm

Can 4.44 final drive ratio's be had with a manual transmission and centre locking differential? :confused:
If it already exists I can save time doing mods and just do a swap. 8)

Such a combination would be very tempting for me to part ways from my 5spd 4wd.

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Post by TOONGA » Wed Mar 21, 2012 8:53 pm

you would need to build a custom box if you wanted a diff lock and 4.44 diffs (and dual range)

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Post by taza » Wed Mar 21, 2012 9:05 pm

2nd Hand Yank wrote:My L Series embarrased your Foz for the first half-second off the line. :mrgreen:
Foot to the floor, it takes about 2-4 seconds before your EJ20 starts to put me in my place.
Possibly my driving but also AWD off the mark in an N/A is quite slow. Thats why I hate having to pull out of intersections quickly as the car just isn't quick off the mark.

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Post by discopotato03 » Wed Mar 21, 2012 10:23 pm

A Forrester has more pork to launch than an L plus the larger diameter wheels add to gearing (all else being equal which it isn't) .
For their capacity EJs have more breathing and valve area than EA engines do and along with more stringent emissions tuning they don't make their torque as low down as EAs do .
I reckon volumetric efficiency and torque is more important when it comes to engine speed vs road speed . In reality horsepower/Kw numbers are marketing tools because peak Hp/Kws almost always occurs at high revs - ie where few spend much if any time in road cars . Engines that make good part throttle torque without a lot of revs make good road type grunt .
Good chamber and piston crown designes/cooling make a big difference to detonation thresholds and being able to run best mean torque timing will always be better than mean stop the knocking retarded timing .
I remember once going in a poverty pak GC8 with the lawnmover engine option and it had real short gearing for highway running . Just a case of a small engine having no torque and geared mainly for urban running .

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Post by RSR 555 » Thu Mar 22, 2012 1:45 am

4.44 manual with centre diff lock is available but not in dual range.. it comes in the form of a 22B :p

But seriously Matt, you're not going to need 4.44, a 4.11 Dual Range box from a Foz will do just nicely. Unless you're planning on using 33" tyres you'll just be spending big money for little gain.

Perfect combo (IMO) in the L is the 4.11 D/R Foz box with L.Series PT4wd low range gears (just the drop down set not the whole 1-5 gears) and a Vortex AWD with centre diff lock rear transfer set and casing.
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Post by d_generate » Thu Mar 22, 2012 3:14 am

2nd Hand Yank wrote:Can 4.44 final drive ratio's be had with a manual transmission and centre locking differential? :confused:
If it already exists I can save time doing mods and just do a swap. 8)

Such a combination would be very tempting for me to part ways from my 5spd 4wd.
That's what mine would be if I got off my arse and put the DCCD in the back of the box, Most STI RA boxes were like the 22B box also, always popping up for sale.
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Post by 2nd Hand Yank » Thu Mar 22, 2012 4:22 pm

TOONGA wrote:you would need to build a custom box if you wanted a diff lock and 4.44 diffs (and dual range)

TOONGA
Can 4.44's go into my current gear box with enough modifications?

I think 4.44's wouldn't be too deep for any tyre taller than 26"; easily fit with some fender trimming.

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Post by 2nd Hand Yank » Thu Mar 22, 2012 4:25 pm

taza wrote:Possibly my driving but also AWD off the mark in an N/A is quite slow. Thats why I hate having to pull out of intersections quickly as the car just isn't quick off the mark.
I'm wondering if it's worth going to EJ now.
I like my bottom end.
It feels like I can get to at least 15 km/h (a fast jog or faster) from a stop within 1 second. 8)

Maybe I'll have to take a closer look at LT65's EA82 MPFI. :?

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Post by thunder039 » Thu Mar 22, 2012 7:22 pm

i understand what taza is saying. i think it the awd shifting the more power to the rear which gives the delay from take off
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Post by taza » Thu Mar 22, 2012 7:35 pm

2nd Hand Yank wrote:I'm wondering if it's worth going to EJ now.
I like my bottom end.
It feels like I can get to at least 15 km/h (a fast jog or faster) from a stop within 1 second. 8)

Maybe I'll have to take a closer look at LT65's EA82 MPFI. :?
If it were me (might be since I just bought an L-Series today. lol) I would put in an EJ22 behind the stock gearbox. Through a LSD in the rear, some 27" tyres and 4" of lift (from stock) and call it a day. That would do well offroad, have decent gearing and enough power to back it up.

The AWD from a stand still makes the enigne work harder to take off, especially on a hill. I find that when I drive a FWD or sometimes RWD car I spin the wheels alot as I take off as im used to giving it ~3000rpm then planting my foot to the floor for a quick take off when pulling out of an interection or the likes..

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Post by thunder039 » Thu Mar 22, 2012 7:41 pm

i find i have to ride the clutch to get a smooth and quick take off in the forester compared to the brumby were its just drop the clutch and go go go :cool:
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Post by taza » Thu Mar 22, 2012 7:56 pm

thunder039 wrote:i find i have to ride the clutch to get a smooth and quick take off in the forester compared to the brumby were its just drop the clutch and go go go :cool:
I found that with my old clutch but this new one is light weight and heavy duty. Allows me to take off quite abit quicker :)

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Post by B00sting » Thu Mar 22, 2012 8:29 pm

TOONGA wrote:you would need to build a custom box if you wanted a diff lock and 4.44 diffs (and dual range)

TOONGA
Good thread!

I've given up on the idea of building the franken-box using the ft4wd and others. basically because i cant be assed sourcing 2-3 boxes i need then splitting them/mix n match!

instead I figure that a brumby with an ej25, rear lsd, manual d/r and 4.44s will make up for the lack of pseudo lockers! (what i lack in grip make up for in power)

and after that I will endeavour to make the r180 diff work with an arb air locker...
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Post by El_Freddo » Sat Mar 24, 2012 8:41 am

2nd Hand Yank wrote:Can 4.44 final drive ratio's be had with a manual transmission and centre locking differential? :confused:
Nah unfortunately anything ratio below 3.9:1 needs to be cut and shut for the L AWD gearbox - so if you're after the 4.44:1 final ratio you'll have to first source the L AWD gear box (for the centre diff lock) then the 4.44:1 R&P gear then find someone that can do the magic work for you...
RSR 555 wrote:4.44 manual with centre diff lock is available but not in dual range.. it comes in the form of a 22B :p
Really?!! I never knew this and that's totally awesome! Do you know if this is the same pinion setup as the EJ or the EA AWD gearbox?? If it's the EJ set it must be possible to get those tools to make some more - for a massive wad of cash!
RSR 555 wrote:But seriously Matt, you're not going to need 4.44, a 4.11 Dual Range box from a Foz will do just nicely. Unless you're planning on using 33" tyres you'll just be spending big money for little gain.
Agreed. Even with this set up you'll keep up with the tough stuff without an issue.
RSR 555 wrote:Perfect combo (IMO) in the L is the 4.11 D/R Foz box with L.Series PT4wd low range gears (just the drop down set not the whole 1-5 gears) and a Vortex AWD with centre diff lock rear transfer set and casing.
I think you've forgotten the requirement of a cut and shut on the pinion gear if you go with the 4.11:1 final drive and the Vortex (or DR L series) AWD with centre diff lock rear case. You can't have both without some custom work.
taza wrote:If it were me (might be since I just bought an L-Series today. lol) I would put in an EJ22 behind the stock gearbox. Through a LSD in the rear, some 27" tyres and 4" of lift (from stock) and call it a day. That would do well offroad, have decent gearing and enough power to back it up.
That'd be a great setup! It's what Ruby Scoo's currently running and is a well tried and tested setup. The only difference will be the extra inch lift. Remember about those brake line extensions before you try lifting it!
taza wrote:The AWD from a stand still makes the enigne work harder to take off, especially on a hill. I find that when I drive a FWD or sometimes RWD car I spin the wheels alot as I take off as im used to giving it ~3000rpm then planting my foot to the floor for a quick take off when pulling out of an interection or the likes..
No offence Taza, but I think you need to change your driving style. All you're doing here is riding the clutch - the power you're wanting is not going to the wheels and ultimately to the road... And it's a harsh way to be doing things all the time!

I reckon the best thing you can do is spend the coin on your Heavy Rigid non-synchro truck licence. It's loads of fun to do and you'll learn heaps along the way. I've since changed my driving style and added a few new things to what I do when behind the wheel. It saved my bacon last night when another driver almost made a what could have been a fatal error.
B00sting wrote:instead I figure that a brumby with an ej25, rear lsd, manual d/r and 4.44s will make up for the lack of pseudo lockers! (what i lack in grip make up for in power)
Power is no use if you don't have the traction (grip)! It's really THAT simple!
B00sting wrote:and after that I will endeavour to make the r180 diff work with an arb air locker...
It *shouldn't* be hard to do, the biggest issue you'll have will be working out the drive shaft lengths and their mounting to the output stubs. You might have an issue with the input shaft flange being a different size to the prop shaft flange. It'd be an awesome mod to have though!

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Post by taza » Sat Mar 24, 2012 11:05 am

El_Freddo wrote:That'd be a great setup! It's what Ruby Scoo's currently running and is a well tried and tested setup. The only difference will be the extra inch lift. Remember about those brake line extensions before you try lifting it!
That will be a good setup, can you put an LSD in the front of an L-Series gearbox? Id throw in a geared LSD ;)
No offence Taza, but I think you need to change your driving style. All you're doing here is riding the clutch - the power you're wanting is not going to the wheels and ultimately to the road... And it's a harsh way to be doing things all the time!

I reckon the best thing you can do is spend the coin on your Heavy Rigid non-synchro truck licence. It's loads of fun to do and you'll learn heaps along the way. I've since changed my driving style and added a few new things to what I do when behind the wheel. It saved my bacon last night when another driver almost made a what could have been a fatal error.
No its not riding the clutch, I come off semi quite but the car doesn't take off quite. theres a real dead spot between idle speed and 2000rpm where you wonder if your going to stall and be hit by a car or just make it away..

Maybe I should drive someone else Forester to see what its like power wise (a SF 2.0l). The L-Series I bought isn't even running on its full 4 cylinders, its missing here and there(slight head gasket leak and badly needs a service) but seems almost as quick as my Forester :? So maybe the engine performance isn't all that bad after all but my engine may have other underlining issues.... even when I bought it :-(
Other people with 1st gen Foresters reckon power isn't much of an issue, like on the highway and merging, etc...
Yesterday when I was on one of the highways to RSR's workshop even with the EA82 missing a few beats its 5th gear pull just from 80-100km/hr (normal driving, not hooning) was much faster than my Forester!

Would be cool to get a truck licence but I can't for another 3 years as you have to be driving for 5 years and im just about to get off my P's (been driving almost 2 yrs).

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