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Pre-70 Performance suspension

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Rampar View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rampar Quote  Post ReplyReply Direct Link To This Post Posted: Jan/05/2017 at 9:15pm
You should take some more pics of this 
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343sharpstick View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 343sharpstick Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 9:45am
Javelin_GT, do you have any information, part numbers and/or manufacturer, on the spherical bearing and housing you used on your lower control arm?

Also, are you certain that straight anti-sway bar will clear the front corner of the oil pan? Did you move the mounting forward of the stock location?
Here is a picture of the '68 T/A car which still used the stock-style bar.


Thanks.
MS
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 10:02am
Originally posted by 343sharpstick 343sharpstick wrote:

Javelin_GT, do you have any information, part numbers and/or manufacturer, on the spherical bearing and housing you used on your lower control arm?

Also, are you certain that straight anti-sway bar will clear the front corner of the oil pan? Did you move the mounting forward of the stock location?
Here is a picture of the '68 T/A car which still used the stock-style bar.


Thanks.
MS


From the length of the sway bar arms and how far up the mounts are in relation to stock, the sway bar is mounted in front of the pan not under it.
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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343sharpstick View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 343sharpstick Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 10:04am
Here are a couple more pictures of the 68 T/A cars. The only year in which the Trunion suspension was used. And a successful year for the Team!
The front ride height looks killer, but I can't imagine it has more than one or two inches of up travel! Given that sway bar they are using the front spring rates must be massive.







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Post Options Post Options   Thanks (0) Thanks(0)   Quote Javelin_GT Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 10:09am
The sway bar is far enough forward not to interfere.

Also I have a build thread for questions.  Sorry for getting your thread of topic Mike.

http://theamcforum.com/forum/amx-rally-car_topic78040.html
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 343sharpstick Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 10:13am
Under hard braking my front suspension drops at least 3 inches, and for a street car my spring rates are about perfect.
Here is a picture from OUSCI braking for the speed stop, which BTW is harder than it looks on TV!



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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 10:23am
Donohue stated the suspension was riding on bumpstops. Very little travel... assuming that was the best one can do with stock trunions for TA work, since the Javelins were running hard against the best setup Camero ever. Proof a solid built suspension, where body roll and deflection on the lower arms can be reduced by making the lower arms more parallel with the ground than angled in stock form. Something I am working on myself on my Javelin, though it is a 71. Really does not matter on what components you use, it matters on how the suspension operates under driving conditions. The more angled the lower arms are the better for off road stability. The more level they are to the ground the better for road coarse. Just look at F1 and Indy cars, the arms are fairly parallel when in the corners. Long arms also help as to keep the change of suspension travel from making the angle of deflection more acute. Less angle better steering and handling in the corners. Plus you get a lower center of gravity in making the body weight rest at the wheel's center rather than above center, where the body will want to roll over than push at the wheels.

Even though I am using a 71 suspension, my changes will work for any suspension. Simply adding an inch in lower arm length dropping the spring saddles, and moving the shock towers to produce best camber and caster for today's tires, and lower the center of gravity. It will ride harsh considering I am expecting 1-1/2" travel with a HD spring setup.

Edited by 304-dude - Jan/06/2017 at 10:30am
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 343sharpstick Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 10:27am
Ahh! I see now, you mounted it in front of the Idler Arm.
All relevant to getting pre-70 stuff working. I hope it helps others down the road.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 343sharpstick Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 11:02am
304-dude. Agree completely. What RKE did in 68 was truly impressive!

I measured and modeled the front suspension at my 2016 ride height, which was lower than stock by about 1.5 to 2 inches using custom springs, and basically the angle of the lower and upper control arms was less than ideal. The upper arms were nearly horizontal! This puts your instant center, and resulting roll center relatively high to say the least.



Getting the lower arms horizontal is a good starting point, but will make for a very short spring using stock components.

Here is where the whole compromise things gets in the way. The rear of my car is nearly as low as I can get it, so If I were to lower the front of the car additionally, it would improve the roll center, but reduce caster, which is already at max and much less than it needs to be with radial tires.

Probably ‘OK’ on a road course, but as it is now getting the car around the autocross with very little steering self-centering is interesting.
The stuff I have in the works for this year that fixes everything except anti-dive.


Edited by 343sharpstick - Aug/25/2017 at 2:26pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2017 at 11:14am
Yeah, them long springs on the pre 70 cars make it difficult without custom springs or mounting coil overs on a modded shoc tower. Caster will always be a problem unless you mod the shock tower or go with a CF suspension.

Offsetting the upper balljoint may be the only simple option to correct the caster issue.

71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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