No Top End Speed in Spec Class

have been having a constant struggle in my 2 years of karting. That is never having top end speed or getting the level of RPMs the other guys do with the same gear.

Some background about what I race. I have a 2008 Coyote SS chassis running a just passed stock clone. My series is the NYKA and everyone has sealed motors with the same parts. The only things we can change on the motor are springs, spark plugs and carb jets. I am running 18lb springs and so is everyone else

So citing the motor as the sole issue is not an option.

I am the quickets guy in the corners pulling 1-2 kart lengths throughout turn in to turnout once I am on the straight I am still gaining then all of a sudden they just pull me. I just have no acceleration or top end. This is even the case when I am running the same gear as other guys (12-62) at the home track (MXK Hotshot Raceway) and (14-62) at GVKC in Avon NY.

The series organizer builds/techs all motors and has been lecturing me about bind on straights. I have been taught to take away camber, and caster. Loosening bumper and nerf mounts to make the kart more free. Currently I am running 0 toe, 0 camber, and I am backed off on caster significantly. Also scaled the kart to get 50/50% left to right The only things I never played with is seat position and carb jet size. I have noticed my motor is ever so slightly crooked, but the organizer said that wouldn’t impact it that much.

I am just getting very frustrated now. I cannot be competitive without that top end speed. I feel like I have checked every box to limit bind down straights.

Generally, as I understand it (i’m not 100% the expert here) when people talk about kart Bind and the resulting speed down the straight that all happens in the 2nd half of the corner where the kart sets down too quickly and “binds” by having too much drag on the inside wheel. The result there is that since it doesn’t come off the corner well, it continues to struggle down the straight because of lack of momentum on corner exit.

You state you’re fast through the corners and fast at corner exit for the first part of the straight and it feels like it’s running out of steam mid way down the straight. To me that points to a mechanical drag situation rather than a chassis situation. I’d check wheel bearings, chain alignment, clutch lock-up, chain tension, Chain friction, etc. Are you tall and sitting upright causing wind disturbance with your body? …possibly change seating position to get yourself out of the wind.

Are you at the class minimum weight?

That sounds frustrating alright and you have a good few variables to figure out.

Have you had anyone else drive the kart, or swapped the engine? While chassis definitely has an influence through bind and or driving… clone engines can be a very mixed bag in performance terms.

Backed off on caster will probably exacerbate the issue as that will make the kart “sit flat” and bind as the inside rear wheel will spend more of it’s time loaded. Moreso on entry, but also on exit.

Hope this makes sense. If you have video on youtube we can review post a link and it will auto-embed.

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