Just recently, got a ford 8.8 rear diff and I'm looking to see if anyone has any experience with the Ronin kit. I'm interested in purchasing but haven't seen anyone talk about their experience with it.
if anyone has links to or any additional info please let me know.

 

I will be posting an article on my Ronin install shortly. It's a great kit, but its important to set the pinion angle when welding the x-brace in. Lmk if you have any questions. What gear ratio and limited slip diff are you using?

 

Running 3.55, I was debating maybe running 3.31 not too sure. Trying to get more info. I was looking at this Kit. Looking forward to your post.

 

Why are you interested in such tall gears? What are the details of the rest of your build? Most Explorer diffs have a 3.55 so you might only need the rebuild kit and LSD. Depending on your application, the traction-lok that you posted might be a good fit for street and occasional track use, which is similar to a stock Mustang's LSD; however for more power or performance-oriented usage might make a TrueTrac a better fit.

 

I have one in my fd and im using 3.27 gears and a t2r torsen in it. I kept the original rubber bushings in the front and ended up cracking the front passenger mount because of the flex and had to have it welded back together. I swapped to solid aluminum bushings and reinforced both front mounts and have had zero issues since. Id go poly or aluminum to avoid this from happening. 550rwtq is fun lol

 

^Holy crap, you did that with just 550rwtq? Talking to Joel at Ronin, he's never mentioned that kind of failure, and i've never seen that before. I'll have to see if he's aware of it. I'm going to assume you have an LS3; is it a street/track/drag/drift car?

For Spintowin: The T2R is MUCH better than the T2, but personally I like the Truetrac which is a lot less expensive and similar (if not slightly better/stronger) in performance than the T2R. But the T2R has changed a few years ago and I have not heard about the same issues and failures in extreme conditions since then so durability and performance wise, the TrueTrac and T2R are virtually identical.

 

I'm still learning what route I'm trying go (still learning about this). I'm leaning towards the Torsen T-2R from the research I did online. I'm still trying to decide on gearing & looking for more info. Maybe you guys have some recommendations. it will be a 13b-rew running it at 550rwhp but planning on pushing it more as I get more comfortable. I plan to use it for street, autocross, and touge runs. Might stay with the 3.55 gearing. I'm running the stock trans but it's going to be built by liberty gears.

 

Having raced both of them and using both of them in personal cars and daily drivers, I would get the Eaton Detroit TrueTrac ($690) over the T2R ($875). The TrueTrac use to be sub $600 until recently but even for the same price, I would probably go with the TrueTrac. You can't go wrong with either but the T2R does not have any real advantages over the TrueTrac.

That power is borderline for the transmission, where the case flexes and causes the gear stacks to separate and then shear teeth in the gears (mostly 3rd). But depending on how you drive it may be fine. I was keeping my stock trans with the 550whp goal but now that has jumped to mid-high 600whp and I went ahead and upgraded the trans. What turbo are you using? I think the 3.73 or stock 4.10 would be better for togue and autocross. Depending on your budget I would pick the TrueTrac and the 3.55 that comes with most Ford 8.8's rather than a more ideal 3.73 and that Traction-lok diff you posted. But look at the different prices of Explorer 8.8's; there are some 3.73 equipped diffs out there for a little more money that might be worth it vs buying a new gear.

 

Perfect, about to order the Easton Detroit TrueTrac. The turbo is a g35-900 1.06. The ford 8.8 diff I have comes with 3.55 gears, I'm planning on getting a rebuild kit for the diff and wondering if it's just worth upgrading to the 3.73 gears. The rebuild kit with the 3.73 gears (I found some negative reviews about Yukon so not sure if I should really order from them). Found this 3.73 gear by itself but having trouble finding a kit to rebuild the diff with. Any suggestions before I order?

 

You could match the stock 4.10 final drive or 3.73 I don't think you could go wrong with either. I got a Motive Gear off Amazon; it was $230. I got the Grannas Explorer Master Overhaul kit for $246 - you can find them a lot less but it doesn't appear most have new side axle seals; which needed to be replaced on my diff.

 

Waking this up from the dead.... Is Ronin still producing the kits or has it all gone to Grannas now?

 

I'm pretty sure. Their site is still up and they have way more products including their own axle shafts that Grannas does not offer:

https://www.roninspeedworks.net/inde...tegory&path=70

 

what is the power range with the liberty gear upgrade?

im in a similar boat looking at trans swap with the 370z trans and looking at diff options.

I like the idea of a 6 speed but the z trans 6th is vary close to the fd 5th so no real avatar an extra gear and strength of trans

with the diff and you looking to have 550rwhp is there an option to stay with stock house or is it just better to go with ford diff and rebuild?

 

I wouldn't recommend going with Liberty Gears. I'm still waiting a year for my transmission, I had to source a stock trans off marketplace to continue with my build. I've been having to call and essentially beg for them to work on my transmission. Powerwise it will probably be able to handle all my power and more since the transmission at liberty is being converted to faceplated gears (I don't have an exact number of how much it can handle, will ask them if I ever receive it). I would recommend doing a magnum t56 transmission with the ford diff, this is the next route I'm planning on taking. I would only recommend changing the diff depending on use, I know I will be abusing the **** out of my fd when it's done and testing my engine building and tuning skills. I don't think it's worth swapping to the ford diff if you plan on never launching it, tracking the car, or some insane 700hp build. It just depends on what you plan on doing with the car. Another option is upgrading to the Kaaz 2 way. Keep in mind for the Ronin kit also, even if you buy the full kit you still have to source your own parts to complete the the diff side of the axle. Let me know if you have any other questions!

 

When using a 350Z transmission, it really needs a 3.55 final drive ratio for the gears to line up and have the benefits of a 6th gear. IMO it's better to upgrade to a Ford 8.8; but if you are not planning on pushing the car (launches, track, autoX, drive it aggressively) and are only going to drive it on the street with an occasional WOT pull; then the stock diff might last a while.

A few good reads:

https://motoiq.com/project-fd-rx7-re...-differential/

https://motoiq.com/project-fd-rx7-re...c-lsd-and-wpc/

https://motoiq.com/project-fd-rx7-re...irs-mount-kit/

https://motoiq.com/project-fd-rx7-re...ssion-upgrade/

Or you can buy the driveshaft shop "Direct-Fit" axles:

https://motoiq.com/project-fd-rx7-re...s-mount-kit/7/

 

so liberty is lagging on communication and build?

im looking at cost effectiveness. Seeing Billj747
Stating the cost of building the stock diff with bracing is about the same as going ford diff with Ronan bracing got me thinking. From my limited reach the cost does look to be very close to each other and ford diff gives you more much more security.

I don plan to launch here and there drift a little and sprites runs on the freeway.

 

my concern with the transmission was 6th being close to the 5th of the FD. Changing the final drive clearly is the way to go seeing that I cannot locate any taller 6th gear for the z trans. Going with the 3.55 how much effect is on the other gears. Seeing the 3.55 is lower I should see lower torque but higher top speed correct?

From my understanding there are plenty of gearing options with the ford diff so I wonder if going slightly higher would allow for slight higher speeds and benefitting from more torque.

I check out driveshaft shop pricing and only see pro kit for the FD. It’s over 2500. A price I’m not comfortable with at this time.

im hoping I can be around 5k for trans and diff set up

 

You can probably get the Liberty or Albins gears and a Ford 8.8" for $5K. You most likely won't be able to get into a CD009 for that. You need to lock in which transmission you are going to go with, and then pick the final drive according to what you are going to use the car for.

At an 8,000rpm redline, here's the top speed for each gear:
Stock FD: 47mph, 77mph, 111mph, 142mph, 180mph, 227mph
CD009 & 3.55: 44mph, 72mph, 103mph, 132mph, 18mph, 211mph
CD009 & 3.73: 42mph, 69mph, 98mph, 126mph, 160mph, 201mph

 

thanks for the speed info. How’s the torque affected. With a taller final would you notice the torque gains?

with the CD009 I’d go used and seen a few right around 1k. I’d roll the dice with used hoping I can get a few years before a rebuild.

im trying to stay around 5k out of pocket for trans and ford diff set up. I think I might be able to achieve if I can get good money for my trans and diff. They only have 26k on them.

 

Which adapter are you going to use? The Fisch one is $2,800 alone without a clutch master cylinder.

Transmissions and final drive ratios are torque multipliers. Engine output torque is multiplied by the trans and diff ratios to determine a car's total torque output at the tire. Shorter ratios equal more total torque and will accelerate quicker and have lower top speeds. However, if you're spinning the tires and can't put that power down, then this increased torque is useless and slower. But you also need to consider your engine's powerband, so you don't fall out of it between shifts.

Most FDs I have seen with 500-550whp need longer gears because they are shifting way too often. Selecting ideal gear ratios are more in depth than most people realize.

 

not sure as builder was looking at a few different options outside of Fisch. (To expensive for me at this time)


looking at FD bs CD the CD looks to have slightly taller gears 1-3rd with a 4th I’m guessing giving you an extra boost in accretion before hitting 1yo1. Is this why you suggested the 3.55 final?

sent you a message on shifter fit finish as well

 

Larger numbers are shorter gears (more acceleration, less top speed).