Z32 Maf, injectors, programming, etc..
 

LAN... I've been wondering something for awhile, and *yes this is off topic... deal with it* (you can PM me the answer if you'd like)

I understand the basics of ECU decoding, however I in no way could do it myself. I've done some research specifically regarding the DSM ecu, and found how time consuming this process can be.

I'm not sure if you've looked into products such as "Hondata" and "DSMlink" however I was wondering if this was even in the realm of possible. (laptop adjustable E-prom. basically lets the end user control most aspects of the stock ECU. PM if you have any questions about the tech)

I know you probably don't want to put the time into it, as SVXes don't exactly have the most lively aftermarket, but if this was something that could be done with some basic programming and modified hardware, I think we could really get these cars preforming at a level beyond most peoples dreams. This would allow tuning with larger injectors, timing maps, really the possibilities are almost endless. Let me know if this is way out of our league as far as cost effective or even possible. Thanks

It's out of the league of the current market that's for sure. Both in price and in doability. The svx ECU isn't as easy to tune as others out there. It's a better ECU than the others but it has more things that need to be adjusted when fuel injectors need to be changed. Some of these things are particularliy hard to adjust. I make a point of only releasing products that I am confident people will have success with and I'm confident end user tuning for the svx right now would be a dissaster. I think with the stage 2v5 software out now that we've met the needs of pretty much everyone for the time being. There are those who insist on trying other things but if they come around they will find that the stage 2 software is all they need. This doesn't mean end user tuning will never be. Should the community develop to where it's a viable product to release then I will revisit the decision.

The Z32 MAF will read 400HP of air right, so are the stock fuel injectors now the limiting factor?

From what I understand, your statement is correct. Even if fuel pressure is bumped up to 60psi, not much more than 300 crank hp can be supported safely.

-Chike

The z32 maf meter will read more like 550hp of air. The fuel injectors are the limiting factor but someone, I think bill or tom has tested them at higher fuel pressures and found that they perform well on up through 60 something psi. This thread is about pistons though....let's not hijack it.

People are finally going to cc the heads of both the ej22 and the svx; that's definitely someting we should keep on track on. It's about time. This year is looking great for the svx; people are actually doing stuff instead of debating it. :)

Tom and I have both run 9 lbs of boost on the factory injectors. 9 lbs is way more than 300 hp.

It was Bill (SVXRide) who got his fuel injectors blueprinted.

I agree with you 100%. Stuff is actually getting done this year. ;)

Keep up the great work Mike! :)

-Chike

I think a 6mt and a 300hp figure is more than enough. We still want to drive a reliable engine (lasting) with an acceptable fuel consumption. For most of us those cars are for daily usage. :rolleyes:

We shouldn't forget these factors. :)

I don't want to send this turbo piston thread too far off topic, but while Tom (Svxfiles) runs 9lbs of boost, the bsfc on a s/c isn't as high as a turbo. Also, ~300hp at 60psi of fuel pressure is assuming an IDC of ~80%. If your stage 2v5 chip allows for higher IDC's (95-100%%), then yes, someone could probably make around 330-340 crank hp depending on the bsfc with the system their using.

-Chike

P.S. I never realized you're on the stock injectors LAN??? I thought the prototype used the nismos?

ya, this is a hijacking allright...... lol

you are correct about the bsfc on a supercharger being better than on a turbo. You are also correct that the stage 2 software will let you run higher duty cycles on the injectors. There is also a third factor that lets the injectors handle higher power--well for most of us: the automatic transmission. RPM is the largest contributor to when the fuel injectors will max out. The higher the rpm the less time the fuel injector has to deliver the fuel. At 6500 rpms there is a lot of time to deliver fuel, something like 18 ms. I don't remember the # for sure off the top of my head but I believe I calculated the base injector pulsewidth on a stock svx with factory injectors and software at max load to only be about 8ms. The stage 2 software further reduces the base injector pulsewidth calculated at higher load levels allowing you to achieve the correct fuel delivery by raising the fuel pressure rather than driving the injectors to higher duty cycles where they would overheat. Stage 2 does well for higher load levels from superchargers, turbos etc and stage 2 allows na cars to runner higher rpms to get more power. The limits of the injectors will most easily be reached by those attempting to run turbos at high rpms (so don't do that).

Thanks for clearing this up Mike. You'll have my stage 2v5 order as soon as I pick up my '95 SVX in February.

Okay, end of hijack! :)

-Chike

split and moved some posts to keep the piston thread on track and keep this good discussion going.

Good call Matt! :)

-Chike

So-
Got my maf from Walter today.
Will be ordering the stage 2 tomorrow.

intake/exhaust setup:
custom butcher exhaust
K&N filtercharger :o (need to clean it)
Intake silencer removed

Will bumping up the fuel pressure at this point be worth anything on my setup or a waste of time for now.

Matt,

I don't think you need to adjust the fuel pressure, as the Stage 2v5 chip will richen the afr similar to the stage 1v4 (or is it v5). With your mods and the Z32 MAF, your afr will probably remain nice and rich in the upper rpms.

If you ever add a mod such as performance camshafts, then bumping up your fuel pressure will be needed.

-Chike