OK, in case you don't know, I'm running a group buy on the J&S UltraSafeguard that retards timing based on boost levels.

One of the things John said he would be willing to do is to add some programming that will retard an additional amount of timing at a certain RPM. I originally asked about this because of the way the stock timing is setup and how it spikes at 6500 RPM.

Here is the thread where we discuss doing this

http://350zmotoring.com/forums/showt...&threadid=4987

Here is the stock timing setup.

3000 RPM - 19 BTDC
4000 RPM - 19 BTDC
5000 RPM - 19 BTDC
6000 RPM - 20 BTDC
6500 RPM - 28 BTDC

My question is what in your opinions would be the perfect setup timing setup for the ATI Procharger kit, if you could have any timing setup you wanted.

I was thinking -2 per PSI with an additional -6 @ around 6000RPM. Is this too extreme?

I know that the Technosquare ECU retards timing around -12 at max RPM.

 

Jesse. Do we have hard numbers that this is true for stock timing? I know it's been posted, but has anyone actually confirmed this? Not saying it's true or false, just wondering.

Bill

 

Jesse, isnt this something TS should be doing if they are tuning your SC 350Z with their chip or am I missing something? Do you think the J&S UltraSafeguard way of doing it is a better option or just cheaper? Sometimes I miss the big picture so advise please. Forgive me if my question does not qualify at the expert level.

Jeff - zland

 

I'm sure TechnoSquare can do it.. but not everyone lives in California. Furthermore, the TS ECU is a one-shot deal. You get it programmed, and that's it. If you decide to change any parameters later, you have to get it re-flashed, probably with some dyno tuning, ideally. With the J&S unit Jesse is setting up the GB for, the parameters are mostly adjustable. This is a timing safeguard only, where the TS ECU is several things rolled into one (backed off timing, altered A/F curve, etc).

 

Guys, read this post I pasted by g3po on superchargersonline.com forum:

The fundamental issue with the ATI "kit" is this.

The DFMU, "though crude" is not really the main culprit to the noted engine failures. Lack of adequate timing control to account for "boost" in a high compression/output engine (>1hp / inch^3), with a factory ECU algorithm that learns driver behavious and adapts "assuming" that the engine is still NA. The factory knock algrithm does not have adequate dynmic range or loop BW to adjust timing to account for a rapid boost slope. The three pics of destroyed pistons clearly indicate "destructive pre-ignition". No amount of fuel en-richment "alone" can fully eliminate this condition. And when it occurs , destruction can occur within seconds (far faster than the factory ECU can dynamically adapt to the pre-cursor of detonation/knock stimulus). If ATI really wants to remedy this situation they shuld include a timing retard controller. A good example of this type of unit is offered by :

http://www.jandssafeguard.com/

Note: N4SPD on other forums has just successfully installed such a unit upon hi ATI'd G35. Anyone installing an Aftermarket FI system on the Z or G should really consider this option, and ATI should bundle " something like it" with future systems, or more pistons will blow...

 

zland,

that pretty much sums up exactly what Jesse and N4SPD have been talking about, and it's precisely why Jesse is setting up the group buy.

 

Without having more solid info in front of me, your recommendation sounds pretty good. I'd rather be on the safe side, so I don't think its really that extreme.

Is the Technosquare you are referring to a forced induction tune?

 

K, technosquare is not tuning my car. I am simply talking about what technosquare has used for it's timing settings on skidazzle's ECU flash. His is TT, but it's logically the same thing.

The reason I do not personally favor the TS ECU flash is because there is no wiggle room. I do not trust the fact that I can send my ECU to California and get it flashed correctly for all conditions. Not only do atmospheric conditions change, but the efficiency of the SC system is never going to be exactly the same for every car.

What happens when I want to add headers, test pipes, larger throttle body, different cams etc??? I've got to get it reflashed.

I'm not talking bad about the TS ECU flash, but basically it's a one size fits all type setup. Once you get your flash your done unless you want to pay more money.

I've said it before and I'll say it again. The ECU is blind to changing conditions within the SC system because it lacks a Manifold Absolute Pressure sensor. Without that, the ECU can't adapt to changing atmospheric conditions.

Using the FMU and the J & S setup is the best option for me. It will be able to adjust for atmospheric changes, efficiency differences within the SC, and will have an adjustable timing retard.

The only reason I would get a TS flash would be to change my rev limiter and to compensate for larger fuel injectors, if I ever get the money. I wouldn't have the car tuned for FI because things change too much.

 

Oh, and another reason for me not to do the ECU flash is because sometimes I don't want to run the SC. I'm moving to Arizona soon, and I don't need to run the SC on the way down there. I use it for just screwing around with ricers in the city, not long distance trips.

What happens if a belt breaks on the SC and I have the TS flash? Basically the car will be running as though it was FI without actually getting any boost. In other words with the TS flash tuned for FI, I can no longer disconnect the SC and drive the car NA. You're stuck with the FI settings.



So, now that that's cleared up... What do you guys think about having an that additional optional timing retard switch that is adjustable for -4, -6 and -8 degrees and will only kick in at a specific RPM range for example 6000RPM to redline. Is it necessary?

 

IJust keep in mind, that retarding ignition too much (8 degrees is alot) leads to very hot EGT's, which can cause there own problems. Hvaing an adjustable switch would be nice though.

We've used the J&S before with Subaru's and it works well- probably the best overall thing to do is when it senses knock, have it retard a decent amount overall (6 degrees or so).

For forced induction, you generally want to retard ignition under boost. Your timing curve generally should look like a mountain under forced induction tuning - a quick ramp up to the torque peak, then a gradual taper down to levels at or a bit higher than your base timing figure, as you hit redline.

I really think that once someone implements real engine management to their forced induction cars is when the truly good reliable HP and torque numbers will start showing themselves.

 

ATI keeps saying that they are more than eager to help customers with the Procharger but they aren't much into participating on newsgroups. So why don't you hold them to their promise and email them the question about which timing settings would be ideal?
--
Jeff

 

I'll do that. I'm not gonna hold my breath for a good answer though. We'll see.