1st Gen R53 Cooper S Most liked posts in thread: Supercharged vs Turbo

CBS, keep in mind that the '04 transmission had a long second gear where your R56 doesn't. That may be some of the difference. Just sayin....

 

Turbos aren't infinite because to get the fast spool up you have a low volume (small) turbo. At higher rpms the turbo can't handle the volume of air and the rest gets shoved through the bypass valve. That's all the mfgs have been and are working on variable volume turbos. The twin scroll is one good simple method. Honda has a nice one that uses a flap that allows more volume as the rpms go up. Chrysler had vanes that moved changing the volume in the 80s.

Now after that I have to say I have been driving a 320hp turbo car for the last 7 years and drove the R56. But after driving my new R53....OMG:drool:crazy:. The power right at throttle tip in is unbelievable.

Now where is my "WHINE is better than whoosh" badge? I'm sold

 

Many auto makers have looked into using multiple small turbos so that spool up is fast and yet by using twin or triple turbos you don't run out of volume. In fact the turbos can be staggered so as to provide a very wide operating range.

Many manufacturers have dabbled with variable vane or variable wall devices to accomplish the wide operate range in a single design. I'm actually a centrifugal compressor designer and have developed a few VGD's (variable geometry diffuser) for specifically that purpose.
I am by no means an expert but Porsche and Mercedes have both referenced one of my patents. So when it comes positive displacement (superchargers) or centrifugal designs....I must admit to being a bit biased.

 

I don't want to hear whoosh or whine! I just want it to go fast!
Quietly!

Dave

 

Mostly MINI hype.... But the "twin scroll" is a way to introduce turbine inlet flow more efficiently...to reduce lag. The link below shows the twin scroll on the left in the photo. Compressor section on the right.

http://en.m.wikipedia.org/wiki/Turbocharger

 

^^ that is excellent advise. Buy what you like.... It's all good....

 

Oh I know Top Fuelers really can't compare to anything.......if you notice, it takes around 900hp to drive the TF SC :eek6: :crazy:

 

Yup that sums it all up. Well said Sir.

 

^^^^^ Well....I've estimated it will weigh about 12,000 pounds so you may need to install stiffer springs....

 

I don't think that's true. Power steering is an intermittent load so it's ideal to electrify as that gets rid of the power loss when no steering is required. The supercharger runs all the time so it needs continual power. In a Mini that's maybe 5hp at peak or 4 kW - five times the size of the existing alternator! Just the fitting the bigger alternator and the superchargers new electric motor under the hood might be a challenge.

Even dedicated supercharger-users like Mercedes are switching to turbos and I think the main reason is fuel economy.

 

I think there's way more to it than cost.....

Emissions for example, imagine the effect an instant on demand only supercharger would have on emissions?

And if you intend to run it all the time, your fuel mileage and the hp needed to run the motor drive would cancel any savings.

There are also weight and packaging issues - a drive motor big enough to turn the supercharger fast enough would be the size of a starter motor or bigger, and need its own cooling system too.

Plus, trying to make the motor variable speed so it could respond properly to light throttle applications would be a nightmare and add cost, complexity and weight.

That's not saying it can't be done, just that there are better more cost effective solutions.

 

The words "cost effective" should never be included in a conversation about making high Hp and Tq.

Power cost money no mater how you make it, period.

 

And turbos do it better!

Dave

 

I'm no engineer, But it is a known fact that the main problem with a turbo set up is upon shutdown the turbo is still spinning at between 100000 and 150000 R.P.M. without any oil going to the shaft bearings. These are built of special materials but without oil going to them at those high R.P.M.'s the bearings take a beating and are what usually cause a failure. There was a Biker back in the 1970's that won half ownership in a turbo company if he could devise a means of solving this problem. His answer was to install a electric pump with a timer that would feed oil to the turbo bearings for 5 minutes after he shut down his Harley and then switch off automatically thus providing engine oil to the bearings upon spindown. Oh and by the way he was a "Hessian" out of So.Cal. and could make it from L.A. to Vegas in a little over a hour and a half. And his bike would top out around 170 M.P.H.

 

:cornut: A WHINE'S WOOSH is to be a WOOSH.

Jason

 

Changed it a little.

I e-mailed Todd to see if we can come up with something, I just want one now. :lol:

 

Put me down for one ! !

 

Originally I was looking at getting a 56 but for money reasons I changed to looking for 53. After reading this I'm felling like should have been looking for the 53 all along. Thanks for all the work every one

 

14mpg at the track?!?!?!

You got 14mpg at the track? What, were you using cruise control?:devil:

I'm lucky to get 14mpg on the way to the track...

 

How about "Pssst the whine wins"