[MINIMANIAUK]

More road testing today -A fine sunny day so I took a run around Milton Keynes, came across a beautiful black DODGE Viper convertible LHD private plate ,anyone know the owner?nice car -couldnt resist - Think the MINI gained some major respect!!! , big thumbs up
Fuel economy with the Opcon is poor to say the least! with the increase in power if used ,there is also a good drop in fuel efficiency,with very very hard driving,returned 15.9 mpg
After a good workout for an hour or so the temps were great ,intercooler outlet was cold to the touch,and the inlet was barely warm,you could grab hold of it with your hand with ease(-I have taken the temp sensor off so cant give you an exact temp but way down on stock)
I will have to put back in the cat as the noise is far too loud with a performance exhaust,and manifold, Ok for the track but way too loud for road use.
The Tilton clutch is performing well,but I think the EXEDY is more suited to the road ,pulling away in first is awkward at normal rpms,thereafter fine and bites well. great on the track but not so traffic friendly
A

[1320autos]

Sounds good Adam, will we be seeing it Tue / Wed??

[Minipnut]

have an opcon/Eaton drag off ? ones that produce about the same Max bhp ? just to show the power of the baby =)

[MINIMANIAUK]

Tue/wed sounds good Paul.
If you drag 2 cars with similar hp ,with similar traction,and similar weight , you would get similar results!!!!!
The point of the conversion is to offer an alternative to the Eaton , which is a bolt on replacement so should your existing charger die you can replace / upgrade with the Opcon .
Or should someone be looking at raising the power output it could be fitted to a stock car as a stand alone replacement providing increased boost without the added heat of overdriving the eaton and using less crank bhp to spin it.
Having a lower output temperature (better efficiency) is the key as this allows more room to push the boost higher should more power be required (a simple pulley change)
Cost wise the bhp for buck would be similar once you go beyond the eaton pulley change,as to match the Opcon conversion on a stock car would require exhaust,manifold,pulley,plugs,head,cam ,air intake,intercooler, and the fitting set up costs, this would add up to a fair amount and still run higher temps and have torque drop off at the higher rpms. (look at eaton dynos above 6000)
The exhaust/manifold/heat etc can all be added to the opcon conversion and have the same benefits as the eaton for those that want more!!

[Ant FR]

seriously interested in this. Is that what the M7 Tuning cars are running as they sound really really whiny!

IS ths an exepnsive unit and does it require a remap to run

[Minipnut]

i thought i read somewhere though that the opcon charger produces quite a considerable amount more torque though ?

[MINIMANIAUK]

Sorry I don't know what M7 are using .
Torque and power are interlinked , the pulley size determines the boost pressure and what rpm the pressure is made at so it can be tailored to the powerband that you require,usually the max engine rpm dictates the pulley size,but the opcon can be worked a bit harder than the eaton so geared to have a higher boost at the higher rpms

[1320autos]

The M7 guys had a play with using an M62 without great success, Spider X is at the forefront regarding the M62 development and though I cant speak for him I believe he probably wouldn't go down that route again judging by his posts on NAM

[MINIMANIAUK]

The M62 is still a pump!!! just a bigger version with the same inherent problems,using a bigger hammer is fraught with problems by design.
Bigger is not always better, ask a V10 8 litre owner!!

[Damo]

Sorry but OPCON? I'm guessing this is a different type/make (both) of supercharger. Is this what Graham (of GRS fame) was talking about? Any chance of a bit more info for the less knowledgable of us.

[MINIMANIAUK]

The opcon supercharger is indeed a different type of supercharger,called a (twin)screw compressor.
The standard Eaton supercharger works like a pump ,air is moved from inlet to outlet of the charger ,but it only pumps a volume of air ,the air pressure inside the charger is the same at inlet and up to the out let.
After leaving the charger, air is pumped to the engine ,if the engine has more air pumped to it than it can suck you get a build up of pressure (boost pressure) The faster you spin the charger the more volume of air gets pumped more boost pressure ,
the screw compressor ,again pumps air from inlet to outlet however as the air is passed along inside the charger the area which contains the air gets smaller and smaller and smaller so the air is compressed as it passes through exiting the charger as boost pressure.(hence screw compressor)
this makes it more efficient and uses less power to turn,providing cooler output temperature at the same pressure ,
cooler air allows higner boost pressures to be used,and the opcon although smaller in size can provide more boost ,and greater volume of air at a lower temp all using less power to turn it!!

[chuntington101]

Quote: Originally Posted by MINIMANIAUK (original)

The opcon supercharger is indeed a different type of supercharger,called a (twin)screw compressor.
The standard Eaton supercharger works like a pump ,air is moved from inlet to outlet of the charger ,but it only pumps a volume of air ,the air pressure inside the charger is the same at inlet and up to the out let.
After leaving the charger, air is pumped to the engine ,if the engine has more air pumped to it than it can suck you get a build up of pressure (boost pressure) The faster you spin the charger the more volume of air gets pumped more boost pressure ,
the screw compressor ,again pumps air from inlet to outlet however as the air is passed along inside the charger the area which contains the air gets smaller and smaller and smaller so the air is compressed as it passes through exiting the charger as boost pressure.(hence screw compressor)
this makes it more efficient and uses less power to turn,providing cooler output temperature at the same pressure ,
cooler air allows higner boost pressures to be used,and the opcon although smaller in size can provide more boost ,and greater volume of air at a lower temp all using less power to turn it!!

sounds like a very intresting piece of kit!

what capacity is the superhcarger? would there be any way of incorperating a chargecooler core to the outlet of the SC (like the US V8 guys have) to help the intercooler out a bit?

thanks CHris.

[MINIMANIAUK]

Yes , an integrated charge cooler/intake can be done ,removing the top mounted cooler in total,and designed for maximum intake flow ,yes it will work ,yes it will show gains,but it would be expensive and few would buy it!!!
There have been a great number of things developed for the MINI which have been shelved as no one bought them!!
A larger Opcon can be used ,but as with turbos correct sizeing important ,the one I am using is good for 300bhp and more than adequate.

[Damo]

Quote: Originally Posted by MINIMANIAUK (original)

The opcon supercharger is indeed a different type of supercharger,called a (twin)screw compressor.
The standard Eaton supercharger works like a pump ,air is moved from inlet to outlet of the charger ,but it only pumps a volume of air ,the air pressure inside the charger is the same at inlet and up to the out let.
After leaving the charger, air is pumped to the engine ,if the engine has more air pumped to it than it can suck you get a build up of pressure (boost pressure) The faster you spin the charger the more volume of air gets pumped more boost pressure ,
the screw compressor ,again pumps air from inlet to outlet however as the air is passed along inside the charger the area which contains the air gets smaller and smaller and smaller so the air is compressed as it passes through exiting the charger as boost pressure.(hence screw compressor)
this makes it more efficient and uses less power to turn,providing cooler output temperature at the same pressure ,
cooler air allows higner boost pressures to be used,and the opcon although smaller in size can provide more boost ,and greater volume of air at a lower temp all using less power to turn it!!

Cheers for that informative answer.

Another question though if I may. If its so much better, why didn't BMW fit it instead of the Eaton? Just cost or other reasons possibly? Or is this one of those "we'll never know" kind of questions

[MINIMANIAUK]

purely a cost based decision the Eaton is a cheap alternative ,hence Jaguar,merc, also use them .if you add £1000 to the cost of each cooper s the manufacturer made it adds up to a lot of money.
They also cannot make their own version as the design is copyrighted and they would have to pay Mr Lysholm or his family royalties...

[roland2003]

Hi Adam, what you planning/needing to include in your kit (other than the charger itself) to offer 275 bhp.
Best Regards Roland GTT

[Penguinracer]

I'd like to see someone experiment with a centrifugal blower on a Mini, a Vortech, Powerdyne or similar. Yes, they are better suited to bigger motors because they don't really alter the normally aspirated engine's torque & power curves, they tend to just give it a parallel shift & the Tritec does really benefit from the boost in bottom - midrange power & torque which the Eaton delivers.

I've seen the characteristics of the various superchargers summarised something like this:

Rootes Type (Eaton) - low efficiency, significant boost to low-midrange power/torque;

Positive displacement (Twin-Screw) - medium efficiency, significant torque/powerboost to mid - higher revs;

Centrifugal - high efficiency, pushes out torque & power at the top end.

It's interesting what the Porsche 928 community are doing with centrifugal blowers :

Supercharged 928 and Performance Porsche 928s

928 SPECIALISTS ONLINE STORE - 30,000+ 928 Parts - 928 SUPERCHARGER KITS!

The ONLY source for 21st century power for your Porsche 928

Admittedly the standard Porsche V8 has big power & torque & it really doesn't need additional torque down low, unlike a Mini. It would still be interesting to see development of a centrifugal blower on a Mini with the appropriate tuning of the brerathing & fueling.

[MINIMANIAUK]

HI Roland,
I still have a fair bit to do regarding all the different combinations ,of different size pulleys ,intake pipes,and throtle body size each can have a major impact on output
also the fuelling requirements for each combination and what the standard car can tolerate .
As a basic conversion
charger,with pulley (maybe a choice ,they are simpler to change than the stock ones)belt,oil lines and adaptor plate,(option for oil cooler)outlet horn(exchange)water pump and hoses,(adaptor for block),intake pipe,dipstick,vent line,brackets

This would form the basic kit , using standard injectors and ecu ,the limitation on power would be the injectors running out so if adding say the jcw ones with the option pulley a second level is available.
beyond that optional pre charger injector(s) can be added in the intake duct (larger)with its own control unit and larger throttle body,plus filter change
beyond that (read expensive) a larger supercharger ,intake pipe,throttle body,stand alone ecu ,charge cooler/intake manifold with laminova cores,traction control system,- this would require engine internal major changes at very high cost , and be far removed from a road car and pretty much undriveable IMHO
What each upgrade produces I have no idea ,but less crank losses and lower boost temps allowing greater boost will have benefits.
So far its all been calculated data used ,and now its time to get actuals , and as you know theory and reality can differ , but so far its been much as expected and close to the calcs
regards Adam

[MINIMANIAUK]

I think the centrifugal compressor has been done (rotrex) top end power is less usefull for a road car ,and changes the charecter of the MINI , The Efficiences of each type of charger varies with boost and rpm and each charger has its benefits the eaton is 90% efficient at low boost for example but drops to 50% at high boost, the screw charger can match the centrifugal but at a narrower rpm band,hence pulley size is important, the centrifugal is next to useless at low rpms --horses for courses
the large v8 engines all run low boost pressures,avoiding compression changes ,and needing huge sizes of charger to supply the large volumes of air.
On balance the twinscrew is a good charger for the car providing the best of each charger type allowing good throttle response and good torque through to the max rpm

[chuntington101]

Quote: Originally Posted by Penguinracer (original)

I'd like to see someone experiment with a centrifugal blower on a Mini, a Vortech, Powerdyne or similar. Yes, they are better suited to bigger motors because they don't really alter the normally aspirated engine's torque & power curves, they tend to just give it a parallel shift & the Tritec does really benefit from the boost in bottom - midrange power & torque which the Eaton delivers.

I've seen the characteristics of the various superchargers summarised something like this:

Rootes Type (Eaton) - low efficiency, significant boost to low-midrange power/torque;

Positive displacement (Twin-Screw) - medium efficiency, significant torque/powerboost to mid - higher revs;

Centrifugal - high efficiency, pushes out torque & power at the top end.

It's interesting what the Porsche 928 community are doing with centrifugal blowers :

Supercharged 928 and Performance Porsche 928s

928 SPECIALISTS ONLINE STORE - 30,000+ 928 Parts - 928 SUPERCHARGER KITS!

The ONLY source for 21st century power for your Porsche 928

Admittedly the standard Porsche V8 has big power & torque & it really doesn't need additional torque down low, unlike a Mini. It would still be interesting to see development of a centrifugal blower on a Mini with the appropriate tuning of the brerathing & fueling.

if you think the porsche guys are doing alot with it you should read some of the US V8 stuff! lol some of the guys are pushing massive power out of pretty stock centri superchargers from the likes of vortech and Prchager. the Rotex units are very good and could work well if fited in parrael with the stock supercharger.

Chris.