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

Posted: Thu Aug 29, 19 10:57 am
by Matt
So been doing a few small jobs on the car.

1) PolyLoc engine mounts arrived from Mancini. There's no discernible flex in them at all, which is just the job.
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Fitted the mounts to the car without any issues. Whilst the engine is now very firmly mounted, which is what I was looking for, there's a significant amount of vibration transferred to the body. No huge problem for me, but you'd probably think twice before fitting these to a road car. I also lowered the rear part of the exhaust about 1/2" on its hangers to get more clearance with the floorpan. Another quick road test confirms that something is still hitting the floorpan though, so even more investigation needed.

2) Rear bumper area . Need to fit a permanent towing eye/strap to comply with regs. There's nowhere that obvious to mount one, and any of the easier options (i.e.) behind bumper irons would probably result in body panel damage during a tow. Made a bracket out of heavy plate which will fit behind the bumper mount, and also extends along the frame rail using existing tapped holes to fasten.
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Also made a small bracket and fitted the rain light centrally on the rear valance while it was off
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finished towing strap
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3) I'm still concerned about cooling , since the rad looks a little small. Panelled in the bonnet slam area using sheet ally , so that all the air coming through the grille is directed through the rad.
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Re: Matt's 1970 'Trans-Am' Cuda

Posted: Thu Aug 29, 19 11:14 am
by Matt
Time for a track day I think !

Passenger seat and belts installed.
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Castle Combe circuit near Chippenham . Early morning fog on what was to be a very warm day.
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First job - attend noise testing. I had ended up fitting a pair of decibel reducers in the tailpipes, and the car tested at 93 dB /3500 rpm, which is good because Castle Combe has quite a low noise limit.
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So we took to the track with some trepidation. This would be the first time the car had been driven for longer than a few seconds.

First issue - something is still *really* hammering on the floor under even mild acceleration. Come in after two laps and jack the car up to try and see what it is. Check all around the exhaust - nothing obvious to see. Maybe it's the gearbox hitting the tunnel - it *is* close after all. Much head scratching. Gary finally spots the bare patch in the paint.

Obviously, with hindsight, it was the diff yoke. The rear of the car has been lowered 2.5" (1" lower leaf springs and 1.5" lowering blocks) and it seems even this is enough to bring the yoke *really* close to the floorpan. Quick fix - remove the lowering blocks !

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

Posted: Thu Aug 29, 19 11:36 am
by Matt
Back out on track. The driving experience is transformed without that constant hammering noise. The car drives really well.

Comments in no particular order:

The clutch action and gearchange with the Tremec box are very nice.
The engine pulls really well. Well behaved, no flat spots. Thanks Dave B.
Temperature stays in the normal zone, even on this very hot day.
The steering is heavy and slow. It's not unmanageable, but you have to feed the wheel through your hands to negotiate the chicanes. If you had to correct a sudden slide, say in the wet, it would be difficult to get the lock on and off quickly enough.

Surprising things

1) The brakes are actually quite good. We had adjusted the bias around 60/40 front-rear and it's about right for now. Yes you need a very firm foot on the pedal, but there is practically no free travel, the feel is really progressive , and the brakes have much more bite than I was expecting.

2) Cornering is really neutral. Amazingly so. There is no understeer at all, and a little extra throttle pressure steers the car nicely. It's an absolute hoot.

Turn In
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Apex (well almost..)
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I did a couple of five-lap sessions and then Gary had a go. It's quite a thing to sit in the passenger seat of your brand new car with an experienced racing driver at the wheel. The experience varies from 'This is great fun' to 'BRAKE NOW!! - That tyre wall is coming STRAIGHT AT US'

Following Gary's drive we let about 2psi out of the rear tyres to adjust the cornering a little, and decided to leave everything else right where it was, as the overall handling was easily good enough for now.

The fuse for the electric fan (20A) blew , so I put a 30A one in . No more issues. We think the car is, certainly at my level, ready to race.

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

Posted: Thu Aug 29, 19 12:23 pm
by Mark B
Superb! Looks great on the track. Glad it’s all come together :)

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

Posted: Thu Aug 29, 19 1:14 pm
by RobTwin
:salute: Fabulous, again =D>

It looks pretty low as it is in those last few pics so I cant imagine you'd have needed to keep the lowering blocks! :shock:

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

Posted: Thu Aug 29, 19 2:21 pm
by Adam
Awesome! Thanks for sharing Matt :thumbright:

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

Posted: Thu Aug 29, 19 7:49 pm
by ScottyDave
Nice one, looks great on the track =D>

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

Posted: Fri Aug 30, 19 6:14 am
by cadboy
she looks so right in that circuit and you have done a great job Matt =D> =D>

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

Posted: Fri Aug 30, 19 6:38 am
by Blue
Nice write up Matt, making good progress!

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

Posted: Fri Aug 30, 19 8:04 am
by Dom66
Looking good :thumbright:

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

Posted: Fri Aug 30, 19 8:47 am
by autofetish
:rr:


Sooooo cool

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

Posted: Fri Aug 30, 19 9:43 am
by Mark B
Your car’s in this month’s Street Machine.
.
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Re: Matt's 1970 'Trans-Am' Cuda

Posted: Mon Sep 02, 19 9:55 pm
by DaveB
looks great :thumbright:

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

Posted: Mon Sep 02, 19 10:18 pm
by Derek
Wel done Matt, it's looks like all your hard work is paying off =D> . What else have you still to do.

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

Posted: Tue Sep 03, 19 6:43 am
by andyrob
glad it all went ok for you