some MSDs comes with different rpm pill for limiting rev but when i emailed MSD to inquire about their 6 series ignitions, the guy told me that those products don't override factory rev limiter so when do you use those rpm pill? are they use to lower the rev limit from factory rev limit? i'm kinda confused on their use.

 

the revv limiter on the MSD 6AL and other models using the revv limiting plug, are usally for vehicles that revv a lot higher than stock revvs. the only way to change your revv limit is to upgrade your ecu chip. for example, if you had like a B16 and you got the Mugen chip installed which let's you revv up to 10,000 rpm, you would use the revv limiter on the MSD to cut out anywhere from 10,000 rpm and below to be safe. so in other words, it's just a safety feature and is not really needed unless you have an insane revv limit.

 

The soft touch rev limited featured in MSD ignitions are basicaly good for such things as a Nitrous fed motor. Along with a window switch, both can provide good safety from damaging your motor since the Soft touch rev limited cuts ignition at whatever pill you have in there. But to bump your rev limit of your engine, you will need a upgradted ECU as stated before.

 

so does that mean that the MSDs can be use without plugging any rpm limiter?

 

its mainly a safety feature if anything... especially if youre force fed. you wouldnt want to hit the stock rev limiter and blow your motor. the stock rev limiters cut off fuel... and when you lean out because of this loss when you have nos or turbo.. then there is a likely chance of blowing your motor. the MSD cuts off the spark before your fuel is cut... safer that this happens.

 

ok. now i get it. thanks.