Has this been addressed yet in any alky kit or application?

[turbot2496]

I'm curious if any of the alky kit guys have added any options to the kits to effectively cut the alky if the engine hits the rev limiter? I know this was discussed a while back but I've never heard anymore about it. I'm toying with the ideal of playing with alcohol at the track but still concerned about this issue.

 

[jurassic five 7]

Eric told me this about that situation. Being my chip is an older burn it has a rev limiter, but he said ''All newer alcohol chips have the rev limiter removed since it can blow the head gaskets if the limiter is hit, and the alcohol keeps spraying (going lean).''

But this is in a Turbo Tweak chip.

-Adam

 

[Razor]

You have to understand the way the rev and speed limiter works. Both cut fuel off.. so alky or not.. KABOOOOOOM is what happens. Since you lean the motor out.

Two ways to limit.. spark or fuel. GM chose fuel cut. If anything alky is a fuel going in while GM is shutting down the injectors.

My first HG was do to rev limit fuel cut. My first broken rod happened the same way. Its real easy to hit the limiter when junk tires are on the car, bad tranny, etc.

My HG went on a 2-3 flare.. My rod went from NOS with DR's..

HTH

 

[Quiky One]

Razor, to be lean though dont you have to have a fuel there to create the spark? I thought that when it hit the rev limiter and no fuel was there, it would just die, not blow. Spark+fuel=explosion...Spark+no fuel=nothing...Spark+just a little alky=explosion but way lean.

Am I way off? Jason

 

[Razor]

Lean means too much air vs fuel.

You cannot have 100% zero fuel instantly. Becuase of residual.

Think of it this way.

Your at 30 PSI boost.. injectors are cranking in at 90% capacity.. your engine is at 6500 rpm's and all of a sudden at WOT you shut fuel off.. there is a small amount of fuel still riding in the engine.. at this very instance is when you have that nasty lean condition.

Then we can get into pre-ignition and other bad things.

Bottom line.. dont bounce off your limiter at heavy loads.

 

[Quiky One]

Lean means too much air vs fuel.

You cannot have 100% zero fuel instantly. Becuase of residual.

Think of it this way.

Your at 30 PSI boost.. injectors are cranking in at 90% capacity.. your engine is at 6500 rpm's and all of a sudden at WOT you shut fuel off.. there is a small amount of fuel still riding in the engine.. at this very instance is when you have that nasty lean condition.

Then we can get into pre-ignition and other bad things.

Bottom line.. dont bounce off your limiter at heavy loads.

ok it makes more sense now.

Thanks Jason

 

[turbot2496]

Lean means too much air vs fuel.

You cannot have 100% zero fuel instantly. Becuase of residual.

Think of it this way.

Your at 30 PSI boost.. injectors are cranking in at 90% capacity.. your engine is at 6500 rpm's and all of a sudden at WOT you shut fuel off.. there is a small amount of fuel still riding in the engine.. at this very instance is when you have that nasty lean condition.

Then we can get into pre-ignition and other bad things.

Bottom line.. dont bounce off your limiter at heavy loads.

yeah but....your way more likely to blow a HG with alky than without from what I've seen. I agree though hitting rev limiter = bad.... yet sometimes it happens.

Anyway, Razor would cutting the spark at 6500rpm solve the problem? Can this be done in the chip?

I like the ideal of the rev limiter to keep it from over-reving in the event of some failure but maybe removal of the limiter in the chip is the best option.

I have never ran meth at the track before because of this. In the past due to tranny problems I have hit the rev limiter at least twice at the track also due to a flare. No blown headgaskets but feel I would have if I had the meth. It was better to have a broken tranny rather than broken motor and tranny.

 

[Razor]

You need to address this with Eric or whomever your chip guy is. I believ 6400 is the upper limit on the stock computer. Wish there was a soft limit or other deal.

Becuase it hits the limiter doesnt guarantee an issue/non issue. But I can tell you when your squeezing all the turnip juice out of that 3.8.. shutting the fuel off is a no-no.

I have bounced of the limiter with alky spraying and not had issues.. but the straw that broke the camels back deal. Even if you shut of injector and alky at the same time.. still would be an issue due to the residual. Guess its like how many times can you hit 40 PSI and not blow a gasket.. Some will say they have a few times and no issues :redface:

If your tranny is toast.. dont tempt the devil. Else you'll be fixing tranny and motor.