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BMR STB- not so hot?

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Old Dec 7, 2017 | 08:58 PM
  #1  
Tootie Pang's Avatar
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Car: 1989 IROC Convertible
Engine: 350 TPI L98
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BMR STB- not so hot?

Just got my three point today in hammered black. It's a beautiful piece but I am questioning the "BMR" flat plate in the middle.

The whole idea of a STB is to transfer rigidity from one strut tower to the other. The flat "BMR" plate allows the bar to flex when pressed. Really? I thought these things needed to get pressed on one end and push 1:1 on the other.

I leaned on one end while the other end was on the floor. I was able to noticeably deflect the bar. I've never been able to do this with the consistent cross section bars.

Back it goes I think.
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Old Dec 7, 2017 | 09:23 PM
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Re: BMR STB- not so hot?

It is their way of slipping the bar in the narrow space between the TPI intake and the hood.

Might not fit anyway.....

https://www.thirdgen.org/forums/ltx-...ml#post6121692
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Old Dec 7, 2017 | 10:12 PM
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Re: BMR STB- not so hot?

I have it on my car. It clears the firebird hood easy. It rubs on the hood liner a bit. Upgrading to a 3 point this xmas. Mine seems to be built strong. One of the few that clears OEM hoods with TPI.
Attached Thumbnails BMR STB- not so hot?-15841074_1185023291594753_845070104_n.jpg  
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Old Dec 7, 2017 | 10:28 PM
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Re: BMR STB- not so hot?

Not all Firebird hoods are equal. Base model hood is worst case scenario and it will not fit that hood.
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Old Dec 8, 2017 | 09:19 AM
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Re: BMR STB- not so hot?

I had the BMR 3 point brace and it made a noticeable difference in creeks and rattles. I too noticed that it flexed, but it did help. Ultimately didn't like the forced advertising of that BMR right in the middle of my beautiful TPI! ...currently running a Jamex 2 point. ....and although pricey, I'd like to upgrade at some point to the Heidts 3 point. Money is needed elsewhere for the time being.

Any "TPI" specific brace should clear a Camaro hood.
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Old Dec 8, 2017 | 11:37 AM
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Car: 1989 IROC Convertible
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Axle/Gears: 3.42
Re: BMR STB- not so hot?

Interesting. I did confirm with BMR that their flat plate design is not optimal but it does clear a tight spot.
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Old Dec 8, 2017 | 08:26 PM
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Car: 1986 Trans am
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Re: BMR STB- not so hot?

The main purpose of that brace is to distribute side load from one strut tower to the other. This is load from a horizontal force, not a vertical force. While you may notice the bar flex in a vertical plane, I would bet it's still very strong in a horizontal plane and will in fact take out a lot of the side to side flex. I will agree that the flat plate is not as strong as a solid piece of tube, however I would also bet that it will perform it's job very well, especially being a 3 point brace.
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Old Dec 12, 2017 | 02:18 PM
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Re: BMR STB- not so hot?

Originally Posted by Tootie Pang
Just got my three point today in hammered black. It's a beautiful piece but I am questioning the "BMR" flat plate in the middle.

The whole idea of a STB is to transfer rigidity from one strut tower to the other. The flat "BMR" plate allows the bar to flex when pressed. Really? I thought these things needed to get pressed on one end and push 1:1 on the other.

I leaned on one end while the other end was on the floor. I was able to noticeably deflect the bar. I've never been able to do this with the consistent cross section bars.

Back it goes I think.
My BMR subframe connectors flex when pressed too.. BMR told me to weld these little metal squares between the subframe and the drip rail. So basically, they wanted me to use the rigidity of the drip rail to reinforce the subframe connectors. No joke..

It's BMR...

-- Joe
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Old Dec 12, 2017 | 02:43 PM
  #9  
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Re: BMR STB- not so hot?

Ran that same one on my car for track days an auto crossing never notice it flexing at all.that flat part that says bmr on it has to be a 1/2 inch piece of steel again never notice it flexing all I know is when I put it on there was a big difference..anyone want to buy one in perfect shape.going to a HSR so it doesn't fit
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Old Dec 12, 2017 | 09:59 PM
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Re: BMR STB- not so hot?

Originally Posted by anesthes
My BMR subframe connectors flex when pressed too.. BMR told me to weld these little metal squares between the subframe and the drip rail. So basically, they wanted me to use the rigidity of the drip rail to reinforce the subframe connectors. No joke..

It's BMR...

-- Joe
By tying the subframe connector into the drip rail/rocker panel at a few spots along it, you effectively add a ton of rigidity to the combined structure. It's common fabrication knowledge. It doesn't take much...you have two long structures of metal running beside each other. Without the welded gussets, they will have some amount of flex independently. Now you tie them in to each other by welding the gussets along them and you create an extremely rigid section now. It's no different than the body mounts along a truck frame tying the two sections together to give the assembly much more structure as a whole.
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Old Dec 12, 2017 | 10:50 PM
  #11  
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Re: BMR STB- not so hot?

The edelbrock (now QA1) STB clears the TPI/hood w/ out any interruption in the design, also a 3 point brace.
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Old Dec 13, 2017 | 07:03 AM
  #12  
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Re: BMR STB- not so hot?

Originally Posted by whitedevilTA
By tying the subframe connector into the drip rail/rocker panel at a few spots along it, you effectively add a ton of rigidity to the combined structure. It's common fabrication knowledge. It doesn't take much...you have two long structures of metal running beside each other. Without the welded gussets, they will have some amount of flex independently. Now you tie them in to each other by welding the gussets along them and you create an extremely rigid section now. It's no different than the body mounts along a truck frame tying the two sections together to give the assembly much more structure as a whole.
That only provided rigidity in one direction.

I can put my car up on the lift using measuring sticks and the body flex is immense with the BMR subframe connectors, even with the welded tabs.

Adding MAC subframe connectors helped a little, but the fact is neither are even close to how strong my other Formula was with SSM subframe connectors.

-- Joe
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Old Dec 13, 2017 | 08:09 AM
  #13  
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Re: BMR STB- not so hot?

I stitched welded the Global West two-cat design from the mid 90's. I was rear-ended at a traffic light, and I believe the SFC saved me from extensive body/frame damage.

Also, I purchased Kenny Brown STB and like it. I seem to have good luck with the mid 90's products!




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Old Dec 13, 2017 | 09:32 AM
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Re: BMR STB- not so hot?

Originally Posted by TEDSgrad
I stitched welded the Global West two-cat design from the mid 90's.
Those are the ones I have on my GTA, along with a BMR STB, and my car has hardly any flex. I can jack up the rear on one side and be able to put jack stands under both sides of the car.
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Old Dec 13, 2017 | 09:33 AM
  #15  
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Re: BMR STB- not so hot?

Originally Posted by TEDSgrad
I stitched welded the Global West two-cat design from the mid 90's. I was rear-ended at a traffic light, and I believe the SFC saved me from extensive body/frame damage.

Also, I purchased Kenny Brown STB and like it. I seem to have good luck with the mid 90's products!




I have a stb that kinda looks like that. No brand markings. N Ed to get around to putting it on .
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Old Dec 15, 2017 | 04:39 PM
  #16  
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Re: BMR STB- not so hot?

Originally Posted by anesthes
That only provided rigidity in one direction.

I can put my car up on the lift using measuring sticks and the body flex is immense with the BMR subframe connectors, even with the welded tabs.

Adding MAC subframe connectors helped a little, but the fact is neither are even close to how strong my other Formula was with SSM subframe connectors.

-- Joe
I can't comment on the BMR connectors vs other brands, however they made a big difference on my personal car. Before them, if I jacked it up by the front frame rail under the driver's foot area, the front of the rocker would probably get a foot off the ground before the rear tire came up. Now, it lifts the rear tire after jacking it a few inches. You can feel it during driving as well. However, a subframe connector is only going to do so much by itself for chassis rigidity. The real and unfortunate solution is a full cage, but that's not ideal for myself as well as most other's with "street" cars.
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Old Feb 4, 2020 | 11:04 AM
  #17  
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Re: BMR STB- not so hot?

Originally Posted by blacksunshine'91
Those are the ones I have on my GTA, along with a BMR STB, and my car has hardly any flex. I can jack up the rear on one side and be able to put jack stands under both sides of the car.
So the BMR STB fits under the GTA hood without issues?
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Old Feb 4, 2020 | 07:18 PM
  #18  
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Transmission: Pro-built 700R4
Axle/Gears: GTA: 3.27, T/A: 2.73
Re: BMR STB- not so hot?

Originally Posted by Firebreather
So the BMR STB fits under the GTA hood without issues?
Fits my '91 GTA and my '92 T/A without any issues.
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