daking350

Not to be a wise ***, but the kits didnt fail...The engines failed..The kits are doing exactly what they are supposed to do, BOOST...The problem is with tuning or lack of engine management...once someone out there figures out this mess I think you will see some well over 400whp Z's out there..

elektrik_juggernaut

Exactly......you have less air, so you're running richer than us cali folks

jesseenglish

MaxHax's cylinders #5 & #3 went. #5 was the worst though.

psfwrx

Just FYI, the elevation in Lenexa KS (where ATI is) is less than 1000 feet above sea level (~850ft, I think). It's not the 'high plains' that was suggested before. And typical gas around here is 91 octane; you can find 92 at BP/Amoco stations, but that's as good as it gets in the area. No idea what ATI tested with, but it would have been 92 max if they were buying 'normal' gas and not doing anything to it.

As for many of the failures being in Cali, well, that's because as a population people in Cali modify their cars about 10x more than the rest of us poor folks. And I'll bet there's a disproportionately high number of Zs in Cali as well.

Regards,

Phil

jesseenglish

Wow, the elevation really drops off there. My bad.

G3po

iTrader: (8)

seems to be mi-interpretation bewteen term "detonation and pre-ignition". Yes there is an indirect correlation to timing and pre-ignition. The correlation is that:
"pre-igniton is frequently brought about by persistent detonation".

And yes once the system is already pushed into a pre-ignition state, pro-active timing has little effect. So the key is to keep detonation in check such that "ignition control" is less likely to occur. Once at the pre-ignition point, it's useually too late, but by early detection of input risk stimulus (such as occurence of detontion (which could be exacerbated by low A/F temperature etc).

This may be a discussion in minutia but there is some good reading on the subject at:

http://www.jandssafeguard.com/tech.html

flynnibus

Once you are at pre-ignition.. its not 'usually'.. it *is* too late The problem is your timing isn't going to affect the fact the mixture is igniting on its own.

Their indirect correlation is simply the heat build up and damage to surfaces and the microscopic barriers that normally prevent the items like the piston head from soaking up more heat. Detonation makes the heat durability of the system worse.. which makes exposure to pre-ignition worse. More 'hot' sources.. more chances for pre-ignition.

flynnibus

Here is a really good article on the topic

(8 pages long tho)

http://www.streetrodstuff.com/Articl...ne/Detonation/

jesseenglish

Every piston I've ever seen die that was a victim of pre ignition, usually had a hole on the top of the piston somewhere near the the spark plug. I've seen quite a few, from drag race aircooled VW motors. Detonation is usually identifiable by destruction of the ring lands, rings and cylinder walls because of the hot gasses blowing them out.

I was just saying that the pics I saw of Ravaz's cylinders were classic detonation to me.

Yes detonation can be a cause of preignition, but I honestly don't think it ever got that far. I could be wrong though, certainly won't be the first time.

flynnibus

So here is a simple-minded question.. flame on... why isn't the stock knock retard enough when it senses detonation? Its not limping the motor enough?

jesseenglish

I would think that there is just too much noise at high RPM from the addition of the SC for the KR sensor to identify knock.

I know someone mentioned this theory before, and I tend to think it's probably not far from the truth.

John at J&S

Don't know if it's true or not, but I've heard that many factory systems disable the knock sensor at "high RPM".

On the Subarus, it's 5000 RPM. Over on the Dodge Stealth forum (3si.org), they think it's 3500 RPM.

G3po

iTrader: (8)

My theory is that the factory timing correction factor WRT to knock sensor input is probalby too sluggish for the rapid onset of knock when under rising boost. I'm sure there is a bit of a "soak-time" in the factory ECU program to minimize false or erratic de-timing. And of coarse "disabling" the knock sensor under High RPM woudl be the slowest "time" constant of all.

I am also curious as to how the factory ECU rev-limiter operates. Does it pull timing on all cylinders at once , a few ,then more etc. Does it always de-time the same cylinder first or in a rnadom fashion. If so this may add to the correlation to why certain cylinders are biteing the dust more often. Those pulled last at the rev-limiter may see more damage first.

Unfortuanately , most questions as to the algorithm used by the factory probably isn't 100% understood except by the designers themselves. This ECU isn't the one your mom's used to. But more info on the subject would be better.

jesseenglish

About the only people who would know are Nissan, Technosquare, JWT and MAYBE AAM. I know Technos ain't talking, how about the other three?

Anyone here got friends or close contacts that work there that might be willing to part with this tiny bit of information? If what John says is true, then the stock knock retard box won't help de-time the ECU. That would suck, but I wouldn't be surprised a bit.

keepupp

In the next couple of weeks I will be meeting with BJ (Dwnshift) and Tadashi from Technosquare to flash my ECU. The mods on my car at that time will be Borla true Dual, Procharger, and Crawford Plenum. Hopefully Tadashi can shed some light on whats going on. What do you guys think I can expect from the flashing of the ecu with my mods?

ravaz

iTrader: (1)

I don't have a couple weeks to wait on this info.. We need answers yesterday.. Why can't TS just fork over the stock timing #'s and answer the questions. I could give a sh*t less what #'s they are throwing in there, what I don't understand is why can't they tell us what the stock #'s are. That's kinda lame.. No one's going to steal buisness from them by letting us know the stock timing #'s etc..

12SecZ

Tadishi signed non disclosures on Compnay secrets when he invested his hard earned money in TS. He is not being mean he is abiding by a contract as requested. He didn't make the SCer or the VQ35 he just tunes them. In fact if you have a sit down with him at his office he will tell you as most Japanese car lovers will, that they prefer turbos over Superchargers.

He bought the black box from Japan that flashes and then he runs the programming on a laptop. He is the programmer there.

He doesn't own the Company he invested in it. That is why Cheston'e ECU was in Japan all of those months.

Try JW and see if he will help because TS won't and I wouldn't either if I was in their shoes, a contract is a contract. Just trying to help.

The KR wire works just fine at high rpm's, as for the Crawford it adds more air but it also leans out your car so defintely get some good TS tuning or something on your A/F for this part and your Supercharger for safety.

John at J&S

Most factory rev limiters cut the fuel injectors off. Zero fuel in a cylinder is safe. I don't see a problem hitting the rev limit.

12SecZ

Rasing the rev limiter (to me) is a buffer so that I don't hit it! It doesn't mean rev like you are in an S2000 it simply gives you a buffer zone so you don't bounce off the rev limiter all day. I still shift at 6600 I just like that buffer. My 2 pennies.

daking350

Well when you cut fuel to the cylinder while still forcing air into it it causes a LEAN condition which is not good...