Topic: GM engineer questions backbone

[Hal 9000]

He also said the clunk was the way I drove it, but it's mysteriously gone now with the new upgraded diff.
 

[Yamatr3]

The only time where the brace will be noticable will be when the frame is subjected to a vertical force that is not equal across the car.  This is nicely showcased with the DDM jack test.  Essentially they are putting a vertical point load on one side of the car.  It creates a moment which a thicker plate will handle better.

In most driving conditions you will not encounter this scenario.  In 99.9% of driving cases the forces exerted on this piece are going parallel with the brace plane.  On paper the thicker plate will handle this force better as well but youll be spinning well before you you max out the stock piece and notice a significant difference in feel.

All that being said I bought a brace from DDM and haveit installed.  On the .1% chance I get a road irregularity that wil cause the torsion effect Ill be ready.

Or every time you accelerate hard when the chasis tries to twist.  The backbone works way more than .1% of the time.

[Sky 5]

  In 99.9% of driving cases the forces exerted on this piece are going parallel with the brace plane.  On paper the thicker plate will handle this force better as well but you'll be spinning well before you you max out the stock piece and notice a significant difference in feel.

Thanks for having the cajones to go against the grain here and speak the truth. Under normal, even spirited, everyday driving conditions with the stock EcoTec, the so-called "backbone brace" has little if any effect.  Wanna make the Kappa feel like it's riding on a rail? Lower it about a half an inch and get some sticky tires. An aluminum belly plate is not some magical suspension fix. Will go get out the asbestos body armor now    and await the flames    which are sure to follow.

[Critterman]

Sky 5 - I don't disagree when talking about a stock N/A  but I will beg to differ with you if you have a tuned GXP or aftermarket power.  I know what my car used to do, and what it does now.  Now it handles the power and doesn't shake and squiggle all over the road.

[Ben L]

Here's a novel proposition:  Let those who ride decide.  

Is it so important to be "right" or controversial?  

If only people who agree with you "speak the truth" or "have cajones," so I guess others are lying and nutless for not agreeing with you?

That's not very nice.

You and everyone else with your opinion will never convince me that my own senses are lying, but you are welcome to your own views.

I installed the brace before I lowered the car and got sticky tires.  You guys weren't in the cockpit with me.

By the way, have you got one installed?    

[G8TR]

Check out http://www.skyroadster.com/forums/f18/bite-out-g8tr-30198/ . I'm sure DDM's parts saved my a$$ and my car. Thanks DDM. 

[chuckdoc]

Please, most of us on this forum have met and know each other.  Some of us quite well so some of you guys who are used to forums where you are anonymous please tone down the rhetoric and treat each of us like a current or at least future friend.  This really is quite a different forum than you are used to.  Simply just read your post before you post and asked yourself if it gets your point across and would be considered done so without implying anything pejorative or ad hominem.  (latin is a little rusty but you get the point)

Don't make me use hidden super powers to cut ya off at the knees.

Chuck

Now back to the discussions.

[Sky 5]

I'm sure DDM's parts saved my a$$ and my car. Thanks DDM. 

See, that's the rare 1% occasion where one corner of the vehicle met with an extreme elevation change and the stiffer tunnel cover helped you out. Thus, as a sort of insurance mod it is definitely worthwhile; but it will not turn a Kappa into a Mazzerati. Just sayin. Remember in the olden days there were owners who pulled that cover plate and the trans cover in their efforts to lighten the car. There were no reported ill effects. Pulled the driveshaft cover and drove it a couple of days and it felt basically the same. Got another OEM plate off the web from a Solstice and bolted the two of them together back up onto the tunnel and still no big change in normal driving. That said, for those who really want the assurance of a sturdier lower center, the DDM piece is surely a good thing to have.

[chuckdoc]

Much better for sure.  Big hug (in a manly way)

[Sky 5]

 

Bone stock... or modded out the wazoo... we all love our Kappas! 

 

[DeepBlueGXP]

I know this much, with my westers tune and the power I put to the ground, I noticed previously (especially at night) that the left headlight would show visible down the road much higher than the right.  After the backbone, both come up evenly when I hit the pedal to the metal...

[Treeman]

You know, the blind testing the engineer was talking about was done before GMPP tunes - stock engine.  Is the big difference for those with the added power?

[PubliusE]

I installed the Race version of the Backbone.  I was one of the few people who immediately stated that I did not feel much difference and that surprised me based on all the positive posts by others.  My car is a GXP with the GMPP Stage II tune.  Sorry, I just did not notice a change.

[baconbits]

You would think that GM had mounted strain gauges on their test cars with and without the tunnel brace..I'm sure there is data other than seat of your pants that prove the brace works..you would think less flexion in the chasis would be a good thing and by the sounds of most of the people that push their car this brace works...jusy my thoughts
Bacon

[lil goat]

Do you clowns that can't feel this live in a vacuum, this is not a new phenomenon, ALL convertibles have frame flex, always have. It's because there is no roof to give the frame rigidity. If you push our cars hard in a corner they will lift the back outside tire off the ground, that is a fact, so will a Miata, a BMW M3 and even several hardtops. That is called frame flex, the car is subject to the laws of physics and the car wants to roll over, that's why we have shocks and springs. It will flex differently from the front to the back that is just fact there is no question about it, that is true of ANY car. The backbone adds some much needed rigidity to the car. I drive my car so hard the backend often breaks loose and slides sideways, I have my car lowered over 3 inches and very sticky tires and light weight wheels, I also have a hot tune. I think that maybe I can tell if it does anything. Some of the people who have endorsed this product are autoX drivers, I would think they could tell. Rhys Millen has his own version on his Red Bull Solstice, he is no dummy either. If you can't feel it I would say you drive like a girl, but I bet I know at least one that can drive better than most men, so I will say quit drag racing and try driving around a corner you bunch of old ladies. I know at least 2 of you that have posted negative comments have a reputation for doing exactly that and I personally wish you would go back to the BB where you belong.

By the way I guess you guys don't believe in sway bars either, or that changing the back one will effect the front handling and vice versa. There is a lot more to car handling than you pencil neck geeks seem to begin to understand. I won't even get into frame flex from engine toque I am sure that would just confuse you.

The GM engineer says he COULD feel when they just took a couple of bolts out of the stock plate, that would led me to believe that there is something going on down there. I know DDM has already stepped up to work on doing a blind test with him, "they ain't skeerd"

[Ben L]

Dave T Demonstrating Frame Flex at the Kink at Cumberland

[MomsSol]

FYI for all .....

About a year ago when Kappasphere came out with their ReBAR, than a short time later DDM with their ProBeam, I sent Steve an email (that was long before he was posting openly on the BB)

I asked him if these bars would indeed improve the handling - in a nut shell he told me that most people would not notice the difference, however, those of us who drive our cars HARD would notice a measurable difference in the way the car handled in curves.  Having ridden in my car with me ... he stated to me that I *would* be able to tell the difference. (he did mention one over the other )

I do understand what he is saying with regard to the BackBone ... he *is* an engineer, and as such more info is needed in order to make him state the advantages of the BackBone.

He will be in Colorado at the National Meet .. perhaps a 'blind study' can be done with some Sol/Sky owners.

[PubliusE]

Do you clowns that can't feel this live in a vacuum, this is not a new phenomenon, ..............
 If you can't feel it I would say you drive like a girl, but I bet I know at least one that can drive better than most men, so I will say quit drag racing and try driving around a corner you bunch of old ladies. I know at least 2 of you that have posted negative comments have a reputation for doing exactly that and I personally wish you would go back to the BB where you belong.

By the way I guess you guys don't believe in sway bars either, or that changing the back one will effect the front handling and vice versa. There is a lot more to car handling than you pencil neck geeks seem to begin to understand. I won't even get into frame flex from engine toque I am sure that would just confuse you.

I guess anyone that didn't feel a difference is a clown that drives like a girl.  I hope you weren't referring to me in your post.  I originally said I did not feel a difference.  So, I didn't do you want me to drink the Kool Aid and lie?.  I never made a negative comment about this product or the company that manufactured it OR any individual who had an opposing opinion.  My original post also wondered f it might be because my car is still new and tight.  I fully understand flex, roll and the importance of strengthening the frame.  That is what the original GM plate does as well.  The question is does it do it any less than the Backbone?  I do believe the Probeam will make a difference and have it on my list.

These are the elitist type of posts that attack individuals for no reason which will eventually drive people away from this board.  It is a shame that someone can't have a difference in opinion without being labeled elementary school names.  

[TecSolOnt]

  The whole point of bulletin boards is information and to trade opinions, we should respect both sides. As I said a few posts ago beauty is in the eye of the beholder.

[TecSolOnt]

 I should have added to my last post despite my thinking there is validity to the engineers point that most won't notice the difference with the backbone when I go down to DDM in July I will be adding both the backbone and pro beam.  If your going spend $4-5k on a STII why wouldn't you drop a bit more and add some stiffness to the suspension, but that's just me. Never know when you are going to push it a little harder into that corner... 

[lil goat]

I guess anyone that didn't feel a difference is a clown that drives like a girl.  I hope you weren't referring to me in your post.  I originally said I did not feel a difference.  So, I didn't do you want me to drink the Kool Aid and lie?.  I never made a negative comment about this product or the company that manufactured it OR any individual who had an opposing opinion.  My original post also wondered f it might be because my car is still new and tight.  I fully understand flex, roll and the importance of strengthening the frame.  That is what the original GM plate does as well.  The question is does it do it any less than the Backbone?  I do believe the Probeam will make a difference and have it on my list.

These are the elitist type of posts that attack individuals for no reason which will eventually drive people away from this board.  It is a shame that someone can't have a difference in opinion without being labeled elementary school names.  

First off I call them as I see them, if you did not feel a difference I personally can't see how. I felt it pulling out of my driveway when I dropped off the lip onto the road, the car just didn't shake as much. In cornering I could always feel the frame flex and "set" then I would accelerate and when I straightened out I could feel it "un-set" This was on two different cars, first my NA then my GXP, both were bought new so they were "tight". I drive very hard, there are many here that can testify to that. I have spent a lot of money to improve handling on my car and very little on "pretty" mods. I am still doing mods to improve handling. I did the backbone by itself to see what it would do, I was one of the original testers. I notice the car no longer had to "set" when cornering hard in sweepers. That is when I was convinced. I do not want anyone to drink the kool aid as you say, I do mean to imply you might need to push your car a bit harder to feel the difference, but first be so kind as to put the stock piece back and go test, then put the backbone back on. As far as you or anyone else leaving this forum, that is your right. I left the other forum for a reason. I have strong opinions, and I express them. They don't call me Mr. Prickly for nothing! This is supposed to be a performance forum, and may not be right for everyone, but for those of us who really push our cars it is "THE" place to be. I have learned so much here from people like Ben and SOB who push there cars in AutoX, and from Dave and Randy who also race. I get advice from my friend Rhys Millen and share when I can. Unlike many I am not new to modding, my Harley has many more than the Solstice ever will, I have said it before I have modded everything I ever owned starting with my little red wagon.

For the record I never said you drive like a girl, knowing people like Momssol and Smartin and others. I said you drive like and old lady, if you are going to take offense at least do it correctly.

[TecSolOnt]

    Since when did old men drive any better than old ladies? Been behind both and can't say I see much difference, lets not forget old is a relevant term, kinda like being called fat. Sometimes its now what you say but how you say it.

[snaponbob]

The name calling was gratuitous, and hopefully was a bit of an "input" malfunction. The level of sensitivity of various people's vehicle dynamics butt dynos certainly vary, and thus some may not feel or sense the same level of flex or changes before/after chassis mods. Steve P. has manned up after taking the "no need" position (driven by the math) and changed his positions IN PUBLIC, and is no clown. There was a Kappa owner (who REALLY knew nothing about sports cars in general) who posted last year about how harsh his 2.4 Kappa rode, didn't understand WHY a short wheelbase car reacted to road input, insisted his MB rode better, etc., etc., etc. NOT a clown (maybe CLOSE) but rather not a sports car type.

You want "CLOWN"? Here is "CLOWN". Blingers take their Escalades into wheel shops, swap their 18" wheel/tire package for 24's, and return a week later to complain about how rough the ride is and   about the noise. Want a Super Clown? The Clown's buddy does the same with 22's on his Range Rover and adds tire rub to his list of complaints. Saw it, heard it. (Amazing what a Sanp-On dealer hears/sees over 19 years!!!!!)

Now, if THAT hasn't pissed off enough people, let me address the Cobra picture. THAT is a picture with seriously mismatched sway bars. Is the frame flexing? Could be. But this car is stuffed in a turn, the right rear wheel is still well up in its wheel well while the right front wheel is extended on its suspension. I saw a Cobra kit car do exactly the same thing in our area. It was a bar issue. IF the frame was flexing THAT much there would be substantial damage to the upper rear of the door jams. I have also seen Cobras with way stiff front bars and soft rear bars do exactly the opposite of the picture.

Lastly, IF a Kappa really lifts a rear wheel off the ground either the pavement is VERY rough or the rear bar is WAY too stiff. Transitioning into a turn WILL lighten the inside rear. I have enough pictures of my car over the past three years to see how my set up AND driving have changed the way the car looks in turns. The better the car is set up (assuming what's under the car is not stock) will determine how it acts at each corner in turns, and the driving technique can be seen if the car (suspension) is properly tuned.

BTW, if someone wants their GXP/RL to act like a "drift" car, try 300 pound front springs and 500 pound rear springs. It is entertain only for about 15-20 minutes. Ask me how I know THAT little gem of information !!!!!!!!!!!!

p.s. There is no need for rocks to be thrown around here. And it should stop. Just look at what the "other" forums have devolved into.

[Sky 5]

  Some of us quite well so some of you guys who are used to forums where you are anonymous please tone down the rhetoric and treat each of us like a current or at least future friend.  This really is quite a different forum than you are used to.  Simply just read your post before you post and ask yourself if it gets your point across and would be considered done so without implying anything pejorative or ad hominem.  (latin is a little rusty but you get the point)

Bump.




Not likely that many Kappa owners "drive like an old lady"

  otherwise they would be driving ... BUICKS.

[lil goat]

Many Kappa owners do in fact drive like old lady's especially the N/A owners, there has been a huge issue with the catalytic converters getting clogged due to lack of RPM's mostly, high RPM's help the cat clean itself, many, many people have posted questions on when to shift and asked why is it so noisy over 4000 rpm, is that a problem. If you guys have an issue with my posts I suggest you don't read them, just add me to your ignore list it's easy. Trust me on the other forum I had quite a long ignore list. While I respect many people's opinion on here I rarely agree with all of them, that is why we are here to discuss things, generally performance related. I try and base what I say on personal experience, facts, or information from people who I consider knowledgeable in the subject matter. One engineer, who do to the fact that he works for GM is limited in what he can say publicly will not change my opinion. I have the utmost respect for his stating an opinion at all, he is going out on a limb. I know I would not state negatives about who I work for, I like eating to much. He has a far more open mind than the engineers I know, he is involved with applied engineering not just theoretical, I also applaud him for that. He has volunteered to do a blind test, in that there will be  resolution for some, I don't need validation personally I know it works, and very well. It is just to simple a concept to me, but I am a car nut and a techie.

By the way I never said I had anything against clowns, they make me laugh. I do see a pattern in the posts of some that they are always negative, I have an issue with that. These people would complain about free gold because it is heavy.