Leaf spring problem

[trikesrule]

Guys the Speedway team I'm with have purchased a 'Junior' car. It's a 80 Corolla with a 3k engine. I was laying under the car checking things out (some of the crap you see is amazing) and making notes of of possible areas to be immediately improved. So going to the back first (the car was up with blocks under the tyres and the shed floor is dead flat). The right rear leaf spring is virtually straight and the left rear leaf is bending the wrong way. Before we purchased this car I have watched this car spin spin spin and thought something amiss there and mused about it. Well the laughter is on the other foot now cause I have too fix her. Now the Rule Makers said NO to me cutting the floor and raising the hangers so I can have the springs reset and regain some suspension movement and they said NO to when I suggested lowering blocks. My intention was to retain the running heights it's set too as it's not far away. Everything must remain visually standard thats the bottom line. Sooo has anyone any fabulous suggestions or should I just reset the leaf springs and raise the rear put the car on the scales and possible raise the front as well.............trikes

[graham bahr]

sounds like you need to have the springs re tempered and decambered whilst at it, that will give them both the correct shape and the ride height you desire

[bdwoody]

If the car is being used on an oval track we used to use new single leaf springs and have the ends hydraulic pressed to lower the car to the ride hight required..one higher than the other..

[trikesrule]

bdwoody I asked the powers that be about single leaf springs. He yelled NO!!! then chuckled and said it must be visually std. Said I'd get away with removing maybe one leaf (grey areas - I found another).........trikes

[coln72]

Shortening a leaf isn't exactly removing them...........its still there

[johnny yuma]

Don't shorten the secondary springs forward of the axle,clamp them to the main leaf to avoid axle tramp,shorten them progressively behind the axle to soften the rate.

[trikesrule]

Hi Graham. What do u mean by decambered?.......trikes

[coln72]

Yes, you need to get the main leaves reset. They should be able to be reset to what ever ride height you wish if the rules allow.

I also run a Corolla, but racing on dirt circuits, and found that I had to soften the rear leaves by removing a leaf fom the pack to try and reduce the amount of oversteer I was experienceing.

Also check to make sure you dont have a dud shock under there aswell and while your under there unbolt the rear antiroll bar as it will cause excessive oversteer on dirt.

[trikesrule]

Took the shocks out and checked them out and all ok. Recorded their numbers and put them back in. Our car model isn't allowed to run a rear sway bar. If it did it would be ditched. I can't run a single leaf cause it's not standard. But I reckon I could get away with changing the number of leafs (rate). A re-set is planned for next week. The right front strut is very cleverly bent about half way down to give the right front wheel some camber. Who ever did that did a really good job.........trikes

[coln72]

Mine has had the front crossmember redrilled to move the pivot point out about an inch (and up slightly). Dont think there is enough metal to do this on a later model though.

Technically this is illegal but no one has noticed as the crossmember is covered with mud

[trikesrule]

Hey coln72 we have to leave our suspension pick points std also. That totally sucks as the kids that drive these cars are not driving a car that is resistant to roll overs. R/o' happen regularly in this class. So it will be a challenge to get this car to 'sit right' on the track at speed. We're not even allowed to put specialized shocks like Afco or other speedway shocks in. This scenerio is just plain dangerous to me. I'm glad one of my kids dosen't run this class. The cars really are a bad accident looking for a place to happen. But I'm making noises so the powers that be can have a look at fixing some of the stupid rulings...........trikes

[coln72]

Trikes - even though you are stuck with the standard shocks, you could refill them with a thicker oil to try to reduce some of the body roll. Just dont use old sump oil like I did the first time, the seals didn't like that too much........

[trikesrule]

Old sump oil? Coln72 did that help with your traction problem? I smell a new thread.........trikes

[coln72]

Stiffened the front up nicely until the oil ate the strut seals and pumped itself back out

If you dismantle the front strut, empty the original oil out and refill with the correct amount of hydrolic oil it should be good. I have the correct amount of oil in a manual somewhere around here.

Bikes have been doing this since the word go. I no of an Anglia that had grease nipples fitted to its front struts...............

[trikesrule]

Coln72 I will have a good hard think and do some research. But I reckon mucking about with shock oil viscosity might be the way to go......trikes (grease hhmm)

[coln72]

Kick my ass later and I'll scan it for you

[trikesrule]

No you'd better not coln (or it might be your ass). I've had a Leaf Spring reset some 70mm higher. The LR is some 40mm higher (static) than it was. Yet to get the car on scales. My aim is to get that RR digging into the dirt and get some diagonal weight transfer happening. This will make the car hook up a lot harder exiting (dirt oval) on the RR. Seems to be the way to get it all happening on the clay. I'm setting this rolla up like our title winning Bomber. And they didn't catch that. Let the games (development) begin........trikes

[coln72]

Could you use pump up shocks (air jackers - like they use to raise up the back of the car if you are towing) but hook them up independantly. This should enable you to load up the RR a bit.

Before you say they dont make them for corolla's, try HK/T/G Monaro (these are what I ran on another rolla) or some Commodore wagons as thay are the same dimensions.

[trikesrule]

Quick scan of the Rule Bible reveals words like No specialist Shocks like and inc. Pump Ups. Shocks have to be std road going but shocks Carrerra Bilstein etc are outlawed so going have to go inside the shocks and play. Not allowed to run a rear sway bar either. So Dennis wouldn't that reverse spring idea sort of work like a sway bar. And if it's done only on the left side (oval racing) it would act like a oneway sway bar??????????? It would change the leaf rate to a increasing rate with roll - yes? Which is sort of the reverse to a std leaf? Effectively I see it tieing the left rear corner of the car down. Which should be a good thing as there are plenty of diagonal roll overs in this class. Anyway I'd like to try it out in about three weeks. Unless u guys think I'm off the planet. Speak to me.........trikes

[Dennis.Doyle]

Hi Trikes, I think the rate will change. In particular I would expect it to stiffen as soon as the reversed leaf began to adopt it's original curvature. However, if this happened at all suddenly, that would be a BAD THING.

I reckon a bigger effect would simply be lowering that corner of the car so, in effect, the car was balanced on the rear wheel on the opposite side & the front one on the same side. I don't know anything about ovals, but is does sound a bit like the 'jacking' built into some of these? Again, it might be a bit too dramatic. On the car I saw it lowered the back about 2". I'd certainly do corner weights before driving it - could be dangerous doing on one side only. Best of luck.