The OS Giken LSD/diff

[j14nsx]

Anyone else here using as OS Giken LSD?

I have one and find that when applying power in corners the diff tightens up the rear wheels, which in turn makes the car push straight on.

I have plenty of grip in the front, but it makes it even harder to keep the car turning, as more force is needed at the steering wheel.

Is there anything that can be done? It's not a general case of understeer as it is dynamic and changes as power is applied and the diff tightens up.

Is it something that will always be there? Or reduce over time as the diff wears? The diff is brand new by the way, about 500 miles on it.

Any help or opinions welcome, even if it is only to confirm what I am experiencing.

 

[Ponyboy]

I have the OSG LSD w/ the 4.44 final. At the track, the only push I would get is just a smidgeon on corner entry. You have the 1.5 way?

 

[titaniumdave]

Sounds like you need to drive faster...once your car takes a set and all 4 wheels have a slip angle, there should be no understeer or pushing. I find the OSG make it very easy to throttle steer and adjust the slip angle.

I like to drive the car a bit loose though, so I am not sure the OSG is a good mod if your driving style does not lean that way...

 

[j14nsx]

All the replies could well be true. I have to say I notice the effect more on the road than the track. It happens on the road as at a roundabout (something you don't really get in the States) you need to slow up when entering, but on exit can accelerate if the road is clear. It's this mid corner application of power that causes a change.

This wouldn't happen on track, as after the initial turn-in I am accelerating all the way through, so there is no sudden application of power.

I like the sound of needing to go faster.:smile:

 

[titaniumdave]

I am getting a clunking sound at low speed tight turns. I am pretty sure this is the diff but I am wondering if any one else has experienced this. My previous experience has only been on the track where I have not noticed the sound, but now I am driving all the time to break in me new motor so I get to do tight low speed turns all the time.

It feels like a binding then 'pop' as it releases, I can feel it through the seat bottom too...

 

[Ponyboy]

I have it as well. Any low speed or just a tight turn will result in the "clicking" sound from the diff. It's indicative of clutch type LSDs and means the diff plates are rubbing against each other and limiting the slip.

Kinda unsettling at first but after a while, you get used to it. IIRC, ak was going to use the KAAZ tranny fluid to see if the noise abated at all.

 

[titaniumdave]

Shawn,
That's what I thought, I am running crappy break in oil right now too, I think it makes it worse...I will get 500 road miles + 100 track miles this weekend.

I will change to Dumondtech BL 154 next week. I report back on how that quiets things down, I hope...

 

[j14nsx]

I have the low speed-tight turn clunking. If possible I find it better not to apply power during such a corner to reduce the clunking. I'm wondering if it's like this as the diff is new, or whether it will lessen with wear.

I'm also wondering if using a racing biased diff on the road like this, will cause premature wear, as it's being used out of its designed environment.

 

[Ponyboy]

Good point! The OSG diff (1.5 way) will still lock under deceleration but much less than under acceleration. Clutch LSD's require more maintenance than other types and eventually you'll have to change out the clutch plates b/c of wear.

I think this one of those instances where if you want to dance you've got to pay the piper.

Dave, let me know how that diff oil works out please. I'm not keen on keeping the Honda oil in there under track conditions.

 

[Like007]

Shawn,
That's what I thought, I am running crappy break in oil right now too, I think it makes it worse...I will get 500 road miles + 100 track miles this weekend.

I will change to Dumondtech BL 154 next week. I report back on how that quiets things down, I hope...

Dave You can talk to Shad ( Driving Ambition ) about killing that noise
Hi alredy did on Kips car
Igor

 

[John McCain Racing]

Dave You can talk to Shad ( Driving Ambition ) about killing that noise
Hi alredy did on Kips car
Igor

What was the cure?

 

[titaniumdave]

The Dumonde Tech BL 154 really quieted down the diff. Hardly any noise at all and I have only driven it 10 miles. I expect it to 'work in' a bit and keep breaking in, continue to get quieter.

If anyone want some, I can sell it for $17/ qt. It's about $60 for a tranny's worth, FedEx'ed to your door on the west coast.

PM me.

 

[DrivingAmbition]

Great to hear the oil is working for you Dave. I have been using Motul Gear FF Competition 75w140 in Kip's, Steve's, and Igor's cars with the Gikens. It is a little more expensive @ $26.26 per litter and you would need three. I usually stock enough for a couple cars worth. Cheers, Shad (916-861-0032)

 

[ak]

Great to hear the oil is working for you Dave. I have been using Motul Gear FF Competition 75w140 in Kip's, Steve's, and Igor's cars with the Gikens. It is a little more expensive @ $26.26 per litter and you would need three. I usually stock enough for a couple cars worth. Cheers, Shad (916-861-0032)

How is the shifting feel with this oil? I've been meaning to get one but been lazy.

 

[j14nsx]

Has the oil changed the operation or feel of the diff?

I have bought a complete gearbox from Dali, and a note attached said Honda MTF only, so that's what I put in it.

 

[HYPERTUNE]

Some companies (such as NEO) sell a friction modifier that you can add to your gearbox in small quantities. This will get rid of the clunking. The friction modifier does deteriorate over time and then the clunking comes back. Some of you have probably noticed that when you fill up with fresh oil, the noise will go away, but gradually comes back with time. I use Omega 680 in my Civic and it lasts quite a while but is VERY expensive.

 

[titaniumdave]

After a couple hundred 'hard' street miles, I have a different noise. The loud clanking/pop on tight corners is still pretty much gone, every once in a while I catch the noise at start up when the car has been parked on a slight incline, in gear. I think that might be from the diff resting engaged in the lock position and it has to 'pop' loose.

The new noise is a quieter, almost rattle, I can hear at low speeds. Quiet going in a straight line, slight turn to the left or right and I can hear the noise. It is most noticeable in reverse.

I guess I will try some Motul and see what happens.

Driving impressions:
The diff is amazing! As long as you stay on throttle the car is so stable, so easy to get it take a set in the corners. Add more power and the rear comes out, nose points in around you go! Yahoo!

Like j14nsx says, the car will push if I don't stay on throttle, or even go neutral. I am finding if I need more speed or cornering correction than I can get with throttle steering, I need to left foot trail brake to transfer more weight to the front wheels and maintain enough traction to keep the front end planted.

First track day on Friday! Yahoo!

 

[redsuns3838]

dont remember if OS giken requires synthetic or dino tranny oil, but make sure you are using hte right one. Using sythetic on a diff designed for dino oil will cause clutch plates to become too lubricated and slip.

 

[titaniumdave]

dont remember if OS giken requires synthetic or dino tranny oil, but make sure you are using hte right one. Using sythetic on a diff designed for dino oil will cause clutch plates to become too lubricated and slip.

It's designed for synthetic oils. If anything, I would describe what is feels and sounds like as the opposite of slipping, seems to have trouble dis-engaging once locked.

I am trying to figure out a pattern, the one thing that is consistent is it is always quiet when cold, no noise for the first 10-15 minutes of driving after is has cooled over night.

Seems to make more noise when it is hot, will see if the track can help me see a pattern.

 

[titaniumdave]

I followed Shad's recommendation, thanks for the lube Shad!

The noise is gone, the Motul is the stuff no doubt. I can still get that nice locker 'pop' on tight low speed corners, but the rest of the noise is gone. The down side is the tranny shifting is very stiff till it gets hot. Not a big down side for a track car, but driving around town I need to remember to slow down my clutch foot, especially for the 1-2 shift.

Track impressions:
The car does push on turn in with street tires. It is a bit hard to manage with my current setup, now I have -3 degrees front camber, street tires sidewalls are not rigid enough to hold. The car never feels solid till the rear starts get a slip angle.

With R compounds, it is a different story. I ended up with a set of Toyo R-888, 235/275 widths. This is pretty much the tire I have set the alignment to accommodate and it is a pleasure to track. Crisp turn in, no pushing unless I really over cook the entry speed, super stable and very easy to throttle steer.

Nice!

 

[j14nsx]

That's good news for me to hear.

I have just got my first set of R888's too. Usually the track tyres that you guys have are not available in the UK and vice versa. I think the R888's are quite new in the US, we have had them for years.

Anyway, I haven't used any form of track tyre before. The first time I'll get to try the R888's will be in a couple of weeks. I'm also going to be using the same sizes that you have.

I've read somewhere else about your alignment settings I intend to set up something similar though I don't have any special camber bushes.

 

[JeffShoots]

I followed Shad's recommendation, thanks for the lube Shad!
Nice!

Ah..good "rear-end" lube job from Shad with the right lube......Huh :redface:

I have to ah STOP.......Now :smile:

 

[titaniumdave]

Ah..good "rear-end" lube job from Shad with the right lube......Huh :redface:

I have to ah STOP.......Now :smile:

:wink:

 

[nsxotic911]

I followed Shad's recommendation, thanks for the lube Shad!

Nice!

So the Motul beats out the DumondE Tech then..?

 

[titaniumdave]

So the Motul beats out the DumondE Tech then..?

For the OS Giken application, yes. I think Motul is a bit heavy for the Honda Differentials, either NA1, NA2 or the Type R mod of the NA1. I would recommend the Dumondtech for those applications.