X frame drive shaft
- Thread starter 59belair
- Start date
CDNpontiac409guy
Banned
Yes, up to 3 1/4" diameter. Driveshaft speed is limited to just under 5000 RPM though ( engine RPM in high gear )
Fred it has to do with a thing call " critical speed" heres a definition...
Critical Speed:
This is the probably the most influential factor in driving the purchase of an aftermarket driveshaft. The critical speed of a spinning shaft is described as the lowest speed which excites the shaft at it's natural frequency of vibration. This will cause the shaft to bend under the stress of vibration coupled with the centrifugal forces due to the rotation. In english, this means the shaft will vibrate very badly and possibly take a permanent bend (if not destroy the car in the process) as the critical speed is exceeded. If you use the calculator to predict the critical speed of a shaft, you can clearly see that lighter materials with higher modulus of elasticity give higher critical speeds. So do larger diameter shafts with thinner material thicknesses. Unfortunately, there is a limit to the diamter of shaft you can put in the car, so stronger lighter materials were developed to make stronger and faster spinning shafts. Just to get a handle on the speed a driveshaft turns, use the 'Tire Stuff' calculator here (NOTE: just remember to set the transmission gear to 1 instead of .7 to get the engine rpm the same as the driveshaft rpm).
====
From here
http://www.pontiacracing.net/driveshaftspeed.htm ...09
Critical Speed:
This is the probably the most influential factor in driving the purchase of an aftermarket driveshaft. The critical speed of a spinning shaft is described as the lowest speed which excites the shaft at it's natural frequency of vibration. This will cause the shaft to bend under the stress of vibration coupled with the centrifugal forces due to the rotation. In english, this means the shaft will vibrate very badly and possibly take a permanent bend (if not destroy the car in the process) as the critical speed is exceeded. If you use the calculator to predict the critical speed of a shaft, you can clearly see that lighter materials with higher modulus of elasticity give higher critical speeds. So do larger diameter shafts with thinner material thicknesses. Unfortunately, there is a limit to the diamter of shaft you can put in the car, so stronger lighter materials were developed to make stronger and faster spinning shafts. Just to get a handle on the speed a driveshaft turns, use the 'Tire Stuff' calculator here (NOTE: just remember to set the transmission gear to 1 instead of .7 to get the engine rpm the same as the driveshaft rpm).
====
From here
http://www.pontiacracing.net/driveshaftspeed.htm ...09
CDNpontiac409guy
Banned
GREAT info, loafer
Belair... You should change the rear shocks to units that are by application for the 65-70 full size. About 2" shorter extended length.
Are you using a big engine ( over 400 CID ) ?
If not, the one piece is COMPLETELY unnecessary
Belair... You should change the rear shocks to units that are by application for the 65-70 full size. About 2" shorter extended length.
Are you using a big engine ( over 400 CID ) ?
If not, the one piece is COMPLETELY unnecessary
Glad you found the info helpful. Here's an even better site...09
http://www2.dana.com/expert/wc.dll?cvsp~Decrits~
http://www2.dana.com/expert/wc.dll?cvsp~Decrits~
(where/why are you digging this up Loafer - don't you already have a hobby? - but thanks, this is good stuff) .
====
Hobby, this stuff is my hobby, was my living for 35+ years. I have literally 100''s of bookmarked sites. I need to spend some time cleanung them up and re catologing them. I am terrible at filing both electronically and physically. That Dana site has changed since I was last there...09
====
Hobby, this stuff is my hobby, was my living for 35+ years. I have literally 100''s of bookmarked sites. I need to spend some time cleanung them up and re catologing them. I am terrible at filing both electronically and physically. That Dana site has changed since I was last there...09
I like the way you cropped out the xframe to accomodate the one piece drive shaft and want to do the same on my '58 Impala but other posts I've read has concerns of weakening the frame and the drive shaft hitting when hitting a hard bump.
How long have you driven with a one piece drive shaft? Anything different you would do to improve the modification?
Driveshaft
I had a new two-piece, 2 1/2" diameter with a slip joint in the rear shaft made for my 61 at the beginning of the summer. I have nearly 100 runs on the car at the drag strip so far. The car has 9" slicks and leaves at 4000 RPM. So far, no problems with the driveshaft.
I had a new two-piece, 2 1/2" diameter with a slip joint in the rear shaft made for my 61 at the beginning of the summer. I have nearly 100 runs on the car at the drag strip so far. The car has 9" slicks and leaves at 4000 RPM. So far, no problems with the driveshaft.
Either way should work!! If you do go with the single ,,,try it the way TM did it.
I have a one piece also but there is heavy mods to my frame and a six point roll bar.
http://dq409.com/engine_page/IMAG006A.JPG
Also take some time and check out my first web site ! Got a few bugs but what the hey !
http://www.dq409.com
I have a one piece also but there is heavy mods to my frame and a six point roll bar.
http://dq409.com/engine_page/IMAG006A.JPG
Also take some time and check out my first web site ! Got a few bugs but what the hey !
http://www.dq409.com
Belair
This spring I install a two piece drive shaft in the Blue
Screamer. It is a 3" shaft with a slip joint behind the center support.
The company is Inland Empire Driveline, in Ontario CA.
This drive line has held up, pushing a 3940 pound car with 9.5
slicks with no problems. I spin the engine at 7200 going across
the finish line. It is on the expensive side, but you might as well go first class.
Allen
Blue Screamer
This spring I install a two piece drive shaft in the Blue
Screamer. It is a 3" shaft with a slip joint behind the center support.
The company is Inland Empire Driveline, in Ontario CA.
This drive line has held up, pushing a 3940 pound car with 9.5
slicks with no problems. I spin the engine at 7200 going across
the finish line. It is on the expensive side, but you might as well go first class.
Allen
Blue Screamer
CDNpontiac409guy
Banned
Thanks Allen !
THAT's the one I'm looking for
THAT's the one I'm looking for
I'm glad I went and checked there site. http://www.iedls.com/ They have had a driveshaft with a slip yoke in the rear section for several years but it seems they now have a heavier version available as well. It looks like they might also make a heavier yoke to fit our rearends as well. Now just add Aubreys differential and axle upgrades and our driveline breaking days are over. 
http://www.bruneauperformance.ca/intro.html Look under " our products for 409 cars"
http://www.bruneauperformance.ca/intro.html Look under " our products for 409 cars"