• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Please help me think through this alignment issue

Share this page

Trevor Jessie

Trevor Jessie

Yoda
Country flag
Offline
I want to adjust/correct the camber issues on my Sprite. I'd like to have 1 or 1.5 degrees of negative camber.

Here is my plan:
Measure the camber by finding a really straight bit of angle iron that will span the rim of the wheel. Use my iphone level app to measure the current camber. Then determine the amount of offset needed at the trunnion to get my camber by using simple trig functions. Finally make some offset trunnions out of this hunk of 1045 steel bar I've been tripping over for the last year.

What are the pitfalls or issues here?
 
I have a few math degrees... I might as well use them for something. :wink:
 
You could always but the poly offset bushings, they are adjustable and when you get it where you want it, peg them so they do not rotate on you.
But there is no math involved and that would be no fun :wink:
But DO pin the bushings by drilling 2 holes in the trunnion and using a couple of set screws or they will rotate when you brake hard.
At least mine did once a week until I pinned them.
 
I've considered the offset bushings, and I may well use them to fine tune things. However, I'd like to have it really close with standard bushings. Honestly, the passenger side is so far out, that I doubt the offset bushings would correct things.
 
This would take all the fun out of it too, not like making chips on the Bridgeport ! Put shims under the shocks at the two bolts. Never done it, nor seen it, but heard 'bout it.
Scott in CA
 
Um ! you just want an excuse to use your iphone app.
grin.gif


There is a company here in UK who make them : Peter May but they are ÂŁ86.00 (not sure if thats each or a pair).
I too have heard about shimms under the shocks, least this way you can adjust each side independently to suit your car.
 
I know about the ones already fabricated, but they are not necessarily the dimension I need. There is a company that makes them here in the US too, but they a pretty expensive... and again not a custom size.

I've never cared for the idea of shimming the shocks... to get any significant camber change the inner pivot point is moved way too high. This really messes with the rate of camber change upon deflection.

I'm always looking for ways to improve my car with the tools I have at hand. And yes the iphone is a bit of a swiss army knife. There are better tools for the job, but it is what I have handy.
 
You've got me really curious on how much your car's camber is out, and mostly on one side as you say. That's more usually due to frame damage I'd think, but I guess you've already considered that. A good frame shop should be able to pull things back true pretty easily, and considering it's a bugeye and the front sheet metal comes off without too much hassle welding a reinforcement bar in across the shock towers when it's straight would be easy. That's a problem I have with my Midget now it seems. It looks like the front crossmember has sagged a bit under the weight of the V6 and the pounding from the road and now shows quite a bit of negative camber on each side.
The offset trunion sounds like a good idea if you have too much camber, but if it's too little then I don't know if there would be room to correct too much.
 
We've discussed this before, and I'm convinced it was built that way. It is an early car and I think someone got sloppy when fitting things in the jig. By "eyeball" I'd guess it is almost two degrees positive. All the suspension parts are new/renewed and the car sits level.

So Mark, what is the status of your front suspension now?
 
OK, I measured it with the iphone level. It is 1.8 degrees positive on the passenger side, and 0.5 degrees positive on the driver side.

I want both sides to be 1.5 degrees negative.
 
Trevor:

I do not think the bushings will not give you that much of an adjustment :frown:

Is the front end of the 1.8 side in good order?

If so, you may want to shim up the shock or ream out the bolt holes a bit before inserting the offset trunnion bushings and see where that gets you.

I think .5 neg is the most that you are going to get unless you do the bottom offset as well.

Pat
 
Trevor, I didn't read thru all this, so excuse me if I'm repeating, but you can go to Racer Wholesale Parts, look in chassis set up tools, they make under own name, a level camber gauge, you can't buy the stuff cheap enough to make it yourself, it's $39.95, I've had one for years to set up my race car, it does all you would ever want one to do, tell you, your camber. Ok, on to setting the camber with a stock lever shock front end, getting a offset upper trunnion bushing is most practical way. Winner circle already has them, and ironicly enough 1.5, I got them in my race car right now, ironicly enough they produce 1.5 degree of neagtive camber when set to the most negative camber positiion. These bushing have been around and used by Spridget racers for decades, they work great stay where you set them too, the are some sort of delron, so harder than poly, but that should matter foir just the upper trunnion, the poly will still do it's job up soaking harshness for the lower control arms. Anyway Racer Wholesale for a darn good cheap camber guage and Winners Circle 216-889-4666 for the offset trunnion bushings to get you 1.5 degrees negative camber, I don't the price off the top of my head, but I can't imagine or rember them being very expensive. Peter May Engineering in the UK also makes a offset upper trunnions, I have a set of those too, they work well with DOT race tires on vintage race car, but they get you about 3.5 degrees of negative camber, but thats way too much for the street or SCCA slick racing tires.

Here's a picture of the Racer Wholesale cheap, $39.95, camber gauge.
 

Attachments

  • 17736.jpg
    17736.jpg
    25.4 KB · Views: 159
Wow Trevor Jessie that's a lot of positive. I think you're probalby right and it was built that way or the only other thing I can think of is that the lower A frames are shorter than they should be. You might have to look carefully at the new upper trunions if you move it that far, you might have interference problems with the wheel or disc at 2 degrees movement if the clearance is already there is already at normal distances. If you can machine new upper trunions it should be within your realm to actually build something similar to the Frontline suspension that would be adjustable for camber so you could get it right where you want, but that at least would require conversion to tube shocks. For me I'd be tempted to take that direction rather than the new upper trunions.
 
I've thought about the offset bushings, but I haven't done the calculations to see if they will get me where I need. I was planning on using them to do my fine tuning. I may scrounge around for some delrin and make my own so that the rotation doesn't swing the adjustment too wildly.

Bill, I've sketched out many possible ideas for reworking the front suspension (both upper and lower arms) but I want to keep the car and its mechanicals as simple and clean as possible. The stock setup is about as minimalistic as you can go and still have a car that handles well on the street.

I've got the g-code roughed out for the trunnions, so it will not be difficult to make different ones for each side.
 
OK, I made a rough mock up while testing some of my code. The mock up is almost usable except I accidentally put the main hole a few thousands off center. There will be a bit of clearance issue with the dust shield, but nothing that a cutoff wheel can't fix. :wink:
 
Here's a thought as to why one side is sooooo far out:
Are the leavers on the shocks the same length? As these tyle of shocks were used on various cars, I believe there are different length arms, & perhaps someone just swapped a shock without knowing this.
 
I think we went through this before you joined the forum, but there are no other shocks that would fit. And besides the shocks have since been replaced with rebuilt units. I've also swapped A-arms. The problem appears to be in the initial construction.

I know I'm treating the symptom rather than look for a proper cure, but I'm afraid that I might really mess things up if I try to move the shock tower.
 
Back
Top