dbwilldo and I have been messing around with weight and HP numbers for the Cooper.

Using stock MINIUSA weight and hp numbers for the Cooper, you get a weight-to-power ratio (WPR) of 21.9 lbs/hp (2524 lbs dry weight, 115 hp). For the stock MCS the WPR is 16.4 lbs/bhp. So I built a spreadsheet that shows WPR vs. Dry Weight for three different hp levels, 115, 130 and 140. I've got an Excel image that shows the graph but I am unable to post the pic. So if anyone can help me post the graph, I would appreciate it.

Anyway, what the chart illustrates is the theoretical wieght reduction required to get an MCS WPR for a Cooper. For stock hp, lose roughly 600 lbs; 130 hp, lose about 400lbs; 140 hp, cut out 200 lbs. So the question for everyone is, what seems to be the best way to go? The hp side seems easier to quantify at this time given all the options. 130 seems a readily achievable goal, but 400 lbs seems like far to much weight to cut out without spending serious dough. What would it take to get 140 hp in a Cooper and is even 200 lbs too much to expect to lose in a Cooper? Wheels are obvious but only a fraction of the savings target. What else?

Thanks in advance.



_________________
Treasurer, SCMM | paul@scmm.org | Future MINI owner.

 

Email it to me i will post for you
caddman@budweiser.com

 

Great Question !!!!!!!!!!!
A lot of people are looking for increased power but there is little talk about weight reduction. One of the first mods I'm going to make is a set of light weight wheels and performance tires (less weight than run flats !). I also believe that some of the performance exhaust systems can save you weight. I didn't want the sunroof package but my lovely bride loved it so we have the added weight of the sunroof !!
Aside from stripping out the interior it would be interesting to hear from people on this subject 1??1?
Best Regards,
Ron
'03 MCS PS/B

 

i shaved alot of weight and made a very noticable difference with my ssr's and tires!!

 

Thanks, caddman.

Its on its way.

 

What would be interesting would be to see how the MC and MCS stack up against other cars in the class that we commonly talk about (Focus, Neon, Golf GTI, etc).

Dont ya think?

 

caddman, the first chart I sent had glaring errors. I sent the good one.

Thanks!!!!

 

0_MINI,
Suggestion: you could sign up for an account and upload it to one of the free website hosts out there, like tripod.com, then paste the link in this thread.

 

orbhot - caddman has graciously offered to post the graph.

I emailed it to him. I hope he caught my blunder.......

I do have webspace though. I should belly up to the bar and use it one of these days.

 

EDIT...this is the correct graph



looking to maintain driveability at the same time. I will be doing intake and exhaust, but I'm leary of chipping and I don't want to miss with any of the internals. I know that switching out the 5 stars with run flats will save a ton of weight too. Just looking for more suggestions

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thanks you beat me to it, i was eating diner sorry!!

 

>>(less weight than run flats !)
<<

I found that the weights of the 205/45/17 Pirelli runflats and the 205/45/17 Yokohama AVS are both: ~22lbs

Do you have different numbers?


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caddman, thanks, but the first one I sent has the bogus-axis label.

Lightened flywheel might be another option. So with light wheels/tires, aftermarket exhaust and lightened flywheel, we've cut out maybe 70-80 lbs??

 

Thanks Don. I sent you the correct one.

Thanks Don for posting the proper chart.

_________________
Treasurer, SCMM | paul@scmm.org | Future MINI owner.

 

>>>>(less weight than run flats !)
>><<
>>
>>I found that the weights of the 205/45/17 Pirelli runflats and the 205/45/17 Yokohama AVS are both: ~22lbs
>>
>>Do you have different numbers?
>>

Yeah, the Pirellis are fine, it is the Goodyears that are bricks:

Goodyear Eagle RS-A EMT 30.37 lbs

People are incorrectly generalizing that run-flats are heavy; clearly, they do not need to be.

 

My Goodyear Eagle RS-A all-season runflats and 17" S-lites weighed 45 lb when I took them off (bathroom scale). My 16x6.5" Enkei RPO1's with 205/45-16 Kumho 712's weigh 33.5 lb. There's 46 lb of rotating, unsprung mass.

 

This graph shows why the 108hp 1990 Honda CRX Si was such a mean little car. Weight and gearing were the major factors in it's performance.

 

The issue becomes the fact that when you lose the weight on the Cooper, the person with an S still has that option as well...

I like the Cooper and the S - both are great cars and both serve different purposes, but the S is a better performance foundation, for several reasons.

1. The larger swaybars and slightly higher rate springs
2. The additional 48 horsepower
3. The supercharger whine
4. The aftermarket availablity of S vs. Cooper effective modifications
5. The Getrag 6 speed gearbox
6. Dark Silver
7. Did I mention the additional 48 horsepower?

The 130 hp goal seems pretty reasonable - but it will take a full exhaust, an intake, and some good luck. 140 will be tough without going to the head and cam.

The other issue relates to #4. The aftermarket for the Cooper is a much tougher proposition, as the Cooper is pretty well optimized stock from the numbers we've seen. You really can't get that nuch out of it with the exhaust for example - maybe 6 horsepower or so. Compared to the S numbers of 10-13 horspower, you start to see that not only are there more options for the S, but they are more effective as well. For instance, after all of your weight reduction and horsepower increases on the Cooper, you may be able to get down to 16/1 or so, but factor in a hot rod S, like mine, which has roughly 210 hp at the flywheel and weighs 2648 lbs - 12.6lbs/hp!

Hope that helps.

Feel free to contact me with any other questions.

Randy
720-841-1002

 

Yes, definitely point #6 Randy.

R

 

Yall need to pick up the latest issue of GrassRoots Motorsports magazine... there is a very interesting article on weight in there.... inc. how changing unsprung and rotating weight compares to sprung weight....as well as torque/gearing issues ect.....

 

I'm looking to shave 20 pounds or so from right behind the steering wheel.

 

Davbret wrote:
Everyone knows that Dark Silver paint has complex magnetohydrodynamic properties that ionize the gasoline particles for more efficient combustion. I think we have a magnetohydrodynamic engineer here on the forum somewhere.

 

Randy, you don't play fair! ) S and show it tail lights!!

_________________
Treasurer, SCMM | paul@scmm.org | Future MINI owner.

 

Paul,

Have you talked to Clo about her opinion? .

 

When considering wheel & tire weight, has anyone looked at measuring angular inertia for different wheel tire combinations?

Two wheel/tire combinations both with the the same overall weight can perform very differnetly. The heavy tire/light wheel combination will perform worse than the light tire/heavy wheel combination. What are the best light tire/light wheel combinations?

Of course this is straight line acceleration/braking and unsprung weight only question. Tire grip in dry/wet and other performance need to be factored in to the equation. I suspect that the racers will sort out the best combination for high perfomance, but they probably won't be too concerned about cost per mile as the non-racers.

Keep up the good work and thanks for the great web site.