Hi everyone on NAM

I dont really no what slip differentail and thermostats are, so please help me on this.

1. what is a slip differential?
2. how does it help ur mini?
3. how much can it help ur mini?
4. how is the mini made limited slip differential?
5. is it necessary to have it?
6. where on ur mini does this part go to?
7. Does the m7 thermostas really help?
8. how much difference can it make?

thx for the help!!!

 

Holy Joe,

These questions have been asked and answered many times here on NAM. Use the Search function and I'm sure you'll find this info pops up.

-Erik

 

get a book on cars. It will help a lot.

Limited slip diffs transfer torque to the wheel that doesn't spin. Think of one drive wheel on ice, the other pavement. Because of how differentials work (see, the book would already be usefull!), they can send all the torque to just one wheel. If that wheel is spinning wildly, this is of little use, and the car won't move. If the limited slip transfers torque to the other wheel, then you get some go out of that one, and the car moves.
This helps a Mini (or any car with an open, or non limited slip, diff) by allowing the driver to put more power down on turn exists. And if you're into burning rubber, by getting both wheels to spin, so you get two nice rubber stripes down the road, instead of just one!
The benefits are more for rough or new drivers, as you can use the gas pedal as more of a switch. For those that are smooth, smooth, smooth, it may not give you much better lap times on a track. For any driver, it is a good thing if you live where the ground can freeze..... Or where the traction surfaces aren't even (think dirt roads or broken pavement).
I don't know how the mini made differential is, you'd have to ask it!
But it's in the transaxle (front wheel drive transmission and axle combo). Not sure on it's internal details either. There are many types available in general. Most use friction disks, some, known as lockers, really lock the two axles toghether. Nice for drag cars.
It's not nessasary, but at $500, it's pretty inexpensive. The Quaiffe is about $1100, not counting installation, which requires transmission removal. So if you want it, get it when you order the car, it will save tons of $.


Thermostats are a different beast. By running with a cooler thermostat, you get some different behaviour out of the ECU (acts differently when it thinks the motor isn't up to full operating temp), and you have a cooler car. Ask M7, as they've posted some conditions where it's helped. I'm from the Mustang world, and this was a pretty standard trick for the pony cars. You ran richer, so you could add more air... It's really dependant on the car and ECU programming as to the benefit you get. I don't have one so I can't speak to it.

In general, it sounds like you're learning about cars operation and their modification. This is a big subject, and there's lots to learn before you can be confident that your money is well spent. Look in the Reviews section, I wrote a review on a book about Mini driving and modifications, and it's a good ready for someone new to the world of Minis....

Good luck and I hope this all helps.

Matt

 

An LSD limits the amount of disparity between wheel revolutions. If your sitting with one wheel on the asphalt and another on gravel and floor it, without an LSD, the wheel in gravel will spin and no power will get to the wheel that actually has traction (this is called an open differential). The LSD will give the wheel on asphalt a certain amount of power so you can get moving. It also helps in tight auto-x corners where it allows you to get power down to both wheels while going through corners. The factory LSD on the '05 and beyond is a pretty good unit and for $500, is a very good deal. If you plan on doing some performance driving, then it's a good idea to get it. It's by no means a necessity though.

As for the thermostat, I can't really give you much info. The idea is to keep the engine cooler by opening the thermostat at a lower temperature. If you open too low, your engine will run in "warm up" mode all the time and dump fuel in the engine to try and warm it up...not a good thing. The M7 thermostat is only 20 degrees colder than the factory one so I don't think this will be a problem. The other thing is that the MCS uses coolant to cool the oil so I'm not sure the implications in cold weather if the oil isn't allowed to warm up enough.

 

The coolant thermostat is a little spring-loaded valve that is calibrated to open at a given temperature. The MINI thermostat is set for 195f, I’ve seen indications of mine opening sooner. In hot weather the coolant will still reach the same temp whether the thermostat opens sooner or later no matter what hype you here (it must work because x #s have been sold). This is one of those parts you should trust the designer’s expertise on especially if you live in a colder climate area. If you live in a hotter area it’s a harmless modification if you do it, and you’re still safe if you don’t.

 

From my data-logging, with re to coolant temps, I think the MINI t-stat operates at 190 degrees F. My charts gavitate right around 190...

And I believe the M7 t-stat is a very safe 10 degrees less, or 180F.

Peter of M7 initially advised me to not get one b/c my winters typically see 30 degree temps in the mornings, with a 20 something occasionally. But after seeing folks in colder climates have no issues last winter with his t-stat, the advice has changed. I'll be getting one now.

I'm going to get my oil temp gauge hooked-up first, record some readings, then install the t-stat and note any differences thereafter.

 

My transmission was just changed because it was leaking oil. How do I know if the new tranny has the LSD in place. I have tried accelerating hard with the traction control off on wet road and it doesn't seem to light up the inside wheel. I can get the tires to squeel a bit under hard acceleration exiting a corner. Is there anyway to tell from the outside?

 

Raise of of your MINI's front wheel, while keeping the other on the ground.
Make sure to have it in gear.
Try to spin the wheel that is lifted.

If it does turn, no LSD
If it doesn't turn, LSD

 

It seems either diff would have the response you are describing. I was thinking lifting both wheels off the ground and spinning one wheel quickly. An open diff would cause the opposite wheel to spin in the reverse direction. Not sure what a limited slip diff would do.

 

I wondered this myself so not long ago I put my LSD equipped MCS up on jack stands and tried this. I thought that I remembered hearing that both wheels would spin in the SAME direction. When I spun one front wheel the other did not turn at all. I never tried this with my '04 MCS, but on the open diff. rear end of my Morgan, the rear wheels counter-rotate at equal speed when one is manually turned.