Biggest effect on fun-to-drive handling - Better tires or rear sway bar?

[db1980]

25plus - I see your vote is for suspension pieces, but what tires do you guys get in Germany? I have a feeling they are not the craptastic Dunlops. I wouldn't be changing rim size, so any width increase would be minimal, just a better tire in general.

cinder - I pretty much agree with all of the reviewers comments. body roll does not bother me, but in real world driving, potholes, expansion joints etc tend to make it even more twitchy and unsettled, and it just feels mushy in general otherwise.

I am not wanting to turn it into a race car, and to be honest, sticking a roll bar on the rear is going to be pushing the budget. I just want a bit more crispness. Something a bit more like how the Mazda 2 handles. I get it that everything works hand in hand, but was just sort of wondering which one I would feel more behind the wheel between the two options. I have a feeling from the responses, that I would feel them equally just in different ways?

[Littlestan]

Has little effect on stock suspension. They aren't driving the car hard enough. The stock spring rates are way too low. New springs/coilovers eliminate body roll a lot better than the UR bars.

OP's question was tires or rear sway bar for the biggest effect on the 'fun to drive' aspect. I stand by
my assertion that the rear sway bar will do much more than new tires.

[cyclopathic]

the car is in very near perfect balance now.

The only weird thing it does now is, it seems to be hunting for grip. Front and rear will alternately lose gain traction along a single turn/corner, so I end up having a dance-like motion.. Waiting for my 17" wheels, hopefully it'll solve the problem. (Or maybe I do need the rear anti-roll bar afterall..)

This is actually an indication of good balance. You may wanna more grip but balance is good.

Which tires do you have? still stockers? What pressure front/rear? have you tried different higher/lower? BTW there are some sticky tires in 15", you don't have to go to 17" just for that.

How is your alignment? have you had it checked? lowering may change toe-in on McPherson. Before you start anything make sure your alignment is good. For best fuel economy you want front toe-in as close to 0. On Prissy I have ran 3/16" toe out, and while it was scary good in turns (it was actually bad b/c it used all 100% of the grip in turns and then loose w/o any warning), the MPG wasn't the best. 0 toe-in on negative camber front is good for economy and feel.

Then make sure that you got the right tires (it doesn't make sense to adjust suspension to 0.8g tires if you will be running 1g tires in autoX), But if you will be running both then it makes sense to find settings which will work for both.

Try this test: set up the cone wave course (or imagine if you don't have cones) and see if car understeers. If it does most likely it will benefit from negative camber. I have not seen the camber kit listed for Mirage, but I think it has 14mm bolts , so the 14mm +-1.75 kit should fit. You will not have to go crazy with negative camber, 0.5deg is a big change. With 1.75 kit I would do it roughly in 1/3 increments (which is 30, 45 and 90 deg from top) and see which one works the best on cone wave. Also neg camber kit on McPherson adds toe-in. I will have to look how much but on other cars you'll look roughly 2 1/3 turn on -1.75 camber to keep the baseline alignment, give or take.

Now if you find that you needed more negative camber in front for slalom it could unbalance car and make it oversteer in turns. Then you will have 2 options either to take sway bar off or shim rear to get balance back. Drifters are setting rear to 0 or even positive camber, but I cannot comment on this. FWD slides are much harder to control, RWD is better to learn on. On FWD hand brake is your friend.

Disclaimer: anything above is a pure speculation; not a recommendation of any sort. Use or not use it at your own risk.

EDIT: almost forgot; when you get the initial alignment print out do not be alarmed that left side has ~0.5deg less camber than right. This is for US, but since you guys drive on wrong side it would be opposite. This is to correct for road crown pull.

[cinder]

I'd say go with the rear sway bar and some slightly wider tires . If you decide on any upgrade(s) let us know how it performs .

[mousee]

Hi Cyclopathic! Thanks for the explanation!

I'm sure glad that is an indication of good balance! I'm still on stock tires, Bridgestone Ecopia 150, 165/65R14. Pressure at 35psi on all 4 wheels. I didn't play with the pressure as the objective of my mod is to get the best look, handling and fuel efficiency. 35psi seems to have a good tyre patch contact with this set of tires, wear seems to be quite even. I'm after the 17" just plainly for looks more than grip actually.. hehehe..

Alignment at the moment is slightly off, still fine tuning the overall height of the coilovers, so I haven't went for alignment yet. I'm actually interested to know more about 0 toe-in on negative camber front since you mentioned it's good for economy and feel. What makes it so? How negative a camber should I go for? What do you mean by 0.8g tires? I wouldn't have any place to do the test... if only someone else could do it and give me a ballpark figure to play with.. hehehe...

[25Plus]

You would notice a false toe-in with higher fuel consumption and higher tire wear. Since fuel consumption of my Space Star is very low (3 l/100 km if want to), I think toe-in of the factory setting is quite good - with standard springs and with lowering springs, too. Since the toe-in is not constant when driving (the tires pull the car and the wheel alignment changes according to the forces exerted on the chassis) I wouldn´t claim a specific value would be optimal.

I have the Bridgestone Ecopia, too, and use a tire pressure of 2.7 bar what I think is best for fuel economy and driving. Of course any adjustment of the chassis would affect driving behaviour - but best values for toe-in and camber depend on the dimension of the tires and offset of the rims so much, that there is not one setting that is best for all cars, drivers and applications.

I would only change toe-in of the front tires (can anything else be changed with the original setting of the car at all?) when fuel consumption or tire wear would be higher than it should be.

Changing other settings should only be done in my opinion if money is no object or if you want to go to competitions with your car. But then settings for best fuel economy and best handling of course would contradict each other.

[cyclopathic]

Hi Cyclopathic! Thanks for the explanation!

I'm sure glad that is an indication of good balance! I'm still on stock tires, Bridgestone Ecopia 150, 165/65R14. Pressure at 35psi on all 4 wheels. I didn't play with the pressure as the objective of my mod is to get the best look, handling and fuel efficiency. 35psi seems to have a good tyre patch contact with this set of tires, wear seems to be quite even. I'm after the 17" just plainly for looks more than grip actually.. hehehe..

Just beware that low profile tires have worse fuel economy, so 17" 205/40R17 will definitely have much higher rolling resistance. Ecopias are not very good gripping tires, but they are still better than Dunlop Enasaves we get here. When they wear we will go to 185/60R14, as there are virtually no tires sold in US in 165/65R14, and I do not feel spending another $500 on 15" rims.

Experiment with pressure, 2-3psi in front may change the way it feels.

Alignment at the moment is slightly off, still fine tuning the overall height of the coilovers, so I haven't went for alignment yet. I'm actually interested to know more about 0 toe-in on negative camber front since you mentioned it's good for economy and feel. What makes it so? How negative a camber should I go for? What do you mean by 0.8g tires? I wouldn't have any place to do the test... if only someone else could do it and give me a ballpark figure to play with.. hehehe....

The answer to negative camber is as much as needed. On track people running -3deg or more, the general consensus for street -1.5-2deg to avoid excessive wear. I am running -2.5 w/o any problems on our other cars (not Mirage), and only b/c it was needed to correct severe understeer on Toyotas. Don't know yet what would be the best for Mirage; once again it all depends on what car needs. Will find out after we get Teins (on order shipped from Japan). Also beware that some coilovers already have additional negative camber built in.

0.8g? most of non-performance tires have ~0.8g of lateral grip, with better ones getting to 0.85. The performance tires have 0.9-0.95g, with better ones 1g and over. They usually have very short life, worse MPG, and some are really bad in rain and cold.

When you get a chance check "Angry Jelly Bean" posts. OP is running RS3s which I think are good for 0.96-0.98g. Not sure what Ecopia 150 is good for but probably similar to 422, which is 0.79g tire. Here is test results for EP422: http://www.tirerack.com/tires/tests/...y.jsp?ttid=155

We are probably going to General RT43 in 185/60R14, since they are similar in diameter to 165/65s and can be fitted on OEM rims. Very cheap, and long lasting with good handling, reasonable grip (0.85) and o'k fuel economy. It is not specifically LRR tire, but they are one of the better rolling non-LRR out there. RT43 were rated #5 in TireRack reviews, but all tires above cost x2 or more.

[cyclopathic]

You would notice a false toe-in with higher fuel consumption and higher tire wear. Since fuel consumption of my Space Star is very low (3 l/100 km if want to), I think toe-in of the factory setting is quite good - with standard springs and with lowering springs, too. Since the toe-in is not constant when driving (the tires pull the car and the wheel alignment changes according to the forces exerted on the chassis) I wouldn´t claim a specific value would be optimal.

Yes the toe-in changes on compression on McPherson. The cars usually set up stock with some toe-in for highway stability, but anything over 1/8" (3mm) will eat tires. Zero produces least drag, and toe-out is big in go-carts for better tight handling (google Ackerman effect). OEM is very good for MPG, but on mine the wheel is slightly off center. Need to have dealer check and correct it.

[Ares]

I have found that I was able to make faster exit speeds with changing wheels+tires to 195-50-15. At the same time, the ride seems a little firmer because of the lower profile. Lastly, the weight of the new wheels+tires and the width made steering feel a lot better than stock.

I have also found that the exit speed was also just a tad faster after I've installed my VW springs (rear) and swaybar. The swaybar does, in fact, decrease roll by a lot. The springs helped by giving the car a firmer ride.

While my exit speeds are almost the same in high speed sweepers, between when I installed the tires and the springs+swaybar, the car does feel 100% more confident after the springs+swaybar install.

Just my observations.

[Basic]

I haven't gotten to put on my rear bar yet, but just to chime in on something no one asked about... the front strut bar makes a remarked improvement. It is subtle, but man oh man does it firm up the wandering feel of the front end... my car was always a bit vague at best, and now it feels much more substantial. I would recommend the strut bar in a heartbeat... cant wait to get the rear sway on!