T4 '14 base setup for CPX tires

morgoth · **Joined:** Sat Oct 19, 2013 20:16:42 **Posts:** 31

This weekend we have a big race over here with handout CPX tires. I haven't run CPX tires in 2 years and that was with a T3 '11. I don't drive onroad a lot so if someone can help me with a good base setup, I'd be very happy since practice will be very limited.

I'll be driving the 2014 T4 in the modified class (4.5T motor)

morgoth · **Joined:** Sat Oct 19, 2013 20:16:42 **Posts:** 31

No one?

coastal · **Joined:** Sat Oct 20, 2012 17:17:10 **Posts:** 91

try this one http://www.petitrc.com/reglages/xray/se ... 201311.pdf

morgoth · **Joined:** Sat Oct 19, 2013 20:16:42 **Posts:** 31

Thanks! I started from the kit setup, but ended very closely to the setup you mentioned.

The only difference is a 1.5mm shim on the rear bulkhead, 3° toe in instead of 2.5° on the sheet and a 1.3 rear rollbar and 2° rear camber.

It's a technical track where you need a lot of rotation. My car is quite good at the beginning of the run, but then the front tires heat up and I start having slight understeer. I think I'll try 2.5° rear toe for Q4 and hope that improves my lap times. The car is a little to safe at the moment. Or are there other suggestions to free up the rear a little bit?

morgoth · **Joined:** Sat Oct 19, 2013 20:16:42 **Posts:** 31

The race is over, but I'm still looking to improve my car. I was a small technical track and my car is still lacking steering/cornerspeed. I raised the inner hinge pins of the A arms in the rear with the 0.5 insert. I felt like my car was more balanced during the race. Without this, the front tires would overheat after 3-4 giving me a lot of understeer.

I'm still looking for more corner speed. My rear end was too planted to go fast. I'm not sure how I can free up the rearend of the car. I have tried 2.5° rear toe by widening RF with 0.5, but that made the rearend loose while accelerating after the corner.

Do you have tips for me Alex?

Here's the setup that I used in the finals: xform/index.php?act=view&ID=55&setup=t4_2014

Skiddins · **Posted:** Thu Nov 28, 2013 19:55:57

Will be interesting to see what Alex say's, but have you tried removing the front arm sweep and putting linear rear springs in?

morgoth · **Joined:** Sat Oct 19, 2013 20:16:42 **Posts:** 31

I haven't tried other springs. Practice time was very limited and I seems that the team drivers use the hard progressive springs most of the time with CPX tires. I haven't driven with CPX tires since the T3 2011, so I started with the recommended springs of the team drivers.

Hagberg · **Posted:** Mon Dec 02, 2013 23:48:16

I would recommend the following changes to free up the rear:

ECS rear driveshafts (50 mm)
Front camber -2, rear camber -1.5
Front upper link shimming 2/2
Rear upper link shimming 2/4

Actually the high rear roll center on the arms which you are using will sometimes make the car feel more stuck in the rear as you will have less turn-in.

-0.5 narrower rear but [·] [·] RF and -0.5 RR

morgoth · **Joined:** Sat Oct 19, 2013 20:16:42 **Posts:** 31

morgoth · **Joined:** Sat Oct 19, 2013 20:16:42 **Posts:** 31

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T4 '14 base setup for CPX tires

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