RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   Race Car Tech (https://www.rx7club.com/race-car-tech-103/)
-   -   6 Speed Sequential Transmission (https://www.rx7club.com/race-car-tech-103/6-speed-sequential-transmission-307294/)

'98 Type RS 05-18-04 01:35 AM

6 Speed Sequential Transmission
 
Is anyone using a 6 speed sequential? Is it worth the money? How much did yours cost installed?

EProdRx7 05-18-04 06:27 AM

So have you looked into what one of these things cost? I only know of two companies that even make them , Hollinger and Hewland. Both are dog boxes and designed for racing, ie: noisy and fast wearing. At around $15k its not exactly an economically sound thing to put into a $15k-$20k car.

peejay 05-18-04 06:51 AM

Don't forget Quaife.

I don't see the point of sequential. Bikes have sequential shifters and I hated it - one thing I *like* about cars is I can grab any gear I want at any time with a proper H-gate shifter. But to each his own. Sequential trannies have been proven to be worth 1-2 seconds per kilometer under certain conditions, if you care about that sort of thing hard enough.

'98 Type RS 05-18-04 07:34 AM

yeah, i've priced them. they are a little less than that over here though. i know it sounds stupid, but i rode in my friends ferrari 360 with the f1 tranny, i liked it a lot. i understand it's not the same thing but the idea is so cool.

TYSON 05-18-04 08:14 AM

The HKS isn't sequential, but it's still a dog gear tranny 6-speed. You might be able to find one of those for a good price since you're already in Japan.

Greddy has something too.

'98 Type RS 05-18-04 09:04 AM

ah, ok. thanks tyson, i didn't know the hks wasn't sequential.

TYSON 05-18-04 12:48 PM

The one that fits the 7 isn't. They DO make one that is, but I think it's only for the Supra.:confused:

Sequential

Non-sequential

j200pruf 05-18-04 03:24 PM

I thought that all dog rig trannys were inline shifters, just like motor cycles. Tyson, could you explain how that would work.

T_Racer 05-18-04 03:49 PM

My .02 Explanation
 
Simply put, all sequential boxes are dog ring, but not all dog ring boxes are sequential.
To understand, what a dog ring box, you have to know how a syncro box works. All modern cars have sprial cut gears with synchros. This sprial cut reduces noise, aka gear whine, and mesh very well. on the ends of the gears are tiny, and many, teeth that match up with the synchro rings. These help everything mesh quickly and easily even under load, aka power shifting.
A dog ring, or some call them straight cut boxes, are same but different. These gears are straight gears, instead of the conventional sprial cut gears, that transfer more load between more surface area for increased load and torque handling of the gears. However, this is a much noisier setup. Listen to in car of a WRC car, and hear the whine, that rises constantly as the speed increases but not with just the engine speed. To compare the noise, ride around in Reverse and you will see how a dog ring box sounds all the time. Cool to me, but the general public is a little more demanding than I of in car noise. :) They also have only 8 teeth to mesh that have a larger area with which in to mesh. This enables the tranny to be shifted without a clutch, and enables a quick, solid shift. A motorcycle has this in them. This is why if one is sitting still in neutral, and he shifts to first, you hear the clunk, and it lurch for a split second. Those have dog box gears.
A sequential box is also like a motorcyle, or Ferrari F1 street car tranny, or if you watch some European and Austrailian Touring or Supercar , have sequential dog ring boxes. These gear shifters go only up an back, not side to side like on a passenger car, with what is called an H-pattern shifter. These are also shifted without a clutch. Just like on a bike, lift for a spit second to upshift, or let off and jam the brakes and start downshifting to the gear you need.
A guy that we race with put a sequential dog box in a Lotus caterham7 replica car, Quaife I believe, and dropped between 1.5-2.5 secs per course we run at. Just one less thing, the clutch, to worry about or mess with.

Cheers,
Travis

diyman25 05-18-04 05:04 PM

THAT also depend how much TQ you going apply. I think the HKS UNIT is sequential 6 sppeds, with out syncro ring, but the gear is not straight cut. cost about 6000 US but is bolt in design.

TYSON 05-18-04 05:10 PM

Not sequential,

http://www.magnusmotorsports.com/pro...erlito_018.jpg


but indeed helical gear.

http://www.steveprew.com/~rextreme/2...hks-tranny.jpg

'98 Type RS 05-18-04 09:52 PM

Good info. Thanks for your time.

EProdRx7 05-19-04 07:08 AM

Don't forget that there are different performance levels associated with sequential boxes. Don't think that you are going to be shifting like Schumy ala "no lift". That would involve intergrating the trans with the engine management. As we all know complexity = $$$$

'98 Type RS 05-19-04 07:17 AM

Good call. The complexities of sequential transmissions are pretty interesting.

mamoodickracing 05-20-04 12:21 AM

anyone that ask's questions like these really should consider logging off and try a book instead...other people can't do the work for you all the time....do research figure out what you need and then listen to heresay. Sequential transmissions, are you kidding me? Work on the stock box and stop trying to make it too easy.

'98 Type RS 05-20-04 04:48 AM

Thanks for the tip mamoodickracing!

EpitrochoidMan 05-31-04 05:28 PM

That HKS tranny may have helical cut gears, but they look like a pretty low angle. That was the notable thing about the old muncie "rock crusher" trannies, they only had a 22 degree cut on the gears.

Heath 05-31-04 07:32 PM

A friend of mine has a sequential 6speed in his supra. It's noisy as hell in every gear but 6th. Even with bushings at the mounting points it wines and vibrates loudly. It's pretty damn cool though if you can deal with it.

jhillyer 06-02-04 11:58 PM

Re: My .02 Explanation
 

Originally posted by T_Racer
Simply put, all sequential boxes are dog ring, but not all dog ring boxes are sequential.
To understand, what a dog ring box, you have to know how a syncro box works. All modern cars have sprial cut gears with synchros. This sprial cut reduces noise, aka gear whine, and mesh very well. on the ends of the gears are tiny, and many, teeth that match up with the synchro rings. These help everything mesh quickly and easily even under load, aka power shifting.
A dog ring, or some call them straight cut boxes, are same but different. These gears are straight gears, instead of the conventional sprial cut gears, that transfer more load between more surface area for increased load and torque handling of the gears. However, this is a much noisier setup. Listen to in car of a WRC car, and hear the whine, that rises constantly as the speed increases but not with just the engine speed. To compare the noise, ride around in Reverse and you will see how a dog ring box sounds all the time. Cool to me, but the general public is a little more demanding than I of in car noise. :) They also have only 8 teeth to mesh that have a larger area with which in to mesh. This enables the tranny to be shifted without a clutch, and enables a quick, solid shift. A motorcycle has this in them. This is why if one is sitting still in neutral, and he shifts to first, you hear the clunk, and it lurch for a split second. Those have dog box gears.
A sequential box is also like a motorcyle, or Ferrari F1 street car tranny, or if you watch some European and Austrailian Touring or Supercar , have sequential dog ring boxes. These gear shifters go only up an back, not side to side like on a passenger car, with what is called an H-pattern shifter. These are also shifted without a clutch. Just like on a bike, lift for a spit second to upshift, or let off and jam the brakes and start downshifting to the gear you need.
A guy that we race with put a sequential dog box in a Lotus caterham7 replica car, Quaife I believe, and dropped between 1.5-2.5 secs per course we run at. Just one less thing, the clutch, to worry about or mess with.

Cheers,
Travis

Quite so about the differences. Helical gears want to slide sideways away from their mating gears like a rudder, pushing against their heavy thrust bearings. The straight gears avoid this diagonal shearing.


All times are GMT -5. The time now is 09:03 PM.


© 2024 MH Sub I, LLC dba Internet Brands