Better handling

[Rockcrusher]

I enjoy tossing my '12 LT hatch around the twisty PA back roads. I'd like to do some functional improvements to handling while still keeping it a daily driver. Here are some points I'm considering:

1.Tires play a big part in handling. I researched that ultra wide meats might not be the way to go. 16" wheels would help with sidewall deflection but are heavier than my stock 15"s. Wider tires also add weight. This is a concern considering the Sonic's relatively low power output and economy gearing. I'm thinking 205s on 16" rims would be functional. There is a statement that the contact patch does not actually increase with tire width given the same weight (the Sonic's curb weight) and PSI. Basically I want a functional upgrade without too much weight penalty.

2.Suspension. Lowering is out of the question in my case from a functional standpoint despite being a great way to lower COG. This leaves sway bars. What is best? Larger front, additional rear or both bars together? I want to keep the body roll down a bit and perhaps reduce front end push through corners without the rear end getting too tail-happy.

I'm a function over form guy and like performance results over all-out looks. 17"+ wheels and wide tire may look cool but the research I've done points out they may not be the best for performance. Some articles actually show poorer performance in every aspect (acceleration, quarter mile, slalom and braking) except lateral grip with wide tires.

 

[Sonicbobo]

I'm bumping this thread in the hope someone will chime in.

I too nixed the idea of upgrading my stock 15's to heavier wheels and tires for the time being. Not enough bang for the buck. Maybe after my stock tires wear out.

But adding springs and a sway bar sound like a good way to improve handling without breaking the bank. My only concern is some don't seem to like the ride on new springs and have been switching back to stock. I wonder if it's because they also have larger wheels. Anyone want to comment on Eibachs in terms of how the ride is affected with 15" stock wheels? Is it a lot harsher or just mildly more firm.

Been searching threads, but kinda got tired of reading 'more low!' responses instead of how they affect the ride and handling of the car.

 

[cndctrdj]

Biggest improvement in handling for every car is better tires.

That being said. Rear sway bars are great next step, prob the best bang for buck.
The rear sway bar makes turn in much faster and controls body roll. Also it helps pronounce Oversteer.

The front bar helps with body roll but will pronounce understeer. Not good for going fast.

Coil overs are great if done correctly. But that's all in the hands of the ones putting them in and adjusting them.

Mpfab has some chassis parts coming soon so we will see what he has to help these cars handle better.

Also driver mods are always welcome


Strut tower bars are not as common nowadays because cars are built better.

Something to think about also is weight. Less wieght makes the car handle better. Less unsprung weight, suspension parts mounts brakes wheels tires. Is the most important weight in the car. The less weight in those areas the better the car handles.

 

[Sonicbobo]

Thanks for the advice.

Was actually exploring the idea of replacing the stock wheels with something lighter -- like a drag 34 15x7 @ 14lbs -- and upgrade my tires to 205 60 15. Then add springs and the sway bar. And maybe small spacers.

Tire diamater would be 24.7 instead of 25". Would that pose a problem?

Or, I could go 225/55/15 but then I'm over a little @ 25.2" Was thinking that smaller might be better.

 

[rdss]

If you go with tuning the tuner will be able to adjust for the offset in tire size.

 

[cndctrdj]

Smaller wheels = better acceleration but worse gas mileage.
What spacers are you talking about

 

[Rockcrusher]

My problem with lowering in my case is the roads around here are also already scraping my front air dam. Given the choice, the GMPP kit with lowering springs/shocks/struts is probably a good way to go for a street car. I always figure that a huge company like GM with all its engineering power (that actually built the car as well) would put out a good balanced approach. Since I'm stuck with stock ride height I'll start with a rear sway bar. A 16" wheel upgrade should cut down on sidewall squirm and allow for crisper turn in as well as increasing tire choices. But there is the a weight penalty. So the question is, do the benefits 16"s outweigh the extra unsprung weight they impose or not?

 

[rdss]

Or you could go with coil overs and just not lower the car with them... Then you get a better spring rate and dampening/rebound adjustment and get to keep a higher altitude.

 

[Sonicbobo]

Smaller wheels = better acceleration but worse gas mileage.
What spacers are you talking about

These guys...

http://www.sonicownersforum.com/forum/153483-post19.html

Sorry if I seem a bit flaky in looking at a number of different solutions. I'm one of those obsessive compulsive types who likes to explore all options before committing to a final solution. Plus it's a whole lot of fun.

 

[Rockcrusher]

I'm the same way. I analyze and research the heck out of everything before committing to a purchase. Its tough with wheels because everybody wants "biggest" and "widest" when it come to wheels/tires nowadays. I finally kicked Sport Edition gravity cast wheels off my list because research indicates they aren't the most durable wheel out there. So its on to researching Moda pressure cast wheels. That's if I even deem 16"s a worthy performance upgrade over 15"s. Sigh. Decisions decisions.

 

[Sonicbobo]

Seeing as we are both OCD, I think I'll just do whatever you end up with. That way, I can get the dishes done.

S'pose I could always use father's day as an excuse to buy a set of 16" Sparcos and new tires. Same weight as the stock 15's. But then I'd have to start obsessing about which color to get them in. If they only still made silver. Meh. I need to take a Xanax.

Aready spent half the day reading preloader's war and peace length build thread. Highly entertaining though. Lots of comedians on this board.

 

[Sonicbobo]

These could crush rocks and you wouldn't even feel it.

205/60/15 for those with bad backs or hemroids. If we drove Hondas, there'd be a ton of wheels to choose from.

 

[Larrymer]

Everybody goes bat**** crazy over wheel weights when tire weights are barely ever published, which potentially negates any weight you save on the wheels. Just put on whatever wheel you like that isn't too heavy and a grippier tire and stop over thinking it. There seem to be a few around the weight of a stock 15" wheel but it's slim pickens with our bolt pattern.

I have 15" stock wheels for winters and LTZ 17" wheels for summers. At 5 lbs. increase on the 17's per corner in the wheels alone *SPOILER ALERT* I don't notice any difference. It's still a slow Sonic. The grip and braking are way better though.

 

[ss2000slp]

Effects of Upsized Wheels and Tires Tested - Tech Dept. - Car and Driver

Interesting read.

 

[laborsmith]

These could crush rocks and you wouldn't even feel it.

205/60/15 for those with bad backs or hemroids. If we drove Hondas, there'd be a ton of wheels to choose from.

Don't know about Honda, but if we drove Corvettes our wheel choices would seem to be endless. Even the C7 which requires a somewhat different offset than its predecessor offers aftermarket choices and it has been in production nine months.


Laborsmith

 

[mitdr774]

Cruze Eco wheel weighs about the same as a stock 15" Sonic wheel.


Stock 15"tire: 19 pounds


For ease of comparison I will use the same tire for this next set of numbers.

Continental Extreme Contact DWS

205/55/16: 21 pounds
215/55/16: 20 pounds
225/55/16: 21 Pounds

205/50/17: 20 pounds
215/45/17: 20 pounds
225/45/17: 21 pounds


My autocross set up is a Cruze Eco wheel and 225/45/17 BFG Rival combination.

Cruze Eco wheel: 17.8 pounds
BFG Rival 225/45/17: 23 pounds



Stock 15" wheel/tire: 36.2 pounds
Autocross set up: 40.8 pounds

 

[Sonicbobo]

Thinking about ordering these in 16x7.5 @ 17.5 lbs. With 3/16" spacers to adjust the 40mm offset to essentially 35mm. Would add .4" toward fender.

If I go with a 205/55/16 tire, specs call for a 5.5 to 7.5 wide rim. A 225/50/16 tire calls for a 6-8 inch rim. Seeing as the rim is 7.5 would it be better to get the wider tire, or does it matter? I don't want the tire to look like it was streched to fit the rim.

 

[Rockcrusher]

I'm going through the exact same tire debate. I truly don't think the 205 will look stretched on the wider rim. Tire Rack would not recommend that size on the 7.5" rim if it was unsafe or stretched. What the wider 225 tire will give you is a little more rim protection against curbs. It also adds 2 lbs more per corner of unsprung weight (in the case of my tire brand selection). The Car and Driver article plainly shows the down sides of heavier wheel and tire combos. Hmmm.

 

[Sonicbobo]

Yep. Probably going to nix those SE wheels because I want to stay with 205/55/16 and I think a 6.5 or 7 inch wheel is best.

Still looking. Besides, it's the journey -- not the destination -- that counts. Right?

 

[Rockcrusher]

Right.