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In Reply to: How much money do you want to spend? posted by JamesM on December 25, 2001 at 10:01:00:
Thanks again,
Ethan
The intake cam is a better upgrade for high RPM power/torque. The chip is a simple $250 drop-in. The chip is definitely recomended. With my bone-stock M5, I noticed maybe a 10-20HP gain with the Jim C chip. A Schrick 282 intake cam will cost about $600-700 plus installation. You do not need to remove the head. About 3-5 hours to install on the car. You may also need adjustable cam sprockets, $400 for the pair. The Schricks should be dialed in per their instructions, and the BMW cam sprockets are not adjustable.
The exhaust cam sprocket does not gain any torque, it only moves the torque peak to a lower RPM. This, in turn, actually decreases the peak HP output! It should be used for cars that are mainly street-driven. M3 owners all hate the exhaust cam sprocket when it comes to track use, because it actually decreases top-end power.
High-lift and high-duration cams like a Schrick 284 work best with more compression. The US engine has 9.8:1 stock, should run 10.5:1 or higher for bigger cams. High-output M3 engines (same as the M5 minus two cyinders) use 11.25:1 JE Pistons.
M5 and M3 engines work best with more lift/duration on the intake side. Check out Korman Autoworks. Good, reputable, but expensive!
So, how much do you want to spend?
JamesM
Which chip did your friend wind up using?
If you were to pick one upgrade over the other, would the Schrick 282 cam be a better upgrade than the Dinan chip/sprocket combo? And would I have to remove the head to replace the cam?
Also, how does your fuel mixture work out with the timing created by the Schrick 282, Dinan chip, and Dinan cam sprocket combination? I'm assuming the Schick 282 was not designed with the Dinan products in mind, or am I wrong?
Is the Schrick cam an exhaust cam? and besides altering the duration and lobe diameter, does the cam have any built in timing retard/advance?
Thanks for all the info,
Ethan Turner
'88 M5
'70 2800cs
'63 Ducati Mach 1 racer