I wanted to share some information that I have gathered about my kit recently.

I have had my kit on my car for over 8 months now with the same set up and have had no problems so far. The set up was the kit with the labree test pipes and Injen dual exhaust set at 5.5psi boost.

I installed a small audio amp in my car connected to the factory knock sensor so I could hear the output from the sensor.

With 92 octane gas and at the 5.5psi I was able to hear very light knocking. If you have ever listened to a knock sensor output, knock is very clear and distinct even at low levels.

My LM-1 wideband showed 10.4 to 11.5 during the run. It was cool (50 degrees) and damp out during these runs. These are the best conditions to prevent knock.

The only cause to this knock has to be the advanced factory timing. I have never heard knock from the car before, even at a few dyno sessions. The knock was light and probably would never be heard by a human. However it could still cause damage to the motor.

I have addressed this by using the TS reflash to retard the timing. There are several options out there and work fine for the job of retarding the timing.

I posted this because with all my previous experience I felt that the 5.5psi was a completely 'safe' setting and not a problem for a motor in good condition. I no longer feel that way and wanted to give others the chance to make that choice with all the information.

I can't say every Z with the Greddy kit does this at stock boost due to how light it was but there is not a large margin anyway you look at it. It may be due to the higher flow of my exhaust allowing higher cylinder pressures.
Gary

 

I agree completely. I also experienced the same thing on my kit. But the pinging was audible at 5.5psi of boost. I dont think the Greddy kit is totally safe...even at stock boost levels...unless you are running 93 octane fuel or higher.

Some small level of ignition timing retard should be considered a requirment. Foretunately, examination of the plugs, and a comp test revealed no damage to the motor.

Thanks for sharing....

 

Wow nice idea setting up a speaker to actually hear the knock. Never thought about that or heard of that before today. I guess that's thinking outside the box. Thanks for the info.

 

Actually alot of tuners use a head set with a knock sensor. I come from a RX7 Twin turbo background. Rotarys can not take any knock at all. So you learn alot of "tricks" to keep from losing the motor.
Gary

 

so how much timing did you end up pulling ?

 

i keep thoughing the check engine light....clear cod comes back misfire in 3 and 5...is this the same thing?

 

booger: I have no idea. The flash is good to 8psi though. Also I verfied it no longer knocks

Redline tt: a knock could change the crank accel rate which the ECU could mistake for a misfire. I don't know the likelyhood of that though.


Gary

 

thanks does anyone know if the greddy plugs come gapped for the car or if it needs to be set.the kit called for 7 but i have the 8

 

the 8's are three steps colder than stoclk. That is much too cold for street usage. The greddy's come pre gapped at .35 and the NGKS's come pre-gapped at .45

 

Not to say it isn't, but misfire codes pop up on cars a lot with replaced injectors if you have a slight leak around the lower o-ring.

Mark
www.Quantum-Racing.com
Home of the Dynapack Dyno

 

Yep, that's why my first project was to get the Greddy ignition harness to work on my Z. The problem is the emanage will scale the MAF signal to to run the larger injectors, this causes the ecu to advance the ignition timing because it's being tricked into thinking the motor has less air coming in. I pull 1 deg per psi with the emanage.

 

Thats funny, I come from a RX7 Twin Turbo(actually single turbo) as well and never heard of that, but I was never with the tuner when they tuned my car. Learn something new everyday I guess.

 

I think GQ answered this question, with that cool of a plug it would foul pretty quick and cause miss fires. With this info I would pull the plugs and see if they are fouled.

Mark is right about the leak but usually you get idle issues also with the leak unless they're really small.
Gary

 

thanks guys for the info-im going to try 7's next see how that go's...the cel went off and the car runs fine still...dont really feel the misfire....wonder why that would happn?

 

Did you run the car hard? That could burn off the carbon build up and allow it run better... for a while.
Gary

 

Very true; just trying to add some more info in here. BTW, I run one step colder factory plugs with the gap dropped down to 35 thou on my own. I only run the wastegate pressure and by inspecting the plugs, the ground strap indicates the plug is a tad on the warm side. That could be due partly to hot ignition. I run the eManage with the diode ignition harness. I've not had any misfire codes that I'm aware of. The idle is always going to be a bit soft on a turbo car (big boost, cold plug, etc.).

Mark
www.Quantum-Racing.com
Home of the Dynapack Dyno

 

yes i did....all seems ok toaday..didnt get the chance to change plugs will do this week...