Do camber plates create drop or just increase travel?

[Hellabad]

good ones dont change a thing. vorshlag are the same hight, within a mm, of stock bushings.

Wouldnt it be better to have an extra 24mm travel? Yes, It would be.

[Hellabad]

suspension travel doesnt change unless you change your damper/spring combo.

Not true. You can add suspension travel via the camber/caster plates, which is what this thread is about. It can be done on a WRX, but is more difficult than an e30, which is RWD.

suspension travel = full damper extension - full damper compression

Not the same as we are discussing. Suspension "travel" is generally (in the racing world and the oem world) defined as the amount of movement available from ride height until contacting the bumpstops. What you are talking about is usually considered suspension STROKE, RANGE, or maybe clarified as "overall suspension travel".

Some people do call the entire "range" simply the "travel", but I don't like to because then you don't have a clear definition for the critical dimension between the ride height and interference.

so, if you install these camber plates on your current suspension, leaving all other things the same, your car will be 24mm lower with equal suspension travel.

gaining 24mm of travel with a camber plate is simply amazing. im coming from the subaru world where not loosing more than 10mm of travel was already good.

zero mm is even better than 10!

http://ground-control.com/ccp-wrx-compare.jpg

the only thing left that im wondering about is the front suspension's camber curve and how much of a penalisation it takes with lowering.

Any "Camber Curving" you try to do with a MacPherson strut is pretty much just talk. The rear camber curve of the e30 is better than the front camber curve, so we try to maximize the front in order to minimize the influence of the rear.

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[nando]

the only thing left that im wondering about is the front suspension's camber curve and how much of a penalisation it takes with lowering.

it really doesn't, unless you're dragging on the ground. as long as the angle between the strut and the control arm is less than 90 degrees, the camber curve is fine. Bump steer on the other hand...

[nando]

the only thing left that im wondering about is the front suspension's camber curve and how much of a penalisation it takes with lowering.

it really doesn't, unless you're dragging on the ground. as long as the angle between the strut and the control arm is less than 90 degrees, the camber curve is fine. Bump steer on the other hand...

Jay, I've seen a couple pics of a custom GC plate for the ix - looked like it added quite a bit of stack height though, or am I mistaken? maybe it was just a RWD plate adapted to the ix?

[Hellabad]

it really doesn't, unless you're dragging on the ground. as long as the angle between the strut and the control arm is less than 90 degrees, the camber curve is fine. Bump steer on the other hand...

Jay, I've seen a couple pics of a custom GC plate for the ix - looked like it added quite a bit of stack height though, or am I mistaken? maybe it was just a RWD plate adapted to the ix?

There is really no such thing as "stack height". It is a misleading term. You are referring to what I would call "thickness" which is more accurate and offers a more truthful comparison.

The 325ix camber plates I have made are thick, no way around it for now, but have always been used with short struts or on a rally car.


jay

[guibo09]

jay, i neglected to include the bump stop in my discussion, and thats where your clarifications differentiate between overall suspension travel and range. EDIT: rereading i also see that are definitions are different, mine includes bump + droop, yours only bump travel.

also, assuming you keep the same spring to damper mounting (camber plate for OEM strut/coil), then camber plates dont change the suspension range or travel. but as i see from your camber plate designs, you do play with that and thats how you get some of the extra travel even with stock spring/damper?

i had seen GC camber plates for the impreza back whne i had one, and it's probably the only design that keeps the limited suspension travel of the impreza. the only way to accomplish that seems to be by mounting the camber plate on the top of the tower instead of below. i was impressed that GC went through the trouble and added complexity to accomplish that all important goal. well now that i think of it, racecomp does accomplish it also with a dished plate, but that brings adjustment limitations.

can you explain to me the differences between RWD and AWD with regards to the camber plates? i think im missing something, cuz i dont see why they cant be made similar.

im asking about camber curves because the impreza's camber curve went to shit after very moderate lowering. a camber plate with the camber set to max aids the situation by increasing the SRI angle, but it's still problematic on the impreza. how does the e30 compare?

you mention that the camber curve is better in the rear on the e30, same is true for the impreza. so why not worry even more about keeping a good camber curve in the front? i know my impreza handled much better at a higher ride height than it did lowered, some of it due to suspension travel, some of it due to improve camber characteristics.

and finally, why is camber curving with macpherson just talk?

[nando]

the ix uses an inverted bearing (sits above the strut tower) to maximize travel, RWD E30s have the bearing under the strut tower, which is why camber plates for RWD cars can be made much shorter. The ix is more troublesome because you would have to design something with an inverted bearing just to keep the stock travel, adapting a RWD plate will always add to the height of the bearing. I don't know how similar subarus are but I'm sure the situation is close.

[Hellabad]

and finally, why is camber curving with macpherson just talk?

Because everybody talks about it, but nobody ever does anything about it. Just like talking about picking up Vida Guerra at The Club. We all talk about but nobody does anything about it.

BTW, I will be happy to answer your WRX questions here. We have some sharp Subaru experts here, who would rather walk into a hornets nest than jump in a Subie Forum and get zzyzzyx'ed in the ass.

Gimme an hour or so.

jay

[guibo09]

the ix uses an inverted bearing (sits above the strut tower) to maximize travel, RWD E30s have the bearing under the strut tower, which is why camber plates for RWD cars can be made much shorter. The ix is more troublesome because you would have to design something with an inverted bearing just to keep the stock travel, adapting a RWD plate will always add to the height of the bearing. I don't know how similar subarus are but I'm sure the situation is close.

it's the same problem with subarus, the bearing sits above the strut tower line. so traditional camber plates mounted from beneath sacrifice travel. im theory, the same solution GC used for imprezas should work for the IX.

overall, in stock form, which has more suspension travel (total bump+droop no bump stop) between the IX and the RWD? i assume the IX has to make the major bump travel sacrifice at the knuckle where it has to pass an axle (same as the impreza).

i need to spend more time staring at the suspension setup on the e30.

[Hellabad]

the ix uses an inverted bearing (sits above the strut tower) to maximize travel, RWD E30s have the bearing under the strut tower, which is why camber plates for RWD cars can be made much shorter. The ix is more troublesome because you would have to design something with an inverted bearing just to keep the stock travel, adapting a RWD plate will always add to the height of the bearing. I don't know how similar subarus are but I'm sure the situation is close.

The actual biggest -design- problem is the "ring" around the 325ix strut tower. They put this here instead of adding sheetmetal like the rest of the civilized world. This ring gets in the way of doing a top mount camber plate to get extra travel (or keep what you have).

So you have to build, like you said, an inverted one, But now the OTHER ridge underneath makes it hard to slide for camber and pretty soon you get frustrated, and it ends up sitting on the fabrication table and you are looking on the internet for pictures of Vida Guerra.

jay

[nando]

it's the same problem with subarus, the bearing sits above the strut tower line. so traditional camber plates mounted from beneath sacrifice travel. im theory, the same solution GC used for imprezas should work for the IX.

overall, in stock form, which has more suspension travel (total bump+droop no bump stop) between the IX and the RWD? i assume the IX has to make the major bump travel sacrifice at the knuckle where it has to pass an axle (same as the impreza).

i need to spend more time staring at the suspension setup on the e30.

yes, the RWD car has much more front travel, even with a longer strut tube - it's just as you said, the ix sacrifices a lot for the axle to pass through.

[guibo09]

yes, the RWD car has much more front travel, even with a longer strut tube - it's just as you said, the ix sacrifices a lot for the axle to pass through.

im looking at google pictures, and correct me if im wrong; but on the RWD front knuckle, are both the wheel center and lower strut offset from the virtual upper strut bearing to lower ball-joint rotation axis?

seems like that would add some scrubbing to the tire beyond the traditional wheel offset scrub. as well as add side loads and friction to the strut movement.

do these offsets have technical names?

[nando]

The actual biggest -design- problem is the "ring" around the 325ix strut tower. They put this here instead of adding sheetmetal like the rest of the civilized world. This ring gets in the way of doing a top mount camber plate to get extra travel (or keep what you have).

So you have to build, like you said, an inverted one, But now the OTHER ridge underneath makes it hard to slide for camber and pretty soon you get frustrated, and it ends up sitting on the fabrication table and you are looking on the internet for pictures of Vida Guerra.

jay

by the ring, you mean the ~1/4" ridge of material on top of the strut tower sheet metal right? whats on the bottom? I don't remember much being underneath, looked pretty flat to me. I should hack the strut towers out of my parts ix for testing..

[Hellabad]

jay, i neglected to include the bump stop in my discussion, and thats where your clarifications differentiate between overall suspension travel and range. EDIT: rereading i also see that are definitions are different, mine includes bump + droop, yours only bump travel.

Exactly. And the reason for the semantics is just simplicity and tradition.

Road race cars: "travel" means how far from ride height to bump stop.
Jeeps: "travel" means how far from ride height to metal.
Off road: "travel" means all the way up to all the way down.
Mt bikes: "travel" means how far from all the way down to all the way up. and travel means stroke, and sag means preload and droop means travel.

also, assuming you keep the same spring to damper mounting (camber plate for OEM strut/coil), then camber plates dont change the suspension range or travel. but as i see from your camber plate designs, you do play with that and thats how you get some of the extra travel even with stock spring/damper?

exactly. The e30 has more room to play with than most cars too.

i had seen GC camber plates for the impreza back whne i had one, and it's probably the only design that keeps the limited suspension travel of the impreza. the only way to accomplish that seems to be by mounting the camber plate on the top of the tower instead of below. i was impressed that GC went through the trouble and added complexity to accomplish that all important goal. well now that i think of it, racecomp does accomplish it also with a dished plate, but that brings adjustment limitations.

yes, exactly.

Can you explain to me the differences between RWD and AWD with regards to the camber plates? i think im missing something, cuz i dont see why they cant be made similar.

Because the axle goes under the strut, on a WRX or a 325ix, the strut is ALREADY very short, so it is difficult to do the "short strut" trick, so you need to be extra clever with the camber plates.

im asking about camber curves because the impreza's camber curve went to shit after very moderate lowering. a camber plate with the camber set to max aids the situation by increasing the SRI angle, but it's still problematic on the impreza. how does the e30 compare?

you mention that the camber curve is better in the rear on the e30,

on the e30, it might be better to say the rear camber curve is dominant.

same is true for the impreza. so why not worry even more about keeping a good camber curve in the front?

You just can't do much about it. The wrx has a bolt on spindle that we mess with, and is allowed in the rules, but the e30 is welded.

i know my impreza handled much better at a higher ride height than it did lowered, some of it due to suspension travel, some of it due to improve camber characteristics.

I'd bet 99% was keeping it off the bumpstops. The front strut angle on a WRX is like 21 deg, so I don't consider the camber curve is ever actually "bad", (compared to others especially).

and finally, why is camber curving with macpherson just talk?

...already answered with gratuitous Vida Guerra reference.


Jay

[guibo09]

You just can't do much about it. The wrx has a bolt on spindle that we mess with, and is allowed in the rules, but the e30 is welded.


I'd bet 99% was keeping it off the bumpstops. The front strut angle on a WRX is like 21 deg, so I don't consider the camber curve is ever actually "bad", (compared to others especially).

i thought it was 14.5 deg, from memory. the software analysis i ran showed that even with only 1-2 inches of lowering, the linear camber curve became very unlinear and poor.

anyway, i know in theory there is an improvement possible messing with the camber curves on an impreza, but maybe in pratice you are right. however i hope not, i spent the last year of my bac redesigning the knuckle of the impreza to improve both the camber curve and the roll center (the other thing that goes to shit with lowering) for a circuit racing STi. the result was quite beautiful (fully modular, aluminium knuckle). however, it has only been fitted to the car and is yet to be track tested.