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Well over Xmas break I got banned so I couldnt post this up but I switched out my stock rearend for my JIMLAB Ford 8.8" IRS setup. The rear differential comes from a 03 Ford mustang cobra. I got the whole IRS rearend for $670 which is pretty cheap and it only had about 20,000 miles on it. I bought the Jimlab kit 2 years ago and the CobraIRS last year but just now did the swap because of the cost and the fact that I am still a student and only work part time, except during the summer.
Also I have one of Tiresmokin'7s Delrin Bushing kits, which I installed during the swap too. I sold the differential bushings since I couldnt use them anyway and bought some Steeda nylon 8.8" IRS bushings. Then I also tossed the trailing arm bushings aside because I am throwing on some aftermarket adjustable trailing arms along with aftermarket toe links. So I started by ripping out the stock rearend, suspension, brakes, PPF, driveshaft, and stock rear subframe. The subframe had to have 2 plates welded on since I have a 93 subframe. Before I had the plates welded on I had my cousin powdercoat EVERYTHING except fot the actual rear subframe because it wouldn't fit in either of his ovens. Powdercoated everything flat black. I also had my stock wheels powdercoated gloss black with a 200% clear coat on top of it. The powder was from Rosey's powder online. I used 2 pieces of cut up 1" conduit for spacers.
PICS:
TEARING EVERYTHING APART......
__________________ 1993 BB Base - GT47R 20B Coming Soon Ford 8.8" IRS Cobra w/ 4.33s Rearend 562 whp @ 24psi w/ GT42R Half-Bridge, Tuned by STEVE KAN 11.209 @ 131.93 MPH - 24 PSI 2000 Honda Prelude SH w/ Giggle Juice - Daily Driver 2007 Suzuki GSXR750 142 WHP - My other Baby
Why did you go with such high gears in the cobra rear end?
I am running my car with 440whp and the 3.90's are way to short. I have a new version samberg cobra cradle and a cobra rear end and am looking forward to the stock 3.55's in it. If they are to short I will be upgrading to 3.30's. The longer they are the better traction you will get down low.
But I am also running a LSX with lots of torque so that might make the difference.
Why did you go with such high gears in the cobra rear end?
I am running my car with 440whp and the 3.90's are way to short. I have a new version samberg cobra cradle and a cobra rear end and am looking forward to the stock 3.55's in it. If they are to short I will be upgrading to 3.30's. The longer they are the better traction you will get down low.
But I am also running a LSX with lots of torque so that might make the difference.
If you are running a LSX then you probably have a T-56 which is a 6 SPEED. I have the stock 5 SPEED so that is why I am running such a LOW gear set. I almost went with 4.56s but that would require me to shift into 5th gear before I made it to the 1320 ft mark so I went with 4.33 gears.
__________________ 1993 BB Base - GT47R 20B Coming Soon Ford 8.8" IRS Cobra w/ 4.33s Rearend 562 whp @ 24psi w/ GT42R Half-Bridge, Tuned by STEVE KAN 11.209 @ 131.93 MPH - 24 PSI 2000 Honda Prelude SH w/ Giggle Juice - Daily Driver 2007 Suzuki GSXR750 142 WHP - My other Baby
Since I was going to change gears anyway, I had the rear differential rebuilt with all new seals and such. That was done in May. I used Ford Motorsports 4.33 gears in it. I cut the stock sensor wires off of the rear differential before bolting it up. Also I had the Jimlab "phone dial" brace to provide extra support. The axles are from The Driveshaft Shop and they are the 1000 HP axles with custom Mazda Race outer CV joints. They ran me $620. The stock outer CV joints had to be taken apart and rebuilt using the parts that came with the custom axles. The axles came with grease, clamps, and brand new boots and they look GREAT. I then took my stock RX7 alxes, the Mustang Cobra Axles, and the custom driveshaft shop axles to a local JEEP shop to have them assembled. Thee shop was GDS 4x4 and they are located in Maryville, IL. I highly recommend them because they knew what they were doing and did it in one day. It cost me $389 though so these damn axles ended up costing me about $1,000. That price also includes them putting in my NHRA legal axle studs. They also modified them for me by punching off the ABS ring gears for some weight reduction. The guy that owned the shop told me that the weakest link in my rearend should be the outer race CV joints. Then I started putting the rearend back together. The other thing I did was when my dad and I were punching out the stock bushings we accidently punched out one of the pillowballs on the rear upper control arms. So I decided to order 6 from Ray Crowe at malloy mazda and damn did that hurt. It was over $300. But atleast I will have brand new everything in the rearend. I also ordered Megan Racing fully adjustable trailing arms and toe links. The one other thing that I noticed when dropping my rearend was that the racing beat sway bar I had was CRACKED in half. Who knows how long it has been like that but damn, no wonder my rearend was so sloppy.
PUTTING IT BACK TOGETHER PICS:
__________________ 1993 BB Base - GT47R 20B Coming Soon Ford 8.8" IRS Cobra w/ 4.33s Rearend 562 whp @ 24psi w/ GT42R Half-Bridge, Tuned by STEVE KAN 11.209 @ 131.93 MPH - 24 PSI 2000 Honda Prelude SH w/ Giggle Juice - Daily Driver 2007 Suzuki GSXR750 142 WHP - My other Baby
I called RX7.com yesterday and begged ARTY to take the scatter shield off of the American Flag race car RX7 to have it copied but he wouldn't budge. So I contacted ErnieT and offered to send him some cheap hookers in return for him having a copy of his scatter shield made. We will see what happens.......
__________________ 1993 BB Base - GT47R 20B Coming Soon Ford 8.8" IRS Cobra w/ 4.33s Rearend 562 whp @ 24psi w/ GT42R Half-Bridge, Tuned by STEVE KAN 11.209 @ 131.93 MPH - 24 PSI 2000 Honda Prelude SH w/ Giggle Juice - Daily Driver 2007 Suzuki GSXR750 142 WHP - My other Baby
I almost went with 4.56s but that would require me to shift into 5th gear before I made it to the 1320 ft mark so I went with 4.33 gears.
You should just barley top out third gear in the quarter mile. No matter what tranny you have. You lose time when you shift. Thats why all American cars can hit 60 in second. Better 0 - 60 times.
As a matter of fact most the guys I know with pro street cars all run 3 speed linko's.
Just giving you a hard time man. Your car is very nice and has a lot of good stuff on it. I remember watching your old threads when you first started building it. I just prefer longer gears to help with traction in first and second. I am sure you can pretty much light them up any time you want in those gears.
How do you like the cobra rear end? Have you noticed any wheel hop? My friend said it eliminated his wheel hop completly.
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Installed the A-Spec Tuning Transmission Brace and then took measurements for my custom driveshaft. It came out to 38" from the face of the Ford 8.8" rear diff and the stock transmission seal. I ordered the driveshaft from the driveshaft shop. Got the 3" steel one for $330 plus shipping.
__________________ 1993 BB Base - GT47R 20B Coming Soon Ford 8.8" IRS Cobra w/ 4.33s Rearend 562 whp @ 24psi w/ GT42R Half-Bridge, Tuned by STEVE KAN 11.209 @ 131.93 MPH - 24 PSI 2000 Honda Prelude SH w/ Giggle Juice - Daily Driver 2007 Suzuki GSXR750 142 WHP - My other Baby
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That price also includes them putting in my NHRA legal axle studs. They also modified them for me by punching off the ABS ring gears for some weight reduction. The guy that owned the shop told me that the weakest link in my rearend should be the outer race CV joints. Then I started putting the rearend back together. The other thing I did was when my dad and I were punching out the stock bushings we accidently punched out one of the pillowballs on the rear upper control arms. So I decided to order 6 from Ray Crowe at malloy mazda and damn did that hurt. It was over $300. 
But atleast I will have brand new everything in the rearend. I also ordered Megan Racing fully adjustable trailing arms and toe links. The one other thing that I noticed when dropping my rearend was that the racing beat sway bar I had was CRACKED in half. 
Who knows how long it has been like that but damn, no wonder my rearend was so sloppy. 
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