Does anyone have experience with this transmission mod?

http://www.minisport.com/new-mini-sh...n-product.html

 

yes, I have the mod on my car, it pulls!

But it's very noisey, top speed will drop to 210km/h, except that, it's quite an exciting stuff.

 

yes , it's on my '03 JCW S, it pulls!

But very very noisy, and the top speed drop a lot! Except that, it's a fine product.

 

man, that looks like a job.

how much if the tranny needs dissasembled to get at the final drive in a FWD car?

i'm still unfamilliar with these getrag trannys....

 

I spend USD 2.1K for parts + labor. I left my car overnight to tunner, so I dunt know how many hours of work would be.

 

It's a complete disassembly.

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I wonder why they used straight-cut gears?

 

I was wondering why, also. That explains the noise, though.

Steve

 

Straight cut gears are more compact and stronger. But as you found out, much noisier. Not a problem in a race car, but not so nice for a daily driver.

 

Yeah, they also give the feeling of having more power. normal gears have a slight slip the moment they engage but these engage instantly when you hit the gas. It's also why straight cut gears are either non-syncro'd or go through syncro's fairly quick. it's like some boxes on old Mini's. gotta love that whine.

 

Does anyone else have this mod?

 

helical cut gears create end load thrusts that waste power.

 

Could you please explain what that means in plain English for those of us that are not so technically oriented. If one has a modded out mini and is still looking to enhance the car further in terms of speed, is this a mod to consider for 02 -04 given that compared to the 05's, the car seems it could use improvement in this area? Why did Mini change the gear ratio in the new cars? And is this a reasonable option to consider instead of a new tranny? Thanks.

 

'could get the same effect running 205/50/15's.... i.e. under-diameter-ed tires...

Just a thought - it's what I use on my track wheels for the shorter/less long straights courses.

Derek

 

helical gears are quiet running because the teeth are cut at an angle which "softens" the engagement. Also because of the angle, side loads are created (the gears try to slide down their shafts away from each other). The result is that a helical gear transmission will absorb more of the power going through it than a straight cut gear transmission.

 

Exactly

 

So, is a transmission with straight cut gears a good thing in terms of performance? I think the gear ratios for these gears are 5:1 and 3.14:1, which makes this pull a little more than the 05 transmission. I don't mind a little more whine for a moderate gain in acceleration.

 

I though about changing the final drive. The cheap way is to go with smaller wheel and tire diameter. If I had the transmission apart I would put in close ratio gears. I have been to several tracks and the gears are too far apart and you can't pull 6th. Of course once you start 1st is useless. So the Mini becomes a 3 speed, maybe a 4 speed depending on the track.

 

Does anyone have the top speed in each gear? How much would top speed suffer in 6th gear? Can't we live in both worlds?

Close ratio with a a high top speed would be nice since I usually reach terminal velocity .. on the way to work

Off topic.... what should I get guys? S2000 or 350Z or G35 coupe? Its going to get alot of mods which ever one I opt for

 

See the FAQ in MINI2. All the gearing and top speed are there.

No you cant live in both worlds. You can get better acceleration at the cost of higher top speed or vice versa

 

you could just run 15 inch wheels with 205/50 tires to reduce gearing

 

Top speed does not decrease with this final drive change. It probably increases. The car can not pull top gear. There is not enough power. 6th gear is for highway cruising fuel economy. It is way too high for performance driving. The 6th gear top speed in the chart is based on the math only. Beside that the motor is limited to 135mph by the computer. Even if you removed the limiter the car is a flying brick and it would take hugh engine mods to get much over 135mph. With one of the close ratio gear sets I looked at it reached 138mph at 7000rpm. You will get there a whole lot faster with the close ratio. That is all you are going to reach at any race track I have seen before you hit turn one. At Thunderhill the stock 03 only got to about 100mph in 5th at about 6000rpm. 6th gear was useless. Magazine reports on the JCW version quote top speed at 143, so the extra 40hp gets you 8mph. Wind resistence is the limiting factor. Get the reduced final drive and the close ratio gears and have a car the performs much better at the speed range you are actually driving.

 

With the minisport crown wheel and pinion, the top speed is decreased about 20mph. Top speed with the 02 - 04 is around 175, but that's limited by the computer to 135. This one drops the top speed to around 155. With software that raises the speed limit, one might actually get close to that with enough whp.

 

Well my CS is not limited at all..I only want to get to 250kmph, and I know it would be a slow process.. I have a goal of 300+hp with drastic weight savings soon...

Plus that 175mph seems obsurd maybe a typo?! Why should they limit it if it really doesn't get over that speed anyway?

ok, have it like this.. if the car was powerful enough what would the difference in top speed be with the stock versus quaiffe?

 

I would think the idea of having such a high top speed on paper is that 6th gear is used as an overdrive for fuel efficiency.
I don't know the answer to your second question, do you mean a quaiffe lsd or quaiffe gears. I would assume the lsd would make no difference.

 

The 170+ mph speed is what is calculated on paper as what can technically be achieved with the current gearing, but 6th gear is used as an overdrive gear, so it doesn't mean that if the 135mph limiter were removed, it is necessarily achievable.