Rearend and half shaft position
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Rearend and half shaft position
Hi all,
I need technical help on the position on the half shafts in relation to the third member. Are the shafts slightly forward, slightly back or centered off the third member? We are mocking up mounts for our cobra build and with the shafts centered there is a binding issue with the toe rods and the upper mounts of the bat wing.
Also, under normal conditions, ie, car sitting parked on a level surface do the half shafts run down toward the tire/wheel, up or are they pretty much level with the ground?
Thanks all.
I need technical help on the position on the half shafts in relation to the third member. Are the shafts slightly forward, slightly back or centered off the third member? We are mocking up mounts for our cobra build and with the shafts centered there is a binding issue with the toe rods and the upper mounts of the bat wing.
Also, under normal conditions, ie, car sitting parked on a level surface do the half shafts run down toward the tire/wheel, up or are they pretty much level with the ground?
Thanks all.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
The 1/2 shafts point downwards slightly (never more than 11 degrees is the rule of thumb). The 1/2 shafts should go 90 degrees from the main driveshaft so do not put multiple angles with 1/2 shafts as you will get vibrations or destroy parts from the miss alignment.
How about some pics of the project?
How about some pics of the project?
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The 1/2 shafts point downwards slightly (never more than 11 degrees is the rule of thumb). The 1/2 shafts should go 90 degrees from the main driveshaft so do not put multiple angles with 1/2 shafts as you will get vibrations or destroy parts from the miss alignment.
How about some pics of the project?
How about some pics of the project?
Le Mans Master
Joined: May 2006
Posts: 9,226
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From: Irvine Ca
yeah, you've done something wrong there.
The Dogbones should be much lower than the batwing mounts. There are only the mounting of the Dogbones and the Batwing, you get those dimensions correct and everything else will fall in line.
The Dogbones should be much lower than the batwing mounts. There are only the mounting of the Dogbones and the Batwing, you get those dimensions correct and everything else will fall in line.
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Not sure I follow. I thought the dogbones were the connecting bars that mount on the hub and go forward. Were you referring to the toe bars as the dogbones?
Le Mans Master
Joined: Jul 2007
Posts: 5,043
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From: Tampa Florida
that's what he is saying. The dogbones are the connecting bars that mount on the hub and go forward kind of like a 4 link deal. By eye it looks like the "batwing" needs to be relocated up a few more inches into the frame. I was actually going to measure the 1/2 shaft angles on my '89 (it's recently been lowered 1" in the rear) yesterday but never got around to doing it. I can do a quick measurement tonight and post back here on this thread what my 1/2 shaft angles are at the ride height if that helps.
Le Mans Master
Joined: May 2006
Posts: 9,226
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From: Irvine Ca
You take the Roll bar off.....take the Shocks off....and the only things holding the D36/44 to the car are the four Dogbones and the two batwing mounts......
(No I didn't count the C-beam...he is not at that point yet)
What you need to do is find out how much higher the two batwing supports are from the top of the upper Dogbone and you'll have that part licked.
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Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
*edit* ^^See his rear end?? That is almost what your rear end should look like. See how much higher the Batwing is from the two Dogbones?? You need almost that much delta in height. *edit over*
Just looking at that pic again....The two mounts you made for the batwing, they seem to be about 4" long.....Just guesstimating, you need to shorten those mounts and actually have the Batwing mount directly to the frame....removing that 4"(possibly more)
But wait, you don't have a spring on there......is it there and I cannot see it??
Just looking at that pic again....The two mounts you made for the batwing, they seem to be about 4" long.....Just guesstimating, you need to shorten those mounts and actually have the Batwing mount directly to the frame....removing that 4"(possibly more)
But wait, you don't have a spring on there......is it there and I cannot see it??
Last edited by jhammons01; Feb 9, 2010 at 12:25 PM.
Thread Starter
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*edit* ^^See his rear end?? That is almost what your rear end should look like. See how much higher the Batwing is from the two Dogbones?? You need almost that much delta in height. *edit over*
Just looking at that pic again....The two mounts you made for the batwing, they seem to be about 4" long.....Just guesstimating, you need to shorten those mounts and actually have the Batwing mount directly to the frame....removing that 4"(possibly more)
But wait, you don't have a spring on there......is it there and I cannot see it??
Just looking at that pic again....The two mounts you made for the batwing, they seem to be about 4" long.....Just guesstimating, you need to shorten those mounts and actually have the Batwing mount directly to the frame....removing that 4"(possibly more)
But wait, you don't have a spring on there......is it there and I cannot see it??
Melting Slicks
Joined: Nov 2005
Posts: 2,736
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From: WAY UPSTATE NY
*edit* ^^See his rear end?? That is almost what your rear end should look like. See how much higher the Batwing is from the two Dogbones?? You need almost that much delta in height. *edit over*
Just looking at that pic again....The two mounts you made for the batwing, they seem to be about 4" long.....Just guesstimating, you need to shorten those mounts and actually have the Batwing mount directly to the frame....removing that 4"(possibly more)
But wait, you don't have a spring on there......is it there and I cannot see it??
Just looking at that pic again....The two mounts you made for the batwing, they seem to be about 4" long.....Just guesstimating, you need to shorten those mounts and actually have the Batwing mount directly to the frame....removing that 4"(possibly more)
But wait, you don't have a spring on there......is it there and I cannot see it??
Team Owner
Joined: Sep 2003
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You need to poke around some very experienced chassis builders sites and just study the images. These people build a fine tubular chassis utilizing a C4-D44. Just open some of the links here and you'll see what direction you need to go. As your chassis and the C4 rear sits presently. I linked you towards a C3 build but using the links to the left just "poke around"!
http://www.sriiimotorsports.com/196382corvette.html
It seems your attempting to replicate "someones" chassis! Whose?
Here's a project done by an acquaintance and in his snapshots there's a very good mounting image of his D44/C4 in an SRiii chassis!
http://www.vettetech.com/projects/c3gs/c3gs113006b.jpg
Here's a link to his website, click on projects and check out Franken-sport.
http://www.vettetech.com/
http://www.sriiimotorsports.com/196382corvette.html
It seems your attempting to replicate "someones" chassis! Whose?
Here's a project done by an acquaintance and in his snapshots there's a very good mounting image of his D44/C4 in an SRiii chassis!
http://www.vettetech.com/projects/c3gs/c3gs113006b.jpg
Here's a link to his website, click on projects and check out Franken-sport.
http://www.vettetech.com/
Last edited by WVZR-1; Feb 9, 2010 at 07:04 PM.
Thread Starter
Advanced
Joined: Sep 2009
Posts: 83
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You need to poke around some very experienced chassis builders sites and just study the images. These people build a fine tubular chassis utilizing a C4-D44. Just open some of the links here and you'll see what direction you need to go. As your chassis and the C4 rear sits presently. I linked you towards a C3 build but using the links to the left just "poke around"!
http://www.sriiimotorsports.com/196382corvette.html
It seems your attempting to replicate "someones" chassis! Whose?
Here's a project done by an acquaintance and in his snapshots there's a very good mounting image of his D44/C4 in an SRiii chassis!
http://www.vettetech.com/projects/c3gs/c3gs113006b.jpg
Here's a link to his website, click on projects and check out Franken-sport.
http://www.vettetech.com/
http://www.sriiimotorsports.com/196382corvette.html
It seems your attempting to replicate "someones" chassis! Whose?
Here's a project done by an acquaintance and in his snapshots there's a very good mounting image of his D44/C4 in an SRiii chassis!
http://www.vettetech.com/projects/c3gs/c3gs113006b.jpg
Here's a link to his website, click on projects and check out Franken-sport.
http://www.vettetech.com/
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
By eye it looks like the "batwing" needs to be relocated up a few more inches into the frame.
I was actually going to measure the 1/2 shaft angles on my '89 (it's recently been lowered 1" in the rear) yesterday but never got around to doing it. I can do a quick measurement tonight and post back here on this thread what my 1/2 shaft angles are at the ride height if that helps.
I was actually going to measure the 1/2 shaft angles on my '89 (it's recently been lowered 1" in the rear) yesterday but never got around to doing it. I can do a quick measurement tonight and post back here on this thread what my 1/2 shaft angles are at the ride height if that helps.
Measuring vertically from the ground up to the center line of each of the two outer "batwing's" frame mounting bolts I get 17". My 1/2 shafts are @ 4 degrees.
Also it looks as if your batwing frame mounts need to be about ~1" - 1.5" forward from their current positon to get the 1/2 shafts more perpindicular to the driveshaft.....your wheel base should not be affected much if any and this will free up some room for the up and down travel of the toe linkage as well. Looking again at the close up pics you posted....if you still need more clearance with your batwing to frame bolts for your rear toe rods when the suspension squats.....reverse the bolts 180 degrees (put the nut on the front side of the batwing.....yes I see that your frame is in the way to do this) to allow more room for suspension travel.
Good luck with the project.
Last edited by engle1147; Feb 11, 2010 at 11:23 AM.
