OTK FA Chassis with Rotax Junior Engine.
i recently brought a set of Alto lasers to help with the front end alignment. with no instructions and no web search results i was wondering if anyone on this forum has these lasers from the UK… in all honestly i dont think they are massively different from the snipers. i have followed this video from PR https://www.youtube.com/watch?v=IhIISTrLF6M
can anyone advise if the video covers everything i need to know. anyone disagree with what is being said or a better way to achieve the alignment.
i have not seen anyone measure the sweep before as a first step so thought to question if this is the right approach.
as always, any help would be gratefully appreciated.
Never used the Alto lasers but the PR video is good and thorough. Sweep should be checked when you first align the kart out of the box or if you’ve had a crash. I really only ever check the sweep if my steering isn’t centered or we’ve put new parts in the front end. Otherwise I tend to set it and forget it unless something gets bent or wonky.
Would setting the sweep, measuring the distance as in the video to the same.each side also centre the steering?
Yes after you set the sweep and get the distances equal as he explains in the video, use a sheet of paper and put it in the middle of the kart so that the lasers shoot through the paper. With the sweep done correctly and all parts on the kart straight, turn the wheel until the lasers overlap on each other through the sheet of paper. This steering position will be geometric centre/Straight ahead.
Note if the lasers don’t overlay each other 100% then the front end is not 100% straight (you can have a bent spindle or at worse the chassis has a tweak in it). In this case get the lasers to align vertically one over the other and this will be geometric steering centre.
From here, when you remove the paper and let the lasers shoot onto the opposing grids, the toe should be the same on each grid. You can then adjust to what ever toe you desire each side.
Great … I have noticed I have slight neg camber on the right hand side (according to the laser) which I would guess indicates a slight bend on the chassis given that the camber setting is the same on both sides…
A related question. Is it normal to run toe out on one side, perhaps on the right on a clockwise track? I noticed a competitor right wheel seemed to be toe out both the other was straight…
Yes if the caster/camber pills are in the same location side to side and the camber is not equal on the opposing lasers then something is bent. Check your kingpin bolts, spindles, steering column, tie rods, rose joints. If they all check out then it may be the chassis itself but you’d need a frame table to validate/rectify this.
In terms of the toe, you almost always want to run with some amount of toe out, even if you’re wanting to achieve zero toe because the wheels toe in with driver weight on track. Standard setting for most karts in the dry is 0.5-1 box toe out.
I’ve never set any of my settings unequally side to side…one of the more experienced guys can comment on that
+1 to Chris’ post.
I always run the same camber/toe/caster side-to-side. Regardless of how many left or right turns there are.
Kind of reviving this topic so I don’t make another one. But on OTK, specifically the 2019+ tony kart 401R, is the camber supposed to be offset from factory? I have everything neutral and sweep done but the lasers don’t overlap. I was told that the kart comes with an offset camber?
Depends who you talk to. I have seen many of them with unequal camber side-to-side and was once told by an OTK guy that was to offset the engine weight. No clue if that’s real or not, but I have seen plenty of karts from a variety of brands come out of the box unequal.
Ah gotcha, yeah that’s what I heard as well. Guess if it works then no point in changing it
How much offset are we talking?
Are you saying that some do and some don’t in your experience?
And you’re certain the pills are all neutral top AND bottom?
I know tj has said he’s seen it before and heard rumours of it being “offset” from factory, I’m not buying it unless I see something come from OTK in writing saying same.
I personally think it’s a manufacturing defect and that it ought to be 100% laser on laser if the kart is brand new and the pills are all in the forward facing direction.
I follow power republic in Australia on their youtube page quite closely and seen him done quite a few alignments on 2018+ brand new karts and it’s always 100% the same side to side, both camber and caster.
If it were me and I’d just paid $5000us on a brand new kart and seen this I’d definitely be following up on it via the dealer that sold me
that is a pretty big difference. Out of my depth here, but I always thought the seat offset was to account for the engine. Oh well.
Yup, everything is neutral on the kart. I agree with what you’re saying and I’ll try and see if I can get clarification from otk themselves. On the track, the offset doesnt seem to cause any issues. Even the tire wear looks good
Ok so just tracking back a bit here. Is this discrepancy you’re seeing from brand new? As in karts never been on track and seeing this?
If not, and it is a used chassis then maybe the frame is tweaked a bit or you have a bent component. I have about the same amount of discrepancy on my used OTK but the kart is still fast and tunes well so its not really an extreme deal breaker.
The point i was making above is that there was no way i was accepting it if the chassis was brand new.
To figure out if its the frame or a component, you need to get the chassis on a frame table
Not really, 2mm isn’t that much…you can offset the pills and get the camber back even side to side and the handling would still be fine. Bad is maybe 4mm+ …then you’d probably start seeing on track handling issues
This is a used 2029 401R. 6 races. Owner told me that otk has them offset for the engine. If it was brand new, never been tracked, I would definitely care more. I wonder if anyone has a new chassis that has this “factory” offset.