New Product: Front Lower Frame Brace
#1
Developer
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I listened with interest when I heard that the mounts for the strut tower brace were starting to fail on some cars. Only those cars that had aftermarket really strong strut braces (like ours) and wide front tires, and being driven really hard. Those guys were talking about deformation of the mount or tearing out the spotwelds.
It reminded me of a suggestion from a customer that had been submitted to our "Best New Product" contest.
http://www.928m.com/newproductcontest.html
Sure enough - I went back through the contest entrys and found it. I'd like to say I thought of this one, but actually I am only able to say I listened. And the customer is $100 richer.
The design is all mine (and a bit different than the customer's idea) but we were able to get a strong, light brace in there, adjustable to fit every car, fits even with any of the alternators that your 928 may have, and inside the engine belly pan if you've got one. It clears the oil pan so you can use any pan gasket you want. I supply shims with it too, so you can tweak your install to compensate for early or late-model motor mounts and alternator size.
Its a pretty sweet deal - and will do more to hold the correct camber angle in corners that any other suspension weapon. Now the upper strut brace will not be over-tasked... it can stabilize the shock tops while this will stabilize the a-arm bottoms.
If you are familiar with your 928 from under the motor looking up, then you know that there is a cross brace between the two a-arms at the back of the motor. The steering rack sits in it. But there is no cross brace in the frame again for 2 feet - the little one that is underneath the radiator.
The front mounting point for the lower a-arm is 5 to 6" below the frame (so it has leverage on the frame), and it has no support for 12" in either direction.
That a-arm can easily be pushed in under hard cornering... and the camber you thought you had set at rest is lost mid-corner.
I took a little longer to roll this one out.... I did not tell anybody about it until I had installed in on both an early car and on a late-model car. I have done both. I only had trouble with the alternator hitting the frame brace on a late model car with collapsed old hydraulic mounts. I replaced them with the solid rubber mounts we sell, and its fine. OEM motor mounts in good condition was also fine. No problems.
I have a full write-up here:
http://www.928motorsports.com/parts/...rame_brace.php
that will provide even more info for you.
As always, thank you for your interest!
It reminded me of a suggestion from a customer that had been submitted to our "Best New Product" contest.
http://www.928m.com/newproductcontest.html
Sure enough - I went back through the contest entrys and found it. I'd like to say I thought of this one, but actually I am only able to say I listened. And the customer is $100 richer.
The design is all mine (and a bit different than the customer's idea) but we were able to get a strong, light brace in there, adjustable to fit every car, fits even with any of the alternators that your 928 may have, and inside the engine belly pan if you've got one. It clears the oil pan so you can use any pan gasket you want. I supply shims with it too, so you can tweak your install to compensate for early or late-model motor mounts and alternator size.
Its a pretty sweet deal - and will do more to hold the correct camber angle in corners that any other suspension weapon. Now the upper strut brace will not be over-tasked... it can stabilize the shock tops while this will stabilize the a-arm bottoms.
If you are familiar with your 928 from under the motor looking up, then you know that there is a cross brace between the two a-arms at the back of the motor. The steering rack sits in it. But there is no cross brace in the frame again for 2 feet - the little one that is underneath the radiator.
The front mounting point for the lower a-arm is 5 to 6" below the frame (so it has leverage on the frame), and it has no support for 12" in either direction.
That a-arm can easily be pushed in under hard cornering... and the camber you thought you had set at rest is lost mid-corner.
I took a little longer to roll this one out.... I did not tell anybody about it until I had installed in on both an early car and on a late-model car. I have done both. I only had trouble with the alternator hitting the frame brace on a late model car with collapsed old hydraulic mounts. I replaced them with the solid rubber mounts we sell, and its fine. OEM motor mounts in good condition was also fine. No problems.
I have a full write-up here:
http://www.928motorsports.com/parts/...rame_brace.php
that will provide even more info for you.
As always, thank you for your interest!
#4
Developer
Thread Starter
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We made it with chrome-molybdium tubing. Stronger in compression than aluminum tubing would be. And very light. The whole piece weighs just 2 pounds. The chrome in the alloy will make it naturally rust-resistant. If you are concerned about rust at all, you could just spray-can it before you put it on the car.
#5
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Carl:
So how does this change the feel of the cars setup. Would you say that because of the bar acting somewhat the same as a thicker swaybar that this should produce More understeer Less oversteer ?
I'm running sticky 275 on the front on a 9.5 inch rim.
Thanks,
Ken
So how does this change the feel of the cars setup. Would you say that because of the bar acting somewhat the same as a thicker swaybar that this should produce More understeer Less oversteer ?
I'm running sticky 275 on the front on a 9.5 inch rim.
Thanks,
Ken
#6
Drifting
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Ken, this won't act like a swaybar at all. What it does is help keep the chassis square so the suspension doesn't flex it. It keeps the suspension geometry closer to what the factory intended during cornering.
#7
Rennlist Member
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John:
I understand that.
But if there is that much flex going on it should have a change in the way the car feels. I'm just trying to equate that.....
I am at the limit of dialing out oversteer with my camber setting, sway bar and shock settings. I don't want to add something to the car that I can't dial out.
Regards,
Ken
I understand that.
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
But if there is that much flex going on it should have a change in the way the car feels. I'm just trying to equate that.....
I am at the limit of dialing out oversteer with my camber setting, sway bar and shock settings. I don't want to add something to the car that I can't dial out.
Regards,
Ken
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#9
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Nice!
An added benefit would be protection of the AC compressor mounting points that can break when the underside strikes something like a parking bumper.
An added benefit would be protection of the AC compressor mounting points that can break when the underside strikes something like a parking bumper.
#10
Developer
Thread Starter
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Good questions all. I'll try to answer all of them.
This will not make the vehicle appear to have a larger sway bar. The flexing of the frame at this point seems to effect camber mostly, but as the swaybar is more securely mounted to the frame behind the steering rack - that part of the frame has not been significantly flexing. (Although it may be worth noting how many of us have removed that little secondary cross-brace that was behind the bell housing in order to install headers)
Will that bolt bend? No, the load is spread over 4 bolts (two on each frame) and the bolts are supported right to the collar by the aluminum mounting flange they go through. So, take the lateral load and divide by 4 to get the load per bolt. Also, we do provide a longer bolt than stock with the FLFB, and we have checked to make certain that we get full penetration into the threads in the frame.
I will say this: you will be surprised how easy it is to add camber by just turning the FLFB with your hand. Without using tools (and with the tires off the ground in this example), I was able to grab the center section and twist it and add 0.5 degrees of camber without much effort. The frame twists that easily. Then it got stiffer, as the frame pre-load came in finally.
Imagine the loads involved caused by inertia alone.... you have a 3000 pound mass that wants to go straight, and the tires are turned underneath it in their effort to change the vector. That'll push on a-arm pretty hard!
This will not make the vehicle appear to have a larger sway bar. The flexing of the frame at this point seems to effect camber mostly, but as the swaybar is more securely mounted to the frame behind the steering rack - that part of the frame has not been significantly flexing. (Although it may be worth noting how many of us have removed that little secondary cross-brace that was behind the bell housing in order to install headers)
Will that bolt bend? No, the load is spread over 4 bolts (two on each frame) and the bolts are supported right to the collar by the aluminum mounting flange they go through. So, take the lateral load and divide by 4 to get the load per bolt. Also, we do provide a longer bolt than stock with the FLFB, and we have checked to make certain that we get full penetration into the threads in the frame.
I will say this: you will be surprised how easy it is to add camber by just turning the FLFB with your hand. Without using tools (and with the tires off the ground in this example), I was able to grab the center section and twist it and add 0.5 degrees of camber without much effort. The frame twists that easily. Then it got stiffer, as the frame pre-load came in finally.
Imagine the loads involved caused by inertia alone.... you have a 3000 pound mass that wants to go straight, and the tires are turned underneath it in their effort to change the vector. That'll push on a-arm pretty hard!
#11
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![](http://www.wisegorilla.com/images/math/parallogram.gif)
I'd think it'd have to have a companion diagonal bar, or be attached to both bolts, on both sides, with an unjointed connection, to keep it square?
Fixed on one end, adjustable on the other, to push or pull the frame to the desired specs.
#13
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Not quite like that.
Remember there is a tubular frame in that geometry that resists the twisting motion now, and it is connected across the car side-to-side in two places at the front of the car: the cross brace that the steering rack nests in (12" to the rear from the front lower a frame mount) and the cross brace under the radiator (12" to the front of the lower a-frame mount).
Between the torsional ridgidity of the tubular frame members, and the two cross-braces, we are finding that they only need a little help to maintain their shape. It's not like those parts aren't there anymore.
It would be a very good idea to triangulate this up to the frame rail in some way, but that goes beyond a) what most 928 owners need, and b) what I can ship as a "bolt-on" kit. To triangulate up to the frame would require the 928 owner to relocate the power steering pump, and perhaps to remove their AC compressor on the other side. Then there would be some welding required to make an attachment point to the frame.
That goes beyond the capability or the desires of but just a very few.
On the other hand, this, by comparison, provides a great deal of added ridgidity and requires only the simplest of installations and no mods to the car.
Remember there is a tubular frame in that geometry that resists the twisting motion now, and it is connected across the car side-to-side in two places at the front of the car: the cross brace that the steering rack nests in (12" to the rear from the front lower a frame mount) and the cross brace under the radiator (12" to the front of the lower a-frame mount).
Between the torsional ridgidity of the tubular frame members, and the two cross-braces, we are finding that they only need a little help to maintain their shape. It's not like those parts aren't there anymore.
It would be a very good idea to triangulate this up to the frame rail in some way, but that goes beyond a) what most 928 owners need, and b) what I can ship as a "bolt-on" kit. To triangulate up to the frame would require the 928 owner to relocate the power steering pump, and perhaps to remove their AC compressor on the other side. Then there would be some welding required to make an attachment point to the frame.
That goes beyond the capability or the desires of but just a very few.
On the other hand, this, by comparison, provides a great deal of added ridgidity and requires only the simplest of installations and no mods to the car.
#14
Developer
Thread Starter
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Viagra bar? Showing your age Jimmy? Or are you suggesting you will go so fast after using the Viagra bar that you, too, will go blind? ![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
(I find it ironic that Mothers have warned for generations that to play with THAT THING too much and "you'll go blind". Now, many years later, some Viagra users are loosing their eyesight. How did Mom know that? )
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
(I find it ironic that Mothers have warned for generations that to play with THAT THING too much and "you'll go blind". Now, many years later, some Viagra users are loosing their eyesight. How did Mom know that? )