MCS boost and crank pulley size???

[car_fan900]

Hi all, im pretty new to all this, but i dont spose anyone can tell me:

1. The boost that MCS have
2. The diameter of the crank/botttom pulley that the supercharger belt is ran upon?

many thanks in advance

rob

[obehave]

Quote: Originally Posted by car_fan900

Hi all, im pretty new to all this, but i dont spose anyone can tell me:

1. The boost that MCS have
2. The diameter of the crank/botttom pulley that the supercharger belt is ran upon?

many thanks in advance

rob

Avg 10.5 psi( stock SC pulley)
5.4" dia.

[car_fan900]

really? i think i remember they only ran about 7psi max? or is that me just being stupid?

im after the psi at say, 6000rpm.

any idea on what sort of rpm itd need to get, say, 8-9psi?

thanks again

rob

[uncle albert]

Quote: Originally Posted by car_fan900

really? i think i remember they only ran about 7psi max? or is that me just being stupid?

Well if you take a look, at the following webpage, it states that the stock intercooler is designed to cope with no more than about 8-9psi, so yes, 10.5psi does sound a bit high.

http://www.grsmotorsport.co.uk/minicoopers.html

James

[car_fan900]

hmmm, it does sound quite a lot. ive tried bmw, but theyre not very helpful tbh.

anyone know of where i cold possibly find out?

or even if anyone has a graph, of a few figues of an M45 boost vs supercharger rpm.

thanks again

rob

[obehave]

Well thanks for making sure I won't be quick try to help you again.
You ask a question, I give you the right answer and then you and others doubt it without even bothering to look it up.
And where on earth did you hear that the IC was only good for 8-9 psi. There's people running 20psi through them. The connector boots blow out or leak first.

Edit: reread your post uncle albert. Please take the time to read Graham's site again.

Quote: Originally Posted by Graham

The standard Intercooler on the Mini Cooper S will only keep Air Charge Temperatures (ACT’s) down to a satisfactory level with boost levels of no more than around 8-9psi. Once the boost pressures have been raised the ACT’s associated with the higher boost levels can be excessive for a standard intercooler.

He's saying the IC becomes thermally inefficient after 8-9psi of boost. Not that there is only 8-9psi of boost.

My parting bit for you.
Here's boost plots from one of the best data loggers in the MINI world. Look carefully at the graph.




All on a stock IC BTW.

I run Graham's IC BTW. I ran 15 psi of boost on the stock IC for over a year with no problems.

[obehave]

Quote: Originally Posted by car_fan900

really? i think i remember they only ran about 7psi max? or is that me just being stupid?

im after the psi at say, 6000rpm.

any idea on what sort of rpm itd need to get, say, 8-9psi?

thanks again

rob

See the graph

[car_fan900]

i didnt mean to offend, not at all, just i had no idea it was that much as standard!

cheers for the info, it'd appear that you are the man on these things!

you dont have the size of the bottom pulleys for each of those runs do you?

is there a formula i can work out the boost pressure, by inputting all the variables, such as rpm, the boost im after etc, to find out what rpm i want it to be spinning.

im running a 65mm supercharger pulley, and im after about 8.5psi, at an engine speed of 7000rpm (if anyone fancies working it out for me!)

sorry if im asking a lot, just have had no help at all from eaton and bmw. and just from a few questions on here you've cleared up loads for me!

cheers!

rob

[car_fan900]

....actually, hold fire on that last question, im being special again, i can just work it out from above, from the stock car's boost as i already know the pulley sizes.

cheers dude!

[obehave]

I'm definitely not the man. Just been here a long time and remember when the 15% pulley was being designed.
Andy@Ross-Tech and jlm and a number of others are the guys.Wicked talented.
I just regurgitate their work

[roland2003]

Yes 10.5ish psi peak 'at the inlet manifold' for a stock car is correct (obe knows you know )
I remmember the 2 days we had our new mcs like that ,before things had to change! Stock crank pulley dia is 5.450" (138.4mm),
Best Regards Roland Gt Tuning