Compkart Setups

Chassis Setup, Tires & Handling Forum
1

Hello, I run a 2019 Compkart 4R chassis in the Briggs and Straton lo206 Senior class. I don’t see a lot of things on here for compkart. I just wanted to help people with my experience and people I race against also with a compkart chassis. At my track, the top 3 in lo206 senior are usually compkarts. I will add any details I remember an answer all questions I can.
Just for reference, I’m a skinnier, 160lbs, 6ft 2inch male.

Base Setup (For a tight, track)
Tires: MG Red SH2
Weight Distribution: 43% Front 57% Rear
Rims: Freeline DF 130mm 210mm
Front Spindles: 17mm
Front Width: 44 15/16 inches (10mm + 5mm Spacer)
Front Ride Height: Middle
Front Bar: Standard Bar In
Pills: Birel 0.5
Camber: +2 (On the stand, each side)
Toe: +1.5 (on the stand)
Seat: Tillett MS (standard flex)
Seat Struts: Yes always (1 on each side)
Brake: CXI28
Rear Axle: Compkart C1.5 (C3.2 on super sticky days with modify setup)
Rear Hubs: 90mm Metal
Rear Width: 53 inches (I use spacers in the hubs)
Rear Ride Height: High (Bottom Hole)
Rear Wheelbase Width: Middle (Center Hole)

2

Just curious why the high rear ride height at your size?

3

At the track I race at, Stockholm Karting Center, we need a lot of help turning in so running the ride height high helps with turn in and my seat is on the stiffer side so not as much flex with it.

1 Like
4

You’re the man. 4r is tough to set up for 206 especially on Vega reds.

I run one as well I’m 185lbs I cannot stop the kart from hopping. Any bigger guys in your class getting the 4R to work? If so let me know.

I made a FB group a while back too it’s not very active though
https://www.facebook.com/groups/1128227439308530/?ref=share&mibextid=NSMWBT

5

That track looks wicked by the way

6

I don’t drive Compkart, but what is your setup? May be able to provide some suggestions for the hopping issue.

7

Stiff axle
53" rear track
0 camber.
I have the 2 compakrt eccentric (I believe it’s .8 degrees caster) I flip it around to take caster out.
A little toe out.
15mm spacers wider on front track (17mm spindles).
Front ride height is middle and rear is high. Wheelbase is stock.

No seat struts or torsion bar.
Vega reds.

8

Didn’t reply the first time [quote=“Kyle Strycharz, post:7, topic:14442, full:true,
username:KStrycharz07”]
Stiff axle
53" rear track
0 camber.
I have the 2 compakrt eccentric (I believe it’s .8 degrees caster) I flip it around to take caster out.
A little toe out.
15mm spacers wider on front track (17mm spindles).
Front ride height is middle and rear is high. Wheelbase is stock.

No seat struts or torsion bar.
Vega reds.
[/quote]

9

First thing I would do to reduce hopping in your case would be go to medium rear ride height.

10

There’s only two option. High and low. The club track (Kelly’s Motorsports Park) is extremely bumpy and lowering the frame any more will cause it to drag and wear out.

11

I agree with TJ, but if you cant do that, then how about some negative camber? What happens if you go wider on the rear? Both those should be the right direction. You could also narrow the front. I would keep going until you lose point in, then come back one adjustment.

1 Like
12

Id try:

Stiff axle
53.5" rear (if youre allowed)
Negative 2-4 camber
5mm or 10mm front width
And, maybe a less common adjustment but could work, some toe in

What rear wheel width are you using?

13

Agree with you and Derek. All good options.
I would vote against toe-in, but getting it a bit more neutral would be a good adjustment.

The negative camber could be a good one. If you can get away with less camber, I always see it as a plus because it reduces scrub in the front end as well. The only risk is increased tire wear, but typically not as big an issue on 206.

2 Likes
14

210mm wheels in the rear

15

How about lowering the seat? You might wear it out but seats are easier to replace than chassis tubes.

16

What about leaning? It’s crude but effective and can be tuned on the fly. Especially with rentals where I can’t change anything, I have found either leaning in to stop the hop from starting or leaning out to maintain the tire’s load can help significantly. I’ve also found it useful for diagnosing which way I need to go with the setup. For example, if leaning out helps, I need to make tweaks to increase load transfer across the rear.

1 Like
17

If you haven’t, reach out to Jim and Vince Scatena. Vince is close to your size. They haven’t raced much recently but they had a lot of success on the 4r.

1 Like
18

I raced with the Scatena’s and the widening the rear and narrowing the front helps. The kart can take a big split between front track width and rear track width. I would also lower the seat a mm or 2 if possible.