Runnung 3.9 or lower final drive with stock motor?

[ae86714]

Just curious of peoples first hand experiences with it. I understand that it will affect the acceleration quite a bit going 3.9 or lower, but just wondering what the real world experience is, if any.

How bad is the acceleration REALLY? Is it like you are just always in too high of a gear and always bogging down a bit? Are very steep grades no longer practical unless you get a good running start up it?

I've also read that it puts more strain on the drivetrain. But is it so much stress to where premature wear/ failure is inevitable regardless of how well it's put together?

I'm not really into drifting or competitive driving at the moment, and really just want to drive drive drive my 86. I like to visit northern California a few times a year and would love to take my corolla up there one of these times. I have very some super short final drive in my car now, and I swear it must me a 5.something: at like 4-4.5k even up to 5k people are just blowing by me on the freeway like im barely cruising. My speedo dont work(of course lol) so I dont know actual numbers. I happened to end up with a 3.727 R&P by mistake, and am curious if it would be even close to useable for me. Any helpful info/ input is appreciated.

[jondee86]

Never tried it, but thinking about it, putting a 3.7 in there would be
like driving a car stuck in overdrive. Compared to the standard 4.3 ratio
you are more or less dropping off your first gear, and adding a super
overdrive gear.

Taking off in first will now feel like taking off in second, so you could try
that for a while and see if you could live with it. And that is compared to
the 4.3 rear. If you actually have a 5.X rear in the car now, you could try
taking off in third for a while

At the other end of the scale, fifth gear would be super tall, and really
only good for cruising on flat roads with a tail wind. Compared to a 4.3
putting in a 3.7 would make 4th as tall as 5th, so I don't expect that you
would use fifth gear with a 3.7 all that much.

Cheers... jondee86

[Gino1X1]

I ran my "other" SR5 Corolla with its 4AC and stock 3.91 gear. No problem whatsoever and yes, with some tailwind it would cruise happily at 70mph. When I bought my USDM GT-S and swapped the 6.7 for a hilux diff and went from the stock 4.3 to a higher 3.9, the GT-S fell flat on its face. On byways I never left third. When I swapped to a lower 4.56 it woke up like it was on 'roids!!

Relatively speaking of course.

[oldeskewltoy]

Never tried it, but thinking about it, putting a 3.7 in there would be
like driving a car stuck in overdrive. Compared to the standard 4.3 ratio
you are more or less dropping off your first gear, and adding a super
overdrive gear.

Taking off in first will now feel like taking off in second, so you could try
that for a while and see if you could live with it. And that is compared to
the 4.3 rear. If you actually have a 5.X rear in the car now, you could try
taking off in third for a while

At the other end of the scale, fifth gear would be super tall, and really
only good for cruising on flat roads with a tail wind. Compared to a 4.3
putting in a 3.7 would make 4th as tall as 5th, so I don't expect that you
would use fifth gear with a 3.7 all that much.

Cheers... jondee86

my AE71 came with a 3.58 You are indeed correct, the need for 5th is nearly irrelevant. In my car with the 4AGE fitted, it wasn't horrible for acceleration, it just held gears far longer - I could do zero to 78mph in 2nd gear

In my black AE86 I used a 4.10, that wasn't too bad, also not a great deal of difference... currently I'm running the 3.9, with the J160's 3.8 1st gear... take off is similar to a T50(3.5) and a 4.3.

[ae86714]

OST- you ran a 3.5 with the 4age? so not horrible meaning you could see it being liveable for a daily driven car? 0-78 in 2nd sounds like it would take all day long lol. Was it pretty miserable actually? or as long as you're not in a hurry or trying to drag race someone its not so bad?

Jondee- I could live with not using 5th gear very often as long as i got what i needed from 1st-4th gear. I dont want to dread every time i come up to a freeway meter and have a few hundred feet to merge into a crazy southern California freeway. Now i have the opposite problem, I'm taching out 5th gear by the time i merge! haha


So what about the whole "more strain" on the drive train thing? is that not really some thing to worry about?

[Deuce Cam]

I've got a 4.778. I agree that it sucks for a daily. 65 mph is around 4300 rpm in 5th gear, and I don't really go faster than that because of it. 1st gear also sucks because it's so short. However, it REALLY wakes a stock 16v up compared to a 4.3 (night and day difference).

4.3 sucks too, but not as bad. IIRC 65 mph is around 3800 rpm in 5th.

Personally, I wouldn't go below 4.1 on a 4age. Even then a stock 16v is going to be a dog. (IIRC 4ac has a lower redline and a little more low end tq. so it's better suited.)

5th gear is the biggest road going problem in regard to ae86 gearing imo. I'm told the national speed limit was 55 mph when these cars were new. That somewhat explains why 5th is geared so low, also the lack of tq/hp.

A 4.3 or 4.1 with an m factory/revolver/etc. 5th gear would be pretty good for a road car imo. If one doesn't want to go through the trouble of tearing into the transmission, a replacement, such as a w58 box - which has a taller 5th gear - would be an alternative.

my AE71 came with a 3.58 You are indeed correct, the need for 5th is nearly irrelevant. In my car with the 4AGE fitted, it wasn't horrible for acceleration, it just held gears far longer - I could do zero to 78mph in 2nd gear

In my black AE86 I used a 4.10, that wasn't too bad, also not a great deal of difference... currently I'm running the 3.9, with the J160's 3.8 1st gear... take off is similar to a T50(3.5) and a 4.3.

Was that a stock 4age though? Doesn't your engine plant 140-150 whp, in other words, more than a 20v?

[ae86714]

well I got a full refund on the 3.727 R&P that i mistakenly ended up with. So now its back to the hunt! 4.3 or maaaybe 4.1

saw this link in an old archived post:

http://store.uslegendcars.com/site/prod ... C181F96C9F

anyone try these? gonna shoot them an email for some details, but just curious if someone has ordered one of these from these guys? be nice to have an extra 3rd member all set up so i could just swap back and forth when i feel like it.

[jondee86]

Worth remembering that the GTS was sold as a "sports car" and the
4.3 was put in there to make the car feel sporty. Plus, the 4AGE was
designed to REV !!! So 4000rpm at cruise is not going to hurt the
engine, and it keeps it in a range where its making a bit of power.

Gear the stock engine down too far, and it WILL feel sluggish. Make
a bit more power than stock, and you can pull a taller 5th gear OK.
It's a kind of balancing act

Cheers... jondee86

[oldeskewltoy]

well I got a full refund on the 3.727 R&P that i mistakenly ended up with. So now its back to the hunt! 4.3 or maaaybe 4.1

saw this link in an old archived post:

http://store.uslegendcars.com/site/prod ... C181F96C9F

anyone try these? gonna shoot them an email for some details, but just curious if someone has ordered one of these from these guys? be nice to have an extra 3rd member all set up so i could just swap back and forth when i feel like it.

that is what went into my black AE86 4.10. ****IF*** you order that, make sure they KNOW you don't want it welded. Since these are for Legend type cars they sell spools, or welded diffs. So if you want one of these, you need to make sure they know NOT welded.

My 4AGE powered AE71 is indeed 140whp, so my car wasn't horrible to drive. My AE86 had a little extra power(112whp) so the 4.10 didn't feel like it was a drag, and yet I could hold a gear(mph) higher then others.

My current mix is perfect... 3.9... also a Legends Car diff - http://store.uslegendcars.com/site/prod ... C181F96C9F

[jdm86gtz]

Do Richmond still sell new 6.7" ring and pinions? They don't have them listed on their site.
http://www.richmondgear.com/index.php/r ... ons/toyota

[ae86714]

OST- cool, so you've bought one of those diffs? Did they have choice of zenki and kouki size axles? And it comes all adjusted ready to go in a 3rd member?

[MisterJerk]

my AE71 came with a 3.58 You are indeed correct, the need for 5th is nearly irrelevant. In my car with the 4AGE fitted, it wasn't horrible for acceleration, it just held gears far longer - I could do zero to 78mph in 2nd gear

This would be awesome with a turbo.

[Deuce Cam]

I wonder what spider gears are used on those third members? I'm assuming they're probably only compatible with zenki gts axles?

[oldeskewltoy]

Richmond makes the gears... so says the Legends guys... How I understand this is Richmond makes the gears for the Legend cars... you can only get them through Legends dealers.

They are zenki splined gears - zenki axles

They are a used housing with all new parts(bearings, gears), and yes they are perfectly set, and are bolt in. They still use crush sleeves on the pinion, so if you plan on abusing this, you may want to get a solid pinon spacer. If you have kouki axles, you can send the whole thing to Weir, and have them slip in kouki spider gears, and a solid pinion spacer....

In my situation... I left it as I got it.





As to break-in - I strongly recommend you break in the rear diff by regular driving... but with at least 300#s over the rear axle. The added mass adds load to help the gear mesh properly.

[ae86714]

OST- that is very awesome! now I can just set aside my low geared LSD 3rd member and just plop in one of these with minimal down time.

Only problem now is that the website doen't seem to be letting me place anything into my cart for some reason. No answer on the Email yet either. Guess i'll just wait it out, this really does seem like the best option for me if i can get it.

[asnfro]

Ae86714 are you gonna sell your old third member? What kind of LSD? Is it noisy or in pretty good shape?

[PDB]

Anyone used these LSD's before ?

Could you tell me what size the spline would be for the axle shafts ? Thinking about fitting one into my KP60 Starlet if it fits ?
http://pages.ebay.com/link/?nav=item.vi ... 1447402646

[oldeskewltoy]

Anyone used these LSD's before ?

Could you tell me what size the spline would be for the axle shafts ? Thinking about fitting one into my KP60 Starlet if it fits ?
http://pages.ebay.com/link/?nav=item.vi ... 1447402646

I have one sitting on my shelf... not yet installed (got it used)

A Torsen diff isn't as effective in a soild axle car, it is far more effective in a car with IRS. The WHY... A Torsen is designed to move more power to the better gripping wheel... but if surface contact on one wheel is lost, a Torsen becomes far less effective then a car outfitted with a conventional LSD. The trade off is the Torsen doesn't tend to effect handling as much as a conventional LSD does

[ae86714]

I'm definitely finding myself at a bit of a crossroads, and NONE of the options are cheap lol. thinking about all these possibilities and what combo would suit me best performance wise and financially... i guess more financially hahah.

transmission

tall 5th and trans rebuild- $711

just rebuild kit-$430

labor for trans rebuild- ... not sure... couple hundred?

LEEN or similar 6 speed- $2500+ or so (very dependent on cost of trans and ability to do small fabrication)

REAR END

buy replacement closer to stock r&p: 150$

get r&p rebuilt and set- parts $200
labor $200

should probably rebuild LSD too- about $160 for kit


richmond 4.10 3rd member- $459 (+tax & shipping) but then no LSD, however it will be easier with an extra 3rd member to swap in and out.

Ideally i will find a decent smooth enough used transmission and just get one of those richmond diffs if they ever respond to me. that could all hopefully be for less than 800. But the benifits of the other options are so nice, very tempting!

[totta crolla]

I think that the 4.3 FD and T50 is very well matched to the 4age engine and Toyota will have looked very closely at the gearing to get the best compromise between performance, economy and comfort.
The AE86 with a 4age is not a highway cruiser, that's what cars with big torquey engines are for.
According to this calculator:
http://johnmaherracing.com/calculators/ ... alculator/
you will be doing 80mph at 4300rpm with 185/70/13 tyres on a 4.3 with a T50 the benefit of the 4.3 will be that it will easily accelerate from 80mph in 5th

[oldeskewltoy]

I'm pretty sure the email link on the "diff" page is dead... try contacting them from one of these.... http://www.uslegendcars.com/about_us/contact/

[ae86714]

Good lookin out OST, shot an email to their parts department.

I'm just curious as to why these are compatible with the our cars? Seems like such an akward cross of application. is the 6.7 10bolt combo just really universal and super common on other rear ends? I doubt all these guys are just running AE86 rear ends lol. Just makes me wonder how many other cars out there have the same 3rd member.

[oldeskewltoy]

Good lookin out OST, shot an email to their parts department.

I'm just curious as to why these are compatible with the our cars? Seems like such an akward cross of application. is the 6.7 10bolt combo just really universal and super common on other rear ends? I doubt all these guys are just running AE86 rear ends lol. Just makes me wonder how many other cars out there have the same 3rd member.

many/most Celica, Carina, Corona, some Corolla's( a few others I'm sure). From 1970 to 1987...

[midwest86]

I've kept the stock 4.30 ratio, but I did install the M-Factory .773 5th gear. It brought the revs down to about 3200-3400 rpm at highway speed which I feel is very sensible. It is an easy install, and well worth the money in my opinion. I installed mine in about 1.5 hours including pulling the trans.

[Gino1X1]

Good lookin out OST, shot an email to their parts department.

I'm just curious as to why these are compatible with the our cars? Seems like such an akward cross of application. is the 6.7 10bolt combo just really universal and super common on other rear ends? I doubt all these guys are just running AE86 rear ends lol. Just makes me wonder how many other cars out there have the same 3rd member.

many/most Celica, Carina, Corona, some Corolla's( a few others I'm sure). From 1970 to 1987...

.... equipped with smaller displacement engines to 1800cc. Like the K and T series as well as the A series engines. I see in the case of the early eighties Carina GT turbo with the 3T-GTE, that it also comes with the 6.7 diff. At least the "kouki" model.

Japanese car makers often build tow or three models on the same chassis, like the already mentioned Celica Carina and Corona models by oldeskewltoy. Hence the same diff.....