Pioneering mods: RX-8 ring and pinion swap and RX-8 diff cover!
#27
Full Member
iTrader: (14)
It does throw it off by about 8% or so, but Dale also found out a way to calibrate the speedo without spending extra money on an external calibrator.
https://www.rx7club.com/3rd-generati...meter-1011051/
https://www.rx7club.com/3rd-generati...meter-1011051/
#34
RX-7 Bad Ass
Thread Starter
iTrader: (55)
Little update on this -
I drove up to Deal's Gap Rotary Rally (which if you didn't go, start planning to go in 2014!) a few weeks back with my 4.44's.
I have a US 5th gear ratio in the gearbox and the 4.44 RX-8 ring and pinion. On the highway legs of the trip, with 2 guys in the car and tons of luggage, tools, and snacks, I got a bit over 22 mpg. This is with cruising at a GPS-verified 73-75 MPH, using cruise control, windows up and AC on.
So, there is no significant impact to cruising fuel economy with this setup, which is good to know.
Dale
I drove up to Deal's Gap Rotary Rally (which if you didn't go, start planning to go in 2014!) a few weeks back with my 4.44's.
I have a US 5th gear ratio in the gearbox and the 4.44 RX-8 ring and pinion. On the highway legs of the trip, with 2 guys in the car and tons of luggage, tools, and snacks, I got a bit over 22 mpg. This is with cruising at a GPS-verified 73-75 MPH, using cruise control, windows up and AC on.
So, there is no significant impact to cruising fuel economy with this setup, which is good to know.
Dale
#35
Hi ppl. I know this an old thread but was looking into putting the rx8 4.44s in my car, and also the diff cover, not sure but im thinking that updated diff cover dale gave the pn for only comes on the 09onwards rx8 so that will mean it also comes with the 4.77 r+p , so if your looking for the 4.44 r+p be sure it has the old style cover if your buying a complete diff unit, just a fyi post so people dont get the wrong gears,
Jason
Jason
#36
Urban Combat Vet
iTrader: (16)
Just finished watching an older video series from Gale Banks regarding useful form and function of the differential cover. He duplicated the cover of a truck with clear plexiglass, but while his examination of covers involved live axle trucks, I think a lot would translate to our cars and the topic of this thread. Hence my bump. 😎
While earlier Dale indicated he didn’t think there would be any significance to the RX8 cover, Banks found a significant dead-air space aft of the pumpkin...so maybe MAZDA wasn’t so crazy adding in that fin appendage. But maybe the big takeaway was how the internal shape affects proper splash lubrication of the pinion etc. Seeing the video and then looking at the shape of aftermarket covers like Greddy make me suspect that despite their extra capacity, the Greddy cover might actually be counter-productive.
While earlier Dale indicated he didn’t think there would be any significance to the RX8 cover, Banks found a significant dead-air space aft of the pumpkin...so maybe MAZDA wasn’t so crazy adding in that fin appendage. But maybe the big takeaway was how the internal shape affects proper splash lubrication of the pinion etc. Seeing the video and then looking at the shape of aftermarket covers like Greddy make me suspect that despite their extra capacity, the Greddy cover might actually be counter-productive.
#37
RX-7 Bad Ass
Thread Starter
iTrader: (55)
I've been watching those Banks Power videos, Gale Banks is a genius and really has a lot of good information in all his videos.
The RX-8 diff cover is a safe bet, it's a Mazda designed and engineered part. The Greddy cover is a question, it's hard to say if it really helps or what.
I've had zero problems with the RX-8 diff cover since I posted this up ages ago. Still doing great. And still love the RX-8 ring and pinion, it's a great mod.
Dale
The RX-8 diff cover is a safe bet, it's a Mazda designed and engineered part. The Greddy cover is a question, it's hard to say if it really helps or what.
I've had zero problems with the RX-8 diff cover since I posted this up ages ago. Still doing great. And still love the RX-8 ring and pinion, it's a great mod.
Dale
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Sgtblue (02-25-20)
#38
Rotary Freak
I got the impression, the extra capacity in the greddy was in the trailing sump of that cover and the high upper input was primarily for a diff pump return to aim the cooler oil at the crownwheel. A stock diff will cook the oil, with heavy competition use inside a day.
I'd be amazed if the fill point was designed as a level check as per a stock cover and would expect a lot more than a litre extra, if someone is using it that way.
There are other options too
I'd be amazed if the fill point was designed as a level check as per a stock cover and would expect a lot more than a litre extra, if someone is using it that way.
There are other options too
#39
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I've been watching those Banks Power videos, Gale Banks is a genius and really has a lot of good information in all his videos.
The RX-8 diff cover is a safe bet, it's a Mazda designed and engineered part. The Greddy cover is a question, it's hard to say if it really helps or what.
I've had zero problems with the RX-8 diff cover since I posted this up ages ago. Still doing great. And still love the RX-8 ring and pinion, it's a great mod.
Dale
The RX-8 diff cover is a safe bet, it's a Mazda designed and engineered part. The Greddy cover is a question, it's hard to say if it really helps or what.
I've had zero problems with the RX-8 diff cover since I posted this up ages ago. Still doing great. And still love the RX-8 ring and pinion, it's a great mod.
Dale
#40
10000 RPM Lane
iTrader: (2)
hopefully Mr. Peabody and Sherman won’t mind me borrowing their Wayback Machine …
I’m working on a PPF delete on an RX8 and am trying to figure out if the PPF/diff mounting on it is the same as on the FD3 diff housing? I recognize the chassis and overall mounting is different, but there’s a part from an FD3 PPF delete kit that bolts onto the PPF position of the FD3 diff housing that would be more advantageous for me to buy rather than custom fabricate if it will bolt up to the RX8 diff housing.
Kind of a long shot, but was wondering if anyone might have ever assessed the PPF mount between the two diff housings?
I’m working on a PPF delete on an RX8 and am trying to figure out if the PPF/diff mounting on it is the same as on the FD3 diff housing? I recognize the chassis and overall mounting is different, but there’s a part from an FD3 PPF delete kit that bolts onto the PPF position of the FD3 diff housing that would be more advantageous for me to buy rather than custom fabricate if it will bolt up to the RX8 diff housing.
Kind of a long shot, but was wondering if anyone might have ever assessed the PPF mount between the two diff housings?
#41
RX-7 Bad Ass
Thread Starter
iTrader: (55)
Not a great answer, but I remember when I had that RX-8 diff that it seemed the PPF mounting points were quite different. I did half look at it for "just bolt that diff up as-is" and I remember it wasn't even close.
Dale
Dale
#43
Urban Combat Vet
iTrader: (16)
Since this was bumped, a little follow-up to the diff cover topic.
Probably to no one’s surprise Banks has come out with their own line of covers. Maybe the first 17 minutes of the below video is all that would interest us, but it would seem to support staying with an OEM cover profile (RX7 or RX8). And it tends to dispel the belief that just increasing gear oil capacity automatically means improvement. And depending on profile it can be counter-productive.
I’ve never seen one of the Greddy covers up close but from what I remember from pictures, other than possibly some additional fins (that may not even be in a clean air stream), it might fall into that category.
https://m.youtube.com/watch?v=vdtmDl5EDJ8
Probably to no one’s surprise Banks has come out with their own line of covers. Maybe the first 17 minutes of the below video is all that would interest us, but it would seem to support staying with an OEM cover profile (RX7 or RX8). And it tends to dispel the belief that just increasing gear oil capacity automatically means improvement. And depending on profile it can be counter-productive.
I’ve never seen one of the Greddy covers up close but from what I remember from pictures, other than possibly some additional fins (that may not even be in a clean air stream), it might fall into that category.
https://m.youtube.com/watch?v=vdtmDl5EDJ8
Last edited by Sgtblue; 07-14-21 at 05:55 AM.
#44
RX-7 Bad Ass
Thread Starter
iTrader: (55)
That series on the diff cover by Banks is gold, lots of really solid engineering work put into that end product.
Dale
Dale
#45
Non Runner
iTrader: (3)
I've been on the 4.44 rear end for a few years now too, it's a nice noticeable upgrade. Being a JDM car I swapped in the .719 5th and RS/RZ speed sensor to balance it out so when cruising in 5th my RPM's are actually lower than they were back when I had the 4.1 diff and original .806 5th.
I also fitted the RX-8 cover with the side vent, definitely looks better if nothing else .
I also fitted the RX-8 cover with the side vent, definitely looks better if nothing else .
Last edited by Ceylon; 07-14-21 at 09:22 AM.
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sharingan 19 (08-24-21)
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Adam P (08-03-21)
#48
Rotary Freak
Originally Posted by Sgtblue
I’ve never seen one of the Greddy covers up close but from what I remember from pictures, other than possibly some additional fins (that may not even be in a clean air stream), it might fall into that category.
#49
F'n Newbie...
iTrader: (6)
Looking on yahoo recently, unless they're using generic pictures, seems to be new styles of trust/greddy covers out there. https://page.auctions.yahoo.co.jp/jp/auction/o480418819 https://page.auctions.yahoo.co.jp/jp/auction/e519933144
It isn't a perfect picture, but you can get a good idea of the diff cover design.
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Carlos Iglesias (09-05-21)
#50
Rotary Freak