new to me ebay suspension

[PUSHER]

Anyone use these http://cgi.ebay.com/ebaymotors/Datsun-240Z-260Z-280Z-Tension-Control-Tie-TC-Rods_W0QQitemZ8020492141QQcategoryZ42609QQrdZ1QQcmdZViewItem

or these?

http://cgi.ebay.com/ebaymotors/Datsun-510-280zx-CAMBER-PLATES_W0QQitemZ8020492034QQcategoryZ33581QQrdZ1QQcmdZViewItem

and why wouldnt these camber plates work on a 280z? whats the difference?

[myplasticegg]

there was a redesign of the suspension for the second gen Z cars.

[PUSHER]

The only reason I figure it cant work is that the shock diameter is different and it wont fit through the holebearingthingy.

[thehelix112]

Yeah that and the PCD of the top is entirely different?

 

Dave

[JMortensen]

I don't know what a PCD is but the 280ZX strut tower has a much larger flatter top on it like a 510.

 

Shock diameter is bushed , either with a shouldered nut that has 12mm threads and 5/8" OD, or with a spacer that slides down the shock inside the monoball that then uses a regular nut on top.

[chmercer]

thoes are probably just stock photos, thoes tension rods are for corollas, the camber plates are for s chassis. techno toy tuning (t3) is quality parts, if you were interested id email them or somthing instead of buying off ebay.

 

heres the page

 

http://www.technotoytuning.com/

[mark]

I've got a set of the TC rods. They are a VERY nice part.

[Mikelly]

I can give you a parts list and you can make your own TC rods for about $75 in parts for a pair, maybe less.

 

The camber plates look like nice quality, but I can get the weld in units for about $200 from AZC.

Mike

[johnc]

Personally, I would avoid TC rods that shorten the arc. If used in conjunction with a poly LCA bushing the front suspension will bind easily and you put a lot of stress on the shock shaft.

[BRAAP]

To reiterate what John said, if you are serious about performance handling, then do NOT use that T/C rod set up. The pivot is moved further outboard which drastically alters the geometry. The only real purpose for that style of T/C rod is for show cars, i.e. “BLING BLING baby…”

[JMortensen]

I agree with what John said, and I know it to be true from personal experience. I had my TC rods made before my control arms, and the poly bushings in the control arms were really tweaked when I got the amount of caster I wanted. That was the reason why I got the control arms with the rod end made.

 

BRAAP, I don't agree with what you said. What the shorter TC rod does is make the caster curve different. You can still dial in a hell of a lot more caster with this rod than with a stock one, so regardless of the less desireable curve, you can still get the vastly more desireable increased caster. I like some of the other designs for TC rods better than this one, but increasing caster has a HUUUUUUUUUUUGE effect on the front end, and this TC rod will get you that.

[Mikelly]

All though I agree with the concerns posted by the last three members, I'd be surprised if someone bought TC rods that were agjustable and didn't buy an adjustable control arm to go with them... I would hope that is the case...

 

Mike

[BRAAP]

Yes, from a competition standpoint, the front end of the Z can stand a bit more caster, helps band aid its steep king pin angle, no argument there. In this example, those T/C rods will allow a changing caster curve through out the travel of that front wheel which, as you mentioned, is something you don’t want, but for argument sake, a competition car isn’t going to go through enough travel from bump to full droop during action for that to be problem, so, the caster arc curve is really a mute point and as you stated, the added caster you can dial in will more than make up for that.

 

A pronounced negative side affect of those T/C rods having the outboard pivot more outboard is it induces more dive under hard braking, depending on the control arm angles of course. Generally speaking, most Z’s set up for performance handling are lowered and as such, making the “side swinging” control arm more of a “trailing arm”, (technically a leading arm), style control arm by moving the T/C rod pivot outboard, allows the front end to dive more under hard braking.

 

In short, the stock front suspension is only “OK”, but in my honest opinion any alterations to the geometry of the front end should do so with as little compromise as possible to the rest of the geometry, unless it enhances the geometry of course, as the front end can use all the help it can get. You don’t want to induce other negative attributes to gain another characteristic unless that is the only option to gain that specific characteristic for that particular application. Those particular T/C rods do allow for caster adjustment, but there are other ways to get this added caster without altering the other geometry characteristics of the front suspension. An example would be a set of T/C rods I built back in the late ‘90’s. I used Volvo Rack and Pinion ball joints in place of the OE Datsun T/C rod pivot location, this allows articulation without binding and keeps this “control arm” pivot point in the same location, (after some modest T/C mount alteration, but in the car we used it in, we started from scratch, so no problem), and then we welded on a threaded sleeve to the T/C rod itself. For caster adjustment, just loosen the Jam nut and twist the T/C rod without even jacking up the car. (When Ron Tyler and myself built Dave Lums VG30DETT powered 510 we installed a complete 240 Z front end complete with 240 rack and rear facing T/C rods and we used this Ball joint set up. Here are a couple of pics of those T/C rods.)

 

 

 

 

In short, I still feel those particular T/C rods are for show cars, not competition cars. Not to mention, some class rules prohibit suspension pick up points from being altered and those T/C rods do technically alter the suspension pick up point.

[JMortensen]

Pretty much any aftermarket TC rod setup available, AZC, the techtoytuning one, Mike Kelly's old one, even yours, moves the pivot point. The center of the ball in that tie rod end you used is probably 1" forward of where the TC bucket is (estimating from the picture). The vertical plane of the tc bucket is where the pivot is when using stock bushings, so you moved the pivot forward in yours as well, although to a lesser degree.

 

Depending on how big the clevis is that is used to attach the rod end on the AZC/Techtoytuning/Mikelly style you'll have varying degrees of change vs the stock setup. The only way to completely eliminate ANY change is to cut the TC bucket off the car and relocate the pivot of the new arm so that it's center point is where the bushings were originally.

 

As far as anti dive I thought the goal there was to get the TC pivot as HIGH as possible. In the same way that roll center affects body roll, I had understood that the TC rod angle had the same effect on dive. So if the arm pointed up from the pivot to the LCA, then as you applied braking pressure this gives the suspension mechanical leverage to force the suspension to compress more, hence more dive. If the TC rod points down then this problem goes away.

 

I don't understand how moving the pivot outboard affects the dive, but if you've got some insight into that I'd love to hear it before I make any changes to my front suspension.

[BRAAP]

Yes, you are correct in that those Ball joints would move the pivot outwards “if” they were just bolted in to the stock T/C mount location, but these particular T/C rods, in their current application actually do pivot in the EXACT same location as the OE Datsun Z car T/C pivot. These rods were installed on a Datsun 510 that myself and Ron Tyler installed a complete 240 Z front suspension under the front, and we retained the 240 Z rear facing T/C rod arrangement so that we could utilize the 240 Z front-steer rack set-up, we custom fabbed the T/C mount a little further back and inboard so that the ball joints do pivot in the same location as stock.

You are also right in that by raising the T/C rod pickup location, this will induce some anti-dive geometry.

 

As for “how moving the T/C rod pick up outboard affects dive”, the easiest way for me to describe this is just picture how a semi trailing arm works. Depending on how the arm is angled, (and to what degree the semi trailing arm is from parallel), dramatically affects the anti squat/dive characteristics. Now by moving the T/C pivot point outboard, the front suspension now becomes a semi trailing arm, i.e. the imaginary line that runs through chassis pickup points are no longer parallel to each other, (technically the front then becomes a “semi leading arm” as the wheel is forward of the pick up points)

 

To look at this in a different way, picture the semi trailing arm suspension on the 510, 280-ZX, or Z-31 300-ZX. (Picture either of those setups for the following examples). If you jack the car up, (chassis pick points being higher than the wheel hub itself), acceleration forces will help “cam” the tire under the car thereby helping to dig the tire into the pavement as the control arm lifts the rear of the car even higher in the air, there by helping with traction, (anti squat), but if the car is lowered, (the chassis pickup points now being lower than the wheel hub assembly) the tire will try and “cam” over the top and thus will loose traction. The opposite holds true for braking forces.

I know that probably confused few of you and if one of you Chassis Gurus caught what I was trying to convey, could you please rewrite it in a format that is little easier to understand?

Any how, hope this helps…

[JMortensen]

Thank you for that explanation BRAAP. That makes sense to me. Just like a semi-trailing arm moves in an arc determined by the pivots, the control arm and TC rod would do the same if they weren't directly in line. I still couldn't say quantitatively how much affect that has though. You've convinced me to change that aspect of the front suspension when I redesign it though.

 

This much I can say: having used stock, then poly, then G Machine, then a clevis mounted setup like the one we're talking about in this thread in autoxes for the last 10 years, the additional caster gained from the adjustability far outweighed the effect of the increased anti-dive. My car got MUCH faster when I added the caster. I don't think it's a show part. I think its a go fast part. I'm sure everyone who uses the any of the setups that change the pivot point would agree with me.

[BRAAP]

Jon,

I couldn’t agree with you more when it comes to caster on the front of the Z, especially for transitional handling situations such as slalom racing and SOLO-II. Adding caster allows the car to “turn-in” MUCH harder and with more authority.

I have to eat some crow and agree with you that even if you do give up a little anti-dive to gain MORE caster with those pretty T/C rods, for someone building an Auto-X/street car, that is a compromise worth making. To modify the T/C mount to retain the pivot location does require quite a bit of involvement and most guys, justifiably, aren’t willing to hack on their cars to that degree.

 

 

 

BTW,

Jon, do you ever make the trip south to compete in SOLO-II much? Portland or even Eugene?

[JMortensen]

Actually the last time I had the car out was 4 years ago. I moved to Seattle and haven't raced since. I am in the middle of a hardcore revamp of the car. Before it was about as serious as you'd want to get and still drive on the street. When it eventually gets done it will be closer to a real FP car. Still not fully built to the extent of the rules, but a lot closer. Should be trailer only, and will lose probably 250 lbs vs last time it was on the street.

 

I'd love to come down to central Oregon and do some autoxing with you guys when I eventually get the thing done. There are some fast guys down there for sure, and I'm sure I could learn a lot from you all.

[mom'sZ]

Now this thread got interesting! Thanks guys, very interesting disscusion. Jon, I've said it before, your knowledge of all thing automotive is amazing. Paul, I saw your yellow car in the fat lip thread... very cool.

[Pop N Wood]

If I am following everything that is being said, wouldn't relocating the TC mount allow the Techno tuning part above to also retain the same geometry?