Fixed Rear Bias?

[Michael Blue]

Is there a system out there yet for going to a 90/10 to 70/30 rear-bias setup?
My center clutch pack is nearly done, and I'm considering the manual swap anyways, so what are my options?
I want a mostly rear bias, and not having the system shift bias around is better, but some limited bias shifting is OK, as long as it remains heavily rear biased at all times.

Thanks!

[GreenMarine]

Manual swap would give you the best "driving experience"... Hoewver, if you want to stay "automatic" then source a JDM auto tranny (tranny, rear diff and TCU) from either Japan or Australia or Europe... I hear those SVXi are fun to drive :)

[mbtoloczko]

Just to follow up on Chris' post... the JDM SVX 4eat is 36f/64r biased. All the manual trannys are 50:50 biased, except for the STi DCCD trannys. The DCCD manual trannys have an adjustable f/r bias.

[Michael Blue]

The DCCD manual trannys have an adjustable f/r bias.


More info?

Thanks!

[mbtoloczko]

DCCD = driver controlled center diff

The f/r bias can be adjusted from 50f/50r to 36f/64r. There is a control module that goes with the tranny. DCCD trannys and control modules are notariously expensive. JDM STi DCCD 5MTs + control modules are probably around $3000-$4000, and the 6MT DCCD 6MTs + control modules usually go for $6000-$7000.

[Michael Blue]

DCCD = driver controlled center diff

The f/r bias can be adjusted from 50f/50r to 36f/64r. There is a control module that goes with the tranny. DCCD trannys and control modules are notariously expensive. JDM STi DCCD 5MTs + control modules are probably around $3000-$4000, and the 6MT DCCD 6MTs + control modules usually go for $6000-$7000.


So a JDM SVX 4EAT would give me the same bias as the maximum on the manual DCCD? Hmm...interesting. I can't decide if I want manual or not. The other car(s) will mostly be manual, so it would be nice to have one auto around...

[oab_au]

DCCD = driver controlled center diff

The f/r bias can be adjusted from 50f/50r to 36f/64r. There is a control module that goes with the tranny. DCCD trannys and control modules are notariously expensive. JDM STi DCCD 5MTs + control modules are probably around $3000-$4000, and the 6MT DCCD 6MTs + control modules usually go for $6000-$7000.

Hi mate this type of control is really just for off road rally work. The control just tightens the limited slip clutch. On the road with full traction on all wheels, the both sides of the clutch are running at the same speed, so it does not matter how much pressure is applied to the clutch, it stays at the same torque split. Just produces binding, in curves.

It is only on the dirt, when the wheels are having traction problems that tightening the LSC will change the torque split. As both sides of the clutch are running at different speeds, like the wheels.

Harvey.;)

[mbtoloczko]

Hi Harvey. Yes, you are right, in manual mode, the DCCD will cause some binding issues during cornering if the clutch is set to full tight. In auto-mode, the DCCD module will vary the clutch action according to several sensor inputs (g-forces, wheel slip, throttle position, and probably more). If those sensors could be enabled, then it would be a more useful device for the street.

[Jnthn_Sctt]

Manual swap would give you the best "driving experience"... Hoewver, if you want to stay "automatic" then source a JDM auto tranny (tranny, rear diff and TCU) from either Japan or Australia or Europe... I hear those SVXi are fun to drive :)

Ok, so how much to source a JDM tranny? (Or are one of the others better?) Are they direct bolt ups? If this is the case, I may get the JDM tranny and have it drop shipped to Level Ten on the way here!!
:D

Jonathan

[mbtoloczko]

Ok, so how much to source a JDM tranny? (Or are one of the others better?) Are they direct bolt ups? If this is the case, I may get the JDM tranny and have it drop shipped to Level Ten on the way here!!
:D

Jonathan

I priced it out earlier this year. Figure about $1500-$2000 for the tranny, TCU, and rear diff. Shipping would be about $750. Worst part is that there is no guarantee that the tranny is going to last any length of time.

[SilverSpear]

how much for this DCCD alone? any pics of it?

[Jnthn_Sctt]

I priced it out earlier this year. Figure about $1500-$2000 for the tranny, TCU, and rear diff. Shipping would be about $750. Worst part is that there is no guarantee that the tranny is going to last any length of time.

I figured that's why I'd drop it at Level10 first. Are the gear ratios the same? What about final drive? Is the 4.44 available in the JDM market?

Thanks,
Jonathan

[oab_au]

how much for this DCCD alone? any pics of it?

You don't need it Danny, you allready have the automatiic version in yours.

Harvey. ;)

[oab_au]

I figured that's why I'd drop it at Level10 first. Are the gear ratios the same? What about final drive? Is the 4.44 available in the JDM market?

Thanks,
Jonathan

The ratios are the same. They only came with 3.7:1 final drive ratio.

Harvey. ;)

[SilverSpear]

You don't need it Danny, you allready have the automatiic version in yours.

Harvey. ;)

but what if i do my 6mt??? do i still have this ratio, furthermore, it's fun to change the wheels division..

[dieingSVX]

on the jdm auto tranny, why would you need to replace the rear diff? thanks

[drivemusicnow]

on the jdm auto tranny, why would you need to replace the rear diff? thanks
because the final drive ratio is different. the actual gears are the same, however its a final drive of 3.7 rather than 3.545. This makes it such that you require the rear diff, because the "front differential" is inside the tranny.

[dieingSVX]

i see, thanks for the info.

[TomsSVX]

danny, are you gonna rally your svx 6mt? Otherwise it has a 50/50 split that is traction enough. Trust me, Jesse's 6mt didn't skip a beat with a 165 shot of n02!!!!

Tom

[floatingkiwi]

I'm not quite sure why you guys rave about the JDM tranny as regards to drivability - my family has two JDM's and they both understeer like ba$tards without even pushin' em too hard. In fact I just about pulled myself off the road the other day as mine couldn't claw it's way through the corner. Certainly doesn't feel like a rear biased AWD!
My tranny is in pretty good nick too as far as I'm aware, and camber etc is all per standards.

Matt

[SilverSpear]

danny, are you gonna rally your svx 6mt? Otherwise it has a 50/50 split that is traction enough. Trust me, Jesse's 6mt didn't skip a beat with a 165 shot of n02!!!!

Tom

I am more racing cars on the highway (there still no real police presence to watch roads...).

The major cars i beated so far are the 2001 - 2002 BMW 330ci and the 97 impreza turbo (at the 100mph run).

and i am still running on my auto tranny, my six speed is still in my garage, just waiting to resolve the turbo matter in this forum... :D

[SilverSpear]

I'm not quite sure why you guys rave about the JDM tranny as regards to drivability - my family has two JDM's and they both understeer like ba$tards without even pushin' em too hard. In fact I just about pulled myself off the road the other day as mine couldn't claw it's way through the corner. Certainly doesn't feel like a rear biased AWD!
My tranny is in pretty good nick too as far as I'm aware, and camber etc is all per standards.

Matt

I don't have this problem, understeering and stuff... you should check your wheels balance. if your front wheels are regulated to their maximum outer distance, you will have this problem. you should squeeze them to the inside as much as you can. and if you have aftermarket wheels, just tell the guy to replace your front ones to make them smaller hence have a better grip than the rear ones. For example if you are running on 8" aftermarket wheels, just replace the front by 7.5" or even less, you will have a better grip. and you can even go to the extreme, by installing new tyres in the front wheels and used (midlife) on the back wheels...

[drivemusicnow]

I don't have this problem, understeering and stuff... you should check your wheels balance. if your front wheels are regulated to their maximum outer distance, you will have this problem. you should squeeze them to the inside as much as you can. and if you have aftermarket wheels, just tell the guy to replace your front ones to make them smaller hence have a better grip than the rear ones. For example if you are running on 8" aftermarket wheels, just replace the front by 7.5" or even less, you will have a better grip. and you can even go to the extreme, by installing new tyres in the front wheels and used (midlife) on the back wheels...


First you really don't want to get different sized wheels because what you're talkinga bout with different sized outer diameters of tires is what F's with the transfer clutchpack.

I'd suggest playing around in a parking lot. I've found in my US version, that with hard throttle application, my car slides completely neutrally. (i do have extra stereo weight in the back) but with light throttle, and taking a moderate turn, the front end can just slide one me. I think mbtolozcko's rear sway bar would be a good solution to neutral handling all the time

[Jnthn_Sctt]

How much of a handling difference would swapping a Euro spec tranny for a US spec tranny really make?

I'm going to have to replace / repair my tranny in the next year or so max, and was considering going with a Euro spec auto and have it worked over by Level10 in Jersey.

A six speed would be nice, but I've gotten used to the auto (I'm gettin' old too.) And would like peoples opinions on what the difference would be? Any Euro or Aussie drivers input would be tremendously appreciated.

Jonathan

[floatingkiwi]

Quote:
Originally Posted by SilverSpear
I don't have this problem, understeering and stuff... you should check your wheels balance. if your front wheels are regulated to their maximum outer distance, you will have this problem. you should squeeze them to the inside as much as you can. and if you have aftermarket wheels, just tell the guy to replace your front ones to make them smaller hence have a better grip than the rear ones. For example if you are running on 8" aftermarket wheels, just replace the front by 7.5" or even less, you will have a better grip. and you can even go to the extreme, by installing new tyres in the front wheels and used (midlife) on the back wheels...




First you really don't want to get different sized wheels because what you're talkinga bout with different sized outer diameters of tires is what F's with the transfer clutchpack.

I'd suggest playing around in a parking lot. I've found in my US version, that with hard throttle application, my car slides completely neutrally. (i do have extra stereo weight in the back) but with light throttle, and taking a moderate turn, the front end can just slide one me. I think mbtolozcko's rear sway bar would be a good solution to neutral handling all the time

Yes, you don't want to screw with different sizes Silverspear - the rear bar in my case is a much better option. In any case, putting smaller tires on the front would make it understeer even worse I would have thought.

Matt