bodie Posted July 19, 2009 Share Posted July 19, 2009 ive been throwing this ideal around in my head for a while and today i pick up a complete cobra irs got it real cheap due to the center section needed to be rebuilt but thats not a biggie for me ive rebuilt my share of 8.8. any how here is the a rought fit the front mount gonna not be a big deal i figure id build some thing similar to the rt mount and the rear id either make a bracket to bolt it to the mustasche bar or modify a nother cover by welding a block of alumun to it and putting studs in it similar to the stock r180. its in a rough location and as it sit now the inboard axles will be 1" forward than with the r180. now do i leave it like that move it back and do it raise it more? let me know what you guy think Quote Link to comment Share on other sites More sharing options...
jbk240z Posted July 19, 2009 Share Posted July 19, 2009 Hmmmmm..... very interesting! I am going to watch this one. Quote Link to comment Share on other sites More sharing options...
stony Posted July 19, 2009 Share Posted July 19, 2009 I was considering this for a while before i went the route i did. should be bullet proof. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 19, 2009 Share Posted July 19, 2009 You can leave it forward like that if you're running CVs. It would be nice to mock up the CV shafts so that you could check for binding and all that as the suspension goes through its motion. I assume Cobra/Explorer CVs will be in the works. What are you going to do to make the outboard end work? Cobra upright? Custom CV shafts? Quote Link to comment Share on other sites More sharing options...
bodie Posted July 20, 2009 Author Share Posted July 20, 2009 swapped a 280 mustache bar instead of the 240 it made a big diffence. made a rough mount out of angle iron and mocked and control arm up and a cv shaft. it looks like im gonna have to raise it another inch to clear the control arm mount. the plan is to get the diff mounted buy gabs setup for the knuckles and see if i can use the cobra outer cv or use the q45 cv but either way get custom shafts made. after looking and studing the cobra irs i found it wasnt gonna be easy to use the cobra subframe a-arm or knuckles. Quote Link to comment Share on other sites More sharing options...
SoCalJack Posted July 20, 2009 Share Posted July 20, 2009 Im definitely interested! Keep it up! Quote Link to comment Share on other sites More sharing options...
bodie Posted July 24, 2009 Author Share Posted July 24, 2009 moved it up 1 inch and it looks good, the front mount looks to be easy. i plan one making and upper and lower mount, i plan on welding the upper inplace and bolting the lower to the diff strap mount holes. i did incounter another problem, since the cast in mount on the cover is off center the diff if to far over to the left and i need to move it to the right 1/2 inch, im gonna try and drill the mustach bar. Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted July 29, 2009 Share Posted July 29, 2009 What kinda gears do you want to run? AFAIK, the R200 S/B stronger w/the same ratios - if you want to run lower numerical I get it. I've heard a lot about the 8.8 IRS diffs breaking with more power applied to them - not so much with the R200... Quote Link to comment Share on other sites More sharing options...
bodie Posted July 29, 2009 Author Share Posted July 29, 2009 ill prob run in the 3.73 range most of the ford guys are not breaking diffrentials there breaking axles the major advantage of the 8.8 is the wide selecion of gears mutiple carriers and be able to get parts to rebuilt them cheap. so no hunting for the right gear ratio and not spending 1200+ for a quafie, ill be able to put bearings and gears in for 300 and get a new posi carrier for less than 500 Quote Link to comment Share on other sites More sharing options...
bodie Posted August 10, 2009 Author Share Posted August 10, 2009 i finally finished my front mounts, i built an upper and lower mount to keep the front of the diff from moving underload. i also had to clerance the body but to to bad. it looks good and i got seven degrees on the inner cv and less than 20 at full drop. i was worried since the inner is a tripod cv and your not supposed to have over 25 on a tripod cv. it looks tight but i still have enough room to run the stock parking brake cables. so far the tough part whas deciding where i wanted the diff, i had made several front and rear mounts before i found the best place for it. where i have it now i didnt have to notch the rear frame. now all i have left is get custom shaft made and finish building the rear suspension. some ford irs info, i used an irs from an 03 mustang cobra. but you can get one from the lincoln mark 8 up to 98, the supercoupe and ford explorer 01-04 cobra has 31 spline diff with 03-04 having stronger inner cv. lincoln mark 8 super coupe and 99-00 cobra have 28 spline diff. the mark 8 diff cave is idential to the cobra, both are aluminum. and the 8.8 internals can all be swapped around. as long as you axles match the carrier. but a 28 spline carrier from a solid axle can be swapped to irs with 28 spine axle and so forth with 31 spine. the ford exporer diff has a diffrent cover then the rest as well as being an iron case. Quote Link to comment Share on other sites More sharing options...
Boy from Oz Posted August 11, 2009 Share Posted August 11, 2009 Great work. I'm interested in this as I'm trying to fit a GM diff and I have a couple of questions. It appears that your input shaft is on the centreline of the transmission tunnel, if so, does that mean you are going to run odd length drive shafts? Have you matched the angle of the diff to the angle of the motor/transmission? Do you need upper AND lower front mounts to limit movement, or is it merely to distribute the forces radially around the mounting area? (I intend to use a spacer through the rubber mounts to seat a large washer and nut on the mounting bolt, thus only requiring one bracket/s , i.e. lower). Will you need to make an adaptor from the outer CV to the Datsun rear axle shaft like I had to? I had thought of using the Modern Motorsport adaptors but the diameter was too large. Quote Link to comment Share on other sites More sharing options...
bodie Posted August 11, 2009 Author Share Posted August 11, 2009 Well it look center but its actually a little bit off to the right to clear the parking brake but since the diff is off center slightly there is less than a 1/4 inch difference from the axle flange to each knuckle, so i should be able to use equal length axles. I havent match the pinion angle yet but when i made the front mount i had slotted the hole in the lower mount to give me enough room to adjust pinion angle with shims if need be, but as it sit not im about 3 degrees, and i can lower it to 0 if need be. I used both an upper and lower so the diff wouldn't move, under acceleration your diff going to move up esp so if you are racing and under decel its goingto move down. making a heaver mount is going to elimate the front movement and should help control any wheel hop. And as far athe the axles i plan of using the tenhno toy set up, using their knuckles and using an outer cv from a z32 and just having shafts made. Quote Link to comment Share on other sites More sharing options...
Boy from Oz Posted August 11, 2009 Share Posted August 11, 2009 Okay - thanks for the info, looks good. You might want to consider a three point mounting for the lower front brackets, though with the upper bracket (which I don't have) you may not need. I've utilised the two existing mounting points and propose to add a third which will mount through the double layer section of the transmission tunnel to a nut and spreader plate inside the cabin. Here is an early version beer-carton template to illustrate the three bolt concept. Quote Link to comment Share on other sites More sharing options...
tx240z Posted January 22, 2012 Share Posted January 22, 2012 ik this is an old thread but... do you have any updates?? Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted July 26, 2012 Share Posted July 26, 2012 At work we put a new 8.8 IRS diff inside of some SUV (it was a quick job so I didn't really have time to see what it was, be more than a couple years old). It was just whining a little and the customer wanted a whole new unit put in it. The old one is sitting on the ground free to the taking. It looks different than yours though, the back cover has two arms coming out the sides with tapped holes for bolting and just one front mount coming off the side. I haven't looked too see what gears are in it but I didn't see anything besides the pin when I looked through the axle holes so I know it's an open one, but that doesn't matter since a LSD and set of gears are cheap for them. I was wondering what you're doing about the axles? What kind of options are there? Quote Link to comment Share on other sites More sharing options...
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