All kinds of claims have been made regarding this topic (Fuel economy). These are the facts regarding my claims. At a steady 70 mph with this gearing you will be turning 7% less rpms and therefore your highway fuel consumption should recieve a nice improvement (As if you were doing 65). The other advantage to this system applies to our turbocharged brethren. You want to be able to reduce wheel spin on launch and other accelerating from low speeds and this will help accomplish that. Also, having the extra power from turbocharging, this gear will allow for potentially higher top speeds.
The units are built by Rick Engman. He has been the engine man on the most successful Mazda road race/ cicuit team of all time, Downing Atlanta, for 30 years. They have achieved numerous championships and prestigious wins in class, like at LeMans and Daytona.
The price for a plug and play unit is $750 plus your core. What a wonderful Christmas gift.
Paul.

I may offer a 3.9 also if there is a demand for it.
Paul.

We should all feel very privledged that Rick make these.
I meet him at SS8 and is one really cool cat.

I'll just cruise 5 mph slower if i want to save gas and put that 750 in the bank lol :)

I thought the RX-8 with an automatic transmission came with a 4.10 gear.

What's the diff? (pun intended)

All RX-8s come with 4.44 ratios as far as I know.

on a turbocharged 8, what will this do to 1/4 mile times and 0 to 60?

I may offer a 3.9 also if there is a demand for it.
Paul.
Paul I'm interest in 3.9 let me know where i can buy it .

thanks :)

on a turbocharged 8, what will this do to 1/4 mile times and 0 to 60?
That's a good question, and a little difficult to answer. The general rule is that lower gearing equals quicker acceleration, however, there are many more factors to consider including traction and amount of shifts necessary etc. It will be interesting to see how how this gearing may affect turbo cars at their different levels of power.
Paul.

Paul I'm interest in 3.9 let me know where i can buy it .

thanks :)
I could probably have it to you by Christmas.
Paul.

I think this is a cool product, yes....I'm WAYYYYY LATE on this.

Anyway, so what you are saying is lower gearing means quicker speed and better fuel economy?

I thought it was the other way around.....???

Bit misleading, the term "lower gearing" usually means HIGHER numerical ratios...

So your stock 4.44 rear gives lots of turns of the engine per mile, but lousy economy. At 4.1, this ratio would give lower revs for economy, with slightly slower acceleration, unless you have more power (FI) to back it up.

With the stock rear I run out of revs in fifth and redline, but in sixth the engine just can't gain and I lose speed - this ratio might make sixth really useful again!


S

Let's crunch some numbers here. Let's assume it costs $450 to install the diff. It makes the numbers easier. $1200 @ $3/gallon and 20 gallons/mile can buy 8000 miles of fuel. We're assuming all miles are at highway cruising speeds--again a simplification so this means it's a best-case scenario. If a 7% gear reduction equates to a 7% savings in fuel, how long would it take to "save" 8000 miles? Answer: once you installed this diff you'd have to drive 114,000 miles in order to break even. During that time you'd suffer slower acceleration and less torque.

Buying this mod to save money does not compute.
________
Lovely Wendie99 (http://www.lovelywendie99.com/)

thank you

Let's crunch some numbers here. Let's assume it costs $450 to install the diff. It makes the numbers easier. $1200 @ $3/gallon and 20 gallons/mile can buy 8000 miles of fuel. We're assuming all miles are at highway cruising speeds--again a simplification so this means it's a best-case scenario. If a 7% gear reduction equates to a 7% savings in fuel, how long would it take to "save" 8000 miles? Answer: once you installed this diff you'd have to drive 114,000 miles in order to break even. During that time you'd suffer slower acceleration and less torque.

Buying this mod to save money does not compute.

yes,
but doing a mod,

priceless!!!!!! :)

i think this will be gold as the turbo and sc come on line...

beers :beer:

I've sold one of these to a guy in Puerto Rico who's running a 3 rotor and he seems quite pleased. He really wanted to mildly reduce his highway cruising rpms but the side benefit is: If you have enough horses you may be able to leave the line with less wheel spin with the taller gear. According to an engine's range of efficiency it can also improve fuel mileage. As far as the mathematical calculation of retrieving one's expenditure, I guess it depends on whether you can put in your own diff. Our's comes in the case so it's just plug and play. As gas prices continue to rise and people consider forced induction this could become more and more of an option for people to consider.

Paul.

Just bumping for a FANTASTIC seller!
Sounds like you have a great product here.
PS You have a PM :P

Sweet item! And definately something every turbo 8 owner should have.

If i want to save on gas money, i would buy a Yaris not destroy my car by putting one junky product!

So should this be considered a must have if you are thinking about, say....Petit SC stage2?

If i want to save on gas money, i would buy a Yaris (#) not destroy my car (#) by putting one junky product!
Rick Engman hasn't produced a junky product in his life n00b, not that you'd even have a clue who Rick Engman is.

Anybody know about the Super Charger? If the mods really really require differential changes, that is a serious consideration monetarily. I really don't know that much about this for sure, please enlighten me with knowledge.

The supercharger won't necessitate a gearing change but one may compliment the other.

Rick Engman hasn't produced a junky product in his life n00b, not that you'd even have a clue who Rick Engman is.
damn.... pwnd

This is exacly what I am probably looking for... well that or swapping in an FD tranny once the turbo gets installed... thanks for providing the diff! At least we have options now.

Rick Engman hasn't produced a junky product in his life n00b, not that you'd even have a clue who Rick Engman is.
Haha, damn.

As said, he got owned. Total ignorance right there.

Haha, damn.

As said, he got owned. Total ignorance right there.

By the way, Mr Engman will be at Sevenstock, so if you're there please seek us out and say hello.

Paul.

Hmmm - differential options are nice to have when you are looking to make decent power. I doubt anyone looking to double the stock HP to the wheels (if not more) has a lot of use for first gear. You simply can't floor the car and maintain traction. If you are cutting throttle to get traction, you are wasting the ponies you invested to get. If you can decrease your overall gear ratios and buy more full throttle time at the drag strip, you will improve your quarter mile times. It also raises the top speed of each gear i.e. 5th is good to 159 instead of 147. If you do not have enough hp to use the traction you generate now, then the modest gas savings possibility of a 4.1 or 3.9 rear might be considered marginal. Those people with a first gear smoke show are probably much more interested.

Are these diff's Rx-8 diff's stuffed with different internals?

Those people with a first gear smoke show are probably much more interested.

^^ And there, in my humble opinion, is the best justification for this product!

Would any type of adapter be provided to ensure both the speedometer and odometer remain accurate?

Would any type of adapter be provided to ensure both the speedometer and odometer remain accurate?
Not in this kit as it's being sold but I can look into what would be involved.

Paul.

I believe the speedometer and odometer are based on wheel revolutions, not the drive ratio. I do not believe the sensor is in the diff.

So... what is the availability, and is there an install guide, and is it still similar to the factory in its workings (I think its a quaife no?)

slavearm

I believe the speedometer and odometer are based on wheel revolutions, not the drive ratio. I do not believe the sensor is in the diff.

So... what is the availability, and is there an install guide, and is it still similar to the factory in its workings (I think its a quaife no?)

slavearm

The speedo readings are not from the diff or the gearbox but based on wheel speed just as you indicated, therefore the readings would be completely unaffected.

We retain the stock LSD mechanisms and change the ring and pinion. We may or may not have one available this week prior to our Sevenstock trip.

Paul.

The speedo readings are not from the diff or the gearbox but based on wheel speed just as you indicated, therefore the readings would be completely unaffected.

We retain the stock LSD mechanisms and change the ring and pinion. We may or may not have one available this week prior to our Sevenstock trip.

Paul.

That is interesting to know...

Couple discussions in "The Tech Garage" seems to indicate changing the ratio does affect the reading in the speedo and odometer :scratchhe

http://www.rx8club.com/showthread.php?t=74954&highlight=final+drive
http://www.rx8club.com/showthread.php?t=44806
http://www.rx8club.com/showthread.php?t=67600&highlight=speed+sensor

I want a 3.9 can you help me??Soon i ll be 450whp+ so i need something good to reduce wheel spin etc...

I ll soon have cusco 1.5 type rs lsd if i have a 3.9 final drive will i have a problem with that??I mean will i have a problem cause i won't have a stock lsd???

I ll soon have cusco 1.5 type rs lsd if i have a 3.9 final drive will i have a problem with that??I mean will i have a problem cause i won't have a stock lsd???

All your PMs have been responded to.

Paul.

Very Helpfull.Please answer my last one so we can proceed.

With arround 500+ crank hp the 3.9 will be good right?Or too much??And also see your last pm

With arround 500+ crank hp the 3.9 will be good right?Or too much??And also see your last pm

The people who I've provided this for have done it with 3 rotor power. They probably have at least your power and more torque. Again I have responded to the PM.

Paul.

I just mean which one will be the best for me the 3.9 or 4.1 with my setup??I just don't want to be "slow" if you know what i mean..But i ll gain a alot from lancing-less spinning etc right??

Please don't forget my total price so we can proceed Paul..Sorry for all the questions but i am very anxious guy and i want only the best parts..I really appreciate all your help

That's a judgement call you will have to make. I don't know what your application is exactly; drag race, road race. Serious racers change final drive ratios and other gearing according to the track they are at. Some rebuild their diffs and gearboxes after every race.

I would imagine that in your application the 3.9 will be effective (Better than 4.1?). :dunno:

Paul.

So please make me a price quote for 3.9 shipped and a price quote for a 4.1 shipped..Just the pinion and ring as we said..Ok??And then i ll tell you which one..

I like being fast everytime anytime anywhere..The relationship with my car is very passionaite so i want to move fast!!

The 4.1 is a big difference over the stock one??

So please make me a price quote for 3.9 shipped and a price quote for a 4.1 shipped..Just the pinion and ring as we said..Ok??And then i ll tell you which one..

I like being fast everytime anytime anywhere..The relationship with my car is very passionaite so i want to move fast!!

The 4.1 is a big difference over the stock one??

I'm going to PM you the total cost so we don't have to stay on this thread all day. I remain busy with my phones going nuts together with walk in customers so I'll try my best to be quick.

None of this is a 'Big' difference. They are pieces of the puzzle that add up to one's desired outcome. Together your selection of parts should combine to make just what you want.

Paul.

That is interesting to know...

Couple discussions in "The Tech Garage" seems to indicate changing the ratio does affect the reading in the speedo and odometer :scratchhe

http://www.rx8club.com/showthread.php?t=74954&highlight=final+drive
http://www.rx8club.com/showthread.php?t=44806
http://www.rx8club.com/showthread.php?t=67600&highlight=speed+sensor

That's what I thought. I could be wrong, but I thought speed and distance are calculated based upon drive shaft revolutions. If I change my final drive by 7%, then the speed and distance will be reduced by the same 7%.

Hey can you please send me total shipped price for the 4.1?Only the ring and pinion cause as i said i can't send my lsd...

You also have pm.
Thanks

Same as I quoted you on the 3.9. I'll have to lok at my notes. I Believe it was $650 shipped to Greece.

Paul.

Yeah something like that..I ll inform you next week so we can proceed..Btw too much money for just ring and pinion...anyhow

Yeah something like that..I ll inform you next week so we can proceed..Btw too much money for just ring and pinion...anyhow

I wish you lived here so we didn't have to include shipping costs.

Paul.

anyone have one installed?

anyone have one installed?

The Puerto Rican 3 rotor folks. I haven't heard any negative reports on durability and they aren't easy on the equipment either if you know what I mean :) .

Paul.