Inherent Push!

1fasttiller

Member
Hi guys, I'm reaching out for some help, I'm at wits end with this Prowler and this constant push we've fought for awhile now. My son has been leading the points all year at our local track in Jr2 but we lost it this past Friday night due to this terrible push that we have not been able to overcome. I've talked to Prowler as well as other local guys on the same chassis and use their setup numbers but nothing seems to work. I'm grasping at straws and need some ideas, all setup info below:

2006 Prowler
Jr2 Purple plate clone
Left- 53%
Cross - 60.5%
Front- 47%
Front stagger- 1.375"
Rear stagger- 1.375-1.5"

I keep getting told we need more cross but anytime I go up the push gets worse. This past Race weekend it started out pushing bad on entry. I went ahead and took 3 washers of cross OUT dropping us to around 54-55% and it was better but would still push up on exit now. However, the kart would turn down on entry pretty decent. He managed a strong second place finish after having to come through the field.

And before anyone says tires, they were Brand new Vega yellows that I get done by a local tire guy who is one of the best in the business. He has karts winning at this track every weekend with his stuff so I'm pretty confident the tires were very close.

Looking forward to any and all suggestions!
 

sundog

Member
If I were pushing on exit I would narrow the front track. Have you tried adding some weight to the front?
 

Bumpy

Member
Man that's tragic.
A push on exit is the LR reloading quicker than it needs to and driving the kart straight which
results in the need for more steering input. I would swing for the wall and pull the LR out 1/2"
then move the LR in if that's too much. Throw in 2more degrees of RF caster also.
 

1fasttiller

Member
If I were pushing on exit I would narrow the front track. Have you tried adding some weight to the front?
Front track is as narrow as I can get it. We do have a puck hanging on the front bumper now, Nose weight is 47-47.3% so I don't really want to go any higher, as that tells me something is off.
 

1fasttiller

Member
Man that's tragic.
A push on exit is the LR reloading quicker than it needs to and driving the kart straight which
results in the need for more steering input. I would swing for the wall and pull the LR out 1/2"
then move the LR in if that's too much. Throw in 2more degrees of RF caster also.
Yes, normally the push is on entry. I did pull the LR out about 3/8" this past Friday night as well as dropped cross on it, that made it better on entry but then it pushed off.
 

Bumpy

Member
Putting 2* more of caster in the RF will take out some/all of the push on entry.
It will unload the LR quicker transferring wt to the Right.
I might would put the Cross back up to where it was.
You pretty much have to enter correctly to exit correctly.
 

1fasttiller

Member
Putting 2* more of caster in the RF will take out some/all of the push on entry.
It will unload the LR quicker transferring wt to the Right.
I might would put the Cross back up to where it was.
You pretty much have to enter correctly to exit correctly.
I've never touched caster in a kart. I've always set it to the recommended setting and left it. To add 2* more do I roll the kingpin forward?
 

Bumpy

Member
I've never touched caster in a kart. I've always set it to the recommended setting and left it. To add 2* more do I roll the kingpin forward?
You should have #'s and dot indexes on top of the spindle.
UR probably at 10 or 12.
Move the top back one notch.
My kart maker had a stroke when I told him what I was running for caster.
But I picked up speed and lowered lap times, so I don't care.
 
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racing promotor

Moderator
Man nothing in your numbers and staggers indicate a bad push, the new tires almost had to be part of it, See what Jr says but I'd be tweaking those numbers slightly I'd add some left, keep the cross in it ( as you should be able to run 62% ), lower the RF camber to 2.5, I'd set rear spacing before re-scaling RR 1/4 " off inside edge of wheel to frame LR 7/8 " inside of wheel to frame.
 

1fasttiller

Member
I know that is what has puzzled me! The exact push was there BEFORE these new tires by the way... lol so it wasn't a tires issue. RR is currently 1/4" off the frame and LR is 1.5" out.

JR suggested laying his seat back some, I have it way up due to his short height, he believes its related to the VCG being too high. I'm going to try laying it back about 2" and see if that loosens it up, then I'll start adding some cross back in.
 

1fasttiller

Member
I'm not sure if you guys can really see seat height in this pic, I'll have to take some better shots when I get home tonight, but its pretty far up.
 

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