Matt's 1970 'Trans-Am' Cuda

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Pete
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Pete »

Fantastic achievement!
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Re: Matt's 1970 'Trans-Am' Cuda

Post by SAV@RPM »

Looking good Matt, one thing about a race car it’s always ongoing work in progress !
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Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Matt »

Now that the exhaust is out of the way, I can look at lowering the front end some more.

The front suspension will not practically go any lower in its current form. I've only got about 1.5" of bump travel before the front end hits the bump stops , which is not enough. Also, at this ride height, the suspension geometry is not working in its sweet spot (such as that is....) and stuff like toe/camber change can become exaggerated.

Drop spindles should go some way towards solving the problem. A 2" drop spindle will allow me to lower the front end of the car another inch, and simultaneously raise the suspension an inch from where it sits at the moment.

Comparison between standard and drop spindles
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Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Matt »

Right hand spindle fitted OK.

Move on to the left, so far so good. Go to fit the disc on , and the outer bearing won't slide over the spindle.

Turns out the left spindle wasn't finish-machined on the outer bearing seat, and is .06mm oversize - which is about 2.5 thou

Very boring. Crap parts again.

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Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Matt »

I bought that Colchester Lathe about 6 months ago and hadn't even tried it yet.


Wired it in . Well it turns, the DRO works, and the gearbox seems good !
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The 3-jaw chuck is too worn to use, but the 4-jaw is good.

I turned a centre to hold in the chuck, and then had to drive 20 miles to Chiddingfold on Friday morning to find a MT4-MT2 adaptor for the tailstock. All set up after that though .
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Ended up with just under half a thou runout before starting work, which is acceptable as far as I'm concerned.



And then turned just over a thou off the radius of the outer bearing seat, after which the bearing slid over with a nice tight fit.
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Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Matt »

Having fitted both spindles, a potential issue appears.

The outer track rod end is now located 2" vertically further down the wheel/tyre, and has come quite close to the tyre. About 10mm or so.
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I'm guessing that the tyre could easily distort this much under cornering.
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So I decide to take the spindles off again, as it's Donington the next day and I don't want to race with a potentially problematic setup.
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Pete »

You could also be home to "Mr. Bumpsteer" as well now, but a valiant effort!!

My "Strange" Brake Drums do not fit my "Strange" Axles shafts, so I know how you feel!

All the best, Pete
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Re: Matt's 1970 'Trans-Am' Cuda

Post by mygasser »

in your race class are you allowed to use 'rose' joints for steering? a pair used as outer track rod ends should sort both problems there.
also you shouldn't get any bump steer issues as the steering arm is where it was before in relation to the rest of the suspension, the drop spindles only move the bearing/hub spindle up on the casting while everything else stays the same :thumbright:
neil.
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Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Matt »

Hi neil,

Yes i was looking at rose joints as a possible solution - nice call !

I’ll have to look at sizes available, and taper pins to mount them on. This may slightly raise the effective height of the outer track rod end , but i don’t think that’ll be a big deal.



Cheers
Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by mygasser »

you could always drill the taper out of the arms or fit a tapered sleeve, either will work. just make sure there's a big enough 'washer' underneath so it can't drop off if it fails.
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Pete »

Discuss with Cheng - he had the same issue with the "General Lim" Plymouth, I think he drilled the tapers out and used Heims, but it is worth checking.
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Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Matt »

Nice one chaps. Drilling the taper could be favourite. Will give it some thought
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Dave999
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Dave999 »

you could also use the old Lowerd VW Bug trick
reverse the track rod ends

put a 1/2 depth reverse taper (or at least ream out small end of taper) into the balljoint arm and reverse the track rod end so its grease nipple points skyward
use big hardened washer under castle nut

you may have to cut the track rod sleeve down by 1/2 an inch or so if you run out of thread for adjustment
will allow the track rods to achieve a more parallel to the ground position at ride height and hence MAY help with bump steer.. or it may make it worse
depends on the level of toe in and out at different suspension compression levels

But leaves you with standard sealed outer track rod ball joints

if you swap to C body track rods as well you will have a less bendy set up that will control the wheel direction in corners better due to less flex

1975 chrylser newport 440 v8 parts

moog parts
ES352R – outer tie rod, 11/16 (need 2)
ES355RL – inner tie rod, 11/16 (need 2)
ES440S – adjuster sleeve (need 2)

i.e fatter sleeves with bigger thread and a set of joints that fit taper but have the fatter sleeve threads

Dave
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Matt
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Matt »

Well Speedfest was mechanically eventful.

Spent the previous three days fitting power steering - a GM Type 2 pump and Borgeson box. I'll post details later of the conversion. It worked fine in the yard but no time to really test.
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Qualifying - absolutely brilliant steering for around 6 laps then lost assistance. Pulled in and drove back to the paddock. Belt still attached, but the fluid had got hot enough to soften the plastic reservoir on the pump, allowing the return line fitting to pull out of its boss. Fluid everywhere. And even the surface of the PS dipstick had melted.

Disconnected the belt for race one. Steering heavy enough to make the car extremely difficult to drive . I could barely hold the lock on round Druids.
Finished the race though. Unfortunately received a couple of taps on the left quarter and door, for no good reason, going round Clearways, but body damage not major.

So what to do about the steering for the Sunday ? Considered plumbing in a cooler but unsure if that would solve what might be an underlying issue, and didn't want to risk the system failing again as fluid would either (a) drop on the track or (b) possibly ignite. I could just refit the manual box, but during the PS conversion I had shortened the car's column and fitted an incompatible UJ on the end. So when I got home that evening I stripped the manual column and coupler out of the '70 Challenger project.

Got back to Brands 7am Sunday and swapped the original manual box, and the Challenger column (after a bit of grinding off of some extraneous parts) back into the car. Manual steering again, and all good.

First race Sunday - after about 6 laps I notice steam coming from the bonnet. Glance at the temp gauge, which is pegged. Pull into the pitlane and open the bonnet. V-belt still on - how odd. Accept the Marshalls' offer of a tow back to the paddock.

Refill cooling system, which was pretty much empty. The problem soon shows itelf as a reasonably large jet of water coming out of the front face of the rad. A closer look shows that a stone had hit and holed one of the tubes. The amount of general stone damage whilst racing is significant - gravel escapes from the traps, embeds itself into the sticky tyre surface, then flies off at high speed.

Five hours till the afternoon race, so a fair amount of time to fix. Pulled the rad out and dried it off, cut the fins away from the damaged part of the tube and cleaned and roughened thoroughly. Had several offers of metal repair putty from other racers, so gratefully took some and fed a large quantity through the hole into the tube using a screwdriver as a spatula. then crimped the tube just a little with pliers, then spatulad a generous coat of putty around the outside and smoothed it off . Left to set for a couple of hours, then refilled the system with water and radweld. No sign of head gasket damage on tickover, and once up to temperature we refitted the rad cap. All is good ! the rad is completely watertight and the engine doesn't overheat.

Made it out to the afternoon race, and after 20 minutes of hard driving the repair is still completely watertight.

Many thanks for the guy from Quiksteel that gave me the repair putty, and I can say that I'm happy to recommend it !
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Re: Matt's 1970 'Trans-Am' Cuda

Post by Pete »

Definitely an eventful time, Matt.

Sorry we did not get to see you, but then again I think you would have been too busy to have chat!

That PAS Pump sounds like a POS.
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