Strut Braces

Workshop Help · Postby **Workshop Help** » 13 Jul 2010 00:35

Are there tower struts for the stock TR7 engine with the stock air box intact?

Mildred Hargis

FI Spyder · Postby **FI Spyder** » 13 Jul 2010 01:22

What difference do they make? I can see them for use on a Group 44 racer with 330hp on tap or on a ralley car where you're flying over the ground as much time as on it but for taking those twisty turns at speeds that make you a little nervous because you can't see if smokey is around the next bend or wipping around a traffic circle leaving that tailgating SUV far behind? Don't know of any car that has it so I guess I'll never find out.

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

Spectatohead · Postby **Spectatohead** » 13 Jul 2010 01:31

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by FI Spyder

What difference do they make? I can see them for use on a Group 44 racer with 330hp on tap or on a ralley car where you're flying over the ground as much time as on it but for taking those twisty turns at speeds that make you a little nervous because you can't see if smokey is around the next bend or wipping around a traffic circle leaving that tailgating SUV far behind? Don't know of any car that has it so I guess I'll never find out.

<hr height="1" noshade id="quote"></blockquote id="quote">

I have one on my, otherwise stock, '97 Nissan Maxima. It made a huge difference in how the steering feels. Turn-in is sharper and more direct. The whole front end feels like it is planted better. It is just more pleasant to drive it at any speed. At some point in the future I'd really like to get one for the TR8 too.

Jim Clark
'80 TR8
'97 Maxima 5spd

Beans · Postby **Beans** » 13 Jul 2010 17:43

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Mildred

Are there tower struts for the stock TR7 engine with the stock air box intact? <hr height="1" noshade id="quote"></blockquote id="quote">

I think this one clears the standard airbox.
Haven't any measurements of the airbox so not sure ...

<center>

1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

Hasbeen · Postby **Hasbeen** » 14 Jul 2010 00:59

Spyder, a good one will not only improve your handling, but will
increase the life of your car.

They improve your handling by supporting the suspension towers, &
keeping the suspension mounting points in place, rather than
flexing all over the place. This reduction in flexing increases the
life of your monocoque.

However, many of us know the story of Collin Chapman, who developed
the space frame concept into a breed of extremely light race winning
cars. What he showed us was that a very light bit of tube could be
immensely strong as long as we only asked it to withstand
compression, or tension.

He showed other manufactures that no matter how heavy the tube, once
you bent it, it became another bit of water pipe, with no place in
a performance car.

Today, with most cars being monocoque, the story of the space frame
is probably being lost to our younger enthusiasts, more's the pity.

Of the two photos here, Beans bar will work exactly as designed,
under even minor loads, the other will straighten quite a lot,
before it supplies any support. Now, in my dotage, I doubt I drive
hard enough to actually stress the chassis enough to get anything
from the latter bar, although some might.

Beans bar will be in straight tension, at even minor loads, & if
anyone is interested enough, & will explain the way it works.

Hasbeen

Workshop Help · Postby **Workshop Help** » 14 Jul 2010 01:31

It looks so simple to make one. Yet, the clearance question continues to vex the works when the stock air box remains in the mix.

To my eyes, the straight across the engine brace is the simple preferred design. I can't see a diaganol brace going to the firewall or radiator core support doing much of anything unless it is triangulated to a cross the engine tube. Perhaps if the strut tower mount was elevated to clear the air box, but would that then foul the underside of the hood?

My brain grows weary this evening. I'll leave the discussion to the rest of your fine minds across the globe.

Mildred Hargis

Marko · Postby **Marko** » 14 Jul 2010 11:03

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Hasbeen

However, many of us know the story of Collin Chapman, who developed
the space frame concept into a breed of extremely light race winning
cars. What he showed us was that a very light bit of tube could be
immensely strong as long as we only asked it to withstand
compression, or tension.
<hr height="1" noshade id="quote"></blockquote id="quote">

not to mention cheap in low volume production, most of last decade's supercars where built like that.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Hasbeen
He showed other manufactures that no matter how heavy the tube, once
you bent it, it became another bit of water pipe, with no place in
a performance car.
<hr height="1" noshade id="quote"></blockquote id="quote">

Not completely true, but in vehicles where mass and volume are important could be taken as a rule. Straight tube/rod stressed in tension and compression is most efficient element( strength/mass or stiffness/mass) to achieve equal stiffness (cars are built for stiffness not strength , we don't want parts deforming and moving around) for an element that is not straight or stressed in bending, we need much more material, thicker sections, which increases the mass and the volume of our element (in this case strut bar).

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Hasbeen
Today, with most cars being monocoque, the story of the space frame
is probably being lost to our younger enthusiasts, more's the pity.
<hr height="1" noshade id="quote"></blockquote id="quote">

shells (monocoque constructions ) are more efficient ( more stiffens with less mass) but are expensive in low volume production, consider that every half stamping tool for each part of the bodywork costs 500k to 1mill euros , 2 stamping tool halves per body panel, 30-40 panels per car, we get awful lot of zeros at the end of the bill.
[:o)] . And thats just the cost of the tools.

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Hasbeen
Beans bar will be in straight tension, at even minor loads, & if
anyone is interested enough, & will explain the way it works.
<hr height="1" noshade id="quote"></blockquote id="quote">

Simplest and most accurate analogy would be with springs, beans's construction is like a stiff spring , for small deformations it can transfer high amount of force.

The other construction is soft spring, it takes a significantly higher amount of deformation to transfer equal amount of force.

swifty · Postby **swifty** » 14 Jul 2010 17:32

So let me get this straight - do these braces need to be under slight tension when they are fitted to a car at rest, or do they just undergo tension when cornering? (sorry if this seems likes a school boy question![;)])

[img][IMG]http://i728.photobucket.com/albums/ww281/swiftstuff/029-1.jpg[/img]/img]

Beans · Postby **Beans** » 14 Jul 2010 20:09

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Marko

... Simplest and most accurate analogy would be with springs, beans's construction is like a stiff spring , for small deformations it can transfer high amount of force.
The other construction is soft spring, it takes a significantly higher amount of deformation to transfer equal amount of force ...<hr height="1" noshade id="quote"></blockquote id="quote">
Think that explains it quite nicely [;)]

And this picture illustrates what can happen if you don't have a strut brace fitted (and drive the car hard on not so smooth roads) ...

The light area on the edge of the bonnet is where the paint was damaged by the wing.
The inside of which hit the bonnet's edge during an event with fairly bumpy roads.
Needless to say I didnâ€™t have the strut brace fitted when that damage occurred ...

<center>

1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

Underdog · Postby **Underdog** » 14 Jul 2010 20:14

I've seen them fitted from the factory so obviously of benifit. Car manufactures don't tend to spend money on parts that are not of any use.

Jim Underwood
72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

Hasbeen · Postby **Hasbeen** » 15 Jul 2010 00:23

Swifty, these braces are fitted with no load.

Any tendency to movement in the towers from cornering or bump shock
loads will put them in either tension, or compression, depending on
the load.

They then transfer that load to the other tower, giving twice, [or
nearly twice] the resistance to frame distortion.

Hasbeen

swifty · Postby **swifty** » 15 Jul 2010 07:43

Thank you, Hasbeen, that makes perfect sense now

[img][IMG]http://i728.photobucket.com/albums/ww281/swiftstuff/029-1.jpg[/img]/img]

V8Wedgehead · Postby **V8Wedgehead** » 15 Jul 2010 13:52

The whole strut brace thing is so interesting and can go in many directions. Group 44 was mentioned in this thread as having used them but in reality they only used diagonal braces from the strut top to the fresh air intake area and nothing between the struts over the engines. Huffaker Engineering ran a triangulated brace. The braces can serve multipurpose. Obviously to stiffen the chassis to aid in flex from high torque engines. They do also allow different body movements. The rally car did not run a cross brace so the front suspension could still even in rough uneven road keep the wheels planted especially bump steer and turning. The road race cars used upper chassis rails in bent/triangulated forms to resist strut tilting. There are strut braces available with solid flex resistant welded connections where the tubes flex only. There are others with rose joints that do allow flex mostly in vertical planes or shifting of the front panels in uniform. I would say if it was me and for a road car with occasional track use to go with a between the tower brace if you want to retain the fresh air plenum.

Michael
1980 TR8 FHC #0020 Rally Conversion

glen oliver · Postby **glen oliver** » 23 Jul 2010 17:58

hoping to get prices of materials next week so i can price them[:D]

nick · Postby **nick** » 24 Jul 2010 22:46

TS has a strut. Call Ted and ask him if it fits the standard air box.
http://www.tsimportedautomotive.com/tr7_tr8.html

nick
'79 TR7

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