Impreza DCCD - RedLine heavy

[AK]

After reading some comments from Jack - redline heavy gearoil making his diff snatchy... it got me thinking.

We changed to redline heavy shockproof in the 6sp DCCD box. This also looks after the DCCD centre diff. I also changed to a single piece lightweight prop at this time.

The changes make a big difference to the car - all of which i put down to the massive reduction in prop inertia (car a lot more prone to bunnyhopping on steering lock at slow speed - rear diff)

Car also became MUCH more understeery -liek the rear diff was pushing <locked> on much lower torque.

Anyone got a feedback from running DCCD with redline heavy before/after? Did you notice any large changes to the car?

Trying to pin point prop or fluid for the big change
_________________
Impreza Race Car, 1200kg, 480bhp - SLS/SMRC
Mini Race Car x3 - SMRC, SMRC, SLS
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
X5 40d M Sport
Mini Cooper Park Lane
MB Sprinter Camper
Track Scotland

[AK]

after a bit more research I think its prob more the fluid...

Will add in some modifier as a start
_________________
Impreza Race Car, 1200kg, 480bhp - SLS/SMRC
Mini Race Car x3 - SMRC, SMRC, SLS
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
X5 40d M Sport
Mini Cooper Park Lane
MB Sprinter Camper
Track Scotland

[Steviej]

This has me thinking, my car has more understeer than id like and have wondered if the rear lsd is too tight, it has heavy shockproof oil in it too, so maybe that's a factor.
Would adding friction modifier to the oil give it more "slip" similar to less preload on the plates ?
I also see that redline do a 85/110 lsd shockproof oil with friction modifier.

[AK]

yup, i'd expect it to add a little slip to the initial lock.

It feels like the DCCD (plates) are snatching on ours, so looking to add a little slip to make it less grabby

RedLine suggest adding 1oz at a time. No idea if they say that for a 1.5lt diff or 4.2lt gearbox though LOL

I'll give it a go - the car felt nice otherwise, just had to adjust setup - Clarks esp
_________________
Impreza Race Car, 1200kg, 480bhp - SLS/SMRC
Mini Race Car x3 - SMRC, SMRC, SLS
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
X5 40d M Sport
Mini Cooper Park Lane
MB Sprinter Camper
Track Scotland

[Steviej]

I saw that, they say add up to 4% or 6% for the heavier shockproof oils
I'll try some in it and see, its pretty noisy / clunky driving it round the pits which makes me think its set quite tight.

[AK]

Its prob not the diff being shimmed tight, but the non slippy thick oil
_________________
Impreza Race Car, 1200kg, 480bhp - SLS/SMRC
Mini Race Car x3 - SMRC, SMRC, SLS
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
X5 40d M Sport
Mini Cooper Park Lane
MB Sprinter Camper
Track Scotland

[Steviej]

I have a couple of things I want to try so have booked the track night on the 31st, are you home for it ?

[Jackstrath]

Just a update from me, Changed back to the Cusco Oil and the diff is now back to its normal self , no jumping,skipping, snatching ect a tiny bit on full lock but its always done that , before it was anything more than 2/8ths of a turn and it was grabbing

[AK]

yup, my main reason for the redline heavy is to mask a synchro baulk/crunch into 4th/5th. Shift is seamless with the Redline, so will try the additive.
_________________
Impreza Race Car, 1200kg, 480bhp - SLS/SMRC
Mini Race Car x3 - SMRC, SMRC, SLS
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
X5 40d M Sport
Mini Cooper Park Lane
MB Sprinter Camper
Track Scotland

[Cullenmin]

How did you get on with the additive Adam?

I'm finding my impreza skipping a bit but i'm puting it down to the Kaaz rear diff. Currently got Millers CRX LS 75W 140 in there just now but going to change that to the Redline heavy.

My next step for added protection of the 6 speed dccd box was to change the oil also to redline heavy. Dont want any skipping though

Rich
_________________
MY98 STi Type R

[AK]

I wouldnt put redline heavy in the rear diff. We use the KAAZ specifc oil in ours, seems to work very well. Didnt really skip

Havent had the car out yet!
_________________
Impreza Race Car, 1200kg, 480bhp - SLS/SMRC
Mini Race Car x3 - SMRC, SMRC, SLS
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
X5 40d M Sport
Mini Cooper Park Lane
MB Sprinter Camper
Track Scotland

[Cullenmin]

Ok, I’ll have a look for the kaaz oil cheers
_________________
MY98 STi Type R

[Steve H]

Why is the Redline oil any better than any other brand?

[Steviej]

I believe that the shockproof oil is designed to spread the load across the gear teeth more, all EP oils are supposed to do this to an extent, but the redline does cling to the gears more.

[Steviej]

Btw my car doesn’t have the shockproof oil in the rear diff.