It seems that from reading on line, the (potential durability) problems that have occurred thus far with the released SC’ers on the market that have been installed on our 350Z's have fallen into two categories.

The first being with the with the ATI SC. Most people on line (including some owners of the ATI SC’ers) seem to feel the burnt pistons have been from a lean air/fuel mixture condition.

The 2nd problem, Stillen products, seem to be with some pinging due to running hot in warm operating temperatures. This will most likely be fixed with the upcoming intercooler. Adding more hp to this system, which is needed, is another issue. Right now, skk100, a Stillen SC owner said Stillen is installing a new intercooler and boosting the SC to 7lbs. The thread is "Stillen SC at 7 pounds. installing intercooler". Maybe this will solve the problems on the Stillen SC?

At this point, it appears that the only engine damage that has occurred in any FI system released thus far on a 350Z has been related to a lean air/fuel mixture.

Maybe someone out there is qualified to answer these questions?

1. What is the best way to set up a FI system on our VQ/350Z that will prevent a motor running too lean yet run optimally in most driving conditions?
2. What systems is the PE TT system using to control the air/fuel mixture? Will these systems seem to be designed well enough to prevent a lean air/fuel mixture yet sophisticated enough to have the motor run optimally?
3. The Greddy TT seems to be using a piggyback system. Are the problems that appear to be related to delaying this product due to integrating the piggyback system to the ECU? I have heard rumors of this system not being able to idle satisfactory. Will this system seem to be designed well enough to prevent a lean air/fuel mixture yet sophisticated enough to have the motor run optimally?
4.Some people have commented that the ATI SC fuel management system works but is crude. Other people have implied the stock injectors need to be bigger and that over time, these stock injectors are prone to failure due to excessive fuel being forced through them exceeded their design. I have also heard that this failure could cause a lean condition thus possible burnt pistons. Do you think a better fuel management system could/should be considered if going with this system?

I am trying to get a handle on this issue. It sounds like a lot of problems related to FI durability could be fixed with air/fuel mixture being controlled better. If you have knowledge in this area, it would be appreciated if you gave input. Thanks, Jeff

 

In order to avoid a lean mixture is to supply more fuel. When you supply more fuel you will have a rich mixture of air/fuel.

 

Of course adding fuel creates a rich mixture. The question is how can fuel be maintain at an optimal ratio. This seems to be easier said then done. We have 3 burnt pistons on FI 350Z's right now. Popular opinion says all those cars were running too lean thus the cause.

 

Thats why it is imperative you tune the car on a dyno with a wideband O2 sensor. This way you can adjust the include EFMU (with the ATI) to supply the right amount of fuel at each rpm range.

 

With the ATI Procharger, an additional fuel pump and Fuel managment unit is included. Since the stock fuel pump cannot supply enough fuel at certain rpm ranges with the increased air of the ATI, the supplemental fuel pump is needed. In order to supply the right amount of fuel for the amount of air, you must tune with the dyno and wideband.

 

I won't answer each question idividually, rather...I'll give you my $0.02 worth and what I've learned from tuning blown cars....Here it goes
Standalone aka DFI would be the most ideal way. Expensive, but ideal. However, this isn't practical, and the FI makers know this. Where does that leave us? Obviously with positive pressure you will need more fuel. You can do this a few ways. FMU or bigger injectors. Anytime injectors operate past 80-85% duty cycle, you are shorterning their life dramatically. Yes, failure of injector(s) WILL cause a lean condition and detonation. If you increase injector size, we can spray the same amount of fuel with less work. Of course, many people are RICH after injector swaps with crappy idle. Why? Because the ECU still thinks the old injectors are in there. Pulse width hasnt changed. This is where ECU tuning comes into play. Injector pulse width must be altered across the board (editable in RPM increments). This corrects lean/rich conditions in any RPM range. However......AFAIK, there arent any ECU flash programs or any way of directly changing parameters to the 350z ECU (correct me if I'm wrong please). So that is why I'm waiting. Fuel controller can help (SAFCs), but it is more of an indirect effect. And I'm not sure if they can alter inj pulse width (anyone know?)

You're other option is to use an FMU with your stock injectors. Not sure about the FMU that comes with the ATI kit, but most FMUs are adjustable with step up ratios. For example: for every pound of boost, the FMU will increase fuel pressure x amount of pounds. FMUs are more of a cheap bandaid rather than a fine tuning tool. Knock retard boxes (decrease timing x amount of times for every pound of boost) can be used in conjunction. Again, this is far from being "correctly tuned" but you can safely run the car this way. 2nd fuel pumps are used with FMUs to reduce strain on stock pump. If the stock pump fails under boost, you're in big trouble. I recommend a FP gauge to keep an eye on the FP during WOT

Personally, I'm waiting. Aftermarket needs to play catchup a little bit more before I jump into FI.
good luck

 

Bigger pump, injectors, and some electronic device is what you need. I always buy bigger and tune less aggressively than necessary to keep it rich. While I may lose a few hp, it's worth it to me to keep it on the safe side.

I always run rich with FI. Too much fuel is better than not enough.

 

Ralphus made me think of something. Do not forget to do spark plugs checks when you go FI. Should be a nice tan color

 

get the car tuned...

 

Yeah, and buy a step colder.

 

I know that at least 2 of the 3 motors that had blown motors (burnt piston) were "professionally" tuned and dyno'ed. I am not sure of the details on car #3.

To say get it tuned might not be enough, especially when those tuners do not warranty the motor that just had about $6-8,000 worth of damage done to it.

I think we as consumers got to make sure all of these varibles are correct. Especially if no warranty is being offered by FI company, vendor, or installer/tuner.

 

Let me revise my previous statement.

Get the car tune Properly. hehe

 

Jeff,

As you know it is extremely important to have proper fuel mixtures, especially with a FI application.

There are many ways to add fuel in FI applications that have proven, time and time again, to be reliable. The most popular include FMU's (these raise fuel pressure in relation to boost pressure) and larger injectors/piggy back engine fuel controllers (these controllers fool the factory computer into thinking there is either more or less air entering the motor than in actuality, and as a result the computer tells the injectors to give more or less fuel).

However, the best way (IMO) for someone who is serous about modifying their vehicle would be to go with some kind of "standalone" engine management. These include Motec, Haltech, DFI, Fel Pro, AEM EMS, etc.. One of my favorites, and the one I am most likely to try on my Nissan 350Z, is the HKS F-Con-Pro. These "standalone" engine management units commonly replace the factory computer, or at least replace all functionality of the factory computer that deals with timing and fuel. These computers allow someone to tune (via laptop) the timing and fuel curves/maps specifically for any one application. This makes it possible to get the car to run similar to factory with substantially larger injectors and substantial power adders (ie. high boost supercharger or turbocharger kit).

The only draw back to the "standalone" type engine management units is that for parts, sensors, installation, and proper tuning (and proper tuning is an entirely another subject for another day!) one should expect to pay anywhere from $3,500.00 to $5,500.00 depending on the vehicle and setup.

Hope this helps,

 

Don't forget about having to adjust it constantly to account for weather and other conditions. Of course, if you're serious enough about tuning to buy one, you probably don't mind. However, if you're not going to actually seriously RACE the car often, I think there is such a thing as too many options....

 

Can we expect some tuners like Technosquare to be able to reprogram an ECU enough to be able to do the things you are describing or is that too much to expect or achieve?

 

Any respectable tuner should know how to tune a fuel controller. This is the route I recommend going Zland. It's as close as you can get to DFI without dishing out the $$$$. I've run the "bigger injectors + fuel controller" with 8psi on 9:3 compression before. Ran great. There are some things you have to remember. Very simple things.

-Run plugs 1 to 2 stages colder than stock
-Use 93 or 94 octane gas
-change oil religously
-change blower fluid religously

Once you're tuned (not talking about DFI here), you will be good to go and shouldnt require any re-tunes for a while. Make sure you get print outs of a/f ratio, total timing and WOT fuel pressure at the time of tune. It's good to have a reference in case **** hits the fan down the road. (so you can set everything back the way it was)

 

Mike@altered and my views were very similar on how to approach needed fuel for FI. I also sent an email to a moderator at supraforums. He used to work as a tuner at some shop in Chicago. I'm sure anyone who's been on supraforums know who he is. But I won't name him since that's not really needed. Basically I asked him what he thought about FMUs. Here was his response:

 

Thanks you guys for all your input. I think the more I learn, the more I am able to select a product that fits my needs and the installer and tuner that will make it operate correctly.

 

aeromotive dfmu works great... i used a super afc2 for fine tuning... my a/f is under 12 all the way to readline... look for the post about the phantom turbo kit...

m

 

Better fuel pump. Better injector. Some kind of fuel control system. Exhaust Temp Gauge to keep eye on mixture all the time.