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Old 10-01-2012, 05:00 PM   #256
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Originally Posted by AdrianM View Post
In order to generate traction there has to be weight transfer. If the CG was at tarmac level this would not occur and there would be little traction. At that point only increases in friction between the tire and surface (adhesion) and aerodynamic down force would increase traction.

A lower CG will reduce traction. However, more chassis flex and suspension settings that increase weight transfer and contact patch optimization (Roll Centers, Link Angles, Camber Curves, etc) will increase traction.

Overall I really like what they did with the T4. It's cool to see Xray be confident enough to take risks and do something different than what Tamiya and Yokomo are doing.
Agree Adrian with your comment.
I hope the total balance is better so that the corner speed increase.
thanks again for you comment.
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Old 10-01-2012, 05:31 PM   #257
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My LHS pre-ordered mine for me today. Was told will ship in a couple weeks. Nice.
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Old 10-01-2012, 08:12 PM   #258
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I'm going to hold off on my order. I want to see track reports if there are broken chassis and or bent motor mounts. I would of rather have had a threaded motor mount where it screws into the center of the chassis with more material around it. I don't see Xray willing to replace those parts if there is a problem.
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Old 10-01-2012, 08:17 PM   #259
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I'm going to hold off on my order. I want to see track reports if there are broken chassis and or bent motor mounts. I would of rather have had a threaded motor mount where it screws into the center of the chassis with more material around it. I don't see Xray willing to replace those parts if there is a problem.
When the first t3 came out, they had problems with the split blocks and they fixed it promptly and offered a free part to everyone who had purchased a t3.
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Old 10-01-2012, 08:18 PM   #260
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Originally Posted by Skiddins View Post
I think the only part of the suspension that is narrower are the pivot block mounts at the front of the rear wishbones, effectively it's the Hagberg mod, but only -0.75mm instead of the full 1mm.

Skiddins
D'oh! you're right on about that. I was stuck thinking in a past life where my suspension mounted to my bulkheads
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Old 10-01-2012, 08:26 PM   #261
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Originally Posted by RCknight View Post
I'm going to hold off on my order. I want to see track reports if there are broken chassis and or bent motor mounts. I would of rather have had a threaded motor mount where it screws into the center of the chassis with more material around it. I don't see Xray willing to replace those parts if there is a problem.
With regard to the worry over a broken chassis. Do a careful comparison between the old motor mount design ( one piece that includes the layshaft mount ) and the new design ( two piece ). Now the motor mount and lay shaft mount are mated together with two screws. There is virtually no difference other than moving the motor mount further inboard. Both methods use three screws through the chassis.
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Old 10-01-2012, 10:11 PM   #262
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I don't remember them replacing the torn out chassis. Since the bumper is not mated to the bulk head I feel that could be an issue.

My other concern is a hard impact from the side hitting the motor. Ever been on a board and get smacked right in the center? I just do not have confidence in it. The thought of a damaged motor, motor mount and the possible expense I would rather not think about. I understand Xray's thought about the lower CG motor mount, but I prefer having more surface against the motor. It don't seem to affect Tamiya at all. These are just my concerns, maybe it's not an issue. Time will tell, I'm in no hurry.


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When the first t3 came out, they had problems with the split blocks and they fixed it promptly and offered a free part to everyone who had purchased a t3.
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Old 10-02-2012, 12:26 AM   #263
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our Pre-Order for the XRAY T4 is also started
expected in next week
http://www.the-border.com/XRAY-T4-No...er-300019.html
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Old 10-02-2012, 01:51 AM   #264
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Originally Posted by RCknight View Post
I'm going to hold off on my order. I want to see track reports if there are bent motor mounts. I would of rather have had a threaded motor mount where it screws into the center of the chassis with more material around it. .
I too have reservations about motor mount but it won't stop me ordering one as I have three option

Suck it and see

Open out the slots in the motor mount and re-tap the motor to take 4mm screw

Mod the old motor mount to fit.


As for the nut bolt arrangement, I understand that completely, the motor mount is bolted to the laysaft mount, any slight variations in that fixing could/would cause tweak if the motor mount had only one fixed position. In addition, it looks like it is poss to shim the motor mount away from the layshaft mount and get the motor even closer to the centre line.

Bb
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Old 10-02-2012, 01:56 AM   #265
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Quote:
Originally Posted by AdrianM View Post
In order to generate traction there has to be weight transfer. If the CG was at tarmac level this would not occur and there would be little traction. At that point only increases in friction between the tire and surface (adhesion) and aerodynamic down force would increase traction.

A lower CG will reduce traction. However, more chassis flex and suspension settings that increase weight transfer and contact patch optimization (Roll Centers, Link Angles, Camber Curves, etc) will increase traction.

Overall I really like what they did with the T4. It's cool to see Xray be confident enough to take risks and do something different than what Tamiya and Yokomo are doing.
LOL at the made-up physics in this post.

Lower CoG = less weight transfer = more overall grip, due to tyre load curves being non-linear. As you transfer weight to the outside tyre it gains a small amount of grip, but the inside tyre loses a larger amount of grip, so you have less grip overall.

This is why every racing car designer in the world tries as hard as possible to lower the CoG.
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Old 10-02-2012, 02:13 AM   #266
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Originally Posted by daleburr View Post
LOL at the made-up physics in this post.

Lower CoG = less weight transfer = more overall grip, due to tyre load curves being non-linear. As you transfer weight to the outside tyre it gains a small amount of grip, but the inside tyre loses a larger amount of grip, so you have less grip overall.

This is why every racing car designer in the world tries as hard as possible to lower the CoG.
You're absolutely right.
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Old 10-02-2012, 02:31 AM   #267
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I suppose the risk of damage to the chassis is increased because its 2.2 vs 2.5 mm.
For me, a "luxury" chassis should not need any upgrade parts, just tuning options. One still needs the ECS drive shafts, steel spool outdrives, graphite suspension and now an enitre new spring kit.
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Old 10-02-2012, 02:40 AM   #268
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Quote:
Originally Posted by daleburr View Post
LOL at the made-up physics in this post.

Lower CoG = less weight transfer = more overall grip, due to tyre load curves being non-linear. As you transfer weight to the outside tyre it gains a small amount of grip, but the inside tyre loses a larger amount of grip, so you have less grip overall.

This is why every racing car designer in the world tries as hard as possible to lower the CoG.
A tractor has traction a go-cart has grip. Traction and grip are not the same thing.

Bb
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Old 10-02-2012, 02:45 AM   #269
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Originally Posted by Reese Bobby View Post
For me, a "luxury" chassis should not need any upgrade parts, just tuning options. One still needs the ECS drive shafts, steel spool outdrives, graphite suspension .....
No, you don't, but people still buy them.

I do have the ECS driveshafts already and I'm currently trying the graphite arms.
None of these things is essential, they are 'tuning options'
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Old 10-02-2012, 02:50 AM   #270
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Quote:
Originally Posted by daleburr View Post
LOL at the made-up physics in this post.

Lower CoG = less weight transfer = more overall grip, due to tyre load curves being non-linear. As you transfer weight to the outside tyre it gains a small amount of grip, but the inside tyre loses a larger amount of grip, so you have less grip overall.

This is why every racing car designer in the world tries as hard as possible to lower the CoG.
If it is as simple as that, why doesn't everyone just raise their roll center's right up so the car doesn't roll at all in the corners?
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