We're thinking of upgrading our suspension. I currently have Koni sports in the stock strut housing with stock springs, stock ride height etc. This has worked pretty well but I lift the rear tires something fierce through tighter corners.
Has anyone installed the Stage 3R suspension kit from Mopar? Was it essentially a bolt-in system? Any gotcha's we should know about?
Bolt-on. Pick your spring rates carefuly. If you are lifting your rear tire in corners you got too much bar in the rear or not enought spring/bar up front. judge by body roll. Id stick with your current setup and fix that first. A lot cheaper and if its working...dont f*ck with it.
D
think about ground control coilover sleeves with some 350/250 springs and possibly get your koni's revalved. It'll be cheaper and offer more options, but the 3r suspension is going to be great if you know how to tune the dampers to get the best performance.
Bolt-on. Pick your spring rates carefuly. If you are lifting your rear tire in corners you got too much bar in the rear or not enought spring/bar up front. judge by body roll. Id stick with your current setup and fix that first. A lot cheaper and if its working...dont f*ck with it.
D
It depends on what you want. The bigger the rear bar, the better in terms of overall grip, but worse for transitions. Your car will tend to oversteer (like in my sig), so you'd better be very comfortable with it's setup, or just don't push it.
I have the S3 suspension and the hotchkiss bars. The rear bar is massive compared to the front, but there is enough damper adjustment in the suspension to tune out the oversteer reasonably well. On the street, I have them adjusted about halfway in terms of oversteer (full soft front and rear).
It depends on what you want. The bigger the rear bar, the better in terms of overall grip, but worse for transitions. Your car will tend to oversteer (like in my sig), so you'd better be very comfortable with it's setup, or just don't push it.
I have the S3 suspension and the hotchkiss bars. The rear bar is massive compared to the front, but there is enough damper adjustment in the suspension to tune out the oversteer reasonably well. On the street, I have them adjusted about halfway in terms of oversteer (full soft front and rear).
Hey atlas you live close.. lets go out and run a few laps on a road course.. you in your really big rear barred car and me in one of my non-race prepped SRT-4's. =]
I would steer away ... so to speak... from telling people this ("The bigger the rear bar, the better in terms of overall grip"). Since its pretty much not completely true.
As I mentioned above once the rear tire has lifted off of the ground there is nothing further anything more lift can accomplish in the grip department. and is detrimental in settling the car after apex.
Due to weight distribution in our cars we have extra grip in the back that we cant really leverage. (sic. the front tires are closer to load saturation than the rear tires and thusly are generating larger slip angles). We can change this some by changing how the weight shifts in the car, eg. If we decrease the roll resistance in the front or increase the roll resistance in the rear, we change the way load is distributed in a corner. In this case, increasing roll resistance in the rear to help offload this work ( of resisting roll ) from the front suspension components. Now here is where the magic occurs, we can sacrifice the extra grip in the rear to get a wee bit more grip in the front. Once the rear tire leaves contact with the surface the load on that tire goes to zero... leaving 3 tires to support the entire weight of the car. I could show you the math here but it would require more space and diagrams. But basicly, we have asked the remaining planted rear tire to support more load than when all 4 are touching the ground. Since the weight is now supported differently ( by 3 wheels not 4) all the tires are loaded closer to saturation. We are giving up a bunch of grip in the rear and are 'overloading' the fronts with a portion of the 'extra' weight that the rear airbourne tire used to support.
Now here is the kicker that makes your statements not so true. Once the load of the rear inside tire has been reduced to zero NO FURTHER load shift can occur... it doesnt matter how much you lift the rear tire now you cant do anything further to improve the traction of the front..... Hence any bigger bar in the rear than is required to lift the tire more than a wee bit is detrimental.
Now you will notice.. at NO time did I say we were increasing overall grip at all. A huge rear bar doesnt accomplish this IN FACT it decreases the overall grip... (lose a bunch of grip in the back for a wee bit more grip in the front) the tradeoff is a net loss in overallgrip. However your comment about transitions is absolutely true. A huge bar makes them suck.
My understanding is that in an FWD car you put a bigger rear bar in to ensure you get use of both your front tires for longer (less roll resistance in the front = less transfer of weight from inside front to outside). You end up having the outside rear and inside front sharing load for longer than you otherwise would if you had less rear bar - a bigger front bar would take grip away from the inside front sooner, causing it to lift along with the rear, giving you 2 contact patches to work with. In a FWD car, that situation leads to an even more overloaded outside front tire.
So in short, the bigger rear bar lets you get more out of 3 tires for longer (2 in front where the weight is, 1 in rear where the weight isn't). A bigger front bar gives you more grip in the rear, but you lose grip from the inside front faster, and the inside rear is so unloaded in either case that it contributes next to nothing anyway.
In autocross, FWD cars go for alot of rear bar - it just makes them faster as long as a heavy transition (like a slalom) isn't as significant as sweepers. The fastest FWD cars I've seen all have very, very stiff rear bars, and either small or no front bars. Our top FWD driver drives a '94 VW in FSP with the only modification being his big rear bar - no other suspension modifications - and I've been faster in his car than I have been in my own. What's interesting is that his car still manages to transition reasonably well.
On a road course, I know things are different. You spend much less time in steady-state cornering, and it seems to me that driver confidence is a bigger factor in speed than the grip of the car. A rear biased car certainly does not inspire confidence at speed - it has to be driven a bit more conservatively.
well little or no bar in the front improves traction on corner exit. My world Challenge SRT-4 AND my world challenge neon were both set up dramaticly different. the srt4 has no front bar, big springs front and a adjustable hollow bar in the back. The neon had stout springs in front a ACR bar and a tiny bar in the back. the SRT4 gets out of corners better and comes around like a rockstar if you tipout a bit towards apex. the Neon trailed really nicely and wouldnt lift inside rear. Driving style is definately a factor here.
But as far as numbers and the math goes what I said above holds VERY true for our cars with stock geometry.
The biggest note is if the inside rear wheel comes off the ground the bar has done its job. No more job can be done by using a bigger tool .... you can eat a cheeseburger with small or big bites, but once the cheeseburger is gone taking really big bites doesnt really matter any more. The bigger the bar the more time that 4th wheel is airborne. I think this is where you are going with this. I see your point but using other ways to increase roll resistance is probably a better plan and would be less abrupt.
D
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Stage 3R Suspension Install
Linear Mode
