RGT84

Aside from the lsd drama out of the factory diff, I mainly want the 8.8 because of the endless gear ratio options. And I want to lose the rear portion of the PPF Im still using to support the factory diff. The gear ratio is 3.73, just finished building the diff and have a new Ford Motorsports TracLok Installed. More than likely going to stop somewhere close to 550-600whp.

John V

iTrader: (1)

TracLocs are... Not good diffs.

RGT84

Your would be correct, things that aren't drag racing the ford trac lok is not the best option. But as of right now I have no plans to track the car in it's current state, its just a toy that I'm trying to get the bugs out of at this point. When I get to a point that I know a change or changes are going to be permanent Ill invest in something better.

TeamRX8

iTrader: (25)

there is a 3.73 option for the Mazda diff, but you have to find it used because new is NLA and add a sleeve to the pinion bearing surface area. Currently inquiring on availability of a 3.58 option new from Mazda Japan, but still needs the sleeve mod too. These were offered on earlier Mazda vehicles with same 8” R&P sizing.

When Mazda put the 8” in the FD3 it received a larger pinion bearing to handle the increased power loading. The pinion diameter at the bearing area was increased to match the larger diameter bearing bore. So it needs a sleeve to make up the difference to fit in an FD3 or RX8 diff. However the rest of the pinion diameter and sizing is all the same. So the pinion itself and ring gear are no different wrt strength.

but yeah, it’s all your choice and just fyi rather than a critique.
.

John V

iTrader: (1)

I highly recommend going the 8.8 route. There are tons of LSD options and as you have figured out, the gearing options are much better when you're using a piston engine.

RGT84

It's a must, with the power I have currently using the 4.44 the car is almost useless. 1st and 2nd might as well not exist and 3rd below 60 degrees will just blow the tires off from a roll. And I dont exactly have a completely **** tire on the back either. Federal 595 RS-RR 265 35 18

Laminar

Not to derail this thread too much, but I know you swapped from the TrueTrac to the OS Giken. Strano sells the T2R on his site, do you think that the higher bias ratio would have helped the deficiencies you found with the TrueTrac?

John V

iTrader: (1)

I think it would have helped but would not have solved the issues. And the T2R is known to be a bit weak when faced with reasonable power.

I'm in the process of building another MZR-swapped RX-8 and that one is going to also get an 8.8 and the True Trac that has been sitting on a shelf since last year. I think it's a great differential for a street car.

RGT84

Well if you're planning to use the kit Ronin supplies for the 8.8 like me, better order it. Ordered mine almost a month ago and its not expected to be here till maybe the end of this month. Its all pre-order due to back ordered axles.

Laminar

Glad I got my axles last fall then!

Syame23

hi guys. recently bought a 1jz vvit gte swapped rx8. everything is working except for the RPM and oil pressure meter/gauge. Any advise what to check/replace? the car was originally on MT then he swapped it with a 1jz AT, if this info is relevant to the issues i'm facing. everything was working well after the engine swapped, the RPM and oil pressure meter just decided to stop working few months back he said.

RGT84

What ecu does the car have?

rhargrove

Great build! I loved seeing this all come together.

20b10ae

This is really cool! I believe a guy near me just got his up and running. Between my LFX swap coming up and him, we should make a few people scratch their heads. Lol

Zerox39

I like it