XRAY - Model racing cars

hi col, i measure mine on the edges of the arms.i run 3mm droop all round.tony v is the man for this problem i feel?? i will try and get a picture for you if required. there doesnt seem to be a definate way of checking droop each person does it different. mine works to be about 1 to 1.5mm by the book way.hope this helps.ian

Are you sure you dont have a tire issue? How about rear toe? Is your rear diff loose enough? Droop at 3 seems best with rubber tires. What rear springs are you using? Is the body rubbing on the front tires when you inter corners as this will brake the front and slide the back out.
Just somethings to look at.
Give us your setup, tire, and track surface.

Rick

Thanks i just wanted to get initial impressions before posting a setup.

at the moment its like this:

Front Diff medium
Rear Diff Loose (as can be without slipping)
Downstop around 5 rear 4 front (reduced to be about 3 rear and front)
Shocks 30w oil 3 holes closed (hardest setting)
White springs all round ( then tried blue front white rear)
anti dive 3 deg
anti squat 3 deg
front and rear c-hub
front 3 deg castor
rear 2 deg toe
anti roll front stiff
middle c-hub connection front
shortest link c-hub rear
1 deg camber front
1.5 deg camber rear
carpet dragons ? posibly sold the wrong ones (out door)
shell hpi civic

Ok.

First of all, I think you were definitely running too much downstops at the front and possibly the rear. Going to 3 front and rear measured under the rear outer corner on the arm as suggested by Ian should be much better.

The tyres are the next biggest factor. Having never driven the carpet dragons I cannot help you here. But I suggest you check with the drivers that do seem to have grip what tyre-insert-wheel combo they are running and also what additive they use (if any). Just follow their lead.

You did not mention ride height, but it may well be that you are running the car too low. It is best to never go below 5mm and, when running soft springs like the white ones, you may have to go as high as 6mm (front and rear). Right now your chassis maybe bottoming out during cornering (chassis roll) causing the car too suddenly loose grip.

I think white springs at the rear is ok but then combine them with harder springs at the front. The blue ones should be ok normally.

You are running 3 degree anti-squat which may well account for your loose rear when entering the corner. I suggest you change this to zero degrees.

You are also running 3 degrees anti-dive which means that with the 3 degree castor blocks you are effectively running 6 degrees of castor. I suggest you try running with zero degree anti-dive to reduce on power steering.

You also did not indicate the wheelbase (number of spacers in front of rear arm), but I also get the feeling you are running a relatively long wheelbase. I suggest you run the wheelbase 2mm shorter if possible. This will help a lot in settling the rear down.

I also suggest you increase the rear toe-in to 3 degrees.

Remember, make one change at a time so you can see what it does. Depending on the cause of your problem some of the suggestions above can actually make matters worse. If so, change it back and try the other suggestions instead.

Good luck!

IMHO
Tony is right on.
I might add the rear link should be long.
The Huddy set up for stock rubber on the Xray site solved all my problems for this rubber on carpet thing.
What Tony is recomending follows this setup closely.
The blue and white springs work but the alternates that are in that setup are even better. Light blue front, Light green rear!!!

The Link is little hard to find so I went and got it for you.
http://www.teamxray.com/teamxray/news/n ... egoria=434

Rick.

My wheelbase was quite short. If anything i think the car was just twitchy because of it so i actually extended it to be a little more calm.

Also top ultra flex deck, i think this may be an issue. I have taken this out of the equation to again provide some stability.

I am running blue springs rear and the violet springs front (or is it purple) the next hardness basically

The wheelbase is now 3+2 infront of the arm was 4 and before that was 2 (i think)

I didn't think of the effect of the caster + antidive setting ! good point, but if i am to reduce one should it be front ad if on power the rear is loose and rear anti squat if the rear is loose off power?

Tires don't seem to be an issue as i am using other peoples they saw how bad things were and wanted to help (bad sign!)

Intresting note for tony the downstop (please don't laugh) would be 7 if i measured it from where i was measuring it !

So yes a definate issue ! Ride height was 5 mm front 5.5-6.0mm rear, so should be ok.

Also when i build my shocks they have a natural tendency to rebound naturally as the oil is compressed. The old shocks seemed to balance over time ... is this normal ?

Also tony the 3deg toe on the rear... the screws pop out on this setting usually if i get any kinda side impact. But if i run this much won't it give you more steering ? and harder to set the back on power ?