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The mkiv Supra Owners Club

Fuel rails - why so expensive?


michael

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Yeah I've been keeping an eye on things over there, nothing suitable so far but I'm watching... :)

 

I'd love to just buy the PHR Stage II and be done with it but at over a grand (which is a bargain compared with UK prices) it still stings.

 

Yeah and how do you pass MOT with a big fuel line most of the length of your car cable tied to the oe fuel pipes?

Maybe you get away with it in G.B. but in N.I. where govt centers do the Mot you have no hope.

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Do you really need a new fuel rail Michael? What turbo kit are you going for? Bigger sized injectors in the stock rail would be the cheapest option.

 

Power Enterprise do up to 800cc injectors to fit the stock Supra rail.

 

I'm (eventually) fitting a pair of Apexi RHX6 turbos, I did consider the standard rail approach but some thread somewhere probably put me off the idea. I was planning to run 850's initially and see how I get on, it's really stage 1 of the project so low boost etc until I get a bit more "built" and upgrade the 'box.

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Why?

 

 

The fuel inlet line from the fuel filter to the rail includes a "fuel pulsation damper" to dampen the injector pulse noise. This dampener uses an orifice and fuel line only about 7mm in diameter. Thats a HUGE restriction. The factory fuel line is capable of supporting only about 520 RWHP at the most, safely. And if the filter is clogged the slightest, that figure can drop by 50HP or more. I would like to think anyone going single would aim at 500+RWHP.

Some bigger rails feed each end with a takeoff in the center for a FPR/gauge, which you can mount remotely to your FP observation advantage.

If you wish to turn your 510bhp into rwhp, your safer changing the rail.

I have used the PHR stage 2 kit, while the fuel line fitment is a bit ignorant, and I was never able to get instructions for the relay, apart from that the rail and injector combination worked excellent however hard I boosted.

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Wez, it would be a good idea. Keeping the fuel system fairly stock and not spending a fortune is possible if say you want 600fwhp. Take a look at Nathan Lay's car on the tdi web site. That ought to inspire an economic way of dong things. He removed the pusation dampener, (uk spec fuel system) used a different pump, and a HKS AIC. Not big expense, but he did get reliable results, as he drove the car for years (tracked it often too), and would probably still be going except when he sold it someone stole it, never to be seen again. ( I am guessing it was stripped).

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So what effect would a modified standard rail (to dual feed) and the pulsation dampener bypass have on the pending explosion?

 

 

Haven't tried that one, has anybody on here? :search:

 

Bound the help reduce the risk. All down to the power level you seek.

I guess it would eventualy get restricted by the small diameter of the std fuel pipes?? alough you may be able to run a similar pipe from the tank top the other end of the rail.

 

Something else for you to consider

http://supra400hptt.homestead.com/files/diagram.jpg

 

Consider the cost of repair if you starve the engine of fuel vs buying a decent fuel system.

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