Need some Help with alignment...New Kmember and BMR A-arms

As your prolly reading thing, i am installing my new BMR k member and Lower A-arms. Im gunna need an alignment obviously...

My question is, what do the adjustments on the A-arms let me do?

From a lil research i found that i should be trying to get"
0 toe in
close to -2 camber???? what does this do?
caster???? dunno either

Car has some 315s on the back so it likes to understeer...mostly used for street and autoX.

Thanks

The new A-arms give you more adjustment than the stock setup.

Toe - I prefer a little toe in for a more on center feel while driving. Currently I have 0.08* positive (toe in)

Camber - Negative camber is where the top of the tire is leaning in a bit. This helps keep the tire more square to the road while cornering. 2* negative camber is great just be aware that this will wear the inside edges of your tires.

Caster - I currently run 4.5* positive caster and would like a little more but my stock adjusters are maxed out. As you start running higher caster it will put a strain on your power steering pump.

I haven't seem the BMR lower a-arms. If they are anything like the G2's, they widen your front track allowing you to get more negative camber without lowering. If you're concerned about being in a certain class, I've read that these may bump you into a ESP/CP SCCA class.

Some like just a hair (1/32") toe-out when auto-xing. Others like to leave it at 0 or just a bit of toe-in for daily driving. I personally prefer 0 toe because I feel it's more balanced that way. I don't mind wrestling with the steering wheel due to road crown.

Like Jeff stated, you want your tire to be flat on the road during cornering. The easiest way to test for this is with a pyrometer. The cooler sections of the rubber aren't doing enough work, so you'd want to tilt the tire a bit towards the cool side until they are even, for instance. Tire pressure plays a role in this equation also. -2 is pretty harsh for a street car unless you religiously rotate tires at least once a month or have a fat wallet, imho. I wouldn't go higher than -1 for a daily driver, and perhaps have it changed just for events.

Caster offers a self-centering effect with a higher positive number. Above 4.5-5.0 can cause the power steering to be unnecessarily overworked. Seems like the majority of F-body auto-x'ers run 4.25 <-> 5.00 of positive caster.

From Performance Handling, by Don Alexander:

Corner entry understeer -
1) Front shocks too soft in bump resistance
2) Too much front toe-in; use a small amount of front toe-out
3) Ride height is too high in front

Corner exit understeer -
1) Rear shocks are too soft in bump
2) Front shocks are too stiff in rebound

Steady state understeer in all turns or low-speed turns only -
1) If front tire temps are optimum and rears are low, stiffen rear antiroll bar; if front temps too hot, soften front (most likely)
2) If front tire temps are optimum, decrease rear tire pressure. Increase if chunking occurs.
3) Improper front camber
4) Too much body roll at front, causing excessive camber change

Steady state understeer in high-speed turns only -
1) If front tire temps are OK, increase front downforce
2) If front tire temps too hot, reduce rear downforce

Your gonna need to take it to a shop....trust me...the adjustment on these things are very hard to get bang on...I eyeballed mine then towed it to a shop...had it done and still it's not perfect...good luck

One more thing...what shocks and springs are you running? Remember the lower a-arms have a 1" drop...so if you have a lowering kit...that arm will rub your disk...

Wait...the BMR a-arms lower the front?? Didn't know this... I am running bistiens and prokit. I was planning on switching to a groundcontrol coil over kit soon when i get some more $$$

I am aware this will bump me up some classes in autoX...but oh well, am having fun and HA...and reach my valve cover from the bottom of the car :D

There a company in texas called brake check thats has life time alignments, so i will be driving it all crosseye over there....

I am always amazed by the wealth of knownlage here(although i cant spell). thanks everybody

I just got some Ground Control coilovers from Sam Strano for up front - unless I have totally misunderstood something, you use these with your Bilsteins up front. They were not incredibly expensive - good news! He also gave Bilstein some specs to revalve my front Bilsteins.

Originally posted by camarossguy2
Wait...the BMR a-arms lower the front?? Didn't know this... I am running bistiens and prokit. I was planning on switching to a groundcontrol coil over kit soon when i get some more $$$

I am aware this will bump me up some classes in autoX...but oh well, am having fun and HA...and reach my valve cover from the bottom of the car :D

There a company in texas called brake check thats has life time alignments, so i will be driving it all crosseye over there....

I am always amazed by the wealth of knownlage here(although i cant spell). thanks everybody


That's funny....I'm glad I told you...I had to grind down my lower arms to work with the pro-kit...but after all that my tranny pan and headers were 3 inches from the ground...that don't work for me. So I sold my pro-kit and got Hal's...buy far the best setup IMO. BMR fails to mention this on there website....I bet alot of people made this mistake...

The BMR LCAs lower the front? How come nobody has ever mentioned this before? You think with all the people that have these things that somebody would have mentioned this if it were true.

-Chris

Originally posted by Chrisbequick
The BMR LCAs lower the front? How come nobody has ever mentioned this before? You think with all the people that have these things that somebody would have mentioned this if it were true.

-Chris


Trust me...it does...I was very pissed off when I found this out after I ground down my arms. Have a look at the stockers and the BMR...see the difference.

...mind you I have the biggest baddest rortors you can buy for an f-body so...you maybe very close with the stock rotors...but really...check it before you drive...I also took a gash out of my Baer's :mad:

Im really confused...

Chrisbequick talking about LCAs, sleeperZragtop saying that the arms lower the front 1 inch whitch is believeable although i haven't check....but what are you talking about brakes and having to grind stuff down??? lost me there plz explain thankx

Originally posted by camarossguy2
Im really confused...

Chrisbequick talking about LCAs, sleeperZragtop saying that the arms lower the front 1 inch whitch is believeable although i haven't check....but what are you talking about brakes and having to grind stuff down??? lost me there plz explain thankx


:o Sorry....when I finished rebuilding my front suspension with BMR stuff...it was ready to so I took her off the stands and started to drive...a bad ass grinding noise was going on so I pulled back into the garage and looked to see what the grinding was...the lower a-arm was rubbing against my brand new Baer brakes...not happy at this point. So I got the car towed to a shop to get aglinement done thinking my camber was screwed...after all that..still rubbing...I wanted to drive the car so bad so we ground down part of the lower control a-arm...down near the lower ball joint...it was fine. I drove away....I called Mike at Stealth saying WTF...he asked what springs I'm running...I told him the pro-kit with Billsteins....oh no he said....so you see the total drop with the pro-kit and BMR arms were 2.7 inchs...way too much. So now I bought a new set of arms and the Hal's and now I have a nice drop of 1.7 inches...perfect. I also had 1.25 inch thick brake rotors which may have played a major part in this..so I'm not sure with stockers...just make sure you check very carefully


Good luck :)