Geez, it's been years since the last time. But basically you take out one spark plug and place in the tool, then you turn ur engine on and leave it on for a few seconds without revving. Then your tool's gauge (forget what it's called) shows your compression numbers. Then you install back the spark plug and go on to the next one.

Basically it finds out the compression of your cylinders to make sure your engine's heatlhy. AEM used my old car (Integra) to make a prototype of their V2 CAI's and that's what they did to make sure my car was fine before they used it prior to development.

 

Oh man...You dropped the soap. Missing gears when you're trying to show your car muscle. Can't get to excited or scared when challenged.

 

yes, and all the electronics in the world won't help you when it happens. This is a very easy way to kill a motor.

 

A "leak down" test is a much better indicator of overall cylinder health. but it does take some time to do and a little practice doesn't hurt either.

 

Never try starting an engine when doing a compression test. All Spark plugs must be removed first and when you do the test make sure the throttle body is full open. YOu should alos use the same number of cranks for each cylinder if you want a valid test.

 

In a serious Mechanical Over-rev condition, you can also float the valves and bend them. Not sure if the VQ is an interference motor or not, if it is, over-revving can bend valves, If it's not an interference motor, it cannot happen. Maybe Q45 tech can chime in and let us know if the VQ is interference or not. I suspect as highly tuned and as high a CR as the VQ has, it is an interference motor.

 

Float the valves, that's the term I never new for what happends if the cam spins faster than the valves can return closed, right? That is a pretty serious issue too. I would imaging our engine is interference. With higher compression I would assume the piston is rising farther up into the chamber, putting it closer to the valves.

 

well once i was driving and something simular happened to me i was in 3rd goin into 4th accelerating hard and i had this gurl i was wit shifting for me..... anyway she missed 4th and hit second i quickly pushed the cluch and put it into 4th i didnt want to seem like i minded but that drove me nuts my car had like 1000 miles on it and i was like damn anyway to make a long story short apperantly our cars number one have a rev limiter inorder to keep us from over revving and it is also set at a safe rpm some say that it is set to early that we could safely revv up higher to varify go to http://www.technosquareinc.com/g35.htm there they tell u its set to low dont sweat it too much jus try not to do it again o and btw dont hit the revv limiter bc it cuts the fuel to the engine while it is revving high which isnt good if u do it too many times so if ur gona revv high get the technosquare ecu

 

daym... thanx for all the feedback, my car seems to be running fine at the moment. It really did stress me out the minute it happen but hopefully my car will be alright.

 

The rev limiter will have no impact what so ever if you down shift to a gear that will cause the engine to rev to 8k. YOu are engaiging the engine to the rear wheels through the clutch and transmission. I dont care if you turn the engine off, If you downshift from 6 to 1 @ 70mph you will push the engine over 8k no ands ifs buts or maybys. This is not a rev limiter issue it is a pure mechaincal issue. The only thing the engine is doing in this case is being a big brake to slow the car.

 

also dont forget to depressurize the fuel lines and disable the fuel pump

 

I did forget to mention that but I just assumed "my fault" that anyone doing a compression test would have already known that.