Carbon fiber Strut bars...

[MNGSX]

Originally posted by ACM
Unfortunately I've seen the 2G Neuspeed bar - I sent it back with a note asking if they would send me some of the drugs their engineer was on at the time.

The one shown in the adverts is a good idea, picking up on the 4 eyebols - this addresses the torque generated around the pickups, as opposed to simply the tension as the towers try to spread.

Unfortunately that's not what Neuspeed built for a 2G - instead they built what can best be described as a large unused staple with tabs welded on each end.

Place one end on the floorand stand on it; hook index finger under top and tug - see that flex ? This STB has succeeded in being worse than useless - it provides zero structural enhancement and also adds weight high up in the front.

About as useful as a lead sheet sunroof.

Charles

P.S. This has become the silliest thread I've read here.

I dont think so...

Guess what?

as JTM says the front upper bars are actually in tension not compression under hard cornering.

Also if a bar does compress briefly at a given point during cornering what happened?

I'll tell you,.... You gained negative camber! As long as you don't run alot of static negative camber this is a good thing..

Now

Take a 6" wide by 20' keeper vehicle recovery strap and stand on it and pull up...

Hey look flex.

Now connect it to two one ton trucks and do a tug of war. Hey look no flex and it did'nt break! It stretched to a point but they are designed to do that...

Ok a metal tube. How much weight can you place on one end of it when it is standing on end before it bends or compresses? Now how much weight can you hang from it before it stretches... It is'nt going to bend because it is getting pulled straight.

Now on a 2G DSM look at the four bolts. One front bolt is under a cruise component and another is at a bad angle to get to due to the timing belt... They market bolt ons for people sometimes incapable of doing anything but bolt something on. So making a 4pt 2g DSM bar would make it a non bolt on part... It's probably a sales, marketing, or exec that made that decision not the design guys.



It's not impossible to make it just not easy.

Hey I got it cheap and honestly there is'nt anything better off the shelf for a 2g.

Like some cheap ass bar that most people buy that flexes more than the n-spd and does'nt even connect the points that actually control the upper half of alignment on a 2g.

I did stand on it... The problem is'nt when you pull up but actually when you put weight on it..

The bends in the bar bend... Which means that under tension they straighten. Not good.


Now with some other mods like an intake manifold I'll have more room to play with.. Maybe a 3pc bar... A main beam like a stout aluminum I beam. Then two triangular brackets one for each pair of upper arm bolts. Something very resistant to tension and compression (not as important) and also keeps the four bolts square.

I guess the ideal 2g bar should tie all four upper eyebolts together, clear everything in the engine bay and not flex when pulled on at the mount points. It will have to be a pretty complex design as compared to the cheap crap on the market..


Oh and before anyone pulls any info out their butt or flames because they don't know what else to do.. read this...



Strut Tower bar theory

Cornering on smooth asphalt induces tension. Driving in a straight line over bumps induces compression. .......... In conclusion; some cars spend most of their lives driving in a straight line. Such cars might experience the strut towers moving together over time. Track cars spend a lot of their time cornering at over 1G. Thus a track car might see it's strut towers spread apart over the years. This means that a strut tower bar can be under tension OR compression, depending on the environment that the car is operated in.

 

[jtmcinder]

Originally posted by MNGSX
Strut Tower bar theory

I have a 2G, so this page doesn't quite work for me. Is there a comparable tech page for those of us with SALA suspensions, because I'd like to see the math. Thanks.

- Jtoby

 

[ACM]

Wow.......

"Oh and before anyone pulls any info out their butt or flames because they don't know what else to do.."

Ha ha ha ha ha :laugh:

I would critique that, honest, but I can't stop laughing long enough.

If nothing else this all good for giggles.

Charles

 

[MNGSX]

If you know so much about SALA suspension... Why not do your own.

The forces on SALA just go into a different area of the tower thru the arm as opposed to the end of the strut.

Oh and ACM that seems to a typical response from you...

I pretty much just say I'm tired of the trash talking... Then you talk trash about that.


Hmm maybe to something like provide a link to a bar that is'nt a POS.

 

[Morphius]

I came across that link you posted 2 days ago, but felt it was pointless to post it. And I think you see why.

The SLA (I thought the acronym for this was SLA not SALA.... doesn't matter, we're all on the same page) just provides an additional load path. The forces through the tower are still going to be very similar.

 

[MNGSX]

Well I thought people could think and make the necessary changes to understand what happens when you have a double wishbone front.

If a cornering load acts on the top of the spindle in a given direction and the two cars weight the same the forces transmited to the frame will be the same and in the same direction.

I think a double wishbone chasis all other things equal is less likey to flex. The lateral loads are distributed across two points and lower than on the top of the tower. So you have more area and less leverage.

The four point n-spd bars in the pictures fit civics or RSX.. Both bars for those cars have the four point attatchments.

In reality on mac-strut cars where a straight unobstructed path exists between the towers a tight steel cable could be used to tie them together and be as or even more effective than a bar...

On a double wishbone car we are better off connecting all four bolts together for the upper arm. But we need something that wont twist so we really need an I beam.

 

[jtmcinder]

Many things are rather different between struts and double-wishbone. Besides the simple things, such as bump-camber curves, you have the complicated things, such as roll-center heights. Because of this, I'm not ready to assume that the difference in suspension type is not going to make a major difference here, too. This is why I asked for a page that is specific to my suspension.

- Jtoby

ps. Morphius - you do realize that the page says the opposite of what you've been saying, right?

 

[igs]

Originally posted by jtmcinder
Many things are rather different between struts and double-wishbone. Besides the simple things, such as bump-camber curves, you have the complicated things, such as roll-center heights. Because of this, I'm not ready to assume that the difference in suspension type is not going to make a major difference here, too. This is why I asked for a page that is specific to my suspension.

- Jtoby

ps. Morphius - you do realize that the page says the opposite of what you've been saying, right?

the tech manual has a diagram with calculations

 

[Morphius]

Originally posted by jtmcinder
you do realize that the page says the opposite of what you've been saying, right?

Wrong. Did you read both pages? Reread my posts. Under normal driving it oscillates in compression. I agree that under hard cornering, it'll will at a point , crossover and induce tension. Where? I don't know, but it depends on the weight of the car and the cornering force.

My point with the strut towers. Let's say they flex 3mm total. If the unloaded chassis (wheels in the air) is not the static point for strut towers, that would mean the unsprung mass is deflecting the towers outboard 3mm when you lift the car in the air. What does that weigh? We'll be generous and say 150lbs. SO, then how much would it deflect then if you set the car on the ground? 3mm inboard? SO, then the weight of the car (700+lbs) is only deflecting it 3mm? The same amount as the 150lbs of unsprung weight? There is no logic there.

^^ my point. The 150lbs unspring weight is not going to deflect the chassis as much as the 700+lbs weight of the car (one wheel). So, knowing the chassis flexes 3mm total, where would you say the static unloaded location of the strut tower should be. (Meaning the chassis hasn't flexed and it's in it's' designed position) I say, it's in correct postion when the wheels are in the air, because the 150lbs is causing negligable deflection.

Thus, by setting the car on the ground to install the strut bar, you are inducing an initial condition, chassis flex. Thereby, biasing the cross-over point for when the strut bar goes into tension on a hard corner. Instead of say .5g's to crossover and induce tension. Now, it might take .25g's. Based on that, I'd agree that could be helpful for a track car to preload it like that.

 

[Morphius]

Originally posted by igs
the tech manual has a diagram with calculations

What tech manual?

 

[igs]

Originally posted by Morphius
What tech manual?

That 2g manual. I'll post a screen capture tonight.

 

[igs]

 

[jtmcinder]

Morphius -

My apologies. It never occurred to me that we were talking about anything other than the effects that STBs have when cornering. I could make some excuses for my narrow-mindedness, but won't bother.

- Jtoby

 

[Morphius]

Originally posted by jtmcinder
Morphius -

My apologies. It never occurred to me that we were talking about anything other than the effects that STBs have when cornering. I could make some excuses for my narrow-mindedness, but won't bother.

- Jtoby

Apology accepted. Likewise, my appologies. Based on my first posts in regards to this discussion, I see how my responses could have been interpreted as talking about the STB and cornering only. Which, in reality, I wasn't. At least I wasn't thinking it. But could be interpreted different.

Given most people don't put a STB on for true perfomance gains. (ie how many people here running a STB actually autocross their car regulary?) ALot of them, just put them on for appearance. At first, I interpreted the initial question as if this was the case..... that the car and STB would likely see only compression most it's life.

Anyway, this is a dead horse. The postive...... I think we all learned some valuable information.

BTW, do you compete SCCA events?

Back home while in school, I ran our teams Solarcar in about 6 events. Don't laugh the car layed down some serious smack. Numerous times I layed waste to late model V8 Camaros and Mustangs. Car was quick, light and handled like it was on rails.

 

[MNGSX]

Thats all cool but lets design a 2g STB that is'nt cosmetic!

My car is built for drag as use #1 and crossing #2... It will have to be in SM class...

I still think rigidly attatching all four upper arm pivot bolts is the best idea.