IRS center?

[import111]

Does the BRM CB005 kit center the IRS 100% in the same way the Steeda IRS alignment bushings do?

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[BMR Tech]

The CB005 does not center the cradle 100%.

The reason it does not, is because when we designed that kit...we had a hard time with consistent installation on various vehicles. The front pieces, do a great job at "centering" the cradle...but they are very strong metal, and we had to leave some tolerance in them simply to help the end user out.

The Steeda Kit, uses Delrin (which a bolt can work through, easier than metal) on all 4 mounts and will center the cradle closer to 100%, than our CB005.

We have found that centering 100% is not necessarily "needed"....but it is definitely not a bad thing to do.

You can combine the CB005 and the Steeda Alignment kit....you just have to trim down the front Steeda pieces around .50"

 

[Commbubba19]

Consider me crazy - i know my other posts may lead people to believe i am....

but...

with your CB005 kit, any thoughts on adding a M14x2 bolt of required length to replace the stock IRS cradle bolts?

Many folks including myself fight with the CB005 kit and trying desperately not to crossthread the OEM bolt but since it is of self tapping design and looks like it was designed to be used only once, a standard replacement would really help. Not sure what that would add to cost. I found grade 8 bolts online for about $2 each.

Do you happen to know what the tension load limit is on the OEM cradle bolts vs grade 5/8 bolts?

 

[BMR Tech]

Consider me crazy - i know my other posts may lead people to believe i am....

but...

with your CB005 kit, any thoughts on adding a M14x2 bolt of required length to replace the stock IRS cradle bolts?

Many folks including myself fight with the CB005 kit and trying desperately not to crossthread the OEM bolt but since it is of self tapping design and looks like it was designed to be used only once, a standard replacement would really help. Not sure what that would add to cost. I found grade 8 bolts online for about $2 each.

Do you happen to know what the tension load limit is on the OEM cradle bolts vs grade 5/8 bolts?

We have considered it, yes. However, we have not seen the need to do so at this time. I am not so sure I agree with the comment about making it easier - simply because we have tested that theory out. We have removed the OEM bolts and installed our own 10.9 M14 hardware and it made no difference in how it threaded (tension).

As for the comment about the capacity of the bolts, an approximation is:

The OEM 10.9 bolts have min tensile loads of approx. 150,000psi
Common Grade 8 will be in the 120,000psi range
Common Grade 5 will be in the 60,000psi range

Then there is shear load capacity - which does not really change much with the bolt Grade, compared to the Tensile Strength.

The best way to improve shear load capacity is to increase bolt size (diameter)

That said, it really depends on the bolt you acquire. There are "extreme", "high", "medium" and "Low" Strength bolts in various Grades.

 

[Commbubba19]

We have considered it, yes. However, we have not seen the need to do so at this time. I am not so sure I agree with the comment about making it easier - simply because we have tested that theory out. We have removed the OEM bolts and installed our own 10.9 M14 hardware and it made no difference in how it threaded (tension).

As for the comment about the capacity of the bolts, an approximation is:

The OEM 10.9 bolts have min tensile loads of approx. 150,000psi
Common Grade 8 will be in the 120,000psi range
Common Grade 5 will be in the 60,000psi range

Then there is shear load capacity - which does not really change much with the bolt Grade, compared to the Tensile Strength.

The best way to improve shear load capacity is to increase bolt size (diameter)

That said, it really depends on the bolt you acquire. There are "extreme", "high", "medium" and "Low" Strength bolts in various Grades.

I guess easier only in that the replacement bolt wouldn't have self tapping threads.

Do you have any recommendations for a replacement bolt? Obviously those 4 bolts carry a great deal of tensile and shear forces transmitted through the drive train and suspension and though I haven't decided yet, I don't want to get a bolt that could fail due to it being weaker than the factory bolt.

 

[BMR Tech]

For some ridiculous reason, I do not have a bolt laying around to measure.

If you can get me a measurement before Monday, I can look into it and see. We have a ton of hardware here.

Or if you just want to order something, and get it quick...McMaster-Carr is my favorite place for stuff like this. I believe they will also give you good bolt info.

http://www.mcmaster.com/#standard-cap-screws/=13appo3

 

[BMR Tech]

OEM uses 10.9.

We use 10.9 for everything.

So, I suggest acquiring 10.9 or better.

 

[Commbubba19]

For some ridiculous reason, I do not have a bolt laying around to measure.

If you can get me a measurement before Monday, I can look into it and see. We have a ton of hardware here.

Or if you just want to order something, and get it quick...McMaster-Carr is my favorite place for stuff like this. I believe they will also give you good bolt info.

http://www.mcmaster.com/#standard-cap-screws/=13appo3

That was the site I was looking at but I think I was looking at grade 8.8.

 

[BMR Tech]

Yeah. Just go to the Extreme Strength section and grab a 10.9

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