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Weld in Camber plates vs adj lower control arms


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Now that I am getting close to finishing all of the nuisance items on the LS1 car, it's time to start the fine tuning. I noticed the car doesn't have nearly enough negative camber, giving that big rollover feeing on the track, so this is the next thing to address. Rear should be pretty easy as the car already has adj control arms and I think I have enough tire clearance even with the 350Z wheels I currently use for street (actually street and track sice I haven't purchased and track wheels yet for the 5 lugs :)) My question is how much negative camber is gained by using weld in plates? I'd like to steer clear of adj control arms in the front because with the car at correct ride height and caster, with no flares the front tires are unbelievably close to the fender and airdam. The airdam already has been trimmed on the drivers side.

 

I'm going one step at a time here guys so the best bang for the buck considering what I am working with is what I'm looking for.

 

Thanks

 

Joe

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You can adjust a lot farther with a plate on top than you can with an arm on the bottom, and it's easier to make the adjustments because they don't change the toe settings. I would guess that you'd probably have 2.5 degrees of sweep on the plates, with arms it depends on which ones you have, but if they're using rod ends and you want to keep to the 1.5x the diameter within the threads then you probably have .3 or .4 degrees of adjustment.

 

When you weld in plates in the rear it is pretty important to make sure that the top of the strut is perpendicular to the control arm. If you weld the plates in towards the front or rear on accident this puts a lot of load on the strut and the control arm.

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...

When you weld in plates in the rear it is pretty important to make sure that the top of the strut is perpendicular to the control arm. If you weld the plates in towards the front or rear on accident this puts a lot of load on the strut and the control arm.

 

Jon, would this be different if the lower control arms are the type with the heim mounted adjustable rear link? Would this relieve any binding from a miss-aligned (fore and aft) camber plate? Or would it contribute to more bending loads on the strut?

 

Sorry, I don't mean to take this thread down a tangent. I just have not seen this addressed in the other "adjustable rear LCA" threads. Maybe I missed it.

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The short version is that there is no ability for the strut to change angle relative to the camber plate because the control arm is an "H arm", so if the two are misaligned you get a side load imparted on the strut. If your adjustable arm is an H arm, you'll still get the side loading.

 

If you want the full explanation this should explain the whole issue and a couple possible A arm with toe link solutions: http://forums.hybridz.org/showthread.php?t=129154

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FWIW Rags I have both on my car. I had just the eccentrics until a few weeks ago. With the eccentrics only I maxed out at -2.5 camber. With the plates and eccentrics I can see more than -6 but like Jon said, it screws you up when setting your toe. I was able to dial in -3 with a 1/16 of toe out and my cross weights are at 50.0% with me in the car. If I were to do it again, I would try to get all I could with plates first and installl rod ends instead of bushings on the inner control arm.

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With the eccentrics only I maxed out at -2.5 camber. With the plates and eccentrics I can see more than -6 but like Jon said, it screws you up when setting your toe. I was able to dial in -3 with a 1/16 of toe out and my cross weights are at 50.0% with me in the car.

Was the -3 the max you could get with only the plates?

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Can't really give you a good answer since I had both installed. The plates added at least -3.5 of camber for me. We played with moving the eccentrics to the top to try and get a little more angle in the control arm but not enough that I could say how much camber gain was just from the plates. I am using the GC camber plate setup and you can vary how much gain and have available by reversing the upper mounting plate. Not the plate it self but the captured monoball assembly.

 

I would think that -3 would be plenty for most track applications.

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I ran the rear plates and eccentrics and couldn't get more than ~3 degrees negative. In the front I struggled to get even 3 degrees, although I didn't run the camber bushings in the front control arms. I ended up making new arms and that's how I got there. And I ran my car LOW. Don't know what rxsleeper has, but I would think that you couldn't possibly get -6 degrees without arms that are 1-2 inches longer than stock along with the camber plates.

 

I am also running the GC plates (which I think are much better than any of the weld in plates).

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Don't focus on exact camber numbers as they can be misleading. In general, wider tires require less negative camber. You want as little static negative camber as possible and base that on tire temps, not postings on a message board. Also, more positive caster reduces your need for negative camber.

 

One data point:

 

-3.2 front and -2.75 back are the most negative camber I've ever run on a 240Z and that's with 225/50-14 Hoosiers. When I was running 275/45-16s the pyrometer and lap times said around -2.5 front and -2 rear worked best.

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^^^^^^^^^^^^

what they said. FWIW, I am at 5 1/4 inches at the rocker, not the pinch weld on OEM lower control arms, shortened struts with coilovers on 225/50-14 R-6's.

 

Pyrometer is in the trailer and I will adjust dependant on temps during a test day this Friday. Last year at the same track I was running -2.5 in front. Hope to see some change this weekend.

 

Paul

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Thanks for all of the great responses guys as this will greatly help with my decision.

To add a little more background, the car is a split duty car, not track only. Street wheels are 350Z wheels, just because they were the right price and tires were new. The car is running 6.5" ride height in the front and 7.5" in the rear (yes I know I need to drop the rear and will probably drop to 7"). No flares. Tire diameter for the street tires I believe is 26", huge, but they don't rub. Once I get the track tires I'm assuming they will be in the 25" range and therefore drop the car another half inch. So I'm trying to do things in a progressive manner where I spend cash wisely, one step at time, and avoid downtime.

Jon, why do you say the GC plates are better than the weld in type? I would have thought just the opposite.

 

Joe

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Ground Control makes the best plates available in my opinion. The weld in plates from AZC use the monoball as the bearing to turn the strut when you steer the car. This setup has more inherent friction than the ones that use a needle bearing between the plate and the top hat for the spring. That style sets the weight of the car on the Torrington needle bearing, and uses the monoball to allow for the strut angle to change. The monoball might twist as well but it isn't twisting under the weight of the vehicle. So there is a reduction in friction. The good part about the AZC design is that the spring perches stay parallel to each other as the suspension does its thing. The TTT design uses a Torrington bearing, but it doesn't allow the strut top to stay parallel to the strut bottom so it is inferior to the AZC setup in that respect.

 

The newer style GC plate has a pivot on the bottom of the plate so that the spring perches stay parallel, and this reduces friction a little bit more, as well as keeping the spring from rubbing the threads off of the coilover sleeve. It also has a torrington bearing between the plate and the spring hat. So it really is the best design. It's not that the other ones are useless, but the GC design really is better, enough that I sold the old style GC plates and bought new ones. Whether this matters to you or not is another story, mine is a quest for friction reduction in the suspension, and that's the rationale for the GC ones being best.

 

Old Style: Flat top of spring hat and bottom of plate. The torrington bearing goes in the recess in the top hat.

DSCN3092.jpg

 

New style: Rounded bottom of plate meets concave steel bearing thingy on the spring hat, which allows the spring hat to change direction respective to the plate. Torrington bearing is under the concave bearing thingy:

DSCN3093.jpg

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Ground Control makes the best plates available in my opinion. The weld in plates from AZC use the monoball as the bearing to turn the strut when you steer the car. This setup has more inherent friction than the ones that use a needle bearing between the plate and the top hat for the spring. That style sets the weight of the car on the Torrington needle bearing, and uses the monoball to allow for the strut angle to change. The monoball might twist as well but it isn't twisting under the weight of the vehicle. So there is a reduction in friction. The good part about the AZC design is that the spring perches stay parallel to each other as the suspension does its thing. The TTT design uses a Torrington bearing, but it doesn't allow the strut top to stay parallel to the strut bottom so it is inferior to the AZC setup in that respect.

 

The newer style GC plate has a pivot on the bottom of the plate so that the spring perches stay parallel, and this reduces friction a little bit more, as well as keeping the spring from rubbing the threads off of the coilover sleeve. It also has a torrington bearing between the plate and the spring hat. So it really is the best design. It's not that the other ones are useless, but the GC design really is better, enough that I sold the old style GC plates and bought new ones. Whether this matters to you or not is another story, mine is a quest for friction reduction in the suspension, and that's the rationale for the GC ones being best.

 

Old Style: Flat top of spring hat and bottom of plate. The torrington bearing goes in the recess in the top hat.

DSCN3092.jpg

 

New style: Rounded bottom of plate meets concave steel bearing thingy on the spring hat, which allows the spring hat to change direction respective to the plate. Torrington bearing is under the concave bearing thingy:

DSCN3093.jpg

Thanks for posting that. I knew you were switching when I saw your Classifieds ad. I wondered what the new ones were like (up close) and what you thought of them.

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Hey Jon, just wondering if you had seen the camber plates that Top End sells and what you thought of them? They seem to have a needle bearing setup as well. Pic below...

 

datsun1.jpg

 

What I've heard is these are very hard on struts and may have broken the top of of some. The rubber is designed to allow for angular change like a spherical bearing, so simply making the rubber a lot stiffer may not be the best thing to do, just like the TC rods.

 

Cary

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What I've heard is these are very hard on struts and may have broken the top of of some. The rubber is designed to allow for angular change like a spherical bearing, so simply making the rubber a lot stiffer may not be the best thing to do, just like the TC rods.

Agreed, those just look like a really bad idea to me.

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  • 3 weeks later...

The newer style GC plate has a pivot on the bottom of the plate so that the spring perches stay parallel, and this reduces friction a little bit more, as well as keeping the spring from rubbing the threads off of the coilover sleeve. It also has a torrington bearing between the plate and the spring hat. So it really is the best design. It's not that the other ones are useless, but the GC design really is better, enough that I sold the old style GC plates and bought new ones. Whether this matters to you or not is another story, mine is a quest for friction reduction in the suspension, and that's the rationale for the GC ones being best.

 

I have just trial fitted my struts and used the original rubber insulator at the top of the struts and was appalled to see the springs were rubbing the threads of the threaded collars - good to know what will cure it!!!

 

I was curious about the NEW style GG camber plates you have their Jon, are they are a weld in or bolt in?

 

The ones you pictured look like these ones below from GG!

 

http://www.ground-control-store.com/products/description.php/II=151/CA=93

 

CCPZ_dp.jpg

 

And this is an extract from the GG website regarding these coilovers!

 

This kit is designed to bolt into the Z, and no welding is required.

Just a little bit confused - are these camber plates bolt in or weld in?

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Well to give an update, I have the GC plates installed in the front and I just went for a street alignment. Nothing radical 1.5 degrees negative camber in the front 3.5 degrees caster and 1/32" toe out. Only the camber has changed from settings pre plates. The biggest surprise I have noticed is a decrease in steering effort! I'm not sure if this is because of the torrington bearings but man am I loving it!

 

Joe

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I drove Joe's car a few days ago and will say the steering effort has gone down plenty! Does not feel like I am holding a 45lb weight to make a u-turn. :-) For cost vs driving improvement I say it is a no brainer to buy it, I plan on doing them as well if my car doesn't handle as well as it did before.

 

I see John said, you don't need as much neg camber with larger tires, I am going to be running 17x 9.5 on the new setup up front and 17 x 11 rear so we shall see.

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