42 replies to this topic

[Jim Boemler]

What's the benefit of the cross-bar in the trunk?  It would seem like the car's own structure is strong enough in that area that the extra bar would be unnecessary.

[davew]

We had a car hit a concrete wall with the left rear corner. Hard enough to bend the "stub" between the crossbar and the floor mount. Had the cross bar not been there the trunk would have certainly folded and made repairing the car much more expensive. Maybe not worth fixing.

 

 

 

 

[Ron Alan]

Oh, "taken out", dinner and a movie ??
 
Sorry to hear. Were you getting ready for the 25 ?
J~

Let's keep to the thread...the comedy routine is getting old...and really poor timing

[Johnny D]

I am sorry, I've been there, done that, last year.

What I made light of was weather you crash or get taken out, your car still has the same damage and doesn't change anything.

J~

[AW33COM]

The tube I'm seeing in the trunk is a dead tube as it does not add to drivers safety.  More, I'm pretty sure it should never be welded that close to the landing perches.  Will not harm much in this case, but those are the rules.  When designing the cage you add minimum amount of elements to provide maximum driver's safety. 

 

One more technical tip: the rear cage down tubes should tie in as close to the shock towers (along the tower axis) as possible in order to create a better handling car. 

[Keith Andrews]

The tube I'm seeing in the trunk is a dead tube as it does not add to drivers safety.  More, I'm pretty sure it should never be welded that close to the landing perches.  Will not harm much in this case, but those are the rules.  When designing the cage you add minimum amount of elements to provide maximum driver's safety. 

 

One more technical tip: the rear cage down tubes should tie in as close to the shock towers (along the tower axis) as possible in order to create a better handling car. 

 

I'm a little confused.  First you say you see a "dead tube in the trunk"  then you say "One more technical tip: the rear cage down tubes should tie in as close to the shock towers (along the tower axis) as possible in order to create a better handling car."  Aren't the "dead tubes" close to the shock towers?  Maybe pictures of one of the cages you built for your car or cars would help explain what you mean.

 

Then you go on to say it shouldn't be welded that close to the landing perches and vaguely reference "but those are the rules".  What rules are you referring to.  

[AW33COM]

I was talking about a tube that's technically known as Rear Strut Brace.  It does work, but in Spec Miata speeds it ends up being one of those "unnecessary" tubes in my opinion.

 

The technical tip was for:

1.  Rear Strut Brace
2.  Lower Rear Stay (SMs do not have it)
3.  Mid Rear Stay (SMs do not have it)

4.  Rear Down Tube (Upper Rear Stay)

 

They all should be connected with the chassis along the shock tower axis.  

The cage in my car was build by BSI, it's a good cage, but if I had to custom build it, it would be a bit different. 

[Keith Andrews]

I was talking about a tube that's technically known as Rear Strut Brace.  It does work, but in Spec Miata speeds it ends up being one of those "unnecessary" tubes in my opinion.

 

The technical tip was for:

1.  Rear Strut Brace
2.  Lower Rear Stay (SMs do not have it)
3.  Mid Rear Stay (SMs do not have it)

4.  Rear Down Tube (Upper Rear Stay)

 

They all should be connected with the chassis along the shock tower axis.  

The cage in my car was build by BSI, it's a good cage, but if I had to custom build it, it would be a bit different. 

 

???? So your technical tip was for the Strut Bracing that you think is unnecessary, am I following this?

 

And the Rules reference, can you point that out.  Are you saying the cage pictured is illegal?

[AW33COM]

Here, I finally found the link to the work I was referring to.  You can PM him and see if he can help.

 

forum page: http://honda-tech.co...=3110862&page=2

 

 

 

 

[Keith Andrews]

http://www.youtube.c...h?v=Oik6dXm-0l0

[Jim Boemler]

That looks like a pretty stout bridge!

[Tom Hampton]

Ok, look. Aw33com you've struck a nerve. Are you a qualified, structural or stress engineer? Or do you have a decade of designing and refining cage designs for countless racecars? If not, then quite frankly, you are not qualified to spout the structural opinions that you are (beyond the fact that you own a computer).

I don't usually call people out. But, when it comes to safety critical systems it is important to have the pedigree to qualify your opinions.

For the record:I'm a chief engineer for a major defense contractor. I oversee the design and construction of major structural modifications to aircraft. I have entire teams of structure and stress engineers who do the detailed designs for these mods. None of them would make such flippant declarations without any substantiation.

[Ron Alan]

Again, AW33com, start by putting your name in your signature. Schabi was the 1st name you used on the forum...is this part of your real name? Tom is speaking for a lot of us...

[RussMcB]

I've been resisting the urge to post something similar.  It's nice to know who is posting, so you have an idea how much credibility to give.  I can't think of a good reason not to put some real name identity to a forum ID.

[Johnny D]

I'll ask Jim what he thinks, if he hasn't read this. I would guess it's voluntary. Real racers can step up.

 

You guys must figure out after a while, who's who? Posted video of them racing etc.

(no disrespect to anyone listed) Kid, wanna be, novice, a few year, pro, retired.

 

IMO, He's new, wants to be one of the guys, tries to help, talks like he know what he talking about.

A lot like me starting out here, sorry to say.

 

Like everything, you have a spectrum of people, and with him, he doesn't lurk, he posts.

He'll get better, with time.

J~

[Ron Alan]

Yep...especially after a few gentle cattle prods

[Keith Andrews]

I'll ask Jim what he thinks, if he hasn't read this. I would guess it's voluntary. Real racers can step up.

 

You guys must figure out after a while, who's who? Posted video of them racing etc.

(no disrespect to anyone listed) Kid, wanna be, novice, a few year, pro, retired.

 

IMO, He's new, wants to be one of the guys, tries to help, talks like he know what he talking about.

A lot like me starting out here, sorry to say.

 

Like everything, you have a spectrum of people, and with him, he doesn't lurk, he posts.

He'll get better, with time.

J~

 

Ok, so everyone gets a gold star and a medal for trying.  Come on....... BS is BS. 

AW33COM
"I was talking about a tube that's technically known as Rear Strut Brace.  It does work, but in Spec Miata speeds it ends up being one of those "unnecessary" tubes in my opinion."

What speed does it become necessary?  What?

 

Thank you Tom for calling it correctly.

[Jim Drago]

I'll ask Jim what he thinks, if he hasn't read this. I would guess it's voluntary. Real racers can step up.

While I am not one who goes crazy with extra bracing and bars in cages personally, I would never criticize someone who puts them in either. Especially if those using them felt they made the car better/stronger/safer in anyway. IMO, rarely do extra bars hurt anywhere other than overall weight and CG. I share some of the same opinions as others, sent Schabi a PM echoing similar comments. New guy, smart guy,(young guy maybe?) good intentions I'm sure. Posts don't always come off the way that people are in real life, just ask Jamz

[Bench Racer]

Posts don't always come off the way that people are in real life, just ask Bench

[svvs]

Guys I know AW33 from around the track.....he's a nice guy in real life.  New to miatas.

 

-Vick