ORIGINAL: JB COMP
what do you do if the engine only has one shim? can it still go from 30% to 20%?
JB...I've run a stock standard (with all the shims still fitted) car engine on zero nitro and 20% castor with no problems at all. As to whether you'll have the same power, that depends. If the plug/compression wasn't ideally suited for the 30% then you could end up having more power with the 20%, it's all a juggling act. You'll have to retune though when you change nitro %.