Mach929

iTrader: (3)

um look up i already calculated it. 23.895cc it's actually really easy if you look at the end, no need to cut it. I don't really know of any calculations to do that would tell you exactly if it supports sufficient flow. the only thing i found is flow through a pipe and it measures pressure loss. this rail is roughly equivalent to a .4" diameter round tube aem sells a .5" rail and they say it's good for 1000hp. I did some rough guesses and pressure losses were around .03psi with flow may more than our fuel pumps can flow. So i'm thinking uprgading the fuel rail is worthless. looking at the rail the only logical thing i can see possibly being worthwhile is to enlarge the inlets and outlets.

magnamx-5

iTrader: (7)

hmm so now we come to the question of fuel delivery to the rail to see if the 5/16 lines are the main restriction, or the rail given that some of us use up fuel at the rate of aproximatley 33 of so cc/sec I wonder if there is insuffecient flow somewhere. Maybe if we steped up to 650's or so at 85 or so %DC 36.8 cc/sec. But loki chad etc are the engineers not me so

TunerToys

iTrader: (2)

Dah, keep for getting I'm not dealing with Hondas. Pretty sure that this can be adjusted for volume of a cube/rectangle.

Sorry Mach, was so excited about posting the idea, I didn't see where you had already solved it.

Craig

TunerToys

iTrader: (2)

In addition to flow in general, aren't there some balance problems with the stock single feed rail? I though this was the basic reason for going with a dual feed, if if it is a modified stock rail.

Craig

magnamx-5

iTrader: (7)

Yes the #4 is past the stock fpr and as a result gets starved for fuel sometimes but the dual feed allows alot more even distribution.

cjernigan

iTrader: (13)

Guess we're back to doing our own dualfeeds then.

M-Tuned

iTrader: (6)

Looks like it might be possible to supply a Billet Rail for $100. You could run it as a single feed, or a dual. I'm heading to the PRI show this week, and then we will discuss it when we return.

ETD is also working on a few other new products for the Miata community.

3barboost

iTrader: (1)

okay heres my take on it and this comes from long years of toil under subaru bonnets with the fuel rails above the hot block and crossing over the block and various water pipes etc etc

its all about the heat in the fuel
the fuel is circulated multiple times from tank - rail - tank and back until its consumed - each time it picks up "heat" from the pump / hot engine components and if you subject fuel to heat you will see that from 40 degree celsius it starts to want to vaporise really really easily, I think the ultimate solution is to protect the fuel from heat and you dont need rails

I think were aftermarket rails come into solving this problem is that when the fuel flows from a small area - ie the std lines to the aftermarket rail - there is a change in volume and/or pressure - there is a law in physicis for this, I just forget its name at the moment and when the fuel enters the rail - it loses the urge (if in temp range) to vaporise - as opposed to the small std fuel rails where it attempts to "vaporise" due to temp and the injector tries to inject a liquid that wants to be a gas - this is where it goes "lean" in my mind - its not about insufficient flow its about a liquid under pressure, where the pressure is preventing it becoming a gas but when it is released by the injector instead of atomising the way we expect it vaporises and bingo it is "lean"

This may not be the best or most eloquent explanation but I cant think of another way to re word it ! so read it a few times and let me know your thoughts on it ?

Loki047

iTrader: (6)

you're wrong

neogenesis2004

iTrader: (12)

I'd say that the heat can only HELP with vaporization, which if anything will improve power.

MiaTurbo

has nothing to due with temps. it's all about volume it can support. of course my theory is if you don't have larger fuel lines, then it's not as critical.

soflarick

iTrader: (8)

You don't want the fuel in the rail to be warm or hot. Cold is going to make the most power. Remember cool cans on carb'd engines?

TunerToys

iTrader: (2)

OKay guys, we have picked up a 90-93 complete intake manifold (injectors, fuel rail, etc is still on it. We also have a Vishnu rail for the same model years on the way. We are looking at several different ways of solving the lean condition on the stock fuel rail.

We are looking at three options.

1. A kit for adding the second feed to the opposite end of the stock rail.
2. An extruded rail kit that does not incorporate the regulator
3. A complete billet solution that would incorporate the regulator.

I think we'll be able to do the sub $100 solution for you guys with the extruded solution, but need to know if you guys are willing to use an external regulator with an aftermarket rail? Not needing to incorporate the regulator will cut costs for us, and allow us to hit the price point you guys want. Of course it will complicate the installation for you guys.

If the regulator must be reused, then our production quantity for the billet solution will have to go way up to make the price point. If we have to make a 1000 of these things to get the price point down, it may exceed the cost we are willing to invest in getting thos product done. I'm not too excited about having 1000 of these on the shelf if we are only going to sell a few a month.

We may be able to incorporate the stock regulator into the extrusion, but must look further into this option. It may not be feasable.

Please let me know what you guys think.

Thanks from Craig

sbrian2

iTrader: (12)

What external reg are people using? How much is it? Does it justify the additional cost of incorporating the stocker into a billet setup? What are the advantages of the external reg over a stocker?

Ben

iTrader: (33)

Option 3 would be most cost effective for us, even if the rail costs a little more, as we wouldn't have to purchase an external regulator.

TunerToys

iTrader: (2)

Sorry to bring this thread back after three months, but we are happy to announce that option 3 above is now a reality. Check out our post in the vendors classifieds! Tuner Toys High Flow Fuel Rails for 90-93 Miatas! We are doing a special introductory price for you guys, since many of you provided input on how to make this a product you guys would really like.

Craig

Teaser pic...



Thanks Guys!