Dual feed fuel rail - good idea??

Dweezle · Postby **Dweezle** » Mon Jan 23, 2012 4:35 pm

Had a bit of a read and now just wondering everyone's opinion on using a dual feed fuel rail such as 949's.

http://949racing.com/m-tuned-dual-feed-fuel-rail-1600.aspx

Aiming around 200hp, would this fall into the absolutely, prob a good idea or not required basket?

I will be using 450cc injectors with a megasquirt controlling it all.

spikes · Postby **spikes** » Mon Jan 23, 2012 4:37 pm

Better fuel distribution, more even fuel to all injectors. Its worth it in turbo applications..

Dweezle · Postby **Dweezle** » Mon Jan 23, 2012 4:39 pm

Thanks Spike.

Sorry about my short post.
It submitted before i had finished

Postby **NitroDann** » Mon Jan 23, 2012 5:21 pm

Disagree with Martin completely, Its totally a waste of money for your application, pats monster has a stock rail, why do you need one?

Dann

Russellb · Postby **Russellb** » Mon Jan 23, 2012 5:32 pm

I use it because I was leaning of No4 cly Had STD inj with 160RWKW
It is a great System as the fuel from each side has to only feed 2 inj.
you need to make sure that you use a "Y" piece not a "T" to split the incoming fuel

Its cheeper than a new Engine so Good Insurance

Dweezle · Postby **Dweezle** » Mon Jan 23, 2012 5:42 pm

That's what i was thinking dann but then while reading i heard about a few saying cylinder 4 was leaning out so when tuning you had to add more fuel and pull timing as a bandaid fix.
But i am more than happy to save the $200 if it is not required.

wozzah1975 · Postby **wozzah1975** » Mon Jan 23, 2012 5:45 pm

I don't think I'd bother if your chasing 200hp. I haven't heard of the standard fuel rail causing any issues at that amount of power.

Cheers
Woz

geofiz · Postby **geofiz** » Mon Jan 23, 2012 8:38 pm

Mine cost me $119 plus shipping. A long way short of $200. Plus I got a cool sticker

Seriously though, in my case I had to run a non standard fuel rail to get the BP4W from an 03 into a 95 NA8. Cheap insurance if it save #4 cylinder.

Dweezle · Postby **Dweezle** » Mon Jan 23, 2012 8:42 pm

yeah its $119 for the rail plus like $67 for the hose kit, coming to almost $50 postage.
So well above $200.

Not by a long shot expensive but if it is not required it would be better in my pocket.

Thanks for everyone's help.
MUCH APPRECIATED.

wozzah1975 · Postby **wozzah1975** » Mon Jan 23, 2012 9:11 pm

Russellb wrote:I use it because I was leaning of No4 cly Had STD inj with 160RWKW
It is a great System as the fuel from each side has to only feed 2 inj.
you need to make sure that you use a "Y" piece not a "T" to split the incoming fuel

Its cheeper than a new Engine so Good Insurance

I'm curious as to how you came to the conclusion that the fuel rail was responsible. I have seen the standard fuel rail used on much higher power applictions than that and find it hard to beleive it was solely responsible for a lean fuel mixture on one injector only, especially at that power.

Woz

Postby **NitroDann** » Mon Jan 23, 2012 9:17 pm

This ^

Also, You could always flow test your injectors and put the biggest ones towards the rear.

Dann

jerrah · Postby **jerrah** » Tue Jan 24, 2012 7:07 am

I use 550cc injectors in the stock rail and I have no issues with running lean.

zossy1 · Postby **zossy1** » Tue Jan 24, 2012 8:33 am

I'm joining the choir on this one. Mark, it is a total waste of money in a 200whp application.

Just get yourself a decent set of injectors. I'd be willing to bet that most cases of #4 leanness arise from issues other than the rail, such as:

* Fuel pump not doing its job;
* FPR on the blink;
* Failure to undertake an effective coolant reroute (leading to the imfamous cooking of #4 cylinder);
* Injector serving #4 flowing less than the others.

Could be any number of reasons for this, and even these reasons (with the possible exception of a clapped out OEM fuel pump) are unlikely to be a problem for anyone chasing 200whp.

wozzah1975 · Postby **wozzah1975** » Tue Jan 24, 2012 12:19 pm

zossy1 wrote:I'm joining the choir on this one. Mark, it is a total waste of money in a 200whp application.

Just get yourself a decent set of injectors. I'd be willing to bet that most cases of #4 leanness arise from issues other than the rail, such as:

* Fuel pump not doing its job;
* FPR on the blink;
* Failure to undertake an effective coolant reroute (leading to the imfamous cooking of #4 cylinder);
* Injector serving #4 flowing less than the others.

Could be any number of reasons for this, and even these reasons (with the possible exception of a clapped out OEM fuel pump) are unlikely to be a problem for anyone chasing 200whp.

Bingo, although in regard to the fuel pump and reg, problems in these areas would normally cause it to be lean over all the injectors.

You are spot on with the no4 coolant re-route problem and injector flow problem, this is more likely. It couls also be related to an airflow/airspeed issue depending on the manifolds and arrangement.

Cheers
Woz

Hellmun · Postby **Hellmun** » Tue Jan 24, 2012 7:06 pm

NB8B has a different fuel rail to NB8A and before. The NB8B system doesn't have a fuel return so as you reach the end of the manifold you get pressure waves bouncing back and that leans cylinder #4 slightly. I've just secured the fuel lines/rail for an NB8A for this very reason for my turbo motor build. Wouldn't say that fuel rail was worth it for 200hp though like stated it's a little more buffer if you can afford it, or just keep the tune conservative. So whether it's a good idea depends on your budget and what you'd be sacrificing to have it.