How much difference would tires/suspension make?

[rvanderpyl]

Did another autocross last night. Best times were from a modified Honda Civic that is specifically setup for autocross. Lowered, stiffened, slicks, etc, along with a few other modified BMW's and a 993 also setup to autocross. Their times were around 1:20-1:22, mine was 1:28 for my best run. Given that my car currently looks like it is on stilts, is running Yoko A520 (205 and 225-16) and is basically stock suspension and a tired 2.2T motor, could I be running similiar times if I did the following:

I have the front suspension and brakes from a 74s that I can install that means I can put Koni Sport Shocks in, update my front brakes to S calipers and vented rotors (or better) and have updated ball joints. I also want to upgrade my front sway bar and add a rear bar.

I have a set of 15" real Fuchs that I was intending to mount 205-15 A032R on for track use. I would also have to ditch the 225-16 rear tires I now have because they would never fit with the next step.

Lower the car and have it corner balanced.

How much of that 6-8 seconds could this shave off?

Next step is to build the 2.5 short stroke motor, but that has to wait.



Note that the course we were running had minimal cones and was relatively high speed with the faster cars hitting 120km+ by the first corner. I was at 105km into the first corner and in 3rd gear through-out, except for a short, tight, cutoff corner set.


Or is it all the driver?

[Reg]

Its the single most important thing you can do ( other than driving experience and skill) to the car that will make you faster. Its also one of the easiest mods too.

Buy the tries first , then do the suspension next year or so and while you are at that , you can do an alignment.

The yoko's are not the fastest tire for autocross. I think the Kumho's may be a better choice, and cheaper too!

[Superman]

Traction. And skill. The best drivers using well-prepared cars are going to be hard to catch. Eight seconds behind the leaders on a 1:20 track....you're doing very well. When you reach the limits of shat your car will do, you will know it. After that, suspension mods get you tiny bits of improvement. Tires are FAR more important. So, tires and seat time will get you WAY more results than expensive suspension mods. Then again, all the tires and seat time in the world may only get you within a couple of seconds of the Big Boys.

[TRE Cup]

For competition use (this means you will experience short tire life and darty behavior on the street): With the 032 R go with 2.5 negative camber , as much castor as possible, and 1/16 toe in on the front. Rear: 3.0 negative camber, 1/32 toe in. Turbo tie rods, 21 mm front/ 28 mm rear torsions, smart products front/rear sway bars (expensive but worth every penny)
7 x 15 wheels will fit front and rear with this alignment set up with 205/50 x 15. The shorter tires will afford you better gear ratios for fast accel off the corners.
If the budget can stand it, raised spindle front struts and get the car professionally bump steered- just throwing in rack spacers is not the way to go.
Don't forget a good race seat that allows you to control all this new found sideways capability.
Watch those 8 seconds melt away!
Have fun