So NAM members, which would you buy if you had the $$$

A new set of Enkei RPF1 wheels or a new Cat Back exhaust system ?

Its not that I need either, but I feel like I want to do something on the Mini.

 

If I did not have LSD, I would install it before the other two.

 

A set of light weight wheels will effectively up your HP available for acceleration; from stock wheels to the Enkeis will add about 10 hp which is noticeable. It will also reduce the unsprung weight which will improve the ride and handling. In a 17" wheel size the Enkei wheels are about 10 lbs lighter, each, than the stock wheels; 40 lbs for the car. The improved acceleration comes mostly from the reduced rotational mass.

A cat back is fun for about the first 20 minutes after putting it on. After running down the highway at 65+ for a couple of hours, the boominess will have you wondering what made you think this was a good idea.

Just my humble opinion from having done both and only sticking with the wheels.

At any rate, it is always fun to spend someone else's money.

Enjoy and let us know what you decide.

 

There is no way you gain 10hp from 40lbs. less worth of wheels.

 

Car and Driver did a road test a while back on "plus-one'ing" the wheel size on a car with wheels from 15" to 19" (all the same overall dia). The car lost about 0.3 sec on 0 - 60 with about a 10 lb increase in wheel weight. So, the HP is whatever that difference in acceleration works out to be.

However, that aside, it's what the butt dyno notices, and a light weight wheel makes a noticeable improvement in acceleration. Much better than the cat back I had on the car.

 

That's interesting. Seems like such a minor thing. Too bad I love my heavy S-Lites

 

You are not gaining any hp. The car just uses less of what it already has to turn lighter wheels and more of what's available to get off the line quicker

 

Light weight rims and/or tires at the 4 corners essentially gains power as said earlier. I dumped my 26 lb mini lite wheels for a 17.5 lb wheel on the 4 corners and the first place I notice a big difference is in the slalom. With less weight the car rolls easier and faster. That my friends is essentially an increase in HP.

 

That is absolutely NOT an increase in horsepower. That's like saying a strip down interior increases horsepower. Horsepower is a measure of output for your motor. Lighter rims do not increase your motors output. It's all weight reduction which makes better use of the horsepower you already have. I'm not saying that it's a bad mod, lighter rims are absolutely a great investment.

But I'm not gonna let miss information be posted for new people to read.

There is NO gain in horsepower from reducing weight of anything on a car.

Weight reduction does indeed make a car faster, but in the same way that you can run faster when not carrying anything versus carrying a 60 pound weight. Dropping the weight didn't suddenly make you stronger, but now you can put more energy towards running and not split that between running and carrying something.

That my friend is physics.

 

Of course there's no gain in horsepower. It's just putting numbers to what you feel.

 

I think one means it " feels" like an additional 10 hp.

I believe any motor vehicle with reduced weight WILL go faster......given no other changes....
Think of stock car racing.....

 

This is mostly true, the motor isn't going any faster. The car is. This is what I'm trying to tell people. Thank you.

 

Nobody was saying the motor was going any faster. Do you really think anyone here believes you gain horsepower from putting different wheels on a car?

 

.........

 

Well, I understand what you both are saying.

With less weight it takes less energy to move the car, which is a good thing.

The reason I asked about the Cat Back, with better flow it helps the motor to
work more efficiently.

Both changes help to make the Mini better.

 

Horsepower remains the same, the Weight to HP is decreased by about 2.2%. There should be somebody here that could run the calculations on the increase in acceleration, but I am pretty sure the 2% would be almost constant.

 

Here's a handy performance upgrade guide that might give some ideas on bang for buck. Cat Back is usually one of the top picks.

http://new.minimania.com/Mini_Cooper..._for_your_Mini

Drive Hard. Drive Safe. Keep Grinning.

 

With respect to the wheels, which are a rotating mass, it is not so much the static weight change that makes the difference in acceleration. It is the rotational weight change that makes the difference, the same as putting a light weight flywheel on the engine to improve the acceleration of the car.

And, yes there are equation that you can use to calculate HP from a car's weight and acceleration to either a distance (1/4 mile time) or a speed (0 - 60 time) or vice versa (e.g. calculating acceleration from HP, weight and time to distance or speed). There are also equations for the acceleration of a rotating mass. These can be found on line.

Hope this helps.

 

I do not need to run any calculations to know with out any doubt that when I was a kid and put baseball cards on my bicycle spokes I went faster.

 

Absolutely!

 

I get more enjoyment from my cat back than my wheels

 

Threadjack alert

Do you notice the LSD on the street? Which LSD do you have? Thanks in advance!

 

id do wheels, I went from slites to ultra leggeras, gave the car noticeable pep. whereas a catback can be done cheaper at a muffler shop. cut a cutoff installed so you can be reckless when you want

 

It is noticeable in what it does positively for the car; nothing objectionable from what I have experienced. Quaife LSD.