Hi all! need to build a system unlike any I've seen... help
 

Ok, I'm kind of a noob but I've been researching for weeks on how to do it my way, but I can't find the answers I need.


I have a 2001 Dodge Ram 1500 with a 5.2 magnum and I want to build my own turbo system. I only want to run 4psi, and to keep my costs absolutely minimum. I want to avoid retuning my pcm... as a tuner is $600 and the tune is $350... I want to build a stand alone fuel supplementing system most likely with a water/meth injecting system, that is adjustable for me to get the best operation I can without reprogramming.


One of the first questions I have is, when the MAP sensor detects the loss of vacuum as the turbo is building boost is the computer telling the injectors to add more fuel or is it reducing fuel? if its reducing the fuel to the injectors due to a decrease in manifold vacuum then I would need to design it to incorporate more fuel to compensate. If it is already increasing fuel levels then I just need to supplement enough to avoid detonation and to accompany the extra air going in to maintain close to my 14.7:1 air/fuel ratio. ( I'm trying to avoid all the acronyms for the noob noobs that might be trying to follow along).


Please don't respond with, "just get it tuned, or get a MegaSquirt, etc. I'm trying to do it differentely and inexpensively to prove it can be done.
And please don't tell me it is just going to grenade, cause I'm sure if you've already tried it then someone else has too and someone would have posted that. I've looked and I haven't found anyone yet that has done it the way I'm trying.


thankyou for your helpful comments... please keep the unhelpful ones to yourselves, thankyou, Edward

Higher MAP readings will tell the PCM to add more fuel - although chances are the factory MAP sensor won't read more than 2 psi boost.

Also, you don't want to run 14.7:1 under boost, even with a small amount of boost - you're going to get 12:1 or so even with 4 psi.

so I did a little more looking and found this video ( ) that explains MAP sensor operation and learned that as more air comes into the manifold vacuum decreases or pressure increases so as I see it as the turbo creates boost the vacuum decreases and becomes pressure so the pcm will be increasing the amount of fuel as the turbo spins up to the threshold of its capability... at that point I need to be injecting extra fuel at an increasing rate to coincide with boost...


that brings the question of what can I use for the control for my water/methanol injection?


and will I need to supplement fuel also or will the methanol be enough?


reading my questions back to myself has inspired further investigation...


I found a lot of the parts I need for my turbo system at SpeedDaddy.com at fair looking prices... Are there any other places you would suggest for parts?

sorry that would be Speed-Daddy.com :rolleyes:

ok... I found this water meth injection controller Progressive Water Alcohol Controller that looks cool, and I think it will be perfect for my setup as it has adjustability to it...


I still need to know if I need to inject fuel too or is the water meth enough?

Use a wideband O2 sensor to see what your AFR is under boost - and lift IMMEDIATELY if you're too lean.

Speed Daddy appears to be your generic cheap Chinese speed parts, and it's unlikely they have any support for their products.

Thanks Matt, I had too look up wideband o2 sensor as I assumed it was just a different o2 sensor for my fuel injection but know I realize that its basically a stand alone Air/Fuel Ratio gauge and sensor. a quick look found a best price of $132 for this one Apsx V2 Anti Glare D2 Digital Wideband O2 afr Gauge Sensor Kit Black Yellow | eBay


would this be a sufficient one and might I find a cheaper one somewhere that is capable? this is supposed to be an ultra low budget build so every dollar I can save is a dollar towards another piece of the puzzle....

Most of what I have heard about ASPX is not good. Disclaimer - the company I work for sells the Innovate line, but I have more respect for some other competitors like Tech Edge, AEM, and Zeitronix than I do for ASPX.

Before going with the lowest priced wideband out there, compare the money you'd save on a wideband to the money you'd spend on new pistons or a junkyard motor if the readings from the lowest bidder wideband result in an unsafe tune.

That's a good point and by putting a little more towards the wideband I will have more confidence in the gauges but I have to go cheap somewhere to make up for it as this is supposed to be a minimal budget build.


I still need to know if the water/meth will provide the extra fuel needed under boost or do I need to inject some gas in there too for boost?

Unless you want to run almost pure methanol, I'd add extra fuel.