Messages

1

Roo Man's Room / Re: 4 link FED anyone

« on: July 21, 2013, 06:30:37 PM »

Shino I really like what you are trying to do but I think you will have a tough time trying to get something like that approved . Years ago we had a guy here in Division 1 build a suspended dragster . I was kind of a cross between an altered and a FED . The car had a ladder bar suspension . This was before 4 links . He ended up taking the shocks out and putting a solid strut in it's place . He held the national record in C/D with this car for a couple of years. 

I know what you mean about passing tech.  i forget the measurement off the top of my head i wanna say 16" on center for the two uprights was the max you were allowed thats why the links are so short. if the axle were held solid where it sits the tube positions fit the sfi book. but there is nothing in there or nhra rule book about how to hold the rear if it were not bolted solidly in place.

The way that you have that package mocked up it will just work like a ladder bar with an adjustable front pivot length. Most of the four link rear engine dragsters are the same way-- the big tube cross shaft that the arms mount to is like a huge anti roll bar and if you add the drive shaft loop package you add even more torsional strength to the package. That is why a lot of them went to the mono shock deal, there was no need for two and the second one just added weight and cost. The four link rear motor cars do work a little better on bumpy tracks and ride nicer on rough return roads but I think that a good hard tail will run just as fast with less complication and expense.

Roo

Roo, thats what i was after when i did this, had no intent of using a track bar or two shocks.  Ill just say it up front, one of my teachers in college is a big drag racing guy, maybe you east coast guys know him, English brothers racing.  This chassis was being built for my senior project when getting my manufacturing engineering degree.  I needed something "different" and reasons backing why i chose that.  saying a nicer ride on the return road was enough of a reason haha.  but correct me if im wrong but knowing the difference between a rigid and suspended RED you can hit the tires differently.  maybe say more consistent when its suspended? again correct me if im wrong but this is what i gathered.  with all that said ive really got my mind going again after talking to said teacher and him telling me about his new project, an inline 6 jaguar powered FED.  Id most likely not use this chassis and just use it for parts.

2

Roo Man's Room / Re: 4 link FED anyone

« on: July 20, 2013, 04:05:59 PM »

forgot i had pics already on the web.





if i were to continue with the build id change the sway bar/torsion/mono shock link.  after making those pieces i thought it would be better to build a frame off of the bottom 4 links to wrap up around the driveshaft with mono shock mounted over trans.  some of the RED's do a similar setup.  this falls in/or at least did, for sfi specs.  only thing in rules state anti rotation device which this would be heavily strapped in place and things added to limit motion. 3/4 heim ends on heavy wall CM tubing.  im curious as to what you guys think.  when i started building it i thought i saw some links on neil parks car and asked them, they told me (in some sort of wording) that it would be pointless to do.

3

Roo Man's Room / Re: 4 link FED anyone

« on: July 20, 2013, 03:55:32 PM »

i got the FED bug again so i was checking out the forum here and came across this thread so i had to sign up.  i started building a 4 link FED when i was 21,  got the back half somewhat roughed in but far from finished.  i lost interest in it and its been sitting for 7 years now.  ill get some pics and post up what i was doing.  its apart now and sitting on a steel pile