: BMR Opinions



SS from the "Wood"
04-09-08, 05:47 PM
I've been considering acquiring some of the stiffening goodies from BMR, but have found some mixed reviews. I wanted to bring them to a new thread. I'm one of those conservative driver's that likes to "Cadillac" my Cadillac, but occasionally (more like daily) I believe it's necessary to feed a little speed into it! I just want to be as precautious as necessary.

I'm considering the anti-wheelhop kit, pinion support, and possibly the trailing arms. Could any of this be opted for in favor of the infamous Hotchkis sways? I do have future plans for a blower.

heavymetals
04-09-08, 07:56 PM
I have trailing arms and toe rods.

Pinion support? eh.

Anti-wheel hop? eh.

Blower? YES!!

Sways? yes.

vegasVowner
04-09-08, 10:56 PM
Pinion Support could bring extra noise into the cabin as it did for me. Its kind of annoying for the caddy/luxury experience part of the car. It's give and take for piece of mind I guess. Also, if the noise from the BMR PS isn't a problem for you, give the GM AWH spacers from the dealership a try. They're free and seem to be working for me so far. They're suppose to be too loud after a month or so of use, so I'll chime in later on that. New non-runflat tires should help with the wheel-hop too. Hope this helps.

1QUICKV
04-09-08, 11:48 PM
I have the pinion support, and at first it's different..... but i can live with the different feel. You forget about it after a while.... Why do you stay "eh" to the BMR Anti wheel hop bar?

heavymetals
04-09-08, 11:56 PM
I say "eh" to most of the wheel hop "fixes" because you really only need them when your pouring on enough power to break it loose and cause it.

If you modify your driving habits, it won't happen.

NO FLAME PLEASE :hide:

This is not to say that I am not extremly interested in the 09 retrofit.:D

vegasVowner
04-10-08, 08:09 AM
Is this 09 retrofit a definite, economically possible solution? That would be great if it comes to fruition. If not, there's gonna be a great aftermarket demand for something, anything better than stock. Especially since warranties are starting to expire.

cable
04-10-08, 01:14 PM
I have used the BMR pinion support and I would have to say after my catastrophic failure due to the pinion support being to ridged I will not use it again. My V went 57,000 and change without a leak, squeak, pop nothing. I then installed the BMR PS and the diff failed in 2 days!! I would strongly advise against it. There is a reason they dont use a solid mount on the front of that case, it has to absorb the deflection somewhere. I am now I'm going to just stiffen the rear end with solid washers (earlier thread) just like BMR does. But I am going to create my own tow rods and trailing arms with johnny joints instead of rubber bushings. I agree with Heavy Metals to an extent about changing your driving habits, but if you stiffen the rear end in the correct fashion you can "almost" eliminate wheel hop. Remeber BMR says there kit will "almost" eliminate wheel hop "up to 75%". Hope this helps.

heavymetals
04-10-08, 02:07 PM
The BMR trailing arms and toe-rods are a solid bearing (no rubber).

heavymetals
04-10-08, 02:10 PM
Is this 09 retrofit a definite, economically possible solution? That would be great if it comes to fruition. If not, there's gonna be a great aftermarket demand for something, anything better than stock. Especially since warranties are starting to expire.

Look at the old threads on this.

Kudos to Luke and Tony for pouring their efforts into it.

Hopefully the gas tank can be replaced by a couple of fuel cells or another tank with some more capacity.

AZ RAD
04-10-08, 04:19 PM
I've had the BMR brace as well as the anti-wheel hop kit along with the lingenfelter snubbers for the last 2 1/2 years without a hitch. I also have Eibach springs.

There is more sound transmitted into the cabin. especially more transmission noise.

My rear diff went out at only 300 miles (Yes-2wks old) prior to putting on the BMR aftermarket equipment.

I just did the rear diff seal recall 2 days ago and noticed much less noise when the car was returned to me with less driveline lash.

Others may know if you'll have clearance problems with regard to a supercharger.

Definite change without runflats- but tires still disappear like vapor with aggressive driving. My current Nitto INVO's won't last too much longer.

Max-Q
04-10-08, 11:11 PM
On the subject of wheel hop- I've wondering something and I wanted opinions on this idea. With the 2009 V they keep talking about half shafts of different thicknesses to eliminate wheel hop. I saw the specs on them and one side is definately thicker than the other.

From what I understand the 04-05 shafts are smaller than the 06-07 shafts. What is the possibility of changing out one of the shafts on an 04-05 with an 06-07 to deliver the same unequal effect as on the 09?

What are your thoughts? Do you think this can eliminate wheel hop on our cars? :confused:

Twitch
04-11-08, 02:25 AM
On the subject of wheel hop- I've wondering something and I wanted opinions on this idea. With the 2009 V they keep talking about half shafts of different thicknesses to eliminate wheel hop. I saw the specs on them and one side is definately thicker than the other.

From what I understand the 04-05 shafts are smaller than the 06-07 shafts. What is the possibility of changing out one of the shafts on an 04-05 with an 06-07 to deliver the same unequal effect as on the 09?

What are your thoughts? Do you think this can eliminate wheel hop on our cars? :confused:

Would be nice if it helps. But, yes, it can be done.

rand49er
04-11-08, 09:24 AM
On the subject of wheel hop- I've wondering something and I wanted opinions on this idea. With the 2009 V they keep talking about half shafts of different thicknesses to eliminate wheel hop. I saw the specs on them and one side is definately thicker than the other.

From what I understand the 04-05 shafts are smaller than the 06-07 shafts. What is the possibility of changing out one of the shafts on an 04-05 with an 06-07 to deliver the same unequal effect as on the 09?

What are your thoughts? Do you think this can eliminate wheel hop on our cars? :confused:Brings up the whole issue of what's the best set of mods at a given cost that allows the Getrag to survive a lifetime of burnouts (i.e. something else on the car dies before the diff). This idea might show some merit.

Max-Q
04-11-08, 09:57 AM
I'll try to find the actual specs on the different half shafts but I know for a fact that one side was thicker than the other. They claim this eliminates the wheel hop issue that plagued the V1. Interestingly, the Cadillac team shared this design/idea with the ZR-1 team. The ZR-1 team incorporated this "asymetrical" half shaft design on the ZR-1 because they were having the same issues with wheel hop.

The only thing I haven't found is what side of the car the thicker and thinner shafts need to be.

Max-Q
04-11-08, 10:20 AM
Well it looks like the GTO guys from LS1 are barking up the same tree. They have a guy who has replaced the passenger side shaft with a thicker BMR shaft and has had no wheel hop issues at all. The only problem is he also stiffened his suspension at the same time so he isn't sure which change had more effect.


I think length of half shaft is less critical than the diameter of the shaft, which is what affects the torsional stiffness. Having a different torsional stiffness on each side of the car is what gm is doing to help eliminate wheel hop if I understand the article correctly. And I think a bunch of cars like yours do not have wheel hop for various reasons. I know for a fact that lots of guys have eliminated wheel hop with their cars for a particular hp/tq and suspension setup. What I am hoping the different size half shafts can accomplish is to help eliminate wheel hop in all gto's with all suspension setups and hp/tq ranges.

I have a larger diameter shaft on the passenger side right now and I didn't have wheel hop for the first time since I started going to the track. However, the real test will be to see if the larger shaft on one side cures or at least reduces wheel hop for other cars with different setups and power levels than mine, which obviously would take a bunch of people to test and find out. The bmr shafts and stubs are pretty expensive so this may never happen (GForce can you make larger diameter shafts at a cheaper price?). Even I don't know if the axle is what stopped my wheel hop or if stiffening my rear shocks did it. But I was ready to upgrade my shafts/stubs anyway so doing just one side made sense for me and is letting me experiment with this idea.

rand49er
04-11-08, 01:24 PM
... The only problem is he also stiffened his suspension at the same time so he isn't sure which change had more effect.:banghead:

lollygagger8
04-11-08, 03:29 PM
I've installed the BMR Anti Wheel Hop Kit, but w/o the cross bar (since I have the B&B exhaust) but at first I didn't think it was working, cuz I still had wheel hop. BUT....it was still cold here (Indiana) Now that it's got a little warmer, it IS working pretty good. Cold Roads + Cold Tires = Wheel Hop at least with our V's.

I would never try the pinion support because, yes it will transfer the power to the road...but there is no give in the drivetrain. Hence, the horror stories you hear about broken diff housings while using those. I think the trailing arms might help a little....but not enough to notice.

I want to try the swaybars, but again, I'm not using my car on the track so I dont know how much that will help me.

Twitch
04-12-08, 06:55 PM
I would never try the pinion support because, yes it will transfer the power to the road...but there is no give in the drivetrain. Hence, the horror stories you hear about broken diff housings while using those.

I could be wrong, but I've only heard of one person who blamed the pinion support for a diff failure. I know Chef had one. All that power, and a bunch of track days with no problem due to the support.
I've had mine sitting since last fall, but I'll be installing it soon (hopefully).

SS from the "Wood"
04-13-08, 04:44 PM
I say "eh" to most of the wheel hop "fixes" because you really only need them when your pouring on enough power to break it loose and cause it.

If you modify your driving habits, it won't happen.

NO FLAME PLEASE :hide:

This is not to say that I am not extremly interested in the 09 retrofit.:D


Could you elaborate on the retrofit? Thanks!

rand49er
04-13-08, 04:55 PM
Could you elaborate on the retrofit? Thanks!http://www.cadillacforums.com/forums/cadillac-cts-v-series-forum-2004/131543-final-word-retrofitting-09-differential.html