How do you make them more rear wheel drive happy rather than understeery!?

 

Uprated anti roll bar destabilising the rear in an effort to provide greater front end grip, or there abouts

 

I take it that there is not a 'simple' gearbox mod to distribute more power to the rear?

 

No. You'd need to change the centre diff to do it via the gearbox. The common way to do this would be to fit a DCCD, which gives you the 35:65 front:rear bias if run unpowered.

The car already has a 50:50 inherent torque split (it is not FWD biased as some have stated). You can make it a lot more positive, both on turn-in and under power, by doing exactly as 53 suggests and fitting a thicker rear ARB. Much cheaper than trying to source a DCCD rear housing (and appropriate drop gears/rear diff) too.

 

Thank you sir, i shall do that, any suggestions on what thickness to go for on the rear? BoB Rawle recommended a alignment check with some numbers that he put on a piece of paper to make it more grippy at the front. I also have an ALK to fit (not got around to it yet). And finally i was advised to lower the tyre pressure at the back.

Are these all sensible steps to achieving a DCCD-like feeling?

 

To be honest I'm not sure you want "DCCD-like feeling", at least if you're talking about just shoving one in and running it permanently unpowered. DCCD with a multi-mappable contol strategy rules. However, unpowered DCCD can be a bit more of a handful than you want in the wet. In many ways a viscous diff with some sensibly chosen suspension mods can feel better and can ultimately be driven closer to its limit than an unpowered DCCD.

As far as size of rear ARB, I'm not sure what size your car will have as standard but the answer would be the same irrespective - fit a Whiteline adjustable one as that way you can tune it to taste. Bob will probably have been talking about adding some negative camber and maybe a little toe-out at the front, which, as part of a full geometry check, is well worth doing. Camber/caster adjustable front top mounts aren't a bad idea either.

 

On my STi wagon I run 24mm rear on hard, 22mm Front on hard. Fast Road Geo, Toyo T1R tyres 37f 34rear, does it go sideways as required...Yes

A host of other handling mods can be done to make the car, for want of a better word, more 'chuckable'....check out my wagon in my profile for stiffness lol.

Interestingly one of the best 'handling' mods I have done (apart from all the others) is upgrading the engine and gear box mounts for uprated/solid items. Car runs much 'flatter' and in conjunction with the RWD handling bias characteristic brought on by the ARB set up, runs spot on.

 

why would the DCCD have to be unpowered?

 

no lowering tyre pressure will give more grip to the back creating more understeer. you want more pressure in the back to fron, a good combo is 35 rear 25 front.

 

22mm adjustable rear anti roll bar should do it, got mine set on the medium setting. I've got dccd as well though and it does go proper sideways if I provoke it. Mate has got a wrx classic with the 22mm rear and it does make a lot of difference along with the solid rear drop links

 

On what tyres, brand, size, profile, those pressures could be death on a stick 25 front is too low on any hard driven road tyre IMHO, will just fold on a car intent on understeer.

 

I didn't say that it would have to be unpowered, I mentioned that the best way to run one is via a mappable controller. However, Chtcpo asked about a "simple" gearbox mod that would alter the power bias - and under these circumstances, simply dropping a DCCD unit in is about as simple a gearbox mod as there is.

As has already been said that's potentially very dodgy advice given without context - like knowledge of the tyre size/profile that's being used, for example. Even on the standard late classic 205/50/16 RE010's, IMO 25psi is far too low. If you need to go to that sort of extreme to get a handling balance that is to your liking, it suggests something's seriously wrong with your suspension setup.

 

I am so glad this got covered, I was going to ask the same myself. I want a bit more of a "chuck-able" side ways feel at times.

Would there be much difference adding a 22 or 24mm anti roll bar to my class wrx?