F1blueRx7

iTrader: (5)

I'm constantly searching for a 6th gear in my t2. There are a few places where I can legally and safely maintain 90mph and It's really working at that speed. For the sake of fuel economy, a 6th gear would be nice. Just needs to be made by getrag or some high-quality manufacturer.

Snrub

iTrader: (1)

Didn't know that either MRX_Rotary.

It's not going to be worth anyone's while to pay for a 6-speed so they can save fuel @ higher speeds. I wonder if when getting the tranny rebuilt it would be possible to have the 5th gear ratio changed to .65:1 or something?

NZConvertible

Have you considered that it's unlikely the savings in fuel costs will not pay back the cost of a 6-spd conversion within the car's expected remaining life?

andrew lohaus

since when has 90 mph been legal anywhere outside of montana?

RSVampire

ummm.... well gas right now in california is $2.69 for 91 octane... so I think it will give me money back considering it costs me $35 bux and before this gas hike it costed me only $24 bux. And I fill up every 3-4 days. Do the math... it'll add up man... pretty damn quick too...

NZConvertible

Since you have given no indication as to how much gas a 6-spd would save you, there is no math to do. You seem to think it'll be alot, which it certainly won't. Come back when you have a valid argument...

Attila the Fun

iTrader: (1)

In a straightforward swap, I believe that the conversion would not be cost-effective. However, if someone needs to replace their gearbox, anyway, the difference in the cost of a used 5-speed and a used 6-speed *might* be recoverable, depending on the 6th-gear ratio.

T2monster

i'm surprised NZ hasn't commented on their fuel prices, which when i found out the other day from my friend Zoe it shocked me. Works out to $5.28/gal for 89, or close to it.

Parastie

Considering how low the torque on the rotary engine is at low RPM, I doubt that the 6th gear is any lower then our 5th gear. There would be no fuel savings.

NZConvertible

It's not quite that high, but it went up again today... It's now ~NZ$1.35/L for 96 (similar to your 89 I believe), or ~US$3.60/gal. Relative to average incomes our petrol is still pretty cheap compared to most countries in the world.

It's still a very weak justification for a 6-spd swap, because you're still assuming a worthwhile reduction in fuel consumption, which is unlikely.

ddub

For those that are interested in the gear ratios of the RX8, here they are. True 5 speed with 6 overdrive:

Diff - 4.444
1st - 3.760
2nd - 2.269
3rd - 1.650
4th - 1.187
5th - 1.000
6th - 0.843

NZConvertible

Well that certainly isn't going to save you any fuel...

ddub

Yep, which is why I thought I'd finally post it up