88lx5oh Posted May 4, 2016 Report Share Posted May 4, 2016 some were there, some heard about it, but figured id make a thread last weekend was the first time i got to get the car at the track. little break down on the mods. Procharger HO kit with D1SC, 12psi at 7200 car made 631 RWHP and 526RWTQ on 93 SW long tubes and MBRP Race DSS aluminum driveshaft DSS 1400 half shafts McLeod RST clutch MGW shifter BMR delrin cradle bushings BMR poly diff bushings Viking shocks Eibach Pro Kit springs race star 17" rear wheels with M&H race master drag radials its a PP car so 3.73 gears best pass of the day was 11.33 @ 126 with a 2.0 60' then the bad part came. in line to make another pass, pulled into the water box, then proceeded to do my burnout, tires started spinning then went into massive wheel hop as one of the staff guys was yelling at me to shut the car down. so i did. then they brought a bolt up to me that came out of the car. asked me what it was. after seeing it i knew exactly what it was. a diff bolt. i got the car out of the lanes, and got it on the trailer to get a better look. the rear bolts that hold the diff to the IRS cradle sheared off, which are 10.9 grade bolts, the front bolts bent. this caused the rear of the diff to sag ALOT. pitching the front of the diff upward, causing the driveshaft to ride high in the back, high enough that the driveshaft ended up getting 2 grooves wore in it from some bracing that is in the rear part of the tunnel. having the diff in the position it was also caused the halfshafts to ride on the IRS cradle, cutting through the inner boots and causing damage to the inner joints. im unsure of other damage at this point, since i have not been able to get the car torn apart. I'm expecting there to be some internal damage to the diff, but i won't know until i get it out of the car. i contacted kelly at BMR, said he's seen front bolts shear but never rear bolts. Moving forward ill be installing the aluminum diff bushings which kelly recommended, which i will enlarge the hole in to accommodate 2mm larger diameter bolts, which will be 12.9 grade. i will also have to enlarge the ears of the diff to accommodate this as well. this is after i remove the rest of the bolts that are still in the rear ears of the diff. if the differential has any damage i will be swapping to 3.31 gears, since even with a 28" tall tire i was still having to shift into 5th before the traps. i also contacted DSS to find out what can be done with my driveshaft and half shafts. ill be sending those back to DSS, and they are gonna retube, and check over the rest of the driveshaft and rebalance it. the half shafts damage are fully unknown at this point because again i haven't gotten a chance to get them out of the car yet, but they are going to inspect them and fix what needs to be fixed. hoping the damage is limited to those items and i can get everything repaired and back in the car quickly. until then i might have to roll around on the stock DS and halfshafts until they are repaired. it was a somewhat disappointing day, as i was hoping to come away with a 10 sec pass, but i just didn't have the grip to support it. and end of the day i had a part failure that caused a lot of other parts to get damaged. here are some pics of the damage. the diff and mounting points/bushings in the rear http://i.imgur.com/ia0iqgHl.jpg http://i1101.photobucket.com/albums/g425/hobglide/Mobile%20Uploads/8FAED004-1634-4A68-A6B1-1D808BF4BDD6_zpseppsbyyt.jpg half shafts laying on the cradle http://i1101.photobucket.com/albums/g425/hobglide/Mobile%20Uploads/0DC88387-282B-4F73-92AF-574D0340516B_zpsz4hgagmp.jpg http://i1101.photobucket.com/albums/g425/hobglide/Mobile%20Uploads/A8A8BC10-EE25-4C75-A5BE-6FA992711973_zpsa8op9yd9.jpg grooves in the DS http://i.imgur.com/3gtEN2Ol.jpg diff dropped so much it dented the exhaust http://i1101.photobucket.com/albums/g425/hobglide/Mobile%20Uploads/1DA36BFE-7E7D-4204-ABAE-0269F45009EA_zpsux8zhngt.jpg a pic of one of the front bolts for the diff, you can see how bent it is, and its not flush with the bushing http://i1101.photobucket.com/albums/g425/hobglide/Mobile%20Uploads/A1990CF7-A26A-421E-8BB0-364BD1FE2D59_zpskkzmt3sp.jpg one of the culprit bolts, the other one i couldn't get out because it was hitting the spare tire relief http://i.imgur.com/JrNGhrbl.jpg http://i1101.photobucket.com/albums/g425/hobglide/Mobile%20Uploads/9D27DD8A-25BA-4C6E-AFE3-0D6F5330E23F_zpsvjevoigs.jpg Quote Link to comment Share on other sites More sharing options...
EssFo Posted May 4, 2016 Report Share Posted May 4, 2016 Note to self, don't try to make big power with these cars. Sucks, reminds me of my Terminator days. Quote Link to comment Share on other sites More sharing options...
Stretch Posted May 4, 2016 Report Share Posted May 4, 2016 That sucks. Hope you get it back together quickly. Quote Link to comment Share on other sites More sharing options...
Richard Cranium Posted May 4, 2016 Report Share Posted May 4, 2016 That sucks. I was in line a few cars back to make my first pass of the day. I was hoping the damage wasn't going to be too bad. Quote Link to comment Share on other sites More sharing options...
Coaster Posted May 4, 2016 Report Share Posted May 4, 2016 Hopefully the halfshafts check out ok and just need a new boot. Quote Link to comment Share on other sites More sharing options...
Aaron Posted May 4, 2016 Report Share Posted May 4, 2016 i will also have to enlarge the ears of the diff to accommodate this as well. i will be swapping to 3.31 gears, since even with a 28" tall tire i was still having to shift into 5th before the traps. I can't see the pictures, but if you're talking about the differential mounting points, I would be careful. I've seen a few big power guys break the "ears" off the diffs... Also, depending on calculations for tires, 3.55 might be better? Quote Link to comment Share on other sites More sharing options...
99StockGT Posted May 4, 2016 Report Share Posted May 4, 2016 Sorry to see it go this way especially after all the time energy and money you have wrapped up in it. Amazing what damage a single bolt snapping can do. Are you able to easily swap back to stock parts? Haven't "passed the point of no return"? Quote Link to comment Share on other sites More sharing options...
iwashmycar Posted May 4, 2016 Report Share Posted May 4, 2016 From a water box too....? Ouch. Crazy the amount of torque going through that stuff. Sucks all that happened. Quote Link to comment Share on other sites More sharing options...
Richard Cranium Posted May 4, 2016 Report Share Posted May 4, 2016 Wheel hop sucks and puts a crazy amount more force on parts than no hop. Quote Link to comment Share on other sites More sharing options...
iwashmycar Posted May 4, 2016 Report Share Posted May 4, 2016 Ahh true that. Didnt think about the wheel hop aspect. Same thing that breaks our off-road trucks. Nothing worse than the hop lol Quote Link to comment Share on other sites More sharing options...
88lx5oh Posted May 4, 2016 Author Report Share Posted May 4, 2016 I'll get her back together, and ready to rock in no time. Until then it's just a shiny garage ornament lol. It may be time to start looking into a fuel system and e85 Quote Link to comment Share on other sites More sharing options...
SpaceGhost Posted May 4, 2016 Report Share Posted May 4, 2016 LOL, broke the car, ok let's add more power. Quote Link to comment Share on other sites More sharing options...
88lx5oh Posted May 4, 2016 Author Report Share Posted May 4, 2016 LOL, broke the car, ok let's add more power. More power helps wheel hop lol. If it can't trip, it can't hop Quote Link to comment Share on other sites More sharing options...
Stretch Posted May 4, 2016 Report Share Posted May 4, 2016 I'll get her back together, and ready to rock in no time. Until then it's just a shiny garage ornament lol. Nothing wrong with a shiny ornament. That's all mines been for months now. Quote Link to comment Share on other sites More sharing options...
Miller Posted May 4, 2016 Report Share Posted May 4, 2016 From a water box too....? Ouch. Crazy the amount of torque going through that stuff. Sucks all that happened. He had already hot lapped most of the day. I assume it was already bent several times from bouncing all morning and just needed one more nudge. Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted May 4, 2016 Report Share Posted May 4, 2016 I told you, put a 10-bolt in it Is BMR assisting with any pricing/warranty due to the failure? Quote Link to comment Share on other sites More sharing options...
Guest GMoney Posted May 5, 2016 Report Share Posted May 5, 2016 The bolt diameter looks small for a bolt that long on a shear load through a bushing like that. I would go the next bolt size up and 12.9 grade. The size up will be the tricky part. What about making a girdle that grabs the bottom diff cover bolts to keep it from swinging up and down? Quote Link to comment Share on other sites More sharing options...
Robochan Posted May 5, 2016 Report Share Posted May 5, 2016 Soild rear axle swap? Quote Link to comment Share on other sites More sharing options...
buelliganx1 Posted May 5, 2016 Report Share Posted May 5, 2016 Check out "Full Tilt Boogie Racing" they seemed to be the go to people for mustang irs suspensions. They might have just what you need to straighten this thing out. Quote Link to comment Share on other sites More sharing options...
88lx5oh Posted May 5, 2016 Author Report Share Posted May 5, 2016 The bolt diameter looks small for a bolt that long on a shear load through a bushing like that. I would go the next bolt size up and 12.9 grade. The size up will be the tricky part. What about making a girdle that grabs the bottom diff cover bolts to keep it from swinging up and down? everything you said is what i have planned Quote Link to comment Share on other sites More sharing options...
Stimmel1647545512 Posted May 5, 2016 Report Share Posted May 5, 2016 let me know when you pull it apart ill call frank and have him hook you up on reparing all the DSS stuff, also let me know whatever else you need! P.S. I have some stuff for you to powder coat Quote Link to comment Share on other sites More sharing options...
88lx5oh Posted May 5, 2016 Author Report Share Posted May 5, 2016 let me know when you pull it apart ill call frank and have him hook you up on reparing all the DSS stuff, also let me know whatever else you need! P.S. I have some stuff for you to powder coat will do, i might have you guys ship the stuff out to them since you probably have an account with UPS. ill be needing a 3.31 gear set for 8.8 its and and install kit get ahold of me on the powder coating Quote Link to comment Share on other sites More sharing options...
DKilbourne Posted May 6, 2016 Report Share Posted May 6, 2016 Note to self, don't try to make big power with these cars. Sucks, reminds me of my Terminator days. Yep. The IRS in the 03/04 Cobra was way worse too. That's why mine was gone not long after I got the car. Quote Link to comment Share on other sites More sharing options...
y2k2gt Posted July 25, 2016 Report Share Posted July 25, 2016 88lx5oh, Whats is the race weight on your car? Quote Link to comment Share on other sites More sharing options...
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