69 charger suspension upgrade

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Pete
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Post by Pete »

Wise words, Roger.

With a stock parts set up, adjust the Caster to "11" and sod the camber.
Don't lower the front ride height, re-bush all the suspension, bigger torsion bars, bigger anti-roll bar, MANUAL steering box, and job's a good 'un unless you want to spend loads, in which case an Alterkation is the only way to go, end of.
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Roger
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Post by Roger »

If my car wasn't what it is, id buy the alterkation, no doubt.

I dont think with a steering box, it will ever be "right". Yes its an old car, and thats how they were, but still......................
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Post by Dave-R »

Roger wrote:Dont forget if you lower it, you will lose castor.
I don't quite see that? :?

If you RAKE the car (lower the front only) you loose caster obviously. But I can't quite see how lowering the car all round would do that? :?

For me I turned the caster up to max and then dialed in the camber (which removes caster) until I had just a bit of negative. I would never try to take into account the road camber. It varies so much from road to road and when I am pusing an american car hard I tend to use more than my side of the road. :lol:

With the stock UCAs that is about all you can do.

If I did this again I would be using adjustable tubular UCAs and strut rods like Drew. It is amazing how much fore and aft movement you can get on the LCA. But with an adjustable strut you can pre-load the LCA.

I have used longer pitman and idler arms too. Still got them somewhere I think? I didn't like them either. I prefered the 20:1 ratio manual box I fitted. Yes it was heavy at very low speeds but boy it was great at decent speed and curvy roads.

Plus all my suspension was upgraded 30% over 440/Hemi spec.

Don't forget. Power steering boxes are already "fast ratio".
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Post by Roger »

You will lose castor because the lower strut rod (whatever you call it) operates through an arc. At its most horizontal castor will be reduced to its minimum. OK, its not that simple becuause the upperarm operates at an angle too, but nonetheless.

Dont get me wrong, i like the high ratio arms. That bit did work and had the benefit of weighting up the steering a bit.

Also, with the castor, i didn't try to take the camber into account. I just got the most i could on the left and matched it on the right. So it still drifts to the left!! Mismatched castor does work if done right. And its what Mopar did, but seem to have built it into the UCA arm geometry which rather buggers things up when they get here.

Manual steering is not an option for me. I drove ivors with manual steering. Way to much like hard work, if more direct. The solution is to engineer a way of making it work, not throw the much needed assistance away.

In fact, the best mod was Antons steering smaller wheel in his car. Takes out that over assisted feel. Toying with the idea of cutting an original wheel down so it looks stock but isn't.
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Pete
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Post by Pete »

On Mopars the one thing I would like to get rid of is the steering box and drag link set up - I can even live with the torsion bars.

However, I have not seen a company that produces a Rack and Pinion set up that is robust and does not compromise some aspect of steering geometry or behaviour - as Blue will advise, the first thing that seems to go out of the window is the ackerman on steering left or right..........
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Post by Roger »

Pete wrote:On Mopars the one thing I would like to get rid of is the steering box and drag link set up - I can even live with the torsion bars.

However, I have not seen a company that produces a Rack and Pinion set up that is robust and does not compromise some aspect of steering geometry or behaviour - as Blue will advise, the first thing that seems to go out of the window is the ackerman on steering left or right..........
You are indeed correct, but thats just physics of trying to work with the stock hubs etc. I take it the alterkation is OK?
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Pete
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Post by Pete »

Yep, Mr Reilly has cracked the ackermann angle relationships on the Alterkation. Bump steer also sorted.

It's a shame that it does not utilise Mopar brakes so usually you have to go and buy more stuff than you would normally have to on an upgrade.............
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Post by Dave999 »

seemingly you can get pretty close to no bump streer using a K frame that has been modified to take GM variable rate rack

you do however have to have a very standard sump

hemi 6 and smallblock

http://www.elkoperformance.com.au/store ... oduct=1160

yes he will do a LHD one
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Pete
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Post by Pete »

That system will still vomit eiderdown if you want to run a big R/B with even bigger Headers............
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Post by Dave999 »

Mmm
you'd never get anythig other than standard into the engine bay

tis true
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Dave999
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Post by Dave999 »

Roger did you try this before you chop up a wheel
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Post by Dave-R »

Roger wrote:You will lose castor because the lower strut rod (whatever you call it) operates through an arc. At its most horizontal castor will be reduced to its minimum. OK, its not that simple becuause the upperarm operates at an angle too, but nonetheless.
I see. :thumbright: But lowering the car would take the strut further away from horozontal and increase caster as it pulls the LCA forward wouldn't it? Unless lowering take it closer to horozontal? Is that what you are saying?

Oh yeah. Hang on. It would wouldn't it as it angles down normally...

Yep. Got it now. :lol:

All the same. Another reason to use an adjustable strut rod.

Yes you are never going to get far with the stock UCAs which is why I think the biggest factor is aftermarket UCAs that are fully adjustable.

In the thread about the race Trams Am cars we were wondering what the suspension/Steering set-up was on those. I seem to remember they were limited to using stock components but allowed to re-mount them to get a decent geometry. No idea if that is something I made up in my head or have seen in a photo sometime in the past. I have a very vauge memory of seeing the UCAs on one of the race cars.
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Pete
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Post by Pete »

I imagine on a roundy roundy car the caster is of less importance than, say, a drag car where straight line stability is all.

The cars back in the day were designed to be cheap and easy to drive, hence very little caster or menas of adjusting it; most of these were 50mph grocery getters; we are not talking LeMans here............
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Dave-R
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Post by Dave-R »

You should see the adjustments on my C5 Corvette.

Similar to the mopar UCA adjustments but on the lower arms instead. Front and rear of the car. Simple to adjust camber and caser all round. And they are marked in increments for easy reference. The UCAs just use spacers to get you ballpark.
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Post by Cannonball »

Pete wrote:I imagine on a roundy roundy car the caster is of less importance than, say, a drag car where straight line stability is all.
yes but would still have to be very stable on the straightways they would pull bigger mph than your drag cars top end, have you ever tried to hang on to a badly set up mopar on the street .......... its Bananarama! dangerous,
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