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Old 03-22-2012, 03:54 PM   #2116
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I thought it would make a great candidate for a RWD Trans Am car. The wheels fit straight away. The wheel base would need to be shortened to 10" to fit all the HPI bodies and a front shock tower mount would be required. One of their other models might work better as a base platform.
No, lots of HPI 200mm bodies are too wide, only few looks good.. I would like more 190mm chassis for Tamiya bodies...

I think best version would be combinating Sakura S fontend and FGX's rear end (or some new rear bulkheads with FGX's gears and suspension parts)
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Old 03-22-2012, 06:00 PM   #2117
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No, lots of HPI 200mm bodies are too wide, only few looks good.. I would like more 190mm chassis for Tamiya bodies...

I think best version would be combinating Sakura S fontend and FGX's rear end (or some new rear bulkheads with FGX's gears and suspension parts)
Most if not all the TA cars old TCs and are 190mm. The rear offset rims fill out the wheel wells of the HPI 68 Camaro at 210mm perfectly.
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Old 03-22-2012, 06:31 PM   #2118
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Cheers liljohn ill try that tonight!
Also this darn 3 racing carbon fibre chassis has a twist in it from left to right.
What do I do bout this abortion lol
I'd check the bulkheads and motor mount.
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Old 03-22-2012, 06:40 PM   #2119
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Most if not all the TA cars old TCs and are 190mm. The rear offset rims fill out the wheel wells of the HPI 68 Camaro at 210mm perfectly.
Wouldn't that make it a 210mm body?

I think most of the trans am bodies are 200 with the hpi mustang coupe and fastback fitting the tightest of the ones I have tried. I could be wrong though.
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Old 03-22-2012, 07:33 PM   #2120
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Wouldn't that make it a 210mm body?

I think most of the trans am bodies are 200 with the hpi mustang coupe and fastback fitting the tightest of the ones I have tried. I could be wrong though.
I have the Mustang GT on my old TC3 and its right at 206 at the rear. It's pretty close to rubbing in the rear width wise. I had to cut the wheel wells further back because wheelbase is fixed on the TC3, not much movement there at all. I think the Camaro is actually listed at 210 rear 205 front with the rims on it. I'm getting a J71 because the wheelbase is right for the TC3. You know, because the TC3 is so wheel base adjustable. So temped to try the Zero S for TA.
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Old 03-22-2012, 07:45 PM   #2121
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I roll a Zero S in VTA.
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Old 03-22-2012, 08:39 PM   #2122
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I roll a Zero S in VTA.
I started with the s model but it has been fully upgraded to a zero. It really is a great chassis.
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Old 03-22-2012, 10:10 PM   #2123
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I started with the s model but it has been fully upgraded to a zero. It really is a great chassis.
Same here. Only the frp chassis is left from original kit. I have t had it on track since November. Should be back in VTA soon though.
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Old 03-23-2012, 05:49 AM   #2124
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I'd check the bulkheads and motor mount.
Cheers liljohn you were right it was the darn motor mount !!
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Old 03-23-2012, 05:51 AM   #2125
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Change gap on the link from the rear arm up to the damper pivot. I had to decrease mine to 9.5mm to get the ride height to stay put.
And liljohn once again you were right
I changed the gap to 9.5mm and was easier to set.

And to everyone else thank you!
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Old 03-23-2012, 06:39 AM   #2126
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Cheers ootael!
So u recommend setting more preload?
Well, to preload on the shocks always influences the dampering of the car. I depends on what conditions you have. If your spring is loose and the damper shaft is not fully pulled then you could go with my solution.

But I guess in your case liljohn1064's solution did it
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Old 03-23-2012, 07:23 AM   #2127
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I'd check the bulkheads and motor mount.
Had the same problem with mine too. Took everything apart and started measuring/checking. For me the tweak was caused where the plastic bulkhead screws into the side of the aluminum motor mount (when looking at the pinoin gear the screws fore and aft of the pinion). Tried to file it flat but could not get it perfect. So I just run those screws a quarter turn loose so they will not introduce tweak into the chassis. Also, the turnbuckle that bridges the gap between the top deck and rear end was too short actually causing the rear of the chassis to curve up.

Once I got those two problems sorted out the car is so much better to drive.
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Old 03-23-2012, 09:21 AM   #2128
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Had the same problem with mine too. Took everything apart and started measuring/checking. For me the tweak was caused where the plastic bulkhead screws into the side of the aluminum motor mount (when looking at the pinoin gear the screws fore and aft of the pinion). Tried to file it flat but could not get it perfect. So I just run those screws a quarter turn loose so they will not introduce tweak into the chassis. Also, the turnbuckle that bridges the gap between the top deck and rear end was too short actually causing the rear of the chassis to curve up.

Once I got those two problems sorted out the car is so much better to drive.
That chassis link is a pain. I snapped mine on then adjusted it until it rolled free side to side. It was way too tight using the kit suggested gap. Just like a link rear end on a pan car, if its not free its tweaking something. And this link really does affect chassis flex so it needs to be free and smooth.
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Old 03-23-2012, 09:46 AM   #2129
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And liljohn once again you were right
I changed the gap to 9.5mm and was easier to set.

And to everyone else thank you!
It was an accidental discovery. Only because I built my first set of links wrong did I catch it. It looked to my eye that the shorter links centered the damper piston better when the springs were preloaded at the ride height I wanted. So then I played with the shorter link theory and the piston in the damper body is now closer to the middle of its full range of motion. It doesn't bottom out or hit its extension limit in my ride height and droop setttings.


So to tune the rear end I:

1. Take off the damper springs.
2. Set the car on a block or ride height gauge at the desired ride height.
3. Estimate where the piston is in the shock body. (or open them up and mark the outside with a sharpie)
4. Center the piston.
4A. Measure the overall length of the damper from ball cup to ball cup and save this for future use.
5. Adjust the lower links until the wheels firmly touch the ground on both sides.
6. Put the springs back on.
7. Adjust the preload on the shocks to gain back the desired ride height.

Do this process once, then do steps 5 through 7 with the piston centered (4A) if you need to change ride height drastically.

My shocks are build to Zero rebound. Preload is NOT the same on both sides. The motor mount damper requires a couple collar turns more of preload to get the ride height the same on both sides. I'm measuring ride height at the center rear for overall and just in front of both rear tires on each side to make sure its the same on both sides.
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Last edited by liljohn1064; 03-23-2012 at 09:59 AM. Reason: future use
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Old 03-23-2012, 11:55 AM   #2130
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Default Car pulling one direction under acceleration or braking

This question was asked a few times over the last few pages and I am finally able to take some time to answer it.


If your car pulls to one side under acceleration or breaking there are two main causes:

Rear suspension linkage setup:
One of the most important setup tips on this car is to make sure all your linkage and arms are perfectly symmetrical. The droop screws on the lower arms should be set identical. Then make sure all shock linkage is the same. Pop the rear shocks off and lift the rear end. The two balls on the damper arms should be perfectly symmetrical. If one is a little ahead of the other this will cause the car to pull. After everything is equal put the shocks back on and equally set the springs. Check ride height from left to right and slightly adjust springs to equal out. (This is assuming that you have made sure your chassis is not tweaked).


Chassis tweak:
If you run the stock chassis and upper deck, most crashes will cause a tweak. The plastics top deck and the very flexible FRP chassis get and hold a tweak very easily. Before Mark Day at Timezone switched to my chassis he was checking tweak every run. Loosen all top deck screws, put the chassis on a flat surface and tighten everything back down.


Of course always make sure camber, caster, toe, front springs, front droop, etc. are all the same left to right as well.

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