Searched for info on this but could not find any so I am wondering if anyone has used one of these on their FC? I have an 88' vert that is receiving the TII transplant and although these look to be functional I am not completely sold on what is promised as I am trying to stiffen up the frame a bit.

 

It looks like it might do a little. When I wanted to stiffen up my vert I ended up putting a roll bar in and it made a world of difference (no more shimmy with the top down when going over rail road tracks).

 

I can't remember if that portion of the car is a load bearing member of the unibody. Where's NZConvert, Evil Aviator, or Hailers to chime in and tell me I'm wrong?

(The following is subject to scrutiny and flaming) It seems to me that it offers vertical support from flexing. Whether it's more than needed I don't know. It looks as though it will provide no lateral rigidty increase and may not be worth the added weight unless you're seeing large amount of track time. Also the mounting to the door bracket may be more of a hassle and not worth the trouble of re-aligning the door. However, if used in conjunction with other suspension geometry components its use may increase significantly to reduce flexing on an un-even surface.

Looking on their site I see no remarks concerning Weight, Rigidity, and price which leads me to believe this product might be discontinued.

 

I'd be interested in these if anyone can find them again.

 

I'm considering going down the rollbar route but am going to go with a custom twin hoop setup instead of the flat top bar. As far as where to get these pieces I am going to go ahead and buy a set (found them for 100.00) and post pics of the install and my general driving impressions of them after a trip to US129~Dragon's tail. Thanks for all the feedback and I agree about the lack of providing more lateral rigidity, but I will take one for the team and let you guys know.

 

Ill translate that last post for all yall.

"I just wanna have something that all the other 7 owners can gawk at!"

But really, if they make the driving feel any better let us kno... i saw those for a 240 the other day and started to wonder....

 

^^ to say you have something that the other guy doesnt. lol But if i had $$ id get em.

 

here's the website: www.ultraracingaustralia.com

 

I'm not an engineer but here is what I see.

As the shock compresses, the top of the shock wants to move toward the centre of the engine bay, hence why shock tower bars are used. The shock tower bar effectively causes the 2 towers to push against eachother which does not allow as much flex throughout the body. These are effectively attached to the outside of the shock tower, and when the shock is compressed it will pull the contact point above the wheel toward the centre of the car. This will cause and outward force on the lower door jam mount and an inward force on the upper. Since the door jam is very near the firewall, this area will be very resistant to flex chances are those two mounts will not move at all. However, the tubes this is made of will most likely twist some. For side to side flex, i'd say this will do a bit but a strut tower bar will do more.

For front to back flex it will have more effect. From the look of things, when the shock compresses this will attempt to put more force on the upper door jam point, pushing it toward the back of the car. The lower door jam point will act as a pivot point. IMO, this will send more load through the upper part of the car, ie. the roof, which would make this limited in value to how much more load the roof of the car can actually effectively handle. I know that the roof does help support the structure of the car but i don't know how much it would in the car's current state and I don't know how much it can in a modified state. In the coupe, I think this could prevent some flex front to back as it looks like it will take some load off the lower frame rails. In a convertable, I could see it making little or no difference, and possibly even causing more flex as it may lever some force to a higher part on the car where the convertable has nothing to support.

All in all, I think these will have a minimal difference side to side and front to back. I have my doubts as to how much more stiffness these will provide in a stock car. If the car has a cage in it, and these can be connected so the forces are applied to the cage then I could see this mod haveing more of an effect. Otherwise, your just moving moving force from one part to another which may or may not be able to handle the force effectively.

Remember, this is just my opinion, and i'm not an engineer.

 

I haven't seen those before but I did come across this awhile back...

http://www.more-japan.com/product.ph...4&cat=0&page=1

 

Useless. Only good in the fore-aft direction, which means it is going to help prevent flexing under braking or acceleration and thats it. I highly doubt that the needs any more rigidity there. I am pretty sure no one has bent the unibody there that wasn't involved in a serious frontal collision.

 

Under braking is key there... from my understanding is less flex when braking means less weight transfer which means better braking???

Correct me if i'm wrong.

 

I had those fender braces on my 240sx. Made a nice difference. Then again, the s13 frontend is pretty weaksauce.

 

That is true, but I REALLY doubt the chassis is weak enough right there that you are seeing much of any flex, and if it IS getting loaded enough to undesirably flex it, that bar probably isn't meaty enough to do anything about it, especially because of the offset of the horizontal member when compared to the front attachment point to the chassis. That loads that skinny upper section completely, which would still allow a bit of flex before the bar even as any effect.

I could be wrong, I'm still a student, but it seems utterly pointless to me.

 

Ok, here's the thing.......JDMSuper7 makes some valid points, but what I am after with these bars is exactly what the company intends the bars to be utilized for: to strengthen and reinforce the vertical loads on the front of the car.


Advertised as advantages of the fender bar:

Improved handling, stability at high speed and cornering, hence safer driving.
Provide a better braking and stopping performance.
Reduce NVH (Noise, Vibration and Harshness).
Increase stiffness of vehicle front chassis.

Now I'm not buying into all of their promises here as I've been around the block more than once at this point but I am hoping that their product will help cut down on cowl shake/shudder with my vert' since I will also be using this in conjunction with a 3 point Mazdatrix Firewall brace among other things (AWE X Brace, uprated front and rear Sway bars, Tein Flex coilovers) which should tie the front end in nicely. This one thing will make it worthwhile to me as I can't remember riding in one stock convertible built in the 80's that didn't suffer from cowl shake or bump steer because of chassis flex. In any case, I paid very little for them and since I already have Origin fenders to offset the addition of the weight I see little to lose other than some of my time installing them. Because this has kindof turned into a debate, I have no problem with installing only these first and taking the car out to an old airport that we used to use part of for a skidpad to see what they will pull with the Gtech Pro with and without (stock suspension as a baseline that is new within the last 10,000 miles according to the previous owner of the car.

 

Too bad skidpad does very little to indicate how the suspension is really performing...
Transition manuevers that use a change of direction is a better indicator.


-Ted

 

I will be interested to see if you see any benefit over the mazdatrix tri-bar. I figured that with that bar in, the fender braces would not do much more. I <3 my tri-bar.

 

I've read that they make a noticable difference on other cars, but who knows if they'll be noticable on an FC.