Independant suspension Rear Dif Options
 

So my stock Mazda Dif is basically cooking and on its last legs. I don't want to do the Ford swap as it seems a little pricey and I would like as much of a plug and play option that I can get. Plus, I want to keep the independent suspension, and somewhere along the way I heard that the Ford swap is a solid rear axle. Is that even true? Anyhow, I need some options. A few years ago I was looking at the Katz 1.5 but I'm having a difficult time finding someone that sells it at this point. I stumbled onto another shop's page that was selling Cusco and I don't know too much about that brand...or that specific product.

Does anyone here have some experience on this? It's basically the one part on the car I've never had to really mess with. I'm thinking I'll have to get axles too...

Any insight would be appreciated.

Thanks!

well you cant have your cake and eat it too. The Ford 8.8 swap uses the IRS explorer differential which uses the factory rear subframe and keeps all of the oem suspension geometry. There are a few people who have tubbed and 4 linked a solid 8.8 or 9” rear into an Fd but its major surgery and requires cutting the back half of the car out.

the reason that diff is so popular is that its really strong, has a bunch of aftermarket support, and its very efficient so it doesnt rob you of hp like a 9” would.

youll spend about the same if you upgrade to a kaaz 1.5 and get aftermarket axles as you would an 8.8 and it will not handle as much abuse. You’ll also be limited to 3.90 as your lowest gear ratio which sucks if you have decent power. The 8.8 you can get 2.90, 3.05, 3.15, 3.27, 3.42, 3.55, 3.73, 3.90, 4.10, 4.30, 4.50.

My recommendation is to get the ronin kit and do it once and enjoy the car.

The gear rato thing is legit. I could super benefit from 3.73's. However, the cost being the same use the Katz as the 8.8 doesn't make sense to me. The Katz seems to be pretty much lpug and play (along with getting axles) where as the 8.8 you have to buy the kit, and then the dif itself. Where are people buying the Ford rear ends these days? Are they buying used etc? I'd like to price this out.

i run 3.27 gears in mine, its a nice balance. The kaaz wont handle the abuse like an 8.8. There are people running 8’s in the 1/4 with 8.8’s but it’s definitely more work. There are plenty of cores from 8.8 irs explorers i got mine off ebay but there are a bunch on car-part.com and lkq can find them too. $300 for mine and I got a T2R helical diff for $600.

Well I'm not running huge power, so I'm not necessarily scared of the Katz not holding up..The most I'll make is 450RW and I may not even go for that. I'm more of a road course guy that does the occasional street launch. Bear with me for a minute, when you say core..do you just mean the case and then you bought the dif to go inside it, or is the core the whole rear end, and you upgraded to the T2R dif?

Sorry for the nube questions.

you might get lucky and itll handle it or it blows up and you lose your entire investment. I have bad luck and im hard on shit so i built it all just in case. When i say core I mean the entire pumpkin and axles, they come with open diffs in the exploders so you have to put an LSD in there anyways. The t2r comes in the heavy shelby gt500’s and can take some abuse. I also like the wavetrac and would go that route if i had to do it over again.