The peaky rpm line is just really a symptom of the problem. The line in its self isnt a problem but the cause of it is.
As i said the cam (or obviously the sensor mounted on the cam) is telling the ECU where the crank is. Problem here the cam doesnt really have a clue about what its talking about. It is hooked up to the crank with a flappy belt and got valvesprings pushing on it and whatnot. THAT is the problem. Here is a graph of my car with new cas, cams, cas-pin and all. 
Not looking very good is it.. Next is a RB25 powered car (they got the same problem) but this one have the solution you have in mind. AEM disk in the cas. Now the line looks alot better. That is what the AEM disk does. Make it look better. Have a look at the line just below it. This is rpm "rate of change". It shows how much the RPM changes pr second. Above the white line meens a rise in rpm, below the line meens drop in rpm. 
The main problem with the cas is trying to guess where the crank is is still there.. Next is a car that have a problem with boostcut. I had a look at the log and saw the same pattern with its rpm line and i told the guy that i was sure the car was suffering from timingscatter. This is a CA18 engined drift car. 
Then the guy said that the car was fitted with a 36-1 timing wheel... That made mo go huuuuh? for a second. Until he posted this picture. 
Note where it is located... NO help at all. But he eliminated the potential problem with worn cas pin... Here is my car with a propper crank mounted trigger.
Also note the "rate of change" line. 
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