Diff help

Homer · 11-12-2013, 10:09 AM

Wot is the lowest diff ratio I can get for my rx8

Kman Art · 11-12-2013, 10:48 AM

What year model is your RX8? It either came with the 4.44:1 or 4.78:1 final drive. Models built 2008 or newer came with the shorter R&P.

Homer · 11-12-2013, 11:14 AM

I need down in the 3. Something ratio mine is a 54 plate so it's a 4.444

Kman Art · 11-12-2013, 11:37 AM

You could source a '93+FD diff, They came with 4.10:1, but not anything from '99+FD as they came with 4.30:1. After that, it's aftermarket.

Why would you want such a long final drive?

I have a JDM FD and can't stand how long my gears are with the 4.10:1. Just installed the '04 RX8 4.44:1 but haven't driven the vehicle yet to see the difference.

FerociousP · 11-12-2013, 12:03 PM

Auto 93+ FD came with a 3.9 diff IIRC.

I believe i've seen it used in Rx-8 before, especially ones with LS1 swaps that use transmissions that would make better use of a 3.9 gear. Can't confirm which generation 8 diff was used though.

Homer · 11-12-2013, 03:14 PM

Need to be down to 3.445 or 3.9 might work where could I find one thanks I need lower revs and if there anyway Thst would stock new parts

RETed · 11-12-2013, 08:26 PM

I don't know why this thread was reported to the moderators, but...

To the OP:
You do not give enough information WHY you want to drop the rear diff ratio.
People have already asked you if this is a V8 swap, but you do not even answer that question.

If this IS NOT AN ENGINE swap, I'm not sure what you're trying to do.
Dropping the rear diff ratio ON A STOCK ENGINE RX-8 IS A STUPID IDEA.
If you're are trying to conserve gas mileage, you're going to end up with a slug of a car.
Lowering (numerically) the rear diff ratio will significantly affect the acceleration of your vehicle.
If you're fine with that, you're better off getting rid of the RX-8 and buying a Fiat 500.

I doubt this is some crazy 20B swap...
If you have resources to do something like this, you shouldn't be asking us how to find such parts.

Please use the REPORT icon to report INFRACTIONS - not because you're not getting the answers you want.

-Ted

Homer · 11-13-2013, 03:52 AM

No one ask wot I'm doing people have hinted why I won't to drop so far I have a Diesel engine in car running about 350 bhp at min with poss off going up higher but it revs are to hight I'm not saying to much cost hope to make a kit out off it

Kman Art · 11-13-2013, 10:25 AM

Ok, my eyebrows just went way up!

You have a diesel engine in your RX7???

If you want to find something below 3.9:1, I would suggest changing your rear end to a Ford IRS setup with the 8.8" rear. Gears are available from all over the place. It is an expensive swap, so I would probably search around for more RX7 gear options.

Homer · 11-13-2013, 03:06 PM

Rx8 diesel

FerociousP · 11-13-2013, 04:38 PM

http://www.mazdatrix.com/8-Diff.htm

^notice the 3.909 gear.

http://www.mazdatrix.com/getprice.as...m=27-110A-P062

^notice it says 93-95 + Rx-8. (says this for all ratios actually).

http://www.mazdatrix.com/g5.htm

^Notice at the bottom. 93-95 AUTOMATIC has 3.909.

Now that I think about it, I sold a Rx-8 R&P to a FD guy who wanted a high number gear. So there ya go.

Obviously, cheap option would be to find an auto FD used diff, and swap in ring and pinion. New, especially from mazdatrix, will be quite spendy.

Homer · 11-13-2013, 05:07 PM

Thanks for help I'm going to look for a rear diff out off a auto rx7 then thanks hope it's low enough for me ?

Homer · 11-13-2013, 05:13 PM

If I find a diff how will I no wot ratio it is I counted my diff I got 40 teeth on crown and 9 on pinion so wot would a 3. 9 diff be thanks

Mitchocalypse · 11-14-2013, 04:36 AM

dude.. lets assume english isn't your first language (and for that matter, hope it isn't).

We can forgive the odd spelling mistake, but even if this is your 5th language, you can't possibly think your punctuation is even remotely correct. I don't even understand what your question is because I just can't make sense of what you're saying.

And for future reference,
wot = what, unless you are trying to convey the term "Wide Open Throttle."
there is a difference between "no" and "know."

Also, I'm not being a grammar nazi here either. There is a big difference between that and just asking you to post something that a reader can make sense of.

Homer · 11-14-2013, 08:15 AM

It a club not a spelling test and I'm use ing my phone predictive tex and thanks a lot for slagging me off what a good person you are

Trying to find out if I buy a diff wot amount off teeth would be on the crown and pinion gear how hard was that Mitch

And I am English born and bread ????

11-12-2013, 10:09 AM	#1
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	Diff help Wot is the lowest diff ratio I can get for my rx8

11-12-2013, 12:03 PM	#5
FerociousP I-had-a-bad-experience... Join Date: Feb 2008 Location: M'boro Posts: 1,046 Rep Power: 19	Auto 93+ FD came with a 3.9 diff IIRC. I believe i've seen it used in Rx-8 before, especially ones with LS1 swaps that use transmissions that would make better use of a 3.9 gear. Can't confirm which generation 8 diff was used though. __________________ '15 Juke Nismo '06 MX-5 GT SOLD '04 S Silver RX-8 GT Track Day Use SOLD '90 Black TII vert w/ Sprint RE stock port/turbo DD dyno (242.6whp@5500rpm @12psi 8psi@redline) and (250ftlbtq@4800rpm @13psi) SOLD '89 GTUs 6p TII SOLD, '87 sport SOLD, '79 SA stock SOLD '91 B2600i 4x4 w/ Rx-8 LSD SOLD

11-12-2013, 03:14 PM	#6
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	Need to be down to 3.445 or 3.9 might work where could I find one thanks I need lower revs and if there anyway Thst would stock new parts Last edited by Homer; 11-12-2013 at 03:16 PM. Reason: Extra info

11-13-2013, 03:06 PM	#10
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	Rx8 diesel Last edited by Homer; 11-13-2013 at 04:34 PM.

11-13-2013, 04:38 PM	#11
FerociousP I-had-a-bad-experience... Join Date: Feb 2008 Location: M'boro Posts: 1,046 Rep Power: 19	http://www.mazdatrix.com/8-Diff.htm ^notice the 3.909 gear. http://www.mazdatrix.com/getprice.as...m=27-110A-P062 ^notice it says 93-95 + Rx-8. (says this for all ratios actually). http://www.mazdatrix.com/g5.htm ^Notice at the bottom. 93-95 AUTOMATIC has 3.909. Now that I think about it, I sold a Rx-8 R&P to a FD guy who wanted a high number gear. So there ya go. Obviously, cheap option would be to find an auto FD used diff, and swap in ring and pinion. New, especially from mazdatrix, will be quite spendy. __________________ '15 Juke Nismo '06 MX-5 GT SOLD '04 S Silver RX-8 GT Track Day Use SOLD '90 Black TII vert w/ Sprint RE stock port/turbo DD dyno (242.6whp@5500rpm @12psi 8psi@redline) and (250ftlbtq@4800rpm @13psi) SOLD '89 GTUs 6p TII SOLD, '87 sport SOLD, '79 SA stock SOLD '91 B2600i 4x4 w/ Rx-8 LSD SOLD

11-12-2013, 10:48 AM	#2
Kman Art The Converted Join Date: Oct 2012 Location: Cayman Islands Posts: 49 Rep Power: 0	What year model is your RX8? It either came with the 4.44:1 or 4.78:1 final drive. Models built 2008 or newer came with the shorter R&P.

11-12-2013, 11:14 AM	#3
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	I need down in the 3. Something ratio mine is a 54 plate so it's a 4.444

11-12-2013, 11:37 AM	#4
Kman Art The Converted Join Date: Oct 2012 Location: Cayman Islands Posts: 49 Rep Power: 0	You could source a '93+FD diff, They came with 4.10:1, but not anything from '99+FD as they came with 4.30:1. After that, it's aftermarket. Why would you want such a long final drive? I have a JDM FD and can't stand how long my gears are with the 4.10:1. Just installed the '04 RX8 4.44:1 but haven't driven the vehicle yet to see the difference.

11-13-2013, 03:52 AM	#8
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	No one ask wot I'm doing people have hinted why I won't to drop so far I have a Diesel engine in car running about 350 bhp at min with poss off going up higher but it revs are to hight I'm not saying to much cost hope to make a kit out off it

11-13-2013, 10:25 AM	#9
Kman Art The Converted Join Date: Oct 2012 Location: Cayman Islands Posts: 49 Rep Power: 0	Ok, my eyebrows just went way up! You have a diesel engine in your RX7??? If you want to find something below 3.9:1, I would suggest changing your rear end to a Ford IRS setup with the 8.8" rear. Gears are available from all over the place. It is an expensive swap, so I would probably search around for more RX7 gear options.

11-13-2013, 05:07 PM	#12
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	Thanks for help I'm going to look for a rear diff out off a auto rx7 then thanks hope it's low enough for me ?

11-13-2013, 05:13 PM	#13
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	If I find a diff how will I no wot ratio it is I counted my diff I got 40 teeth on crown and 9 on pinion so wot would a 3. 9 diff be thanks

11-14-2013, 04:36 AM	#14
Mitchocalypse Rotary Fanatic Join Date: Jun 2012 Location: Edmonton, AB Posts: 179 Rep Power: 13	dude.. lets assume english isn't your first language (and for that matter, hope it isn't). We can forgive the odd spelling mistake, but even if this is your 5th language, you can't possibly think your punctuation is even remotely correct. I don't even understand what your question is because I just can't make sense of what you're saying. And for future reference, wot = what, unless you are trying to convey the term "Wide Open Throttle." there is a difference between "no" and "know." Also, I'm not being a grammar nazi here either. There is a big difference between that and just asking you to post something that a reader can make sense of. __________________

11-14-2013, 08:15 AM	#15
Homer The Newbie Join Date: Oct 2013 Posts: 15 Rep Power: 0	It a club not a spelling test and I'm use ing my phone predictive tex and thanks a lot for slagging me off what a good person you are Trying to find out if I buy a diff wot amount off teeth would be on the crown and pinion gear how hard was that Mitch And I am English born and bread ????