Hello All,

It's been awhile since I've posted any updates on my car, but there hasn't been anything new up until last weekend. I've just been driving the wheels off of it and enjoying the heck out of this little car. Here's my last post: acceleration run at 5psi

As much as I wanted to stay at 5psi and the Greddy/Vortech FMU forever, the lure of more power is a strong one, and I decided to address the next item with my car: more fuel and better fuel control.

My first step was getting my hands on and installing a Walbro 190 high pressure. I got the kit from lightning motorsports.


After seeing some pretty rusty deck panels, I was happy to find that this one was in good condition.


For those that haven't seen it, here's what the gas tank and pump assembly mount look like.


Ahh, so that's what the inside of a Miata gas tank looks like...


Here's a shot of the fuel pump assembly with the new Walbro in place. Perfect fit! The stock pump is on the right.


After completing the pump, my next task was to get those teeny stock injectors out of there.


Stock rail with injectors


Since I planned on taking the Greddy FMU out of the picture, I needed a good rising rate fuel pressure regulator. I went with this one from Aeromotive, which is made for Hondas but bolts to the stock Miatafuel rail. The pics show the fuel pressure gauge mounted in the FPR gauge port, but that setup wouldn't fit. I ended up running the gauge in a separate location.


Here's a shot of the back of both FPRs. The Aeromotive unit uses an o-ring instead of the protruding piece that the stock FPR uses.


For injectors, I found a good set of Supra 430cc black tops. I had to wire in resistors, but that was no biggie. I replaced the o-rings and rubber isolators while I was in there.


Pic of the FPR installed.


Another FPR pic, and you can see where I installed the fuel pressure gauge.


Lastly, I redid my gauge panel and installed a leftover autometer blinky A/F gauge from an old car (until I get a wideband) and Knocksense.


I also installed an old Apexi S-AFC that I had from years back. This is where I mount it if I need quick access. Otherwise, it lives in the glovebox. I used a pressure sensor since the Miata does not have a true throttle position sensor. It's working great!


More to come, as I've been busy with work. I plan on turning up the horsepower **** and seeing what this thing can do!

Thanks for reading,

-Tom

 

You seem like a competent and smart feller. Get that WB already.

 

Lookin good. Cant wait to see the results. Have you considered the DIY dual feed fuel rail?
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I am very curious to see how it works out. Great pictures! We tried one of those FPRs on a civic recently and it never worked right, but they are great in principle. The car hauled but it ran super lean sometimes and rich other times (You really need a wideband). He ended up going aem ems.

 

Underdog,what's the model number on the walbro pump and is it the HP version? I'm looking to change my fuel pump also,but can't figure out which one I need.

Nices pics BTW.

 

there's a link in my sig.

supposedly, this link provides a lot of diy turboing information.

I heard on the grapevine the part number for the pump is on there somewhere, but dont take my word for it.

 

UD how is the map sensor working i meant to try that with my 460's but ultimately just gave up and wnet back to 1.8's still safc is a good tool i look ofrward to seeing some numbers man

 

just curious how is the car running with those big injectors?

 

I was under the impression that the stock computer would have a hard time idling injectors of that size.

 

Tom, you get stuff done.

I'm taking a more complex route since we last talked but I am sure your car will always be faster.

 

+1

 

Tom knows his stuff. With the SAFC I am sure he is running ~-50% at idle to dump way less "fuel" then stock to trick the ecu.

What Tom has done to his miata is pretty basic DSM modifications. Considering his DSM experience, it is no suprise.

Keep up the good work dude.

 

Yes, this is standard DSM stuff. I've gotten injectors to run on a DSM at about 150% larger than stock with an SAFC. Granted, the two ECUs work differently and the AFM/MAF is different, but I don't see why it won't work on a Miata. In fact, I asked about running an SAFC the same way Tom is in one of my first threads here. The answer was NO. I just took everyone's word for it because I knew nothing of Miatas. Now I am eagerly awaiting Tom's results.

 

I want to know how Tom hooked up the Safc. S-afc are cheap to get and I still got a spare DSM injector so I would love to see the injector install.

more power for less money, seem like the DSM way of life. The good old days

 

dam i love the way underdog is setting up his miata its such a clean set up and its done so right haha good job man
how did you get that pump for

i meant to say how much?

and another funny thing is i have the same player that you do

 

It's pretty standard. You tap into an RPM signal, tap TPS/MAP, intercept the AFM signal, power and ground. The trick is using the MAP sensor in place of a TPS since the Miata doesn't have one, both are a 0-5v sensor, plus on a turbo car the MAP sensor will give the SAFC a better indication of load than a TPS. You're still running the SAFC in MAF mode though because you're still intercepting and altering the AFM signal to the ECU, you're just using the MAP sensor to indicate load.

 

betcha a MS would be cheaper and extremely more robust.

 

^Werd to that.

 

You can get SAFCs for about $125. In Tom's case I'm sure he had it laying around. I've had so many over the years I probably have one in a box somewhere in my house too.

 

Well the MS would be better but I can find S-afc between 50-125 and the MAP sensor is free from GM through a buddy.

MSPNP is my future goal but I with drifting i would prefer to be able to run bigger injectors without losing my MPG, that and I have a set of 450 DSM injectors sitting next to me from my old DSM...