Do the front cross members offer rigidity?

[1fastlaser]

1fastlaser, is there any chance of getting you to take your car into a frame shop to see if it is flexing more or less with your k-member versus the stock one? You said it feels stiffer but I'd like to see some data besides the butt dyno Maybe when you pull everything this winter you could drag the car to a friend's shop and see what happens.

Yeah definatly, thats a good idea also didnt think of that one. Id rather have solid numbers also.

 

[wishihadatalon]

So, you don't run a front roll stop at all?

Paul, talk to Angelo, I am pretty sure he doesn't run either north/south bars in his car. Just the one that goes side to side for the motor mount. For what you want out of your 14b car it should work fine to not have them.

 

[99gst_racer]

I'm taking some chrome moly tubing home from work today, and I'm going to start on making a front cross member. I decided to use 1.500" x .083 tubing instead of 1.250". I'll post pictures of the progress tonight or tomorrow morning.

Chris - I removed most of the front of my 1G a couple days ago. It seems that the front cross member and radiator support both share the responsibility of front end support and rigidity. I removed both from the car, and I couldn't imagine running the car without at least one or the other. I'll also make a point to weigh the pieces that I removed. I'll post my findings within the next day or two.

 

[Ludachris]

I'm taking some chrome moly tubing home from work today, and I'm going to start on making a front cross member. I decided to use 1.500" x .083 tubing instead of 1.250". I'll post pictures of the progress tonight or tomorrow morning.

Chris - I removed most of the front of my 1G a couple days ago. It seems that the front cross member and radiator support both share the responsibility of front end support and rigidity. I removed both from the car, and I couldn't imagine running the car without at least one or the other. I'll also make a point to weigh the pieces that I removed. I'll post my findings within the next day or two.

Cool, can't wait to see the potential weight savings.

 

[bmoha2]

I know these are for a 1G but a lot of us 2G guys are looking at them and drooling. Anxious to see how these turn out.

 

[99gst_racer]

FYI: I built a jig two nights ago. It fits the factory cross member and front mount just fine, so it should be perfect. I already have the mounting ends finished for the tubular cross member - I just need to notch and fit the cross bar, and cut the pieces for the mount. Hopefully I'll have a finished piece to test fit in about a week or so. If all goes well, I'll probably make a few and sell them to make a few bucks to help fund my race car project.

EDIT: Another option that this provides is for the 1G guys running 2G trannys - it would be one simple change to move the roll stop over to the tranny side to free up more block-side room for a large turbo or large manifold/header. Just a thought...

 

[Lonnie gandee]

So, you don't run a front roll stop at all?

I'm not clear on what the roll stop is... But like wishihadatalon said, I run neither bars that connect the the front motor mount cross member to the chassis... My belief is they were made as a saftey provision to help aide in a front on collision... Not for chassis support.


Also... I reinstalled mine on my last car, before I sold it... No chassis flex, or any problem lining them back up...

 

[drivemusicnow]

I though you were talking about the rear subframe assembly. I guess I got a little confused as this thread started talking about 1G front crossmember and then went to 1G rear tubular subframe replacement and then went to strut tower braces. My bad.

The tube construct is a front subframe replacement. the 4th member of the square subframe...


Believe me, the two front to rear bars help with torsional stiffness. It's one thing to replace them all with tubular steel, but to eliminate them on a road course car or a street car is dumb.

And if you take offense to dumb, try "not the best idea" on for size.

 

[Ludachris]

Yes, removing them on a road race car would almost definitely have an adverse affect. I think the question is more of how replacements should be designed in order to not lose the rigidity. The whole point of building up a road race car is to make the chassis stiff. Removing braces does nothing to help that cause. And you have to be careful when changing them out too.

 

[99gst_racer]

Well, I finally finished the moly crossmember that I was working on. I plan to use one of these on my own 1G. It will allow for complete elimination of the north-south bars, and it's small enough to build around. This piece only weighs 5.1 lbs. The factory one weighs 12.0 lbs, not including the north-south bars. This should equate to a total savings of about 25 lbs.

I don't have any type of 1G autocross car to test this out on. Some say the north-south bars add rigidity and support for a vehicle that does road racing and autocross. For a street car or a drag car, I've concluded that they are just not nessacery. Although, it probably wouldn't be too much work to add a north-south bar to this design to have some extra support for the guys racing through the twisties.

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[Lofty]

Those welds are amazingly clean.
Nice job, looks really good.

 

[gixrman]

Santa brought me a tubing bender for christmas, will be making 4130 suspension shortly......

 

[DSMTriad]

Wow those welds do look great... I wish I could weld. I plan on doing some roadrace/autox next year(early spring). I also have an extra FWD shell, I'm willing to give away for the cause a perfect test subject for these tubular crossmembers.

 

[gixrman]

Wow those welds do look great... I wish I could weld. I plan on doing some roadrace/autox next year(early spring). I also have an extra FWD shell, I'm willing to give away for the cause a perfect test subject for these tubular crossmembers.

To bad its not a 2g i need a K member to make a jig.

 

[Sp1kE]

I want one.

 

[Sp1kE]

maybe make a tubular rear subframe ?

 

[99gst_racer]

To bad its not a 2g i need a K member to make a jig.

You could always uninstall yours to make the jig. What better time than the winter months.

 

[gixrman]

You could always uninstall yours to make the jig. What better time than the winter months.

I was thinking about that but I have just a onecar garage and need the car mobile. Maybe if I could do it in one day.

 

[Slippi84]

I'm waiting on the next batch to pick up one of those tubular front support/roll stop bars and if anything I might try and rig up a traction link like jake did instead connecting this bar to the lower control arms on both sides which should be good enough for drag racing as I have no plans of road racing a car with a hx52 anyway

 

[Ludachris]

How does one make a jig? Being that I will start welding here at some point, I suppose I should get some info on jig-building.

 

[Slippi84]

How does one make a jig? Being that I will start welding here at some point, I suppose I should get some info on jig-building.

I take it a jig is like a outline or cast somewhat like you have for CF or fiberglass but I have yet to see one

 

[1992awdlaser]

A jig will look something like this:

They are not that complicated o make.

Put down a plate of metal.
Use the stock suspension piece to make the jig.
Slide a piece of tube where the bolts go and weld them to the plate.
If it is a straight piece like this front cross member, nothing else is required.
If it is something with curves (think control arm like above), you can either weld other pieces of tube to the plate around the outside of the curve or draw the lines. I use the first method since I don' have to eyeball the curve.

 

[Slippi84]

A jig will look something like this:

They are not that complicated o make.

Put down a plate of metal.
Use the stock suspension piece to make the jig.
Slide a piece of tube where the bolts go and weld them to the plate.
If it is a straight piece like this front cross member, nothing else is required.
If it is something with curves (think control arm like above), you can either weld other pieces of tube to the plate around the outside of the curve or draw the lines. I use the first method since I don' have to eyeball the curve.

Got ya well someone rig up a jig so we can get some tubular K memebers going. The traction bar setups that the honda guys have sell like hot cakes from what I hear from teh honda guys.

 

[99gst_racer]

How does one make a jig? Being that I will start welding here at some point, I suppose I should get some info on jig-building.

Basically, all you need to do is triangulate any and all points of importance, including mounting points. Take the front crossmember that I made for example. I had to build a jig that precisely defined the outer mounting points in correlation to the location of the front motor mount. In a sense, once the jig is complete, fabricating the final piece is basically just like connecting the dots.

To build a jig, you basically just want to build around a completed piece. I used the factory crossmember to build my jig for my chromoly piece.

 

[Slippi84]

Basically, all you need to do is triangulate any and all points of importance, including mounting points. Take the front crossmember that I made for example. I had to build a jig that precisely defined the outer mounting points in correlation to the location of the front motor mount. In a sense, once the jig is complete, fabricating the final piece is basically just like connecting the dots.

To build a jig, you basically just want to build around a completed piece. I used the factory crossmember to build my jig for my chromoly piece.

If it's that easy get jigging Paul