Diving into rearend swap
 

So read a couple forums and watched some youtube and have decided to swap out my first gen diff with the gen two diff.
I only wanted to hear latest info on this sway if there is any.

Would anyone be interested in discussing over the phone there experiences good or bad? Before i spend 2000 just want to make sure i have everything covered.

Thanks guys.

They're directly swappable.

https://www.rx8club.com/series-i-tec...7/#post4638227

There is one for sale on ebay? Worth the risk for 300 buck?

Well not much response i see. Talked to mazmart today. Found a used 2009 diff to swap in for 1100. I will also get the mount incase its needed to swap over. I am going to just replace the axle seals and add poly bushings to the mount. I will keep you posted... Anything else i should be covering im not thinking of?

What's worth swapping for the 2nd gen?

4.77 gears

Exactly

Hmm I see but will you need to find a way to recalibrate the speedo? And make sure the diff you get isn't blown. If you see pieces of shrapnels size of a dime almost its no good.

To be honest unless there is an easy way to calibrate for the gears and rims i went to then im not to worried about it. My buddy will just drive beside me and give me his speed. Then i will know how far off i am. Not the correct way to do things but there it is. When i receive the rearend i will take cover off and inspec fluid, visual condition of parts and take my measurements before install.

Just to update. Winter is finally winding down so time do the swap. I went with a totally new rear end from s2 rx8. Paul from mazmart had it shipped right to my door. took a week straight from japan. Im not going to mention pricing so get ahold of paul if your interested. Only thing im not sure of is what kind of fluid im going with. I will start posted pics tomorrow and give my impressions after its broken in. Hope price is worth it.

They sell around $500 used from the salvage yards. There is no speedometer calibration. The speedometer signal comes from the front ABS sensors, not the drivetrain. Any 75W90 gear oil is ok.

They are swappable, but this is a differential swap, not a transmission swap

here are some pics just to post them up. i will do a write up and thoughts after i break everything in.

Initial driving impression are good and bad. First thing to mention is i replaced the mounting bushings with poly mounts. The rear feels must more planted however there is noticable driveline vibration. Im ok with it but its worth mentioning. Second, and a good thing is rpm stays closer to powerband and revs up alittle faster. I havent pounded on it yet. My only comparision for rpm gain is before swap at 70mph i was at 3500 rpm, this was on 17in tire. Now im at 4000 rpm same speed, same tire size. I drive some highway but mostly city and overall i like this swap. however i dont think its worth it for the money i invested. I would probably say if you could go the cheaper way and find a relible used one and can do the swap your self then it would be worth it. If anyone has questions feel free to ask.

Hows the fuel mileage with the 4.77. I know top speed is lower in relation to rpm with that rear. So I'm guessing highway driving at about ~80mph would be approximately 5k rpm.

Any big change in mpg's? I'd assume it to drop a few digits.

at 60mph in 6th gear its about 140 rpm difference, you could calculate it out easy using this thread for reference

https://www.rx8club.com/series-ii-te...ussion-135710/

I will post a long term impression next week. I am taking it out of town and can get a better idea of fuel mileage. Im sure it will obviosly take alittle hit however i was fully prepared for that

Only thing i wish i could have done before and after this swap was to get a side by side comparison video racing another rx8 just to show acceleration difference. I never went to a drag strip or track before to have any improvement comparison. I do some autocrossing and i think this swap will help lower my times. Of course i should just spend money on becoming a better driver. Haha

Thanks for the link team.

Someone needs to do 5.12 gearing

Rowing through the gears faster doesn't really equate that much to actually accelerating faster. The 4.77 may be new to you, but not this forum. Same for the 5.12, which is only a benefit at very high speed i.e. racing. Glad you're having fun though ...

Dont get me wrong, and i have had alot of fun with my eight but i believe i am getting to the same place many people on here seem to get to. Either you spend a huge amount of money and still will get beat buy a newer g37x or somthing plus giveup reliability or get out what you want from the car and move on to a better plateform to work with. Which brings up a good question. I am certainly always going to keep my eight but car would be a good stepup overall performance wise to get next?

Sorry dont want to start a firestorm of hate on here just asking opinion.

Still get beat by a newer G37? :lol:

Define better platform and define beat. This isn't a straight line car, but you can challenge some years of M3s and some trims of Caymans with it in a track day setting, for an example. Either of those cars I would consider a step up, but they're 2-3 times the cost.

Your question of what car to get depends a lot on what you want to do with it...

If you want red light racing, get a Mustang, it'll be way easier.