Via proccess of elimination I (and two others here) have confirmed that using UR Pullies while spraying will cause KR at exactly 99 mph each and every time.

Step one;

Run 65 shot and get 13.4 stock pulley's and ZEX

Step two up N20 jets to 100 Shot;

13.1 at 107-108 stock pulley's street tires.

Step 3 introduce UR Pulley's and ET Streets
Friday Test and Tune 5-23-03

On motor a 1.7 60 foot @ 103- 104 mph

On N20 same 60' but trap is 99mph.
*Look* not just one trap seven runs all at exactly 99 mph.

Step 4 disconnect alt belt on UR pully (not crank) make a final run

E/T increases by 3mph.

Today 5-26-03

Have two friends (mechs) over inspect stock pulley (remember I posted a series of pics and no one caught it and neither did we!

We see a very thin maybe 1/16 in ring of rubber all black matching stock pulley uh oh damper webcar connection was right but never confirmed with pic (probably busy just look at his car!)

Step 5

Reinstall stock pulley's,

Use GTECH Pro Compeition,

Trap goes up 8 mph!

Bottom line, I am manning up that I was ignorant not to notice that thin rubber band inside but no one else including the installer did.

This explains that on N20 the vibrations (although not humanly noticable) kick in with N20 and KR slaps the car in the face at 99 mph and I don't hit 12's even with MT ET Streets.

This also explains why I can go to and from work in Emergency situations at 132mph all motor and have zero vibrations.

Balanced no, dampered yes.

Motor runs effected or daily driving NO

N20 runs effected YES.

Hope this helps some of you on your upgrtade path my road of problems and losing the battle to be the first in the 12's is now your gain.

Decide if you want N20 before you buy the pulley's.

More later have to run to work, meanwhile find the pic and look closely maybe you will see.

AGAIN, this will increase you HP and ET and trap on a motor car but hurt it on ZEX (can't and won't speak on N20 pps I haven't used.)

Max

Peace!

 

This may be a dumb question, but what is KR?

 

Yes, please be a little more clear. That was hard to follow.

 

knock retard. Thanks for the update!

 

Hey man, that wasn't very nice.

J/K!



Thanks

 

so u don't really know if the problem is zex or the pulley?

 

Can someone now explain what Knock Retard is? Why would vibs in the pulley at the crank effect this? Thanks

 

When knock is detected by the knock sensors (very sensitive on the 350Z) it sends signals to the ECU to retard the timing in order to eliminate the knock. The vibrations that the combination of nitrous and aftermarket pulleys was enough to set off the knock sensors and caused his car to slow up a bit. From his statements it sounds like you can run one or the other just fine but both together (at a certain shot (100), I am sure) it caused some knock.

 

Edit: VandyZ beat me to it. NM

 

So is Knock Retard different from the problem some moded Zs supposedly have with other mods where the ECU detunes the mod?

 

Yes, the mod thing is different. There is a very strong suspicion that the ECU escalates performance to a certain point and then goes back to some base "mapping" and learn to deal with the mod. There are many theories behind this and I think the ECU programmers are slowly figuring things out.

I do know my car is very cyclical with the way it "feels" performance wise with no mods at all. I think the mods just enhance the process.

 

quote:
--------------------------------------------------------------------------------
Originally posted by VandyZ
knock retard.
--------------------------------------------------------------------------------


I was hoping someone wouldn't pass on an opportunity like that. Thanks, Zrated...

 

is detonation knock? i know a knock sensor will send a signal to retard when there's detonation, but is that what u mean by knock? in this case, it would just b bad vibration, correct? a 100-shot is fine, just not with the crank pulley.

 

Yes, when it is at the wrong time

 

so his car wasn't detonatin, just knockin. what about just the crank pulley and not the whole set?

 

Ok, Ok....So let me get this straight. You say you are having ZEX WITH A RETARD???

 

so the UR pulleys don't like the N20 setup too well.... but if running without N20 runs fine.

What did your run on just the pulleys I'm curious. You said 1.7 60ft and trap of 104 but what was the time?

And my last question. How do you think the UR pulleys will do with a turbo set up? Single turbo and twin turbo??? any speculations?

 

Keep in mind, as products are developed, someone may develop a device that can emulate a normal signal from the knock sensor. In essence this is what the piggyback ECM's are attempting with other signals. Changing things, but at the same time telling the stock ECM that everything's fine. We'll just have to see how big of a factor this becomes with other mods.

 

I can't comment on Turbos or SC because I don't have them, like Vandy said these cars are sensitive.

I can only say for certain that the pullies were the culprit only when spraying!

With ET Streets, pulley's, intake and exhaust the best was a mid 13 I think I didn't keep any 13 second slips out of DISGUST!
On test and tune you are not handed them at the end of the run from the booth you have to climb some stairs at a tower after every run and I never saw a 12 a left in disgust and confusion after dropping 175 each on tires!

You would have had to been there. I spent money on the pulley's the tires, filled my bottle and payed 40 to test and tune (I'm talking like 800 here) to run 13's!!!! ARGGHHH

Sorry just got home from work.

Vandy Z summed it all up, there wasn't any detonation I am aware of it was just KR and the culprit was the pullies while spraying (the combo) obviuosly you can't pull the pulley's at the track at night so I had to wait to do more research.

Want a mid 13 car get the pullies but don't introduce N20 it's a bad combo!

Pullies, good.

N20 Good

UR Pulley's and ZEX N20 no good 99mph trap.

I hope that's clear.

As an aside I think it was Vandy Z that first mentioned this dampening not webcarconnection I was in a hurry when I posted and I am too tired now to research it.

I did everything right but the pulley's go figure.

Last friday on stock pulley's and the 100 shot and just introducing the ET Streets instead of the pulley's who knows where I would be at since I did 13.1 with the exact setup on stock street tires! Live and Learn. I am guessing mid 12's.

It's all good and my sheets are calling me

As EJ stated the ECU issues can be worked around but it's a task a chore a well I need sleep I think I made my point and I hope I helped someone out there looking at a roadmap of mods.

To the guy that bought my pulleys here I will refund your 170 if your plan was N20. Otherwise I still recommend this mod, car runs fine with them even at extremely high speeds and my plastic under carriage shroud isn't even in place. No vibrations at 132 mph (haven't been fater yet.)

Peace!

 

We don't know. Detonation can be knock, but I was trying to point out that detonation happens everytime a cylinder fires, it is detonation that happens at the wrong time that is always knock

The question here is if vibration from the crank not being dampened was close enough to knock that the ECU retarded.