im assuming detonation is a form of backfire that can bust a seal, etc.
i get a huge gunshot-like backfire once in a while and it lifts me out of my seat. if i push the car for a second, like past 4k, and then i come to a light or something, and i give it just alittle gas as the motor is rev'ing down, ill get it.

what r some ways to prevent this? anyone?

 

more fuel with injectors and pump, and a a/f controller and monitor.

 

good thinking..i think i knew that already..lol

i guess i should get a more flowing pump.

 

haah yeah
i'm actually learning too cause I popped my motor 2 weeks ago.
Theres alot of stuff that me and Aaron Cake are talking about with Gizmot. You could make a custom wastegate with alot of piping to make your turbo like a supercharger in which you can turn the boost high or low.

 

One way is not to **** with the boost until you get your fuel **** in place

 

detonation has nothing to do with backfiring. most rx7's with an open exhaust will backfire.

detonation is when the fuel inside the engine lights all at once instead of slowly. this causes extream pressure inside the engine and blows the seals. higher octane gas burns slower. thats why it helps to prevent detonation. It is caused by to much heat. which means you are running too lean and/or your timming is not retarded enough.

(assuming everything else is working as it should and you don't have other problems)

 

Detonation is also called pre-ignition.

Basically the air/fuel mixture in the combustion chamber is ignition at the wrong time - this is a basic description.

What is actually happening is...normal combustion pressures are around 1,000psi.&nbsp If the air/fuel mixture is ignition BEFORE it's supposed to, that explosion is working AGAINST the rotation of the engine - BAD thing.&nbsp If something other than the spark plug ignites the air/fuel mixture, the resulting explosion skyrockets in pressure - some as high as TEN TIMES normal combustion pressures - this is what causes the engine to blow apart due to detonation.

How can you minimize this?
1) Run colder spark plugs.
2) Retard the timing.
3) Run the highest octane fuel you can get your hands one.

All of these will minimize chances of detonation.

Of course, don't get stupid with the boost, and make sure your engine has enough fuel - get an upgrade fuel pump; this is "cheap" insurance as the Walbro 255lph fuel pump is a little over $100.

Now, what you're decribing is more like backfiring in the exhaust; detonation in the engine sounds like popping popcorn for mild examples, and hammer on a metal pipe in extreme detonation cases.

Almost all rotaries with open exhaust system will backfire at one time or another.




-Ted

 

thanks everyone..
i would know if i was running lean if i had a damb gauge pod to put my air/fuel gauge in.
its been sitting on my room just waiting for a pod.

thanks!

 

run water/methanol injection if you wanna prevent detonation

 

[QUOTE]Originally posted by RETed
[B]Detonation is also called pre-ignition.[QUOTE]

well they are 2 different things. just normanly classed together to keep things simple.

detonation is all at once. pre ignition is at the wrong time.

 

yeah detonation is uncontrolled combustion at the 'right' time
pre ignition is 'deisel like' combustion

 

Pre-Ignition is also cause by hot spots in the engine. Or a piece of carbon buring on a spark plug. The hotshot or burning carbon ignites the fuel before the spark plugs do. Very bad stuff.

James

 

I'm glad you people are still awake.

They are correct.&nbsp Detonation describes any type of uncontrolled ignition.&nbsp Pre-ignition is ignition of the air/fuel mixture before the spark plugs ignites.&nbsp Pre-ignition is detonation, but not the other way around...sorta like the square/rectangle thing.


-Ted

 

You can also get backfires if you are running the ignition too retarded. The mixture will be exploding as it exists the chamber into the exhaust system.

C