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Re: Limited Slip Differentials

Posted: Thu Aug 09, 2012 11:26 pm
by DaWaN
archyman wrote:Well, i felt the whole car losing grip, drifting a bit sideways to the left, but especially the front tires..the steering wheel was at 45 deg. and the vehicle continued forward for a moment...
I will definitely check my suspension, however there are no visible signs of wear...
My tires aren't old either - Toyo Proxes CF1 (185/60/14) on 2 or 3 seasons with plenty of rubber left.
Even though I've read some bad reviews about that tire getting old too soon...
Do you guys know if the d15b LSD would fit the S40, and what type of diff principle is that?
Forget the LSD, my guess is that it would not have saved you in that situation.
There are 3 main factors to your understeer:
Shitty tires
Heavily loaded car
Going downhill

The Toyo Proxes CF1 are not very good performance tires. I guess they will excel in road noise, wear and price yet you should not expect great cornering ability from them.
A heavier car simply puts more strain on the tires, going through the corner with the same car yet 100kg lighter will allow a higher cornering speed
The same applies to going downhill, it reduces the cornering speed.

So in the end you simply went to fast through the corner and the car did what it was designed to do: understeer.
You did the right thing to correct the understeer: gently remove the throttle
The speed went slowly down and the car recovered from the understeer situation.

If you want to improve your cornering speed the first thing I would do is upgrade your tires. I would suggest a performance tyre (something like Yokohama Parada Spec-II or similar) in the size of 195/50/15
The second thing I would do is lowering your speed through corners in a heavily loaded car
And the last thing is to remember that going downhill affects the amount of grip ;)

Suspension upgrade is beneficial to tweak the balance and control-ability of the car, the effects on the total amount of grip might not be as profound as some people would say (would not be my first upgrade)

Remember that the LSD only limits the amount of speed and torque difference between the two front tyres from and to the engine. An LSD is mostly beneficial during acceleration out of corners. In your situation you simply went too fast and a LSD would not have made a difference

Re: Limited Slip Differentials

Posted: Fri Aug 10, 2012 12:26 am
by saxophonias
Nicely put ;)

Re: Limited Slip Differentials

Posted: Fri Aug 10, 2012 8:40 am
by sktaroins
can you imagine i had the same situaton but in al old nissan datsun bluebird 1970 model and its already a tank meaning heavy car and it was loaded with " 1driver - 2bunkers sitting infront - 5bunkers squeezed at the back.

i was cornering a big wide right down hill " more like a mountain with no borders "

to make it more serious the road was slippery coz it already rained.
when i was steering very very slowly and i say very slowy stering to the right to turn inorder to move on.
guess what - my car slipped from the front towards the left side for about 1+1/2 meter .

i stupidly pressed my brake and then removed all my legs from the cluthches and the pedal ...
the car - thank god stoped at the edge and those bunkers were all drunk and laughing
i was the only one very serious and was the chauffer.

when the car stoped ... imagine that it even skit when i accelerated so slowly ... the road was soooo slippery.
thk God i had changed new tyres that day .

it was night and no lights at all except my dim lights in that old car but really if it wasnt for that good tyres and suspensions that i changed that day - we all would be toast by now...

OMG what a story i just remembered.

gd luck though with lsd
iam looking forward to get one 4my car.

Re: Limited Slip Differentials

Posted: Fri Aug 10, 2012 8:45 pm
by archyman
DaWan, i guess you are right about all the factors that put together led to the understeer...but was kinda suprised how low the limit of the car was that day.(didnt push it too hard at all, did this corner zillion times)
I am actually very disapointed of the rubber quality of the cf1 toyos, at a close look i found little ripples forming..
sktaroins, you had luck that day man, where i come from people make special lunch every year on the same date to honour the "escape" :)
As far as the LSD, i think that it could extend the cars limit in all conditions and its a must in modern vehicles (not like all those cheap ESP and etc systems that block the brakes)
I hope whoever intalled LSD on a d14 to share the experience.
Be safe all!

Re: Limited Slip Differentials

Posted: Sat Aug 11, 2012 8:17 am
by sktaroins
Yeah man, indeed it was a new life 4me. Some roads no matter what the pavement is made of. Once it looses its black colour " that means its getting very soft and smooth like butter, especially in big mountainous areas where the gov dont maintain roads ... But the only thing they do is drill holes in zebra shapes uphill and down hill for grip in the summer and in winter just drive slow .
Plz hey archyman you can call me Sam.
R1R TOYO ARE THE TYRES THAT ILL GET - INLOVE WITH THEM
LSD IS A SURE THING , I think some one already installed lsd ..
Cant remember but its here somewhere ... This place is big..
Carry on lad :)

Re: Limited Slip Differentials

Posted: Sat Aug 11, 2012 10:46 am
by saxophonias
I was about to install it but I am bit sceptical as I have been spending a lot in the car lately. Still I am pretty sure that if you ever drove the civic with a decent suspension and semislick tyres you would think you could turn any curve at any speed. In the real everyday world though with low friction roads it might be a necessity even to our underpowered cars. Where I live in the majority of roads during hot days you can drift with 50km/h if you want to.
As for the lsd, Hondanick has installed one but we haven't heard from him lately

Re: Limited Slip Differentials

Posted: Mon Oct 12, 2015 7:36 pm
by Dodo Bizar
I am sure my D14 tranny needs 35mm bearing sized LSD. Getting me a helical right now. So measured my diff.

What I extrapolate is that the D16Y7 engines also need 35mm LSD. This since the service manuals found online refer to the thrust shims that are 72mm for D14 and D16Y7. Which is the outer size of that bearing.

The D16Y5/Y8 engines have 40mm bearings and thrust shims, hence outer bearing sizes of I believe 80mm (from the head, not sure). But that's how I extrapolate that. So not sure about D15Y6 etc. Though I saw the 35 printed on the drive shaft seals. So probably if you are dyeing to know, just remove an axle and check the numbers.

Re: Limited Slip Differentials

Posted: Mon Oct 12, 2015 11:23 pm
by saxophonias
And what happens with the d14a8 mb series gearboxes? The same 35mm bearing? :roll:

Re: Limited Slip Differentials

Posted: Mon Nov 30, 2015 9:55 pm
by hondaNickx
I'm driving my Build D16z6 transmission for a few months now.But it needs to get out again after some issues with the Gear-X first gear for the fourth time :-s )
It has a Mfactory LSD in it and i can truly say it helps A LOT in the corners.Where i usually would slip and get understeer the car now just grips and turns in better.
I noticed it now even more in the rainy and cold weather the front tires have more grip .
I also need to make a video of the gearbox in action before i remove it again .
It has these specs :

1st : 3.250 Oem D16z6
2nd: 1.900 Oem D16z6
3th: 1.346 Oem Crx D16a9
4th: 1.033 OEm Crx D16a9
5th: 0.771 OEm D16z6

Fd: 4.4 Oem D14a8 Civic aerodeck
Carbon synchro's from synchrotech,new bearings ,seals .
This is the shortest gearing you can get with OEM gears.If you want shorter you need to use aftermarket gears.

Ow yeah There are 2 types of transmission cases B000 and A000 .B000 case all have the 40mm Differential bearings ,these also have bigger bearings on the counter shaft and can handle more abuse.

All these transmission have got the big bearing case:

D16y8 Civic Coupe esi (S40) Steel shift forks
D16y8 Crx Del sol 95-97 (S8G) Steel shift forks
D16z6 Civic Esi (S20) Aluminium shift forks
D16z6 Crx del sol esi 92-95(S20) aluminium shift forks
D16B2 Civic MB 97-00 (A9) Steel shift forks
D16a9 Crx 88-91 (L3) Aluminium shift forks

You can reconise the big bearing case by the code B000 which stands above the oil fill plug.

The A000 code is a 35mm bearing and also have smaller bearings on the counter shaft.
These are the most commen d-series transmissions you will find around.
Basicly what honda did is give all the motors that produce around 120hp the big bearing case .All others with less hp has the smaller bearing case.
D14a8 has a small bearing case 35mm .
You can also look up the bearing number of the differential Big bearings are 6208 , small bearings are 6207.The Seals are the same afaik because they have a 35mm opening for the driveshaft.

I'm currently rebuilding my oem D14a4 transmission in which i also found the gears are different then the book i took my specs from .
(Or my gearbox is changed before i bought the car .)
My oem D14a4 gearbox has these specs :

1st: 3.250
2nd: 1.909
3th: 1.250
4th: 0.909
5th: 0.750
Fd: 4.058

According to the book i have here my transmission should had have a 4.250 FD and a 0.702 5th gear .

Re: Limited Slip Differentials

Posted: Wed Dec 02, 2015 9:39 pm
by saxophonias
Great! Please upload a video to see how it goes! I am in serious thought about whether I should open the a8 box to shorten it using 2nd and 3rd gear from stock the a4. But then the distance between 3rd and 4rth will be wide, meaning that revs would drop somewhere like 5000rpms. Now the distance is minimal at 5800 when i shift at 7000 from 3rd to 4rth. Check the my video
https://www.youtube.com/watch?v=9MZEmUsBliI