so no work around except replacin the ecu?

 

I am a little ignorant about the type of vibration the UR pulley causes. But doesn't it seem like if the engine is sensing vibration with NOS and retarding timing that this bad vibe is also there
all the time (just at a lower level).

Point being that long term use of the UR pulley might be very bad for the main bearings on the engine whether you are spraying or not.

I would guess the VQ is an internally balanced engine, but if Nissan put a rubber damper ring on the stock pulley there is probably a reason for it.

comments?

Ja

 

yeah, i don't know if i should even install mine now .

 

If running both N2O and pulleys, you might be able to escape the Knock Retard by disconnecting the Knock Sensor while running on the N2O. I'm sure this would give an error code, since this is a DTC detectable line, but that MIGHT keep the ECM from trying to correct the false knock. I'm not sure if the ECM has a "safe mode" in case of sensor failure. If not, that could possibly work.

 

Sounds like a great way to destroy the engine! The only failsafe the engine has when spraying is being able to deteck knock and back off the timing a little bit (or a lot). And with a 100hp shot on pump gas, there's a good chance of developing slight inaudible detonation.

 

The sensitivity of the KS can be reduced signifigantly by relocating it and grounding it to it's stock location. I owned an 02' spec V before I got my Z and this is a must do mod on the spec V as the KS is extremely over sensitive. As an example of how effective this mod was I made 3 dyno pulls without the mod and then made 3 more after grounding and relocating the KS. The pulls were more consistant and the Air/Fuel ratio was smoother accross the whole power band where before every dyno pull was completely different due to KR. I can do some research on doing this on the Z.

 

well, movin the ks is one work around. is there only one ks? the other issue here is the pulley, which i am currently questionin it's functionality.

 

i'm not sure about 350's, but on the max there is a rubber ring between the crank pulley and crankshaft. this is the oil seal, and it's recommended to replace this everytime your pulley is removed. it's about $6.50 for the replacement ring from nissan. might this have been the problem, max? if there was a rubber ring there before and u didn't put it back on, please look into this.

 

There wasn't a rubber ring, no. It's the damper that is the problem and this should have been mentioned by UR doest anyone agree on this???

Sounds like the thing to find out now is if this inaudible detonation is also a culprit. This would require equipment I don't have.

Moot point for me my pulley's are off and sold and heading out in the mail!

Problem solved mid 12's (for now.)

 

No, I think you are getting your terms confused. You don't get detonation every time a cylinder fires. If you did, the engine would be toast pretty quick I think. You get ignition every time a cylinder fires. You want the fuel to burn, not explode, which is the difference. Knock and detonation mean the same thing, fuel that is combusting on it's own, prior to being ignited by spark.

Or so I've been lead to believe.

 

Good words to hear:
Clean burn
Stoich burn
Ignition

Bad words to hear:
Knock
Pinging
Pre-ignition
Pre-detonation
Leaning out
Ruuning rich (not as bad a leaning out)

Many of these are tossed around ot mean the same thing though, gas is burning in the combustion chamber prior to when the spark plug ignites it, this leads to uncontrolled conditions and things bend/brake/burn/melt quickly if left unchecked!

Ben

 

I said exactly what I meant. "Detonation" as a word defined in relation to a car engine is the explosion in the cylinder. When it is by spark plug, that is good. When it is off sequence due to excessive heat in the cylinder, it is bad. The second case is generally called "knock" or sometimes just called detonation for short, but it is an unwanted detonation. If you didn't have "detonation" when the spark fired, your car wouldn't run

Detonation, by true definition of the word is the explosion or the firing in the cylinder. You just don't want it happening at the wrong time.

I think Ben above gets what I meant. There are semantics involved, but it is kind of like "sway bar" vs "anti-sway bar". One is technically correct, the other is shorthand, but generally understood.

 

Semantics are stupid, IMO detonation is a poor word but by definition it works. I prefer combustion (combustion chamber) now back on topic!!!!

Ben

 

OK, now I am really confused. How does this sensor work? Is this detected from detonation or vibration? I dont know how the two can be mistaken for each other? (unless vibration is the result from detonation itself and it is the vibration the sensor is monitoring???)

I also agree with 'jelledge'. How much more wear will be on the bearings?

 

Now to really confuse you . . . it is more of a noise sensor!

 

I am by no means an engineer:
The motor will have it's own continuous vibrations and such, knock or pre-ignition is a much more violent experiance.

Typically as the piston is still on the way up towards TDC the combustion mixture ignites much earlier (sometimes prior to spark in which case you have SERIOUS problems) pushing down on the piston while the piston is still traveling upwards. This causes some serious shudders and triggers the knowck sensor.

Apperently the vibrations cause by the UDP set while under the loads seen with a 100 shot are unable to be absorbed and are mis interpreted by the ECU and pre-ignition causing the ECU to freak out and retards timing.

Ben

 

Thanks, that helps alot. Sounds like use of FI would have same results... to some degree anyway?

 

well $hit..... I wish you woulda said that's why you were selling MaxHax...

I refuse to install a pulley w/out damper ring.... good way to get a snapped crank later on down the road. I have experienced first hand what a non-harmonic balancer equipped engine will do when it has had enough..... I had a converted auto engine in an airplane that had the harmonic balancer removed to make room for the propellor hub.... after about 300 hours of operation (estimated 3 hours of that in operation of the 2nd harmonic frequency) the crank snapped and I had to bring the plane down.

so.... that being said.... anyone wanna buy the pulleys I bought from MaxHax that haven't even been delivered to me yet? I'll leave them in the box and just ship them out... maybe someone else feels comfortable trying them. $175 + $7 shipping for the crank and A/C pulleys.

PM me if anyone is interested.

oh well.....

 

haha. zex with a retard....

 

umm, are you sure it wasn't the big propeller on the end of the crank that snapped it?