I am currently installing Crane Gold Alum extruded 1.6 full roller rockers in my car.
I have heard from a number of different individuals that they make a considerable amount of noise which in turn makes the knock sensor retard timing. A friend of mine who has these 1.6rr's said it made him noticeably faster when he removed the knock sensor oneday. He runs an Ed Wright custom chip also!

I still have the stock chip. I talked to Ed Wright and he said they reduce sensitivity of the knock sensor if the customer has 1.6rr's. But my friend had the Ed Wright Chip and the knock sensor still retarded his timing with the same roller rockers I have.
What should I do?

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91 Formula
305 TPI 5speed
1LE/G92/WS6
Custom cold air intake w/K&N, SLP airfoil, ported plenum, TB coolant bypass,Crane AFPR (47psi),94 octane,Crane Extruded Alum. 1.6 full roller rockers, Timing set from 4*BTDC to 10*BTDC,MSD6AL, Holley 9mm Annihilator Laser shot 50 wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, SLP 1 5/8 headers,SLP catback,3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

Street legal with stock throttle body, runners,intake manifold,cam, and heads.

[This message has been edited by theformula (edited December 18, 2000).]

 

With 1.6RRs, you will be increasing your airflow, thus you will be running leaner if you do not get a PROM burnt to compensate for this additional air.

Further, the 1.6RRs will affect your torque curve, thus affect the VE tables in your PROM, so you PROM will not be optimal for your engine. Lastly, if you are installing 1.6RRs on your original heads, there could be additional noise due to tired/old valve springs.

Have you considered burning your own PROM? These "custom" PROMs are based on various specifications given to the PROM burner and it is their best guess. But there are so many variables just from one engine to another. I wouldn't expect the "optimal" PROM needed for a brand new/rebuilt engine to be the same as a 100,000 mile engine, even if the specs were identical.

 

I should add, that 1.6RRs do affect the geometry. I am willing to bet that a lot of "knock" could be caused by incorrect valve train geometry.

 

Thanks for the replies Glenn. How does one go about to correct their valvetrain geometry?

I'm going to get a custom chip burnt as soon as the supercharger is ordered.

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91 Formula
305 TPI 5speed
1LE/G92/WS6
Custom cold air intake w/K&N, SLP airfoil, ported plenum, TB coolant bypass,Crane AFPR (47psi),94 octane,Crane Extruded Alum. 1.6 full roller rockers, Timing set from 4*BTDC to 10*BTDC,MSD6AL, Holley 9mm Annihilator Laser shot 50 wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, SLP 1 5/8 headers,SLP catback,3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

Street legal with stock throttle body, runners,intake manifold,cam, and heads.