[fullerton]

has the persuasion gotten anywhere?

[QuickSilverSTi]

Originally Posted by Saabaru STI

I understand that the chromoly would be stiffer. My point is the function of a subframe brace should be equally, if not more, weight vs. stiffness. If someone is that hardcore about chassis stiffening, get a welded roll-cage.

It was cheaper and easier to bolt on the chromoly RPM subframe for me.

[twiSTies]

Originally Posted by TheLimitedProject

Supermarkus mentioned that there'd be no where for the engine or tranny to "submarine" in a front end collision because of all the stiff bracing underneath.

Would that be a risk with this subframe? If so, that would rule me out, and probably a lot of guys daily driving their STI's who wouldn't want to risk eating fuel lines and intake manifolds in a crash

This is why I'll be getting the BeatRush subframe.

[fullerton]

Originally Posted by twiSTies

This is why I'll be getting the BeatRush subframe.

Kinda a moot point for me, as my cusco mounts probably negate any submarining.

[twiSTies]

Originally Posted by fullerton

Kinda a moot point for me, as my cusco mounts probably negate any submarining.

doubt it, because even sti sells the group n mounts. i think its more of the way the frame collapses, but i might be wrong. either way, not something i'd want to risk as a daily driver. i love the sti drivetrain, but not in my lap

[fullerton]

Originally Posted by twiSTies

doubt it, because even sti sells the group n mounts. i think its more of the way the frame collapses, but i might be wrong. either way, not something i'd want to risk as a daily driver. i love the sti drivetrain, but not in my lap

the cuscos and group n's are VERY different beasts. the subaru mounts are two pieces of metal (that bolt to the frame and engine) connected with a piece of soft or stiff rubber. the cuscos connect the frame and engine with two fat bolts. the little rubber there is will not separate like the suby ones will.

this all is assuming that the engine submarines by way of tearing the mounts in half.

[Draco-REX]

Crumple and submarining of the engine is not a way to keep it out of your lap. If anything, it'll bring the engine CLOSER to you in a crash.

Crumple zones are there to absorb the force of an impact and dissipate it by deformign the structure between the nose of the car and the front of the passenger compartment. Submarining does the same thing by letting the engine move downwards so it doesn't act like a second bumper inside the compartment and transmit the force of the impact into the body shell; defeating the purpose of the crumple zone.

If the increased rigidity prevents the crumple zone from compressing, or the engine from diving, what will happen is that more of the impact force will be transmitted to the passenger compartment. This can be bad, true. But with today's seatbelts and airbags, it's not as big of a deal. And this is assuming that the subframe brace will eliminate all crumple and submarining of the engine, which it won't. It'll only reduce it; this isn't a front tube-frame we're talking about.

[Draco-REX]

BTW, I really want one of these if it can come with an undertray. I'm working on firming up my entire suspension, and the way this ties together points that are normally lef tunconnected by other solutions really appeals to me. I'm keeping an eye here in hopes these will get produced.

[Rookie84]

I just really want the undertray RPM was supposed to come out with one for theirs but there have been no news from them at all... they said they were in R&D stage for it few months ago but I guess they will never come out with one. Hopefully this one will go into mass production!

[twiSTies]

Originally Posted by Draco-REX

Crumple and submarining of the engine is not a way to keep it out of your lap. If anything, it'll bring the engine CLOSER to you in a crash.

Crumple zones are there to absorb the force of an impact and dissipate it by deformign the structure between the nose of the car and the front of the passenger compartment. Submarining does the same thing by letting the engine move downwards so it doesn't act like a second bumper inside the compartment and transmit the force of the impact into the body shell; defeating the purpose of the crumple zone.

If the increased rigidity prevents the crumple zone from compressing, or the engine from diving, what will happen is that more of the impact force will be transmitted to the passenger compartment. This can be bad, true. But with today's seatbelts and airbags, it's not as big of a deal. And this is assuming that the subframe brace will eliminate all crumple and submarining of the engine, which it won't. It'll only reduce it; this isn't a front tube-frame we're talking about.

Sorry, but unless you've crash tested one of these, I'm going to be a very hard sell on theory alone. There has to come a point where a line in the sand is drawn for what is acceptable for safety and what is not. Losing any front end collision protection so I can stiffen the front of the car X% over the Beatrush brace or factory U brace isn't worth it to me. You're dealing with a car that got 5 stars for front end impact. I'm not about to throw a monkey wrench into that system.

[Draco-REX]

Originally Posted by twiSTies

Sorry, but unless you've crash tested one of these, I'm going to be a very hard sell on theory alone. There has to come a point where a line in the sand is drawn for what is acceptable for safety and what is not. Losing any front end collision protection so I can stiffen the front of the car X% over the Beatrush brace or factory U brace isn't worth it to me. You're dealing with a car that got 5 stars for front end impact. I'm not about to throw a monkey wrench into that system.

Well, really, there's no evidence currently that it'll have an adverse effect on crash saftey either. We're both doing the same thing. We're looking at the design, comparing it to what we know about the front of the car and how that part behaves in a crash, then drawing up a conclusion we feel is reasonable. As you said, unless someone crash tests it, or a few of thes have gone into trees, we can't know for sure either way. There's definately something to be said about erring on the side of caution, I'll admit that. But going back to the first part of this, in my estimation such caution is unwarranted.

Hell, this is just a prototype, it may not ever go on sale which makes this all moot anyways.

[twiSTies]

Originally Posted by Draco-REX

Well, really, there's no evidence currently that it'll have an adverse effect on crash saftey either. We're both doing the same thing. We're looking at the design, comparing it to what we know about the front of the car and how that part behaves in a crash, then drawing up a conclusion we feel is reasonable. As you said, unless someone crash tests it, or a few of thes have gone into trees, we can't know for sure either way. There's definately something to be said about erring on the side of caution, I'll admit that. But going back to the first part of this, in my estimation such caution is unwarranted.

Hell, this is just a prototype, it may not ever go on sale which makes this all moot anyways.

Good point!

You know, the thing I'm wondering about is how the subframe bolts react. They're made to only be removed once, then discarded. I wonder if they're intended to snap off during a collision, which would drop any subframe and make this a moot issue.

Wish we knew more about how this works! In the meantime, my response is to play it safe and get something that doesn't block the engine off. Come ot think of it, doesn't the M1 brace leave a hole under the engine, too?

[Draco-REX]

Originally Posted by twiSTies

Good point!

You know, the thing I'm wondering about is how the subframe bolts react. They're made to only be removed once, then discarded. I wonder if they're intended to snap off during a collision, which would drop any subframe and make this a moot issue.

That's a good thought.. I wonder if anyone has one of these bolts left over. I'd be interested to see what happens if one end is clamped in a vice and the other is struck laterally with a hammer.

[fullerton]

bump! i wanna see this thing get made!

[steelgraySTi06]

I didn't read all 8 pages so this might have been addressed if it was i'm sorry for wasting time. The subframe looks great how is the clearance for the down pipe? i had a m1 subframe and it didn't fit with a few different downpipes.

sweet looking subframe i'd buy one