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-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   Gearing Product. Anyone use this? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/gearing-product-anyone-use-794870/)

Rx7TyreBurna 10-19-08 05:44 PM

Gearing Product. Anyone use this?
 
https://www.rhdjapan.com/jdm/OS-Gike...-S14-S15-16746

Just curious. Looks interesting. Expensive, which most FC people stay away from, but.... That gearbox setup with a 4.3? Quick 0-100?

Thanks.

wheelsx 10-20-08 03:10 AM

The gear ratios being lower would cause less acceleration, wouldn't it? Although the 5th gear is a bit higher, giving some usable acceleration. I would say this would decrease 0 to 100 speed compared to a stock transmission if you compare using the same diff and engine with the two, since to get to 100, you only use gears 1 through 3. It would provide higher speeds in gears 1 through 3, leading me to believe this may work fairly well on a track if your engine has enough power to offset the acceleration loss, as the car would be overall faster through the first 3 gears and have usable acceleration in fifth. Of course, all of this is based on the OEM valeues they list, assuming they're accurate (and they appear to be at least close).

Edit: After comparing with Mazdatrix's values for gear ratios, all match except the 5th gear. They are using the ratios of a TII, but for 5th, they say OEM is 0.806, whereas Mazdatrix lists 0.762 for 68-88, and 0.719 for 89-95. This would mean a larger difference between new and OEM gear ratios for 5th, resulting in more acceleration than previously thought.

Turbonut 10-20-08 06:32 AM

Need a lot of engine to pull those gears. First gear, even with a 4.3 rear, will only provide a 11.08 overall ratio compared to stock 14.2 with a 4.1 rear. Second 7.396 vs. 8.2 stock etc.

Just a quick calculation with the stock 4.1 gear:
OE first gear @ 6500 RPM-32 MPH
Gilken first gear 6500-45 MPH

Gilken with a 4.30-43 MPH

ITSWILL 10-20-08 06:50 AM

Yeah I cant imagine why anyone would want those unless they had a beast of an engine.

WingsofWar 10-20-08 11:41 AM

probably designed for those wangan runs...crazy japs

ITSWILL 10-20-08 11:57 AM

yeah it makes the tranny more close ratio

Black91n/a 10-20-08 02:13 PM

Stuff like that isn't meant for the street and it isn't meant for the drag strip. Stuff like that is usually meant for road racing where having a taller 1st can make it so that you can actually use it, and it tightens up all the other gears so that when you shift you don't drop as many revs, giving you more power to the wheels after the shift. This will definetely make you faster on track, since you're never going to be starting from a standstill anyway (most races are run from a rolling start, and even if they're not, that's a slight disadvantage for a few seconds vs. an advantage everywhere else).

RETed 10-20-08 06:28 PM

Wow, someone has money to burn...

By your sig, it sounds like you have a non-turbo?
Why you want to spend money on something that is not made for your car?


-Ted

ITSWILL 10-20-08 09:49 PM

I don't think he was actually planning on buying this, as he said he was just curious. I can see why as the website had a relatively small amount of information on the gears.

Seriously though for that money an NA guy could go turbo.

Rx7TyreBurna 10-22-08 01:58 AM

Oh, definently not buying that. :)

My next upgrades are MegaSquirt and TII motor. MS first. Rebuilding and porting TII motor. Figuring it will take a year or so to get everything done. Lots of N/A stuff done, but still hardly any power. :)

I was just curious about the gearing. Maybe a high HP motor? 400-450 HP? Eh, they do seem a lot closer, and first gear if you have a bunch of power, might actually be able to use it. First gear for a lot of people I know with HP just burn tires then hit second and sometimes gain traction. :) So, my thought was that the gearing was to make first gear more useful.

Even if I go turbo, I wouldn't be getting it. Just wondering if anyone on the boards had it.

:).


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