Close-ratio gears are the most important change you could make to an MS3

[prlichtman]

In about 50 years of automotive speed engineering, there is one thing of which I'm absolutely certain from personal experience: almost all cars have gearing that is very wrong for obtaining maximum performance. I have completely transformed the performance of Mercedes Gullwings, supercharged BMWs, hotrod VWs and other machines by revising the gear ratios.

I am more impressed with the engineering of the Mazdaspeed 3 than with any other car in the last 25 years. Usually when I examine a new car, I compile a list of about 100 items that could be done better. In the case of the MS3, there are fewer than a dozen. Many of them are simple. For example, the tach should be in front of your face, not off to the left in a hard-to-see tunnel. I have corrected this with a big warning light right in front of my face. It comes on at 6000 r.p.m. and prevents overrevving without diverting my attention from the road.

Now we get to my main point: the MS3 gear ratios. First is way too short. Sixth is way too long. You can do your own calculations, but you will find that the following gear ratios will greatly increase the quickness of the car and be a hell of a lot more fun to use - the car will feel like a race machine.

The ideal ratios expressed as speeds in gears (miles per hour) would be:
First, 40; second, 60; third, 80; fourth, 100; fifth, 120; sixth, 140. All these speeds are at 6000 r.p.m. You could up the top speed by revving higher in sixth. Acceleration through the range would be greatly improved.

Wouldn't it be nice if we could convince Mazda to produce gearboxes with these ratios? The change would actually be minor, involving mostly geartooth numbers.

Do you think we could have any success in this endeavor?

 

[Brian MP5T]

Welcome to the forum.

Interesting and correct observations.

However, I will point out that the MS3 is a Sporty Car, Not a Sports Car.

It's Gears are for universal enjoyable driving in all conditions.. not really for Racing..

 

[SPEED305]

actually, i find them to be kind of short.

 

[Speedy3]

I agree. First and second are way too short. When I first bought the car, I got an invitation to review it and provide feedback. The two things I noted were no mud/rock guards at the front wheel well (this car really spits rock!) and the second was to extend first gear.

 

[clos561]

i think the gears are fine for the amount of power the car produces stock... 6speeds are always shorter than many gearboxes some may have become used to....

 

[Max Freed]

I find the gears way too short as well, especially considering that power drops off considerably after 5.5K RPM. I don't feel sixth is too long though, if anything, it needs to be a bit taller also, in order to reduce the RPMs at freeway speeds and get better gas mileage.

Also, consider that you can't even reach 60 MPH unless you shift into 3rd gear; this hurt's the car's ability to get a better 0-60 time.

The engine is a torque-monster, and taller gears would be a much better match to the engine's capabilities.

 

[ill_eagle94]

I find the gears way too short as well, especially considering that power drops off considerably after 5.5K RPM. I don't feel sixth is too long though, if anything, it needs to be a bit taller also, in order to reduce the RPMs at freeway speeds and get better gas mileage.

Also, consider that you can't even reach 60 MPH unless you shift into 3rd gear; this hurt's the car's ability to get a better 0-60 time.

The engine is a torque-monster, and taller gears would be a much better match to the engine's capabilities.

The person who started the thread stated that 60 should be at 6k rpm in 2nd. Almost exactly what you're saying.

 

[Capt Crunch]

Wouldn't it be nice if we could convince Mazda to produce gearboxes with these ratios? The change would actually be minor, involving mostly geartooth numbers.

Do you think we could have any success in this endeavor?

Sadly, no. The only way to convince mazda to do such a thing is to get them into some kind of motorsport. Short-ratio gearboxes are plentiful for Subaru, because they put out group-n cars. I bet that I could count on one hand the number of people that would actually buy a shorter gearset, so it's not worth Mazda's while to make them.

As for aftermarket, PPG makes some killer gears, but be prepared to pay out the nose for them ($4.5k!). I have yet to see them break even on 600 whp subarus.

Honestly, I don't think the gear ratios are too far off. The HP curve is relatively flat for this car, and as long as the gears don't drop you out of the powerband, which they don't, you're not going to get much increase in speed. Shorter ratios are better suited to high strung NA motors, whose hp usually increases proportionally with rpms.