matefis

Hello,

I just finished installation of tubular front and rear end conversion from BMR (level 2). I got 2" lowering springs with it while I used OE lenght of spindle (spindle is new). The issue is that now, when everything assembled, the car has quite a lot of negative camber with no shims installed. Would you guys recommend an offset cross shaft (global west/moog) or longer springs?

PS.: Right now I have 350 in there but would like to go with 455 down the road. According to BMR these spri g should handle the extra weight of the big block. But who knows.

Thanks in advance for your advice.

Matt

Thanks

oldcutlass

It depends on how much negative camber you have.

matefis

I would say that quite a lot.

RetroRanger

hey Matt
i cant comment on your camber situation other than to wonder is there a rule of thumb for how many shims is the limit (you do have a lot of - camber showing)

i can comment on the 350 and 455 weight about 50 lbs different. if you put and aluminum intake on the 455 there is only 25lbs difference.

70Rocket

Call BMR tech support. They are very good about providing assistance. I am not sure who you should ask to speak with. If this was a Ford S-197 or S550 chassis, you would want to speak with Kelly Aiken.

Check the upper A-arm crossshaft. I think they are machined with an offset in them already. If so, you may need to simply unbolt the arm, rotate the shaft 180 degrees, and bolt it back together. There is mention of the shaft being offset to allow for aggressive camber settings for race and pro touring cars.

If this was a road race or auto cross car, I don’t see an issue with what you have pictured. With sticky tires, I would start out at around -3.0 camber for a track car. For a street car, I would set it between -1.0 to -1.5 camber and around 6 degrees positive caster with a 1/16 inch total toe in or possibly 0 toe. But, that’s more negative camber than what a lot of the baseline street alignments for these kits say. That’s most likely because they are worried about tire wear.

oldcutlass

Call TC at BMR
contact TC @ 813-986-9302
tc@bmrsuspension.com

matefis

Thanks, I found the dual setting yesterday while having a loong look at it, I'll definitely flip the cross shaft first. Little septic though that it will give me enough camber to get at least to 0.

joe_padavano

I am not familiar with the BMR suspension. Are their upper arms designed for stock height spindles or tall spindles? The tall spindles require shortened upper arms that would cause your camber problem with stock height spindles.

matefis

They are claiming that this set should work with both standard and 2" drop spindles. I am gonna flip the cross shaft and I already ordered 1" drop springs (BMR). Hope this two things will solve the issue for good.

joe_padavano

Lowering springs will cause the arms to be at a different place on the camber curve when at nominal ride height, which is why drop spindles are a better choice.

matefis

Joe, yeah I realized that too late. 1"in drop is in my case 1" rise as the photos show my car with 2" drop coil springs. I hope that in combination with the large/deeper offset cross shaft settings it will get me to correct camber. I was also considering sring spacers but didn't like it much. What's the best in your opinion? Spacers, drop spindle, longer coil or off set shaft? I really appreciaty this forum, always so many good lads chirping in trying to help!

70Rocket

BMR makes three different upper arms. One if for short OEM spindles or OEM type drop spindles. Another is for tall spindles. The third is for short OEM spindles but are designed around longer ball joints.

All three of the upper control arms are shorter than OEM. This increases negative camber. Combine this with an offset shaft, you can get what the OP has in the pictures above.

matefis

Never heard nor found different types of upper arms for A-body on their sites. Should have looked better. But anyway shouldn't offset shaft add camber? At least the BMR shafts are designed like that... they have two different depth of cut outs... hence pushing the swivel mount forwad creating "positive" camber. Also I installed the lower BMR arms with the uppers and BMR is claiming that in that combination you should get more than 4° of positive camber over the stock.... doesn't really sounds like to me. More like 4° negative.

70Rocket

Ignore the factory alignment specifications - they are not a good setting for any kind of a performance objective. They were designed around a bias ply tire and reducing steering effort with a manual steering gear.

You do not want 0 camber. That defeats the purpose of installing the arms. You are trying to add in more static negative camber to compensate for the poor OEM camber curve. BMR recommends -0.5 to -0.8 camber for a performance street setting. This is a pretty mild amount of camber. The car will handle better with more negative camber. I run -1.5 on my own car with no tire wear issues. I've run a little over -2.0 on other cars with no tire wear issues. Most modern performance cars have around -1.5 from the factory and may have a track supplement that goes as high as -3.0.

Before you start swapping springs, talk to BMR. They designed the kit as a system. Most likely they can talk you through getting the alignment specs where they need to be with the existing kit components. If the upper arm's ball joint is sitting above the horizontal plane, a taller spring might help reduce static negative camber. But, if the ball joint is at or below the horizontal, then a taller spring will induce more static negative camber and make your issue worse.

Check / verify that the arms arm are mounted on the correct side of the car. Both the upper and lower arms have relocated the ball joints to increase caster. Compared to OEM, the upper ball joint is pulled back toward the firewall and the lower ball joint is moved toward the front of the car. Combined, this is supposed to net an addition 4.0 of positive caster. You then use shims to try to get the caster to 6.0 or as high as you can if you can't get 6.

If you are going to swap any components, I would talk to BMR about a kit or upper arm with their taller ball joint. That would help address the poor factory camber curve and reduce bump steer with an OEM short spindle. I really do not understand why BMR isn't using their control arms with the extended height ball joints in these kits. They make an arm for them, so why not improve the camber curve as part of the kit?

70Rocket

The lower A arm is designed to increase positive caster by 2.0 degrees, not camber. The upper also adds in another 2.0 of positive caster, not camber. Together, they net an additional 4.0 positive camber without the use of shims. This is done by relocating the upper and lower ball joints.

The upper arm is shortened to increase static negative camber.

Depending on how the cross shaft is machined, it can either add static negative camber or reduce it. You want the machined part of the shaft positioned to move the upper arm and ball joint towards the outside of the car and away from the engine or car's center line. My assumption is that you currently have the machined surface oriented toward the center of the vehicle in such a way that it is adding additional negative camber.

You ultimately want negative camber, but probably not as much as what is in the photos. I would guess that you are somewhere at or above -2.0 degrees right now.

Have you set your toe? If not, you need to do that. Toe settings impact camber settings. Typically you have to check and adjust all of the alignment specs a couple of times because they all impact each other. You can rough in the toes using a couple of pieces of 2x4 lumber extending in front and behind each front tire as make shift toe plates. Then take your toe measurements using a couple of tape measures.

You need to roll the car backward and then forward each time you make a change to any of the alignment specs.

Kevin11

I have UMI uppers with tall upper ball joints combined with BMR 1" lowering springs. My UMI's have the offset cross shaft as well; I have mine set to the less-aggressive orientation and I'm currently sitting in a more street-friendly adjustment range...so 100%, I'd say you're definitely on the right path with flipping the cross shaft first.

I went from tired stock-height springs with blown shocks to BMR 1" lowering springs and Koni shocks; I haven't scraped my headers over highway bridge expansion joints like I used to (yet...knock on wood). Mine is a 350 with factory air. My only complaint is that the dampening could be a bit more aggressive. Or, I need less bulbous wheels/tires ("factory" size 225/70R14).

I'd second 70Rocket's comments, especially about target caster and camber, double/triple checking that the arms are on the correct side of the vehicle, and pursuing taller ball joints.

matefis

Thanks. I believe I installed both sides upper and lower arms correctly.... I double checked yesterday. I was also marking the arms when pulling theme out as well as I did left side first and then moved to the other. One more question though, do you think that the drop spindle would solve this?

70Rocket

No, drop spindles will not reduce the negative camber. Drop spindles move the wheel pin up higher on the spindle. This lowers the front of the car without impacting suspension travel. A drop spindle is still the same overall height and the ball joints are in the same location as OEM. Therefore, it does not change alignment specs.

Keep in mind, when your camber is where is should be, the tires are going to be tipped in at the top. Just not as much as they are now.

matefis

I am sorry but that's not how BMR cross shafts looks like. What you are describing is more like Global West offset shaft. What BMR has are two degrees of cut out hence you choose from +X° or +XY° but not -X° or +X° .

I haven't set my toe (except from eyeballing it) or aligned otherwise as I thought I should start with the camber and then bring it to closest service for proper alignment,

matefis

So are they adding caster or camber. I am sorry, I am getting lost. I believe you just made a typo and you are right about me being wrong thinking they are designed to add camber whey they are adding caster.

70Rocket

This is what -1.5 degrees looks like. Your not as far off as you think. Also, the pictures exaggerate the tire lean.

matefis

Great, thanks. That clears it up. No need to look into different spindles then.
I understand that there will be some negative camber. I just got spooked when I saw how much I got. To sum i up from what you're saying my best chances to fix the amount of neg camber are these:
1. Flipping the cross shaft to see if it helps a little (although I doubt it will add enough to sort the amount of negative camber I have)
2. Getting longer upper ball joint and maybe longer spring (I still do not want to give up on that one )
3. New (longer) upper arm

matefis

OK. This gives me little bit of hope that the cross shaft flip together with correct toe might really help.

70Rocket

Your missing the point. One orientation of the shaft will give you higher static negative camber. The other lower static negative camber - which is the same as adding in positive camber....the end result will probably still be a negative number because that is what the kit is designed to do.

Stop comparing this to your OEM setup and alignment. The kit is deliberately designed to deviate from OEM and induce negative camber. If that is not what you want, send it back to BMR and put you OEM pieces back on. But, if you want a better handling car, the tires are going to be tipped in at the top.

matefis

Oh, OK. I understand what you're saying. I can choose from negative or less negative. I do not mind negative camber though I just do not want this much.

matefis

So, I got in touch with TC from BMR, he was nice and willing to help, we were going back and forward foe last two weeks, yet we weren't able to find the culprit of my issue. He confirmed that all parts are correct as well as correctly installed. According to TC I am kinda left with the cross shaft "deeper" setting, although he states that it's not gonna do much. I also suggested him if the taller upper Ball Joint would help and he said that he does thinks so, but I wasn't able to get the reasoning behind this, could someone here help me explain why taller upper ball is not gonna help with the negative camber? BTW. we figured out that I already have 1inch drop coil springs installed.

Thanks

Matt

70Rocket

Have you flipped the cross shaft to the “deeper” setting? If not, do that before you start swapping parts. Also, set the toe - it impacts camber. Have you made any camber measurements or are you just going off how things Look?

To to figure out your issues, you need to start taking measurements. First, what is your camber, toe, and if you have turn plates at home, your caster? Don’t rely on your eyeballs, take the time to figure out your actual settings. It’s not that hard. With some straight edges, tape measures, and a basic angle finder you can do a decent job setting toe and measuring camber in you garage. Just make sure the floor is level and I’d it’s not take that into account when measuring camber.

A taller upper ball joint may help your issue, but it can also make it worse. To figure this out, you again have to measure things. Specifically the ball joint pivot point in relation to the pivot points on the frame mount / cross shaft.

The upper control arm is a fixed length. Because of this, the ball joint moves in an arch around the frame mounting points. If the ball joint pivot is lower than frame mounting point, as it moves upward in its arc it will reduce negative camber until the ball joint pivot is horizontal to the frame side pivot. Once the ball joint passes through the horizontal in its upward arc, it will begin to add negative camber.

You need to figure out if your current upper ball joint pivot point is below the the frame side pivot point at static ride height and by how much. If the ball joint is lower, then a taller ball joint will reduce negative camber provided it does not raise the pivot past the horizontal at static ride height.

matefis

Got it! Thanks. Yeah I am eyeballing most of it because the floor in my garage is far from level. As said above, I am trying to get to the point I am confident to take it for proper alignment to a shop around the corner... btw what shop would you guys recommend? Some of the big brands like Mavis or Goodyear or should I rather take it to small shop? I already asked around and not many of them has the alignment head that mounts by the rim anymore.... and with the current drop they are unable to mount the alignment heads that mount by tire without hitting the fender. I will be swapping the cross shaft in about two weeks when I get back home, that's already settled. If that does not help I'll figure out the pivot points and see if the longer BJ might help, if not I guess I'll have to go back to stock height coils springs and look into the longer BJ again.

Thanks for all your time and help. I appreciate it!

Battenrunner

We have the same BMR 2" drop springs on our 67 Cutlass. I will double check what settings we ended up with, but, our reasoning was more for street/strip and not so much for handling, as we have 15 x 5 inch Weld ProStar wheels on the front, so I don't want to push them too hard in corners and want as little drag as possible with the minimal toe in as well. We have factory A-arms with greasable poly bushings installed, a Z bar on the top with ProForged tall ball joints top and bottom.

We set ours with this longacre tool: http://www.longacreracing.com/produc...%84%a2-Adapter

matefis

Thanks for reaching out... May I ask what have you found?

matefis

After long tome out of home due to work related travels I had some time to flip the cross shaft and it helped. I reduced the negative camber a little, right now I am looking at somethin around -1.5 it's less than before, but still too much (BMR recommends - .75). I reached out to TC and asked if he thinks if spring space or longegr springs itself would help but without a reply so far. Hence my question is... do you think I should take it to the shop for alignment or should I look for the spacers and/or longer coils? If anyone has any experience with inserts fitting the BMR lower A arms I would love to hear about it as I am worried if the regular one will fir due to the locking tab that BMR uses. Thanks a lot!

oldcutlass

I think you need to take it to an alignment shop and see if it can be adjusted.

matefis

JUST FYI... car is aligned to BMR specs now. It took me to rotate the cross shaft to deeper setting and after discussion with TC addition of 1/2 inch thick rubber coil spring spacer from Global West. According to the tech it did not needed any shims at all.

oldcutlass

I find it hard to believe it didn’t take any shims. What alignment settings did the shop use?