Ok came across a decent deal on a Works 24mm RSB... I have Swift Springs on my MR shocks so nothing crazy.

Is it worth upgrading the RSB? Just looking for thoughts from people that have..

 

if you like a little more oversteer and quicker turn-in ability, i would recommend. i run a 27mm adjustable

 

depends what you use your car for, if you dont drive your car too hard the evo is still an evo and handles great!.. if you are finding that the car tends to understeer under high speed cornering then this will def help ! also look into roll centre kit as i've heard lowering our cars even slightly from stock affects it and creates more roll

the roll centre kit fixes the understeer problem, while the RSB i heard masks it by adding in more oversteer.. both combo'd would be great

 

Alot of that really depends on your current suspension mods. Upgrading the rsb before really addressing the rest of the suspension first is one way to get the car to rotate a little better. The issue might be later on down the road after you start having more suspension mods you may find yourself actually having to back to the oem rsb.

The TRE max lock rear diff is another option to get the car to rotate better as is acd map reflashes. Depending on whether or not you ever plan to get these mods might dictate whether or not you will need a rsb. FWIW I have the TRE max lock 1.5 rear diff and a acd race flash and I actually found myself needing a FSB to due too much oversteer on fast high speed sweepers not allowing the fronts to grip. Maybe if I got some really wide slicks I may be in a situation where a rsb will be needed, but so far its not.

 

As I understand it, Ralliart suggests to run a larger sway bar up front to help dial out understeer. They also recommend a large sway bar in the rear.

I do not know exactly how this will change characteristics if you only go with a larger bar in the rear. TommiM, correct me if I'm wrong, but I suspect it will have the opposite effect and induce more understeer if you are using a smaller OEM sway bar.

 

Not for your situation.

 

If you upgrade just the rsb the evo should kick out the rear from mid corner on out. Just upgrading the rsb might also give a tendency to tripod on tight turns, but if OP is mostly dd then this shouldnt be an issue on the streets. Running a larger swaybar up front will allow the front tires to do more of the work. If they are able to use the available traction then what will happen is the fronts will keep gripping with the added force and keep the weight planted and carry you through the turn. Thats the theory anyhow, its when the tires have exceeded the traction then you understeer. So you can look at it from two different ways, dialing out understeer with a rsb that will increase rear force to make the rear slide out easier or dialing out understeer my increasing available traction of the front tires. Pick your poison.

In an autox type of layout the first choice mentioned above is common. Autox courses are usually really tight slow turns, especially if you go to events hosted by Porsche Club guys. Getting that rear to swing around quickly is important. Way different than a road course where you dont necessarily want that because that setup will have so much oversteer it can slow you down on fast sweepers or S turns because your gonna spend alot of time recovering from sliding out so much.


With all that said, for OP perspective, I dont know what he is trying to get out of his suspension or what he uses the car for. If its strictly a dd then I say pick whichever one really. it really doesnt matter which way you chose because you will never see the max benefits or weaknesses of your setup just dd on the streets. my .02

 

If you got a IX with ACD, get the ECU remapped instead. It's almost the same coin. After that get a TRE Max-lock or similar and you will never look back and not think about different bars unless you want to get way more serious ....

 

having done both of those already my opinion would be to do the rear diff first, then flash the acd ecu.

 

I did them the other way around, though my ACD flash when I got it was already set up for the Max-lock that was waiting to be installed. I would do them in that order again. The flash is just so easy to do - just pull the box out and stick it back in. And the car is transformed in every way. The high speed light throttle understeer disappears with the flash and the steering is way better. Yes, the Max-lock transforms the car all over again and now you can throttle steer the car ... a total delight. That said, I haven't driven the car with the Max-lock w/o the flash.

 

did you have acd-tuning flash your acd ecu? I cant speak for them as I have not tried theirs. I should have explained myself a little better. I have the Gruppe-s flash, which is not as 'refined' as what acd-tuning does. Turn in on tight turns, like an autox didnt improve much. On faster higher speed turns like a road course it did. The downside was that the Gruppe-s race flash didnt initially like slow autox layouts. It wasnt until I installed the max lock diff that I was able to not freak out whatever maps gruppe-s put in.I dont hear about those issues with the flashes that are available now and yes, removing and installing your acd ecu is much easier.

 

Have a custom ACD flash from Matthew at ACD tuning. Generally, I would agree with your observations. For hi-speed and road use the flash is spectacular. The car is what it should have been from the factory. There was definitely better rotation w/ the flash but likely not enough for autocross - though I should note that did get the flash set up for slight understeer for hi-speed stability but able to throttle steer. For autocross there probably is not enough rotation w/o the diff upgrade. The two work together to make the car a very different animal - I really like it now, whereas I was a bit disappointed about the car at first - I don't think there really is much out there that even comes close. You can change the attitude of the car with the throttle at will - at least at lower speeds. The car feels much more linear now and you can set it up for the turn and it responds beautifully to all inputs. Haven't had the chance to do the really hi-speed stuff yet, as I just put the diff in a while ago and have had only road use on it so far.