R&M Racing BMW M20 Adjustable Camshaft Gear

[guibo09]

i have a pulley off the car, but no accurate means of weighing it.

im gonna compare it to your pics tonight. im wondering where your pulley has less material to be lighter.

[r-mracing]

Just weighed the Gear and Our Adjustable lightweight pulley ways 13.1 ounces. Again, I have to wait to get my hands on a stock gear to weigh that one as well, but any of you who have had a stock gear and off in your hand just know that it isnt 13 ounces or less. Its heavier.

[r-mracing]

i see. so the claim that this pulley is lighter than the original non-adjustable is false?

It is lighter! That claim is not false. I will weigh both with pictures on sunday when I can get my hands on a stock pulley thats off of a car but it is slightly lighter. Not by too much though.

[guibo09]

None of this part is re-used. It is a fully new piece. The outer part with the teeth is steel as well as the center part that bolts to the cam. The part that connects the two steel pieces is aluminum. (that is the blue part that you see). All of this was cut out on a combination of a CNC machine and metal lathes.

i see. so the claim that this pulley is lighter than the original non-adjustable is false?

[r-mracing]

it's not clear in the picture alone... is the tooth part remachined out of aluminium, or is it just the original steel gear that has been cut?

None of this part is re-used. It is a fully new piece. The outer part with the teeth is steel as well as the center part that bolts to the cam. The part that connects the two steel pieces is aluminum. (that is the blue part that you see). All of this was cut out on a combination of a CNC machine and metal lathes.

[guibo09]

it's not clear in the picture alone... is the tooth part remachined out of aluminium, or is it just the original steel gear that has been cut?

[Paukert11]

I put it on my car. and yes right now it is stock. I moved in up a notch and i lost a little torque but a higher end speed. nut thats with a stock m20b27

[E30 Racer]

it's basically just going to move your torque curve around, there's nothing free to be had here. also useful for an aftermarket cam, or a head/block that's been shaved. I'm guessing BMW got it pretty well right with the stock cam timing.

$90 is a good price point though. May end up picking one of these up. :)

Agreed that the price is decent. Again, I understand what it does (or rather what it should theoretically do), but I want to see some data before I commit.

[nando]

it's basically just going to move your torque curve around, there's nothing free to be had here. also useful for an aftermarket cam, or a head/block that's been shaved. I'm guessing BMW got it pretty well right with the stock cam timing.

$90 is a good price point though. May end up picking one of these up. :)

[E30 Racer]

Dyno results are COMPLETELY different case by case. While some cars could only benefit in very small hp or torque increases others it could make a big VERY noticeable difference.

The most important part about this mod is that it gives the ABILITY for a tuner to make QUICK changes to his valve timing while at a dyno session or other event. Without an adjustable camshaft sprocket, the ONLY way to change valve timing is by removing the timing belt and setting it a tooth off or whatnot which OBVIOUSLY isnt really feasible if you are dyno tuning your car or in a limited time situation. So in reality, this gives the user the ability to "play" more with his settings and chose a valve timing degree that he feels works best for him and allows him to change it if he so feels like it.

I hope that explaination helped you realize the true purpose of adjustable camshaft gears. :)

Thanks for the reply. I understand what an adjustable sprocket is (I've used them before on VW motors). My question pertains specifically to the M20B25. Have you installed one on a basically stock motor and made a few pulls at +5, 0, and -5 degrees? I'm looking for a bit more low end torque, but would like to know how much top end hp is affected.

[r-mracing]

reply

Any results from dyno testing to show what the adjustability can actually do for you?

Dyno results are COMPLETELY different case by case. While some cars could only benefit in very small hp or torque increases others it could make a big VERY noticeable difference.

The most important part about this mod is that it gives the ABILITY for a tuner to make QUICK changes to his valve timing while at a dyno session or other event. Without an adjustable camshaft sprocket, the ONLY way to change valve timing is by removing the timing belt and setting it a tooth off or whatnot which OBVIOUSLY isnt really feasible if you are dyno tuning your car or in a limited time situation. So in reality, this gives the user the ability to "play" more with his settings and chose a valve timing degree that he feels works best for him and allows him to change it if he so feels like it.

I hope that explaination helped you realize the true purpose of adjustable camshaft gears. :)

[E30 Racer]

It will let you advance full to 10 degrees but will only retard up to 6 degrees.

Any results from dyno testing to show what the adjustability can actually do for you?

[r-mracing]

By the indicator it looks like 10 each way, marked at least, that is if it can use that whole distance or less. Should though..

It will let you advance full to 10 degrees but will only retard up to 6 degrees.

[Justin B]

By the indicator it looks like 10 each way, marked at least, that is if it can use that whole distance or less. Should though..

[nando]

well it's $30 cheaper and you don't have to buy from IE. Not as nice as the stuff from the likes of PPF but it doesn't look terrible either. how many degrees of adjustment does it give you?