Sway Bar
I also found a 36mm front.
Do I just need a front or just a back or both or what.
I will have around 500hp + 250 shot. Daily driver maybe 10 times at the most a year at the track. I just want some improved handling. please help thanks.
The 25mm would most likely be too stiff. If you are wanting to do this cheaply, a ST 35mm solid is fairly cheap {something like 140 bucks I think} and keep the factory 19mm rear, works well for most people. If you are still wanting more bar in the rear, try a solid 21mm. They are fairly cheap also.
If you don't mind spending more money, try the bar that CamdLs1 recommended. I have it and I like it. Also had the 35mm/19mm set-up too. Like it also, just wanted to step it up a bit and lose some weight.
There ya go, both that bar and the stranno bar are top notch quality, cant go wrong wtih either one.

