Trez83

iTrader: (8)

Is it worth getting the 2,4 and 6 degree caster C-hubs or would I be able to get a similar effect just by adding shims under the front suspension arm mounts?

Doing that seems like it would accomplish the same thing.

Am I wrong?

Gtr r34 m-spec

iTrader: (29)

It does change the castor, but also changes the arm kick up or anti dive which has a different handling affect.

gearhead_22

iTrader: (10)

Tom putting shims under the front suspension mount will increase the amount the front of the car dives or drops down towards the ground under breaking or cornering forces, which increases the amount of weight transfer to the front of the car. by doing that you will get more traction to the front of the car which translate into more steering on and off power.

Trez83

iTrader: (8)

So, if I wanted a bit more steering, I would start with a 1/2 mm shim under BOTH mounts or just the front mount?

I have no shims under any mounts - front or rear and the car is nice, but I'd like a bit more on-power steering. Off-power, it's AMAZING. Damn VTA tires and their lack of grip.

You've been such a BIG help with set up, Juwan, I can't thank you enough. I don't wanna bug you on race days. Team Serpent has a killer representative in you.

Worst87

More steering in general: Put 0,5mm shims under the rear suspension mounts
BTW: How much shims (mm) do you have at the front upper inboard mount? Here you can add 1-2mm and get more steering also.

More steering on power (and a bit less off power): Harder Oil in the gear diff...

Johnny Wishbone

iTrader: (6)

I can tell you the aluminum c-hubs are on the soft side and can bend, so you have to stay on top of them for bending them back.

For VTA, i'd look at going to a heavier sway bar.

Also play with the ackerman.

Trez83

iTrader: (8)

Thanks!!

I don't know how many shims I have on the front inboard mount. The link is quite level now, if memory serves me right.

I may try the thicker diff oil. Bout time that thing gets rebuilt anyway.

Trez83

iTrader: (8)

Front and rear, or just the rear?

Johnny Wishbone

iTrader: (6)

Try a 1.6 front, our local CTA/VTA racer seems to like that.

Trez83

iTrader: (8)

Any idea what he runs in the rear?

So many new ideas to try.

YOU ALL HAVE BEEN AMAZING.... Thank you for your time and expertise.

The car is sooooo close to dialed. I'm a noob to touring car, only been running for about a year since rejoining the hobby after a long layoff.

I just need that extra 1/2 second to be right with the big boys. I know it's getting lost in the corners.

I know it's not my driving because I drove one of the big boys' car and was turning faster lap times than he was.

cwoods34

iTrader: (10)

Running 0 shims under the rear arms may feel like more steering than running .5mm shims under the rear arms, but it's actually that the back rolls further throughout the whole turn, so it is increased rotation, not necessarily steering. Basically from mid to exit the back of the car is doing more work to help the car turn. It's more of changing the balance than just literally "adding steerig". That's why on high bite not running shims under the rear can sometimes cause exit/onthrottle traction roll.

If you think the back of the car is stable and rotates appropriately, you can make small changes to the front to increase overall steering without upsetting the back too much.... like shocks down 1 hole, slightly thinner swaybar, etc

Phoenix82

iTrader: (5)

I personally run the 1.6m front sway bar, car seems alot happier(flatter in the corners). I also run 2k diff (rear) oil as a start. I have been switching from the spool to a 2.5k front diff on tight tracks. and the rest is personal choices. Ill post my setup from my last WCICS race where I TQ and took 1st place.

Nick K

Trez83

iTrader: (8)

Thanks!
I'd be interested in seeing what your set up is compared to mine.

Steve S

iTrader: (5)

As Nick mentioned, WCICS Round 6 was this past weekend. I did my homework before the race and felt like I really had the car dialled in for the spec tires. Sure enough, the car was awesome and I took 1st in TC Mod and 17.5. Unfortunately I made a mistake in the last round of Mod qualifying and lost TQ by a fraction of a second. Darn rocket round qualifying

The track had some challenges as the grip was pretty decent in the groove, but very dirty and slippery off-line. There were also some washboard-like bumps going into the high-speed turn #1, and a lot of people had grip-roll problems in that section. The car was great though. The only change I made all weekend was to move the wing back a notch to make the car a bit safer in the high speed S-curves (there were 3 sets). My driving was definitely the limiting factor!

Couple notable things in this setup:
1. Only 2.5 degrees rear toe. This gave the car lots of corner speed and rotation. Running 0 deg front toe makes it drivable.
2. Relatively light diff oils. This also helps the car rotate freely, and also allows early power application on corner exit.
3. All the droop! For me, this makes the car really predictable on throttle and brake. It also helps keep the car planted through the bumps. If I started having grip roll problems, I would start dialing it down.

Worst87

Hey Steve thanks for report and setup!
Especially your shimming of the front upper link shocks me a bit, because only 3mm inboard would cause quite some binding while suspension uptravel(on my eryx 2.0).
Have you checked, that you can push down the front of the car to the ground and still move the wheels up a bit?
All the factory setups from serpent tend to use 4 to even 6mm shims there...