Wheel spacers

[andypipe]

Whats the pro's and con's of using wheel spacers to bring the rims further out into the arch and clear suspension units?

[trikesrule]

Which wheels andy? Front / rear or all........trikes

[andypipe]

All wheels

[andypipe]

On a car

[trikesrule]

Widening the rear will make the car a bit looser. Widening the front will add a little push. If you do all four at once basicly you should be a little quicker thru the apex'. But it will take a little longer to bring the tyres 'in'. How much spacing do u require?.....trikes

[andypipe]

Basically im concerned about the extra loading, due to having to space the wheels out approx 1"

[trikesrule]

Andy u are going to need longer wheel studs and any reputable wheel stud manufacturer will provide the goods for u there, no worries. Is there a company that makes anodized alloy spacers for your car? Widening the front will increase your Scrub Radius. Is it for your Escort?..trikes

[greenamex2]

My cars wheels (Toyota Corolla GT) are spaced out about 2 inches using 'spacers' and wheel offsets.

I''ve not had any reliability problems yet but we check and change the brearings regularly with the best ones we can get.

The wheel studs are also cold formed high quality items, not the cheap ones.

And the spacers locate on both the hub AND the wheel.

[StephenRae]

Originally Posted by trikesrule

Widening the rear will make the car a bit looser. Widening the front will add a little push......trikes

Haven't you got this the wrong way round?

[Al Weyman]

There is some good advice on the right and the wrong way to do this Andy in Phuns book How to make your car handle. Basically longer studs as has been said and a nice snug fitting machined alloy spacer which must be easily available from DT's or wherever for your car, I know they have the studs as I use the Ford ones on the Chevies believe it or not. I have about a half inch spacer on the front of my yellow car to get the wheels to clear those massive Wilwood 6 pot GN calipers.

[trikesrule]

Stephen how u going? I regularly change our cars and thats the way it works. Wider in the front gives a little push. Steve Smith agrees with me......trikes

[Hitech]

Widening the track lowers the spring rate at that end by increasing the lever arm effect, and by inference increases the weight transfer at the other axle. All things being equal on a stiffly sprung race chassis, widening the front track will induce more oversteer and visa versa. Basic Kart tuning technique.

[Lukin]

Originally Posted by trikesrule

Stephen how u going? I regularly change our cars and thats the way it works. Wider in the front gives a little push. Steve Smith agrees with me......trikes

There must be some weird things at work with your cars in terms of geometry. Widening the track should increase the grip at that end as you reduce the load transfer and keep the inside wheel loaded higher, reducing the overall grip loss due to tyre load sensitivity.

But there are other things to consider. If you change your offset and nothing else you will increase the scrub radius. I don't think the steering geometry will change, but I'm unsure about camber curves and bump steer curves if you set it up with x track, then increase it 20mm later on without resetting everything.

[trikesrule]

Widening the front track. Wouldn't that depend on how much weight was already spread across the front wheels and how the car or kart was handling in a certain situation? I'm just talking about what I've got. Andy has to adapt our discusssions across to his car. Static loading and dynamic loadings are different on most cars even in the same class. Yes? I don't believe any of what we say to be gospel. We're all in the same boat, it's what works in our given situation at the time to achieve a balance that is acceptable ........trikes

[StephenRae]

I would guess that the biggest effect of widening the track would be to soften the suspension if no other changes were made. I run 1" extra offset rims at the front of my FF1600 when it's really wet. I could probably achieve the same result...less understeer...with softer front springs.

[thebear]

It also increases the load on the front spindles. Magnaflux or other crack detection is mandatory on a regular basis . . . .

[andypipe]

Originally Posted by thebear

It also increases the load on the front spindles. Magnaflux or other crack detection is mandatory on a regular basis . . . .

This is what i thought

[Goran Malmberg]

Widening the track on a doubble A-arm system axle may have different effect on the wheelrate depending on scrub distance and A-arm angle. I have an equation for caculation elswhere on this list.
However, we may look at what happen if we widen the front track. The car has equql track front-rear of 1600mm, same Wr all around (10kg/mm), 1000 kg weight with 500 front and rear axle and 400 mm cgh. At 1g cornering force we will transfer 125 kg at each axle, 250 kg total. We will now widen the front track, other things beeing equal,to 1700 mm. The weight transfer will now be less due to an average wider track, 242 kg. The front weight transfer will still be 125 kg, and the reduction will show at the rear to 117 kg.
I dont say what will hppen to the over-understeeer situation, only the weight transfer.

Goran Malmberg

[trikesrule]

Goran your a champ. I totally agree. Works for me and I win a lot of races..........trikes

[retro_msport]

I think Andy's concerns are for another Escort Driver who wants to use 7" wide Sierra Cosworth 3dr Rims on a Mk1. Due to the offset of those rims the need the hub mounting flange spaced out to sit the wheel in the normal place that the RWD wheel will sit, this is commonly done with hubcentric spacers.

The center line of the wheel with the spacers is sitting in the same place as the RWD offset wheels centerline.

[retro_msport]

Originally Posted by thebear

It also increases the load on the front spindles. Magnaflux or other crack detection is mandatory on a regular basis . . . .

If you have a 6" rim on a Mcpherson strut and then fit a wheel of 10" width to that hub you have an extra 4" of tyre either side, the load centerline has also moved out by 2" ... this puts the load further out and yet it has been accepted for years on loads of race Escorts.

In the last 3 years I have only heard of one spindle failure (on a RWD mk4 YB powered Escort) and the way i have always thought about this is this...

Race the car ..
lap 1 ride the curb on turn 2 ... and crack the spindle.
lap 2 ride the curb on turn 2 .... spindle breaks.

[nscirocco]

Originally Posted by Goran Malmberg

Widening the track on a doubble A-arm system axle may have different effect on the wheelrate depending on scrub distance and A-arm angle. I have an equation for caculation elswhere on this list.
However, we may look at what happen if we widen the front track. The car has equql track front-rear of 1600mm, same Wr all around (10kg/mm), 1000 kg weight with 500 front and rear axle and 400 mm cgh. At 1g cornering force we will transfer 125 kg at each axle, 250 kg total. We will now widen the front track, other things beeing equal,to 1700 mm. The weight transfer will now be less due to an average wider track, 242 kg. The front weight transfer will still be 125 kg, and the reduction will show at the rear to 117 kg.
I dont say what will hppen to the over-understeeer situation, only the weight transfer.

Goran Malmberg

actually, both f and r load transfers will change. If you simply look at the geometric load transfer then the opposite of what you said happens .. front is reduced to 117 and rear stays the same at 125, but there's more to it than that..
the unsprung load transfer on the front drops and in the rear stays the same .. but what really makes the biggest difference is the roll (or anti-roll) torque distribution front/rear. The front will increase it's share of the anti-roll causing more load transfer in the front (more than the drop from the geometric transfer)


-nigel.

[meb]

....so then, all else equal, are you suggesting that the car will understeer more? I'm trying to figure out the same problem with my Mini.

[nscirocco]

Originally Posted by meb

....so then, all else equal, are you suggesting that the car will understeer more? I'm trying to figure out the same problem with my Mini.

changing the track can change so many other things at the same time, like wheel rates, weight transfers, scrub radius, caster trail, kpi trail, even roll centers...
i think the end result will be that if you increase the track on one end then that end will have less grip than before due to the percentage of anti-roll torque on that end increasing.

-nigel.

[trikesrule]

Bingo! thats what I said (understeer). But depending on various things like how the car turns in now combined with driver preference etc. U/S can be a good thing or bad. Just do what I do 'experimentation without fear of recrimination'. If it dosen't do what u want it to do just make sure u can put it back the way it was then think (picture) about it some more.......trikerule