Looking for some inside secrets, black magic, motorhead mojo, on front end camber. I know our cars are a mixed bag in terms of what you can get in front. My '73 with the GPR/tarrott camber plates can get 2.4 neg on one side, only 1.8 on the other. The chassis measures out fine, no tweekage. It'd by nice to be able to equalize them both at around 2.5, or better still, 3.0, but how. I have no interest in taking this car to autocross nationals or get into hard core scca auto x stuff, just want to putter around and make a better local car, so bending the rules a little doesn't scare me, depending on how far the bend is.

So what do you all have, and how'd you get it?

Anyone use an aftermarket bolt on camberplate like all the little ricer guys run? I've never seen one for our cars, but they don't look hard to make. I was wondering if one could be designed to hold the top strut bearing up over the plate, thus allowing: 1) a little more strut travel on lowered cars, and 2) if the bearing is up over the adjustable top plate, the strut could maybe "tip" more to the inside, as the slim diameter of the strut rod would be smaller than the bearing or strut tube, and could be tilted in, closer to the edge of the factory hole.

I'm picturing something like this: http://cgi.ebay.com/ebaymotors/Steeda-Cast...1QQcmdZViewItem

i got -3.2 LF and -3.5 RF when i had my car. could have used more. had to grind the strut mounting slots out, and had to slice the side of the strut plates off a fair amount. i actually didn't worry about getting them equal side to side. castor (and toe, obviously) is more important to have have equal, imho. my RF would lock up slightly before my LF, but most of our turns in NorCal are left.

this was on a lowered car, but it still had some good suspension travel left. (A arms parallel to ground). narrow bodied, 205/50's on 6.5" wide wheels.

they make camber plates (weltmeister, elephant, and others), but I prefered to just modify the stock ones. I also replaced the upper busings with monoballs.

oh, also look for the elephant decambered balljoints if you don't want to grind (check your rulebook).

i'm going back to 0 (yes, zero) camber front and rear.

them schlicks don't like negative camber ...
Andy

Actually slicks like enough camber be it positive or negative to keep the tread temperatures equal across the face.
Depending on your suspension and the amount of suspension travel you have will determine how much negative or positive camber you need.
The only way you will find the optimum camber settings is to take lots of tire temps.
make adjustments and take more temps until the temps are equal across the tire face.

Not running slicks (yet) so thats not a factor in the set up.

Saw those elephant decambered ball joints, but whoa, they don't give those away, do they...

I might look a little harder into more aggressive grinding of the camber plates I now have, or maybe selling them and hacking up the stock plates.

Nebreitling- did you get all that camber w/out missing w/the center holes? You say you had to cut the sides of the plates off a fair amount- how about the center of the plate, where your upper bushing mounts, need to grind/modify that at all? Any pics?

[
Actually slicks like enough camber be it positive or negative to keep the tread temperatures equal across the face.
Depending on your suspension and the amount of suspension travel you have will determine how much negative or positive camber you need.
The only way you will find the optimum camber settings is to take lots of tire temps.
make adjustments and take more temps until the temps are equal across the tire face.
[/quote]

EXACTLY!!!!!!!!!!!!!
I am running -.5 up front and was running .-7 out back but may be less now that I upped the rear spring by another 100 pounds.

I use my tire pyrometer alot. Sometimes ask my competition if they would like to know what they got. Pretty interesting data.

OK back on topic. When I ran DOT-R tires I was able to get -2.8 on each side. by slotting holes and using Weltmiester camber plates and removing the cover from the shock piston. After -2 degrees it starts to hit the inner fender. Ride hieght is a big player in the amount of camber. might want to set your ride hieght dead nuts even all around then mess with camber.
If you have stock sway bars or stock torsion bars you probably have enough body roll that you are going to positive camber in a corner anyway.

I gotta get me some of that neg camber. I've only got -1.5 in the front! Has anyone modified the lower a-arms to get more camber? Seems like a little extra length would add some track width and camber.

yes. but they generally don't like a very agressive setting like the ones suggested above.
i'm running -0.7 left/right right now and them schlicks only use the inner half of the patch.
tire-temps tell the same story.

regardless of your suspension setup, there is a certain range where your tire will work best,
and the goodyear R250 seem to like to be run with very little to no neg. camber.

brad told me -0.7 would be too much and he was right ...
Andy

Dude, good info!
Just to clarify, you are talkin about the "dust cover" that stays put up on top above the strut housing, right?
If you are still drivin all the time to races w/o the dust covers, it can't be too bad to remove them. I left them on thinkin that grime and stuff might harm my new KONIs, which cost more than my entire engine.

Otto or Bill - I have an extra set of stock camber plates (and struts, calipers...) that you could play with if you feel like. My alignment is being pushed back to August due to other delays

I'm also using the tarrett camber plate and got about 2.1 on each side. When I first put these in several years ago I thought it would improve grip a lot (I also did camber on rear) but for someone of my (lack of) skill it was not noticeable. But at least with victoracers I had then, the wear was much more even and helped them last longer.

Pull the 1.8 leg out, take out the insert, put in vise and heat and bend. You can calculate how much to give the same as the other side with the camber plate in the same position.

Yes you have a point about the shock covers up front. But I argue the point of not having shock covers on the rear.

HMMMM, kinda makes you wonder huh?

BTW I bought some spiffy covers to go over my new AFCO coil-overs. Nylon cover with velcro fasteners. But then again my coil-overs are inverted. (piston down).

Mr Man- I've heard of this, but can it really work? Would heating up the body of the shock cause problems with the oil/gas inside the shock? And wouldn't this just angle the rod up thru the threaded collar that secures the shock into the housing? Do you need to hog out the hole in the collar so the rod can come out at an angle of other than 90 degrees? I think I need a little more explaination on this one.

Ah DUMan: I'm afraid I don't understand what part you're bending. Are you bending the axle? If you bend the strut then the insert won't go back in.

A little more explanation for the mentally challenged please.

The further detail:

1 Remove the strut insert from the leg by undoing the round gland nut on the top.
2 Remove the brake caliper and hub.
3 Mount in vise by the leg below stub axle.
4 Heat the leg just above the stub axle, or as close to it as you can.
5 Put a big long tube over the top of the leg and heave gently. You need a fair bit of heat.
6 My recollection is if you move the leg by 2.6 mm measured 300mm above the stub axle that equates to approx 1 degree. You can measure it by clamping a straight edge on the caliper mount.
7 If using leg in race car its a good idea to gusset leg to stub axle so that it doesn't unbend.
8 Don't bend it too far without checking that the insert goes back in. There is a few mm clearance between the side of the insert and the inner wall of the leg.
9 Paint and re-install in car.

This was done to Boge 911 legs and it works.

Cheers,

It's been a while since I put my konis in the struts, but IIRC they were a pretty snug fit. I would think that bending the strut tube would make assembly almost impossible.

i believe i do remember enlarging the "center hole" area. DID have to remove dust covers. once you have it apart and start grinding things out with a die grinder, you'll figure it out.

I should have mentioned that the inserts are Koni yellows, and there is enough clearance with the inner wall to get a couple of degrees. The insert is located only at the bottom of the leg and by the nut at the top.

OK that splains it! I'll have to give it a try.

By all means, get more negative camber. Brad Roberts says good drivers use lots of negative camber so if you wanna be thought of as good, get -3/-4. You may wear out the iinside edges of your tires quickly, but you'll look cool doing it.

As long as I look cool doing it that's all that matters! Actually I'd like to like good on the results page too. I remember Brad's posts about the euro drivers using so much camber and going so fast. Gotta be the way to go!

A recent copy of Grassroots Motorsports profiles a 240sx champion that is running 4.5* neg up front. And Nathan did very well when he was running his teener. I had no idea he was running so much neg camber. The way I see it, the more body roll you have the more neg camber you have to put in to get the tire upright in the corner. Of course, all of this seems to go out the window when you start talking about bias ply slicks.

OK JP, what you running and how'd you get there?

run whatever you need to go fast, regardless of what JP or Brad or anyone says (actually, that's exactly what Brad is saying). for me (running hoosiers/710's), this was -3.5~ish. was about to go for more, but I sold the car. tire temps, wear, and timeslips will always reveal the truth.

yeah, I think of myself as good. not because of freakin' camber.

I run -.5 at both ends and that's too much up front...meaningless for guys running R spec tiars. When I ran Rspecs I used right around -2 which gave good temps across the face & a good wear pattern.

As to "good", competition reveals the truth. For me, top 5 at PCA = top 20 at SCCA......sometimes better, seldom worse. Britian (my co-driver) does considerably better, so I know my place in the pecking order.

BTW:
I'm off tonight for Packwood WA & a NW Region SCCA AX tomorrow. I've never run with these guys before and looking over the pre-reg. (177 entered thus far) there are some well known names coming....class ass kickers at the Nats. I'd prolly better find some pillows
to stick on my backside cause it's gonna get kicked a lot

Ah well, you can't make an omlet without breaking a few eggs.

Good luck JP. sounds like Packwood is where the big fish swim in the deep end.

un-like the local stuff where only a few regulars show up and nobody upsets the tea cart.

I like going to other regions and never say nothing to anyone. Just be cool get set up and walk te course. help out if needed. then Let the time slip stand.

Next event I bring all my cajon friends and we put a whoopin out.

Then buy a round of beer at dinner. answer all the question about the car. like is that a 6?

So, seems for DOT R's, more camber is more better. For the schlick guys, less gets the job done.

For us DOT guys. anyone got pics of what they had to do to get what they got? I'd be interested to see some of the grinding and such needed to take a factory camber plate and modify it to hit 3 degrees or so.

This picture show would be interesting. Who wants to show thier cards at the poker table? Some people have to run under the rules of thier sanctioning body for the events.
I'm not taking pics. However I am totally legal in X prepared SCCA. You would really not be able to tell anyway unless you had a stock car and a measuring tape.

What I don't like is people doing this shock tower mod and then claiming stock class eligibility

Up to a point... Check the latest issue of Grassroots Motorsports, they do some testing with a MINI Cooper. Their lap times drop from -1 to -3 camber, then when they go to -3.5, they have real problems putting the power down and braking. (Actually, those problems were cropping up earlier, but the gains in mid-corner speed more than offset the losses from those.)

More static negative camber means less tire on the road when the car is going straight. Therefore, less traction for braking and accelerating. So at a certain point you are trading off traction in the corners for traction braking and accelerating.

Alignment setup is always a series of compromises...

--DD

Hi Dave!

I saw that article. They were running on a mini road course, Streets of Willow Springs, where I believe braking effort is a more important factor than on an AX course. Though I've never seen the "Streets". I make changes from one event to the next and analyze how the car feels and see how I'm doing in the overall rankings of the competitors. It's just smart to see what others are doing and what works for them. I guess it's just about time to pick a pyrometer.

I've been running a rear sway bar and as of late been having a problem getting the power down on corner exit. I just like the idea of having a rear bar cause that's what race cars have and I put a fair amount of time into mounting it!! Next AX I'm going to run make a couple runs and then disconnect it and see how it feels.

I use brakes a lot and hard at AX. Your HP may differ.

There were a fair passel of big dogs there....not like a Tour event, but a good
crosssection Brit got all but 2 I think. I sucked as usual.....but I got the tiars hot.

Bout 170 drivers.

That was my job last year. "tire warmer for my own car".

It is time for me to put on a pair of big boy pants and drive the car fast myself.

I am holding auditions for a tire warmer for this winter and ramp up for the Early tours next year.

Static negative camber is essential for a strut car on radial tires. Critical even. The strut will decamber as the body of the car rolls. But it's a compromise. The more camber you dial in, the more tire you're likely to have on the ground in the turn (to a point), but the less tire you'll have for braking and acceleration.

The stiffer the roll rate of the car is, the less this decambering effect is. In some cases, a monster front sway bar can actually reduce understeer by helping keep the front wheels from decambering. The 914 is not an extreme example of this however. A VW Gti though... MONGO front sway bar will actually help reduce understeer.

SLA suspensions really minimize that, and radial shod cars can get away with less static negative camber.

Then up front, there's caster... Caster is good, more is better. And, up to a point, giving up a little static camber for more caster is a deal worth making. Caster is -dynamic- camber. The more you turn the wheel, the more camber gain you get.

Bias ply (slicks) shod cars, that another story. The relatively soft tread face of the bias ply tire allows the contact patch to move with the shifting loads. And the more rigid sidewall, prevents the tread face from rolling away from the ground. And cars with these tires can take advantage of less camber than their radial shod cousins...

A setup that's good for slicks is definitely NOT good for radials, and vice versa.

-Josh2

Holy crap Josh you been peeking in my race car books?
I like JP's idea of Cantilevered slicks in front and regular slicks on the rear.

Odd, I checked my front camber as I pushed it to the bump stop. It gained negative camber all the way....maybe sumthins' bent. This pic isn't quite all the way, but the angle on the tire is more revealing.

Body roll, we got some.

I think you are overstating the effect on camber of a strut suspension or taking something out of context. Also, caster adds camber to the outside wheel as one turns which is why AXers run as much caster as they can get.
I may be fulla shit, but pics don't lie.

Then again, I read your post more carefully and find we agree....put it down as a senior moment.....my work here is done.

Of course you gained camber. Just follow the geometry. As the a-arm rotates upwards, the hub goes with it, and as it pivots up, gains negative camber.



It's not just the suspension movement to consider. As the body of the car rolls, the strut top moves with it, and because the strut is directly coupled to the a-arm, if there's body roll, the strut will loose some negative camber. In some cars, this is really severe. In other car, not as big a deal.



You betcha!!!



Yes sir... I think it's time for...

-Josh2

Well, strut suspensions usually gain positive camber when they get up toward the bump stops. Have you done anything unusual with your fronts? Raised spindles, perhaps?

When the A-arm goes upward past level, the horizontal component of its length starts shrinking. That effectively pulls the bottom of the tire inward a bit, which gives you more positive camber than you have when the A-arm is completely parallel to the road. If you start with your A-arms pointing downward, then you gain negative camber up until the arm is parallel to the road.

Unless the A-arm is very short indeed, the effect is generally fairly small. With more sophisticated suspension designs (multi-link, SLA, double wishbone, etc.) you can get the tire to gain quite a lot more negative camber in bump.

--DD

Chuck Moreland (of Elephant Racing) posted a very good observation on the Bird Racing forum. The key being that it's the angle of the A-arm with the struts that induces the camber change, and that the struts are something like 15 degrees tilted out! So you will keep gaining negative camber until the A-arms are ~.15 degrees up. But the gain is larger when the arms are down further, so it's still not a bad idea to have the arms tilted downward.

If Chuck OK's it, I will post his note on the subject.

--DD

Chuck assented, so here is his reply on the Bird board:



--DD

Dave:
I agree that you get camber with suspension travel, but it's not that much. My rough analysis show that 3 degrees of body roll will give the outside tire 2.5 degrees of positive camber if it started with 0*. So if I start with 2.5* neg and the suspension travel gives me .5* then the wheel will be upright when the body rolls 3*. Obviously more body roll will need more camber to start with. Some AX photos have shown that my car some others have about 3* body roll in some of the tighter corners.

OK, now drop your car into the weeds so that the A-arm points upward slightly toward the outside. You're going to gain even less camber that way than if your car were higher off the ground. (Trade-off: Your car will tend to lean less because of the lower CG.) So you may need more static negative camber to counteract the body lean.

If you can lower the car's CG without shrinking the amount of negative camber gain, you sort of get the best of both worlds: You get reduced body lean and you get a little more negative camber when you do lean. That's one of the many joys of raised spindles...

--DD

My first attempt to get more negative...my wife says I'm always too negative.

Just poured these yesterday, gotta wait for em to cure up gud.

Chris, thanks for the support plates!

Can't wait to hear how they work out!

-Josh2

Ok so I must have a mental block. if you lower the car to the point where the control arms point up then how do you prevent the shock from bottoming out.

The same thing with raising the spindles the length of the spindle never changed just the hieght of the upper shock mount and the whole car for that matter is lower. What kind of suspension travel is left.

That looks interesting. What exactally have you got going on there?

How plyable is that stuff you poured?
Just asking because if it sets up solid as a rock then you will chance bending your shock piston rod.

If it is too plyable then why bother it will allow the alignment settings to go EVERYWHERE.

I popped out the stock bushing/rubber grommet and removed the rubber. I then positioned the bushing to the side of the support plate and poured rtv around it to hold it in place. It should be about 80 durometer when fully cured. that stuff was expensive..$54/lb!! not available at Home Depot!

I'm not an expert, but I think that stuff is just gonna separate from the metal as soon as you apply a load. The original bushings are done like the trailing arm bushings, vulcanized.

Still, if it works, might be pretty nifty.

-Josh2

We use this stuff called "chock fast"
More on the line of what Josh is talking about.

I would be scared to try the RTV thing unless you did a destructive test on one 1st.
Like what does it take to push/pull/twist that stuff out. If after an hour of beating on it and you can't get it out then make a new one and put them in the car and take the front hood off. go to a parking lot and thrash it. If it stays put then it is maybe OK.

The RTV thing is a two component polyurethane that cures to about 80 durometer, very similar to the stuff they use for suspension bushings. I used the stuff years ago, it's great stuff!! I'm not worried. I got them installed today and got a little over 2.5* negative. Haven't driven it yet, gotta an AX Sunday!