Heading into the off season I am trying to get a game plan with components I may need in order to get more overall grip into my kart. Chassis is a 32mm energy eclipse with a ka100. Thinking about trying an amv tiger wheel but then I came up with an idea that I’d like to hear some feed back from.
I’m 5’11 and roughly 190 on a good day before lunch. I currently have a tiller T11 VG that’s mounted really far back on the kart to increase grip.
Here’s where I want input though. If i were to go to a T9.5 of the same stiffness, would it put more grip into the kart with the center of gravity being lower and being laid back more over the rear. It’s an interesting idea I think but would love to hear feed back before I go dropping +250$ on a seat that won’t work.
The difference in body position from the T11 to the T9.5 is rather small. I would only recommend the 9.5 for very tall drivers. If you’re looking to make a change in the seat department I would try a stiffer seat, such as the T11t (medium), or even the standard T11 (medium stiff).
The AMV Tiger is a great wheel, and is on the higher end of the spectrum in terms of grip. What wheels are you running currently?
There are probably other chassis changes in addition to the wheels that would take you in the right direction.
Just a thought, but I kinda think you may be going the wrong way. With a 32mm chassis and the seat already really far back, I’d think that the rears are just getting instantly overloaded making it feel like you need more grip, when really you might need to go the opposite way and take some load off them.
I tend to agree with David and Evan here. If your goal is to flatten the kart for grip, you can try a bunch of free and easy adjustments like lowering rear ride height, tossing in a rear torsion bar etc. before toying with seat tuning, but I don’t know if that’s what you actually want. Seems unusual to me that a 32mm kart in KA wouldn’t have enough rear “grip”. In fact, it would be the opposite in my mind. The Eclipse looks like it’s a higher horsepower chassis; they use it for KZ as well. Maybe it’s just flat-sliding constantly because the frame is too stiff and never actually getting the flex it needs to get side bite.
OP: I agree with the folks above. I think seat tuning could help, but it appears you might want to try other things first.
Evan/TJ,
One day can we start a discussion on “flat slide tuning”?!?! There is speed to be found in using a stiff chassis and barely loading the outside rear enough to grip. Do you guys ever use that philosophy? Is there ever a time that works better than you “conventional tuning”?
This tuning philosophy is why @CrocIndy, @Matt_Geist and I are all still on Arrow 4s Chassis that are 15 years old…
The only time I’ve tuned a kart purposefully to act this way is when I was running Bridgestone YDS tires in Yamaha Sportsman/Junior locally. The track never built any grip and the tires were rocks, so you could never get any sidebite to flex the kart. Instead, if you got it to slip the rear just a bit in a controlled way, you could keep up apex speed without too much scrub.
So in 206 on a hard tire I can see how this could be a legitimate method. This becomes kind of hard to pull off once you get to either a softer tire that won’t slide as nicely, or higher horsepower where wheelspin legitimately becomes somewhat of an issue. Even a KA will powerslide the back a bit. So I would say reserve this for low low HP stuff.
I’m curious to hear more about flat sliding. That in it’s self would seem like an accurate description of what’s happening. At Norway I went super narrow in the front my last time out and finally had some luck on getting the kart to hike a tire. Mainly running at Norway but will probably do more at ncmp next year. I got rid of my 30mm space because as soon as the sun appeared it would be tighter than hell and could not for the life of me figure out how to free it up. Only option I thought was the eclipse because I like the way they drive.
Currently running Douglas mags and I think i have a stiffer seat hiding somewhere in the shop that’s still a t11. I’ve tried full negative camber before thinking that if the karts truly not flexing that it would dive on to the outside front tire for grip. In my reply to TJ though you’ll see that I tried only a half spacer in the front hubs and it awoke some but i know for a fact there’s still speed to be found somehow someway
Sometimes with a stiff chassis like that it’s easy for the front to overpower the rear in terms of balance, so detuning the front is a good way to settle the rear, and also work the tire more. The stiffer seat is worth a shot, but I would try a few other things before making that change:
raise rear ride height (lower axle)
narrow rear width
reduce caster
Have you tried adding/removing the front bar, or adding/removing seat struts?
I use the Eclipse in kz, the floor pan is totally loose. No front bar in and a soft seat to get it to flex properly. Never ever uses the front bar, way to stiff .
One stay at each side of the seat. Loose side bars and slightly more caster
Also using the outer holes on the spindles. Turning like crazy
You should try seat stays to help it unload the inner rear more easily. Also loosen rear bumper
Given the information above from Lucas, who has experience using this chassis in its intended application, refer to bullet point #2 in my earlier Costanza reply. Partly joking, but mostly not…
Doesn’t hurt to try, could be different because I drive a shifter. But I feel like it has good overall grip and turns really well. Also uses medium axle with the third bearing tight but without grubscrews.
Test if you have time, but I think a soft axle should be better to gain more lift for the inside rear. Settles down faster tho
The stiffer kart will be better feeling to drive because it’s more stable, but you might be compromising performance for feel in this case.
One thing I will note about Norway is that the surface there is so worn out that it never really builds grip, and the corners are all almost banked so a kart will never really lift like it’s supposed to on that track specifically.
If it’s flat-sliding, it’s lifting either too much or not enough on initial steering input, and then it sits flat right away after that, causing the rear to just skate across the track.
There are two routes to get a kart to dig better in the rear:
Increase weight-jacking so it hikes the inside rear harder and generates side-bite. So increasing caster, widening the front, narrowing the rear, raising the seat/rear ride height etc.
Decrease weight-jacking so it sits flatter and generates traction, relying on some flat-sliding to get rotation.
I would defer to Lucas here and try what he says, as he has direct experience with the chassis. To me, narrowing the front and getting MORE inside lift is backwards, so personally I think this is the wrong chassis as it sounds like the baseline is already outside of the tuning window for what you’re using it for.
