2003 Cooper S - Which Pulley?
Discussion
Hi all, thinking of a pulley and plug change on my 2003 S, was looking at this kit http://www.1320.co.uk/products/522-1320-bmw-mini-c... but not sure what pulley to go for.
Can anyone help explain the differences please?
Thanks muchly
Can anyone help explain the differences please?
Thanks muchly
How about getting this http://www.1320.co.uk/products/563-1320-mini-r53-k...
Includes the reduced pulley and belt but also includes bushes and dyno run. Have heard that anything upwards of 15% reduction needs a intercooler upgrade. So if you budget doesn't cover that cost stay at or below 15%.
Includes the reduced pulley and belt but also includes bushes and dyno run. Have heard that anything upwards of 15% reduction needs a intercooler upgrade. So if you budget doesn't cover that cost stay at or below 15%.
Gregory CooperS said:
in a nut shell - the higher the % the higher the boost. but then the higher the boost the more heat there will be. So if get a 17% or 19% you will need to get upgraded intercooler. I have a 15% and its fine.
This.I have a 15% Alta pulley and the difference is pretty sensational, considering what you pay. Certainly a much more rapid surge in power delivery, and an excellent whine that isn't too intrusive. Also, my MPG wasn't effected at all in everyday driving, if anything I thought I was getting more, but that's just me being silly
I'm thinking of having the 17% done to mine. I think the works has 11 or 12 as standard so it won't be a massive difference to me.
You don't really need the intercooler upgrade for road use as the period at full boost is relatively short at any given time so the temps self regulate to an extent. Track use or extended hooning maybe you do. The upgrade just increases the surface area of the intercooler from what i hear?
You don't really need the intercooler upgrade for road use as the period at full boost is relatively short at any given time so the temps self regulate to an extent. Track use or extended hooning maybe you do. The upgrade just increases the surface area of the intercooler from what i hear?
JamesK said:
I'm thinking of having the 17% done to mine. I think the works has 11 or 12 as standard so it won't be a massive difference to me.
You don't really need the intercooler upgrade for road use as the period at full boost is relatively short at any given time so the temps self regulate to an extent. Track use or extended hooning maybe you do. The upgrade just increases the surface area of the intercooler from what i hear?
You clearly don't understand what the intercooler is there for. It's not like a coolant radiator that cools a volume of water that is used to keep the engine at the right temperature. With a supercharged car, the instant you give it full throttle you have the full pressure from the charger. Pressurising air heats it up. The more pressure, the more heat. It's not something that builds up, the heat is there as soon as you put your foot down. The intercooler cools the air before it reaches the engine. If the air reaching the engine is too hot it will cause the fuel/air charge to ignite early which is known as ping or pre-ignition or knock. That's a very bad thing to have as any pre-ignition will destroy the engine very quickly.You don't really need the intercooler upgrade for road use as the period at full boost is relatively short at any given time so the temps self regulate to an extent. Track use or extended hooning maybe you do. The upgrade just increases the surface area of the intercooler from what i hear?
A water to air intercooler is limited by it's ability to cool the water it uses (just like the coolant radiator) but an air/air intercooler doesn't have that problem, their only real issue is that they increase the throttles volume which dulls throttle response.
Whether the standard S intercooler is beefy enough for a 17% pulley I have no idea but I wouldn't go against common accepted limits.
I'm not sure what your point is. Following your explanation logically, do all supercharged engines have the potential to damage themselves in very hot weather then? An air to air intercooler can only cool the air that flows over/is forced into it. A slightly larger one cools more air and a bit more efficiently but it's no failsafe against temps the way you describe it.
I don't have a 17% pulley so am interested to know and don't want to mislead. I will say though that Mini-craft do not say I need a bigger intercooler for normal use with that pulley.
I don't have a 17% pulley so am interested to know and don't want to mislead. I will say though that Mini-craft do not say I need a bigger intercooler for normal use with that pulley.
Very hot weather doesn't increase the temp by enough to matter but the answer can be yes. Manufacturers build in big tolerances to cope with such things as extreme weather conditions, bad fuel, air filter in need of changing etc. so generally an unmolested car should be fine. If you have increased the pulley ratio or had the timing remapped to give more power then you will be eating into that safe reserve so you are risking engine damage under extreme conditions.
Generally though a very hot summer day will only be maybe 10C over an average summer day and 10C is nothing compared to the temperature of the air coming out of an SC giving, say, 10psi. My own car (supercharged 1.8 MX5 with MP62 and big IC) runs around 8-9psi and after a bit of a run you can't touch the pipe from the SC to the IC but the pipe from the IC to the intake is barely even warm so they can be very effective. You can't really do that test on a Mini but it's easy on the MX5 as you can see:
My MX5 has a 1.92 pulley ratio and makes around 245bhp (145 is standard). Without an IC you can't really go over about 190bhp on an MX5. With this IC you can push over 270bhp. Add in water injection and 300+bhp is possible but a built engine would be needed for that. I've had mine mapped using 97RON fuel and asked them to map it for reliable track use rather than for ultimate power. That way, when I take it on track I use Optimax or similar where available to give it a little extra headroom.
A turbo is similar but not the same. They tend to create less heat than an SC. Also, boost with a turbo isn't the same as boost from a positive displacement SC (which you and I both have). With an SC boost is a measure of restricted airflow. If for example you have an SC that makes 8psi. You then improve the airflow, bigger valves, gas-flowed head, free-flowing manifold/exhaust etc. you should find that the power will increase but without changing the pulley ration the psi "boost" will decrease as there is less restriction and more of the air is being consumed. A turbo on the other hand will make a set amount of boost. If you improve the breathing in the same way the boost will still be the same. Without anything to control the turbo boost it would actually increase as the improved airflow will drive the turbo quicker.
Generally though a very hot summer day will only be maybe 10C over an average summer day and 10C is nothing compared to the temperature of the air coming out of an SC giving, say, 10psi. My own car (supercharged 1.8 MX5 with MP62 and big IC) runs around 8-9psi and after a bit of a run you can't touch the pipe from the SC to the IC but the pipe from the IC to the intake is barely even warm so they can be very effective. You can't really do that test on a Mini but it's easy on the MX5 as you can see:
My MX5 has a 1.92 pulley ratio and makes around 245bhp (145 is standard). Without an IC you can't really go over about 190bhp on an MX5. With this IC you can push over 270bhp. Add in water injection and 300+bhp is possible but a built engine would be needed for that. I've had mine mapped using 97RON fuel and asked them to map it for reliable track use rather than for ultimate power. That way, when I take it on track I use Optimax or similar where available to give it a little extra headroom.
A turbo is similar but not the same. They tend to create less heat than an SC. Also, boost with a turbo isn't the same as boost from a positive displacement SC (which you and I both have). With an SC boost is a measure of restricted airflow. If for example you have an SC that makes 8psi. You then improve the airflow, bigger valves, gas-flowed head, free-flowing manifold/exhaust etc. you should find that the power will increase but without changing the pulley ration the psi "boost" will decrease as there is less restriction and more of the air is being consumed. A turbo on the other hand will make a set amount of boost. If you improve the breathing in the same way the boost will still be the same. Without anything to control the turbo boost it would actually increase as the improved airflow will drive the turbo quicker.
There are plenty on Minitorque who have not done the intercooler upgrade, look at the packages offered by 1320 and othjer mini tuners, all offering uprated pulley and not saying you need an intercooler upgrade.
personalyl I did and I do trust Trevor and the Minicraft boys to steer me right, they do know Minis inside out adn have built some epic cars.
personalyl I did and I do trust Trevor and the Minicraft boys to steer me right, they do know Minis inside out adn have built some epic cars.
M@1975 said:
the difference over stock is really quite noticable... though somewhat tame after a Cerbera I'd imagine.
Why not you only live once so why not make it fun Mrs Scotty_d is up for it as it is really her car so that has to be a good thing as well I have it booked in to a local Garage who will be servicing it and doing this at the same time. Does it affect insurance by much? An insurance company won't care what the modification is. All they will car about is that the engine is modified to give it more power and the power increase. They will have a scale for how much the premium will increase due to the increase in power. Some companies will also refuse to insure a modified car.
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