PVP.. front end alignment ??

Jeff Metter · Posted: Thu Jan 31, 2013 7:13 am Post subject: PVP.. front end alignment ??

I am planning on running a PVP at Roebling Road and other than eyeballing the front end alignment will any of the Sniper old style or V2 work without the laser hitting the Caster /Camber uprights ???
Any suggestions ??
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Anderson /GasGas
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Bobby Butler · Posted: Thu Jan 31, 2013 9:00 am Post subject: laser

Hey Jeff, thought about you at Daytona each time I went by turn 5 !! Ha!

Try shooting the laser under the kart....works for me.... Confused

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Bobby Butler......."GO BOY GO" RACING, HOUMA, LOUISIANA

250 Twin PVP / Anderson

John Benson · Posted: Thu May 09, 2013 4:52 pm Post subject:

Hi all,
this looked like a good place to ask this. How do you know when you have to much castor?What will the kart do or act like? My PVP is like driving a truck with no power steering! I have the wt close at 37% on the front ( 91lbs lt 90 rt ) camber 3deg positive( unloaded), tires look good 10psi in the front 14 in the rear. 1/32 toe out. I was running dunlops and thought that was the problem but went back to b-stones and only a little better. Evil or Very Mad

It feel OK on high speed stuff ( I have the nose all the way down )slow speed is bad rt or lt .Thanks for any input, John.

Ian Harrison · Posted: Thu May 09, 2013 5:27 pm Post subject:

Hi John

Your comment regarding ultra heavy steering indicates that you are running a lot of castor (or need to visit the gym Wink

).

3 degrees of positive camber is too much as well and serves to magnify the problem. Set your "hanging camber" to 1 degree pos as a start.

The effect of castor is to unweight the inside rear wheel by twisting the chassis as the lock is applied. You can see how much by observing the behaviour of the chassis as you wind the steering from lock to lock on a flat patch. Too much castor will also knife edges the tyre in the turn, so typically you feel good initial turn in bite. You will then see decreasing grip towards the apex when application of further lock and throttle will see you loosing back end grip.

Conversley, too little castor makes the kart too flat and will tend to give a light "wooly" feel to the steering accompanied by an impresive level of understeer (push).

You need to try some structured track testing were you can make an adjustment, do a couple of laps, come in and make another adjustment, etc, etc. You will quickly learn how and what to adjust and by how much to make your chassis work.

Best Regards

Ian Very Happy

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Ian Harrison
Viper Racing UK
www.viper-racinguk.co.uk
sales@viper-racinguk.co.uk
+44 7984 225 564
+44 161 343 2009
Championship winning Superkart race team 1997-2012

John Benson · Posted: Thu May 09, 2013 5:48 pm Post subject:

Thanks Ian,
I started with 1 deg + camber and 19 castor and it was eating up the inside fronts. Ended up at 3 and 23 with no real change but to be honest that was before I had the wt right. Has anyone ever solid mounted the rear bumper?Bad idea? Also I don't think I've ever felt WOOLY ! Shocked

John.

Ronald Kuhn · Posted: Thu May 09, 2013 7:24 pm Post subject:

I use the setup info on the PVP website, and mine handles like it's on rails.It gives you caster and camber angles tire pressures and wet setups also.

Bobby Butler · Posted: Thu May 09, 2013 7:52 pm Post subject: Set up

Gees Ian,

Just when I thought I had this sort of stuff figured out you come along and wreck my train. Now I ll spend another sleepless nite deciphering your post.

BTW, Poul has the base line settings on the PVP site.

Still waiting for your next visit...Daytona 2013???
_________________
Bobby Butler......."GO BOY GO" RACING, HOUMA, LOUISIANA

250 Twin PVP / Anderson