All,

Has anyone ever dynoed an Rx7 with all four wires hooked up and then without the trailing wires. At the moment I have my trailings disconnected and you cannot really tell the difference.

Why do I have the trailing disconnected?

Because when they are connected the motor is pinging at 5-10psi @ 5000RPMS+ when they are connected. I have tried reversing the trailing wires and it would barely rev.

I am using a Haltech E6k. All worked well before my last rebuild. Since the last rebuild the only things that changed was the porting. This weekend I am going over all wiring from the ignition input to the MSD's, from the MDS's to the coils and the coils to the Spark plugs. I am then going to crank the car with the plugs out and see if they all are sparking. (injector output disabled)

When I take the trailing signal wires to the coils off, the car will drive normally. When they are on the motor will ping.
Things that I have checked so far....

Crank Angle Sensor Wiring - all good
Spark coming from all coils and wires - all good
Set the base timing - good
I tried various advance timing and also the trailing split - same thing, still pinging
Fuel maps are good, not too rich and not to lean. Loaded a previous fuel map where everything worked well and still pinging.

This weekend I am going to check all the wiring once again.

Any ideas?

Back to the original question.....Has anyone ever dynoed a rotary with the leading and trailing hooked up and then the trailing disconnected. THe reason I ask is because I have heard you only lose minimal HP and was just curious.

Thanks

Anthony

 

i'm curious about this too, anybody have any input?

 

I used to run without trailing, because I was having detonation problems. Solved my trailing timing issues (leading timing was not touched, it was a case of a loose nut holding the wrench trailing was firing 180deg advanced of where it should have been... yes N/As will detonate if you get stupid like that) and trailing was worth quite a bit in the 1/4mi, I'd estimate 20hp for a car that was then making about 120hp.

 

I used to work at a Mazda dealership and they did that **** to Rx7's all the time. They would do all kinds of test with the motor all torn apart. A mechanic there once told me that the Rotary is easier to diagnose because of its versitility

 

Try replacing the plug wires. The spark could be arcing under load. Try checking for leakage in the dark while revving the motor.
It is best to find the problem than to eliminate the trailing plugs.

 

I have not personally done it, but I have a lot of old date on RE engines running T plugs only then comparing them to running with both T & L set ups.

The conclusions were as follows, not very much difference in peak power (- 2 to 3%) big difference in fuel efficiency (- 10 to 15%) with out T plug.

I agree with waynespeed, see how you go solving the problem first.shame about having to test the car and have it ping though, this may cost you an engine...........see if you can get hold of a knock sensor ?

 

Thanks for the responses !