MSD and NX sell a window switch that uses pills from their ignition box to set your RPM limits. FJO has a PC programmable setup http://www.fjoracing.com/products/waterinjection/

or you can set parameters in your EMS if you are using one.

You should also avoid bouncing off the rev limiter at all costs as there really is no way to protect you when your on the rev limit.

It must be treated much like Nitrous Oxide, only difference is shuting off your methanol injection a few hundred RPM too early before your rev limit; like some do with nitrous; can be catastrophic as well.

Be aware of your engine RPM, and if you cant hack that, us old schoolers just prefer straight C16, and no meth injection.

 

this happend to my friend to who was running alky injection on his magnus manifold. on 25psi on a DSM. And his was only 2 months old.

 

Time to put a pop-off valve on the intake.

 

Actually if they make pop off's with enough capacity that is actually a damn good idea. Get a pop off with a pressure rating of 50 psi and it should prevent manifold explosion in the event of a backfire, but not leak under normal boost pressure. Hell, a simple "blow out" diaphrame style would work fine.

Keith

PS: If we can't find an actuall pop off valve, a BOV without any vacuum lines attached and the correct spring pressure may be useable.... not sure about that though.

 

What about using a product like the B*ee R Rev Limiter which pulls timing at a adjustable RPM instead of letting the stock Rev Limiter pull fuel........ ? (by "pulll" I mean shutoff)

 

So this is obviously a problem, not necessaryily with the Magnus, but with inappropriate timing. So, how can we avoid this?

 

Damn Son

 

running meth or nitrous? sounds like a good investment to me.

 

+1

I can vouch for these, I have seen them save a couple engines when a backfire occurs.

 

As others have said, it is rich misfire, not sparking with with intake valve open. How would that even happen with the car running fine before? Spark timing that far off would cripple from the start.

 

why is it that this kind of explosion is not seen (or maybe not reported) in cast type intake mani like the stock ones?

the sheet metal intake mani has lots of volume for methanol to pool......

 

Same reason the top fuelers run the burst pannels on the blowers....

 

This is an interesting thread to me...as I just had my motor blow friday nite. I too am running 30psi on a meth injected hp61. My fpr vaccuum line had been blown off at some point during the explosion.

I was awfully close to the rev limiter, and the stock tach does begin to lie as it cannot keep up with the engines revs once you get around the 450-500whp+ mark. I'm still trying to figure out exactly what happened and it seems something along these lines could be a feasible possibility.