fuel pressure regulator
Joined: May 2006
Posts: 36
Likes: 0
RE: fuel pressure regulator
here's what i know-i have a customer with a 5.9 grand cherokee-headers, magnum heads 3" exhaust etc. a walbro 255 pump is feeding it just fine. you need a way to control fuel pressure-you also need a way to increase pressure during boost, the stock reg won't cut it. get rid of the stock reg. get a rising rate fuel reg. at a 1 to 1 ratio this will be your starting point. you'll neeed to modify your supply and return lines to install the reg. the reg connects to a boost source and adjusts fuel pressure accordingly.
what are you doing in the line of engine control? i'm assuming at least a map clamp.
about 8 psi of boost you're going to run i assume
what are you doing in the line of engine control? i'm assuming at least a map clamp.
about 8 psi of boost you're going to run i assume
Joined: May 2006
Posts: 36
Likes: 0
RE: fuel pressure regulator
For the laymen who can't distinguish a camshaft from a halfshaft, here's turbocharger theory 101 in a nutshell. Engines are designed to work like a pump. Air and fuel are mixed together, and then ignited. The explosion provides power. Air and fuel must be combined in a specific ratio -- 14.5 of air to one part of fuel. If there is too much fuel in relation to air, the engine runs in a state of "richness". This leads to poor performance and lower fuel economy. An excess of air in relation to fuel will cause the engine to run in a state of "leanness". This leads to bad bad things -- detonation (explosions happening before they should, when the engine is in a poor position to receive the benefits of it), and high combustion temperatures (which, if hot enough, WILL melt parts of your engine). The point is to maintain that magical "stoichiometric" ratio of about 14.5 to 1. Ok. Pay attention -- this part is where power comes in. The more of this 14.5-to-1 air/fuel mixture you can force into your engine and ignite, the more power it will make. A turbo charger is essentially a double-sided pinwheel. The rapidly flowing exhaust gases spin the exhaust side (the hot side). This is connected via a turbine shaft to the compressor side (the cold side), which spins up in the range of tens of thousands of RPM. This action pressurizes the air intake charge -- thereby forcing more air into the engine. Now, if you've been following along this whole time, you should be asking yourself, "won't all this extra air cause the engine to run in a state of leaness?" That's correct! Specially designed fuel injection setups provide the extra fuel your engine needs.
this is a basic idea not saying you don't know this already spud but it's the general idea
Rising rate regulators are designed specifically to add fuel to modified EFI engines (turbo's, superchargers and normally aspirated). This is accomplished by using the manifold vac/pressure to drive the fuel pressure up as the boost rises, or with the N/A engines, as the vacuum goes toward atmospheric. The broad range of tuning capabilities by changing fuel pressure is unlimited! the rising rate fuel pressure regulator has been created for the purpose of increasing the fuel flow through electronic fuel injection systems when conditions of engine load demand more fuel. Unique to the rising rate regulator is that the pressure only increases when needed then returns to stock. This concept does not keep the fuel pressure up all the time. The concept of the rising rate regulator is particularly useful under these circumstances:
1. The factory turbo/supercharger car when the stock boost pressure is increased.
2. An aftermarket turbo/supercharger system applied to an EFI equipped car.
3. If you cannot afford the high costs of aftermarket engine management systems.
Prices $220.00 and up.
this is a basic idea not saying you don't know this already spud but it's the general idea
Rising rate regulators are designed specifically to add fuel to modified EFI engines (turbo's, superchargers and normally aspirated). This is accomplished by using the manifold vac/pressure to drive the fuel pressure up as the boost rises, or with the N/A engines, as the vacuum goes toward atmospheric. The broad range of tuning capabilities by changing fuel pressure is unlimited! the rising rate fuel pressure regulator has been created for the purpose of increasing the fuel flow through electronic fuel injection systems when conditions of engine load demand more fuel. Unique to the rising rate regulator is that the pressure only increases when needed then returns to stock. This concept does not keep the fuel pressure up all the time. The concept of the rising rate regulator is particularly useful under these circumstances:
1. The factory turbo/supercharger car when the stock boost pressure is increased.
2. An aftermarket turbo/supercharger system applied to an EFI equipped car.
3. If you cannot afford the high costs of aftermarket engine management systems.
Prices $220.00 and up.
Thread Starter
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Legend
Joined: Feb 2006
Posts: 9,284
Likes: 1
From: mendota, illinois
RE: fuel pressure regulator
there are so many of these regulators that i dont know what to choose.....there isnt anyone that i know in person to really give me any help, so i have to do all this on my own which is becomming very confusing...im almost redy to just sell all the turbo parts i alredy have and then just keep the car N/A.....i guess im just getting annoyed.....i want to get all this completely and positively figured out so that i dont go wasting anymore money...so i wanna get everything right the first time....
so here are a few more questions,
1: if i go aeromotive, which do i get??? i know then that it needs to be a rising rate and what not, but there are so many....does jegs have any that will work??? if not then does anyone know where to get one???
would it be like this one??? regulator
2: does the return line that goes back to the fuel pump start at the regulator????
3: do i just tap the regulator into the stock fuel line under the hood??? or do i run a different line????
4:what do i do about the stock regulator in the top of the stock intank fuel pump?????
i dont know anyone that has done the srt4-dohc install, nor have i ever messed with a turbo.....(alot of the srt forum guys were ignorant about this, so i figured i would ask it here instead)......
another thing that i am confused about is the 3 different vaccum line fittings on the turbo, not including the wategate...what do all these hook up to??? i know a vaccum source, but do i use the stock vaccum off the engine, or do they route around the turbo, or what???? i dont know where to even hook the boost gauge too, or where the wategate vaccum line goes too....
ugh[&:]
so here are a few more questions,
1: if i go aeromotive, which do i get??? i know then that it needs to be a rising rate and what not, but there are so many....does jegs have any that will work??? if not then does anyone know where to get one???
would it be like this one??? regulator
2: does the return line that goes back to the fuel pump start at the regulator????
3: do i just tap the regulator into the stock fuel line under the hood??? or do i run a different line????
4:what do i do about the stock regulator in the top of the stock intank fuel pump?????
i dont know anyone that has done the srt4-dohc install, nor have i ever messed with a turbo.....(alot of the srt forum guys were ignorant about this, so i figured i would ask it here instead)......
another thing that i am confused about is the 3 different vaccum line fittings on the turbo, not including the wategate...what do all these hook up to??? i know a vaccum source, but do i use the stock vaccum off the engine, or do they route around the turbo, or what???? i dont know where to even hook the boost gauge too, or where the wategate vaccum line goes too....
ugh[&:]
Thread Starter
|
Legend
Joined: Feb 2006
Posts: 9,284
Likes: 1
From: mendota, illinois
RE: fuel pressure regulator
yeah but i just wish sumone would tell me exactly what regulator to get....the rest i can figure out from the guy down the street...
i just wanna know what regulator....and preferably why a 1:1 and not a 6:1..wouldnt a 6:1 be better if i run higher boost in the future????
i just wanna know what regulator....and preferably why a 1:1 and not a 6:1..wouldnt a 6:1 be better if i run higher boost in the future????
Joined: May 2006
Posts: 36
Likes: 0
RE: fuel pressure regulator
regulator
the one that you have listed will work
you should get rid of the factory reg. fuel system would then run pump to reg. and then return line would run from reg. to tank. vac. line would then be connected to a boost source. there is probably a tap at the turbo for this or you could even add it somewhere in the I/C piping.
i'll post a simple vac diagram when i find the correct one
i would start at the factory fuel pressure setting then adjust from there.
remember with a 6 or 8 to 1 FMU you will be adding a lot of fuel at that ratio it's possible to supply too much pressure to the injectors depending where your idle pressure is set.
I never liked the vortech fmu's i always tossed them and ran a 1 to 1 and sized my injectors accordingly
the one that you have listed will work
you should get rid of the factory reg. fuel system would then run pump to reg. and then return line would run from reg. to tank. vac. line would then be connected to a boost source. there is probably a tap at the turbo for this or you could even add it somewhere in the I/C piping.
i'll post a simple vac diagram when i find the correct one
i would start at the factory fuel pressure setting then adjust from there.
remember with a 6 or 8 to 1 FMU you will be adding a lot of fuel at that ratio it's possible to supply too much pressure to the injectors depending where your idle pressure is set.
I never liked the vortech fmu's i always tossed them and ran a 1 to 1 and sized my injectors accordingly