Wheel size

[Rhyno]

Hey all,
I am running 205/40/17 tires on my Aveo. Very close to stock circumference. The problem I am encountering is second gear is to high a gear in some spots on the courses but first is to low.
If I went to a 225/30/16 size tire would that equate to something below second gear in my Aveo with my present tires? Any thoughts would be appreciated.
Thanks

[Corey]

Smaller diameter tires will definitely give you shorter gearing (higher engine speed for given road speed). Your odometer will be off by the same percentage though, if that matters to you. Does someone make a 225/30R16?

The easiest solution is to go faster in the tight corners. ;)

Your car actually has pretty good grip and the gearing is pretty good. Well, from the whole 60 seconds or so I drove it. If you went to a smaller diameter tire you may wish you had taller gearing once your skill level improves and you're able to carry more speed.

[Gemini]

That change would have your speedometer showing 10% slower than the speed your going. If it was my car I'd go with springs before wider/grippier tires. Tall cars make me nervous.

[Rhyno]

Smaller diameter tires will definitely give you shorter gearing (higher engine speed for given road speed). Your odometer will be off by the same percentage though, if that matters to you. Does someone make a 225/30R16?

The easiest solution is to go faster in the tight corners. ;)

Your car actually has pretty good grip and the gearing is pretty good. Well, from the whole 60 seconds or so I drove it. If you went to a smaller diameter tire you may wish you had taller gearing once your skill level improves and you're able to carry more speed.
YODA!!:)
Ya, you only drove it for 60 seconds but you made 2 runs, I made 1? I did feel much more comfortable this week. And after some advice from Jim and Sue (IE- pedal to the metal) I did do better. I had actually put a couple of signs on my dash but forgot to read them. Pedal to the metal and look ahead. And than I screwed up by lowering my rear tire pressures. It would plow or the rear end would get loose. But none the less absolutely a blast. My tire question was due to wanting to get a wheel/tire set for racing only. It is a thought for latter. Still have a pretty big learning curve to get through. But every one has been fantastic with tips and advice.
And YOU showed me there is more in the car than in me just now but I am like a sponge- I will learn.
Thanks to you and to all.

[Rhyno]

That change would have your speedometer showing 10% slower than the speed your going. If it was my car I'd go with springs before wider/grippier tires. Tall cars make me nervous.
Hey there,
I have been enquiring about springs. That is actually one thing that IS available for the Aveo. But tall cars? Remember the hey days of the old minis, they were either in front or upside down on road courses.
Thanks for the advice.

[Corey]

My tire question was due to wanting to get a wheel/tire set for racing only.
Gotcha. I can't really say for sure about that, and I'm guessing there aren't a lot of guys autocrossing Aveo's to pull experience from... :o Continue to do research while you're thinking about buying the wheels, tire size is a very hotly debated subject for most cars.

For reference: Most autocrossers seem to size their tires to get around 100 km/hr in 2nd gear at the rev limiter. Any loss in low-end torque seems to be made up by not having to shift to 3rd as often.

I'm a _huge_ proponent of getting shocks before springs for autocross and general sporty driving. But that's getting a bit off-topic. ;)

[conebasher]

According to Tirerack, your tires are about 23.5" in diameter, the 215/40-16's R ccompounds I run on the MINI are 22.6"-this might be the way to go for you. Wider tires, lower weight and smaller diameter-a winning combination.

[Corey]

In all honesty, if he put your tires (Kumho V710's for those that don't know) and wheels on his car he'd* be on his roof by the third cone in a slalom. :(

Stick to street tires for now.

* "He" = anyone driving it. Most certainly not a slam against Rhyno's driving ability!

[Gadge]

I have to agree with all of the above. My Sprint has 145-80R12's stock and the acceleration is far better and responsive than my 14" R's that use for competition. I had to give up one for the other, grip over speed. If I could get (and afford) a set of 12" R's I'd be all over them. I will be going to 13's when these wear out. The down side of a high car with grippy tires is that it becomes tippy, lowering is very important.

[conebasher]

In all honesty, if he put your tires (Kumho V710's for those that don't know) and wheels on his car he'd* be on his roof by the third cone in a slalom. :(

Stick to street tires for now.

* "He" = anyone driving it. Most certainly not a slam against Rhyno's driving ability!

Sorry, I got distracted and didn't add the part about "Must have lowering springs before installing R compounds"

[Rhyno]

In all honesty, if he put your tires (Kumho V710's for those that don't know) and wheels on his car he'd* be on his roof by the third cone in a slalom. :(

Stick to street tires for now.

* "He" = anyone driving it. Most certainly not a slam against Rhyno's driving ability!
Hey there,
No offence taken at all. All of this is new to me and ALL of the advise and help are appreciated. And I understand some of the more basic concepts from my motorcycle. Lower is better but with control. And EVERYTHING you do often creates another issue.
An example for me was lowering the gearing on my bike, installing a larger, stickier tire on the back and first time I tried a 3,000rpm launch I broke a bullet proof drive belt. Lots of work but there is the pride in doing the next to impossible:)

[rsx_jeremy]

Lower is better but with control. And EVERYTHING you do often creates another issue.


Its great that you understand that already, because there are definitely downsides to lowering springs. They may actually increase body roll even if they are a bit stiffer.
See:
http://e30m3performance.com/myths/Weight_Transfer/weight_transfer2.htm

or google "roll center".

You also have to worry about running out of suspension travel which can create handling issues.