BMR Watts Link - Teaser

[Whiskey11]

BMR already has one for the Camaro owners


On to a serious question / clarification on the chassis vs differential mounted watts link:


I know there's a difference in sprung vs unsprung mass.

I respect norm, but sometimes its like he's speaking Chinese.

Am I understanding him that a diff mounted unit will have less roll steer and essentially do its job without using the suspension at all? I assume that makes (although my butt dyno isn't calibrated that high) the diff mounted unit superior as far as handling characteristics are concerned?


Can someone explain it in window licker terms please?

Ehhh... there are advantages and disadvantages to both methods. The biggest difference between the two is how body roll is produced. On a chassis mounted unit the RC and CG are fixed relative to each other. This means that at a given lateral load the body roll should be consistent.

With a diff mounted unit the RC is fixed height relative to the ground but not to the CG. This means that the RC and CG are constantly getting closer and further apart from each other. The end result is a progressive amount of body roll and one that changes with ride height fluctuations. If you have the same static RC as a chassis mount unit, at the same lateral load with everything else about the vehicles the same, the chassis mount should produce slightly less body roll as the arm length between the CG and RC remains constant whereas it will change in length with the diff mounted unit.

I think at the end of the day, Norm was of the opinion that there might be a slight edge to a chassis mounted unit from a tuning standpoint. Either is far superior to a PHB.

 

[Thekid760]

Thank you for clarifying that, makes more sense now. It's been on my to buy list for awhile but quite frankly haven't been impressed with the cheaper offerings and the $1k units are more than I can cough up right now.

Looks like chassis mounted it'll be for me.


Misspelling courtesy of my fat fingers...

 

[sheizasosay]

Or more plainly stated: with a chassis mounted watts, the roll couple will remain constant. This is not the case with a diff mounted watts.

That is the big difference IMO.

 

[BMR Tech]

^ Bingo.

Even then, you have people who's theories clash and believe one is better than the other (vice versa).

The primary reason the Diff Mount is more common, is because it is easier to make.

 

[Norm Peterson]

Am I understanding him that a diff mounted unit will have less roll steer and essentially do its job without using the suspension at all? I assume that makes (although my butt dyno isn't calibrated that high) the diff mounted unit superior as far as handling characteristics are concerned?

While rear ride height is changing, a diff-mounted Watts will result in lateral load transfer through the suspension to take a little longer if the rear has risen under braking than with a chassis mounted Watts. The diff mounted Watts also has a slightly more stable axle steer, and both of these effects go to the difference in "twitchiness" mentioned by popeye in post #152.

The chassis mounted Watts is somewhat more stable in terms of roll moments (and tuning via springs/bars/shocks tends to remain more consistent as the suspension moves up/down).

All pretty small differences, but since they all vary with time and at different rates, differences in the overall result can be felt during transient maneuvers. At least by some, and I'm not necessarily including myself.


FWIW, the stiffer the suspension is in 'ride', the smaller the differences between chassis and diff mounts becomes.


Norm

 

[BMR Tech]

FWIW, the stiffer the suspension is in 'ride', the smaller the differences between chassis and diff mounts becomes.


Norm

And, the presentation of negative effects from a Panhard Bar lessen.

 

[Pentalab]

And, the presentation of negative effects from a Panhard Bar lessen.

Lowered cars have a PHB that is at a shallower angle. On paper, that alone should reduce some of the negative effects of a phb. I see steeda's relatively new adjustable length phb, can also be adjusted up + down...at both ends of the phb. That's as good as it gets...for an adjustable PHB.

 

[AutoXRacer]

Alright, I just discovered this thread...where we at with the product?

Do we have a final config?

 

[Thekid760]

Thanks for the clarification.


Kelly when are we going to get an eta and price on the chassis unit?


Misspelling courtesy of my fat fingers...

 

[GoneFord]

Kelly!

Christmas is coming... I need this part!

 

[tbrock]

Kelly what's the word?

 

[LAStang1234]

Kelly!!!!!!!!!!

 

[Barricade]

Well dang...i just about spent it all now. Stupid sales.... lol

 

[BMR Tech]

Design is final.

Ran into one issue holding us back, and that is the vents on the axle tubes. Apparently they are on different sides over the years...and we based them off the vent on our 2011 GT.

Working on a resolution now, for that. The other items, the fixtures are built...orders are in with our material suppliers....and it's just a matter of time until we get everything completed, and begin the product release on these.

The good news is, I am doing everything I can to make this system the most cost effective Watts on the planet. To be honest, that has taken A LOT of time - because designing something with pricing and function in mind, is MUCH harder than many may think. Each gusset, plate, weld, etc....has a cost factor involved. Making the baddest of the baddest, generally means making the most expensive. We try to land in the middle on most parts, while retaining a solid product. These Watts....we are trying to have the lowest price point, with the highest bang for the buck factor.

The time is nearing. I want it here, more than anyone. lol

 

[Scott]

Kelly thanks for the update.

 

[Mr. Q]

so......what i'm hearing is that......you can release them for 11-12 models?

LOL jkjk

Thanks for the update!

 

[tbrock]

Kelly,

Thanks for the update my axle vent is on the passenger side.

TB

 

[mavisky]

Was hoping to pick one of these up this year on the Black Friday sale, but perhaps there will be a similar sale for Christmas.

Since the design is final can you provide us with details on the following:

Will it fit a convertible?
What swaybars are we sure that it works with? Assuming BMR will clear obviously.

 

[claudermilk]

Kelly,

Thanks for the update my axle vent is on the passenger side.

TB

...and there's the problem they have run into. Mine is on the driver side. Well...was; now a fitting with a tube to the catch can.

 

[DPE]

By no means is this proof that it's consistent, but in looking under several cars it would appear that '05-10 vents are on the passenger side and '11-14 vents are on the driver side. There may be exceptions, or it may be totally random, but across the 10 or so cars I've looked at and/or worked on that has been true.