DOB Install

[GallopingFord]

Thanks for letting us know about the injectors. I'm not sure yet if I want to buy the 55lbs or just get the 72lbs when I put on a TVS later in the Fall.

 

[BruceH]

Thanks for letting us know about the injectors. I'm not sure yet if I want to buy the 55lbs or just get the 72lbs when I put on a TVS later in the Fall.

Keep in mind that the GT500 injectors will flow more with a higher delta pressure. As long as you keep the fuel system returnless fuel pressure is adjusted in the tune and can be programmed to do it on the fly. This means that the psi can be 39.15 at lower loads and ramped up for higher.

I'm sure there is a reason people go with a return system but I can't figure it out.

 

[99horsey]

That's crazy about the price increase on the injectors. I went with the 2013+ 55 lb injectors on my DOB install because they were cheaper than the 2012- 47 lb injectors (I think I paid $178 shipped from Tasca). I wonder why they thought they needed to jack the price...

 

[Dubstep Shep]

I'm sure there is a reason people go with a return system but I can't figure it out.

It's far more consistent than a non return system.

It's much easier and more accurate to create and program a valve to maintain pressure than to create and program a pump to maintain pressure.

 

[2L8IWON]

Does DOB have a website? I'm interested but don't know how much the whole deal would cost and how much research is required to lay rick bottom?

 

[GallopingFord]

http://departmentofboost.com/

 

[BruceH]

It's far more consistent than a non return system.

It's much easier and more accurate to create and program a valve to maintain pressure than to create and program a pump to maintain pressure.

People just aren't having problems with returnless on this platform. The tune portion is fairly simple, I'm speaking from experience. I maintain commanded fuel pressure and lambda. I doubt that's the issue.

What's your experience been with a returnless that would make you go return? What's your definition of "far more consistent"?

This is from an old log. The FRP line is pretty stable at wot commanded psi of 58. It ramped up from 39.15. You can see the a/f is pretty stable too, doing as commanded.

 

[01yellerCobra]

Is that a high gear pull? I think the issue comes when shifting fast. When on the gas the pumps are at 100%. When lifting to shift the ECU senses this and tells the pumps to slow down. Then when you get back on it the ECU has to tell the pumps to spin back up. I know this all happens quickly, but when you start dealing with high horsepower and high boost it doesn't take long to go lean. At least in my experience. With the return system the fuel volume is always available. It's a lot quicker to close a vacuum operated valve then having pumps spin up to increase pressure.

This is just my opinion of course. I'm no expert.

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[Dubstep Shep]

I'm not saying a returnless system is inferior to a return system performance wise. I'm just saying that a return system is MUCH easier to design and tune for a given performance level vs a returnless. No calculations, no varying voltages, nothing.

There are certain performance advantages of a return system based on parallel vs series rails, pressure regulator before or after rails, etc. it's all about constant pressure above your manifold pressure in the fuel rails.

I actually designed a "returnless" hydraulic system for my capstone project. It's far more heavy duty than a fuel system, we were operating at 3000 psi and it was required to be within plus or minus 50psi. Returnless just wasn't cutting it. Using a solenoid relief valve and pulse wave modulation for the pump we couldn't get anywhere near what we needed. I switched the system to an adjustable relief valve and ran the pump full throttle all the time. A return setup. Our pressures are easily controlled and within 30psi of our set point. Far superior control with less programming, complexity, or otherwise. That's just my personal experience.

 

[jodadejss06gt]

So Bruce, in my experience with the twin 405's in a gt500 hat.....
The pumps are so large that at part throttle small changes in commanded voltage to the two pumps create a large variation of pressure. The variation in pressure tells the voltage to drop and then a dip in pressure. Its hard to get it worked out. My tuner made it better but it was still rough before I started the build. It would really take a lot of fine tuning to get these pumps to not create pressure spikes returnless. I'm going return just for drive ability since I don't think twin supercar in returnless would be enough to make the power i want on corn and the 405's are sucky and not meant for corn.

 

[BruceH]

Is that a high gear pull? I think the issue comes when shifting fast. When on the gas the pumps are at 100%. When lifting to shift the ECU senses this and tells the pumps to slow down. Then when you get back on it the ECU has to tell the pumps to spin back up. I know this all happens quickly, but when you start dealing with high horsepower and high boost it doesn't take long to go lean. At least in my experience. With the return system the fuel volume is always available. It's a lot quicker to close a vacuum operated valve then having pumps spin up to increase pressure.

This is just my opinion of course. I'm no expert.

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It's a second gear pull. Big bore motor, gasoline, stock intake manifold and tb.

I'm not saying a returnless system is inferior to a return system performance wise. I'm just saying that a return system is MUCH easier to design and tune for a given performance level vs a returnless. No calculations, no varying voltages, nothing.

There are certain performance advantages of a return system based on parallel vs series rails, pressure regulator before or after rails, etc. it's all about constant pressure above your manifold pressure in the fuel rails.

I actually designed a "returnless" hydraulic system for my capstone project. It's far more heavy duty than a fuel system, we were operating at 3000 psi and it was required to be within plus or minus 50psi. Returnless just wasn't cutting it. Using a solenoid relief valve and pulse wave modulation for the pump we couldn't get anywhere near what we needed. I switched the system to an adjustable relief valve and ran the pump full throttle all the time. A return setup. Our pressures are easily controlled and within 30psi of our set point. Far superior control with less programming, complexity, or otherwise. That's just my personal experience.

There must be a point in time when a return style becomes favorable over returnless otherwise people wouldn't do it. However, tuning for returnless is quite easy, at least it has been for my builds. I considered going return once and was quickly talked out of it. Pump life is less, fuel gets heated up, and there was no good reason to do it.

Returnless hydraulic? Not the same thing, especially with the psi involved. Plus all the hydraulic systems I've seen or used don't consume fluid so it has to be able to return it. Fuel gets consumed, imo that's what makes returnless possible. As I understand it returnless was designed to help with emissions, being able to add psi via software was just a bonus, lol.

 

[Dubstep Shep]

You'd be surprised how much fluid this hydraulic system used lol. The setup was designed to test dynamic sealing elements on down hole applications. Suckers use a lot of fluid.

 

[JoshK]

So Bruce, in my experience with the twin 405's in a gt500 hat.....
The pumps are so large that at part throttle small changes in commanded voltage to the two pumps create a large variation of pressure. The variation in pressure tells the voltage to drop and then a dip in pressure. Its hard to get it worked out. My tuner made it better but it was still rough before I started the build. It would really take a lot of fine tuning to get these pumps to not create pressure spikes returnless. I'm going return just for drive ability since I don't think twin supercar in returnless would be enough to make the power i want on corn and the 405's are sucky and not meant for corn.

How much power are you looking to make? I have GT500 pumps

 

[01yellerCobra]

There must be a point in time when a return style becomes favorable over returnless otherwise people wouldn't do it. However, tuning for returnless is quite easy, at least it has been for my builds. I considered going return once and was quickly talked out of it. Pump life is less, fuel gets heated up, and there was no good reason to do it.

I'm not sure I'd agree on the pump life going down. Just consider the stock applications that go well over 100k. I'm sure it's a little different with big aftermarket pumps, but not something I've heard about. Most guys I know with aftermarket set ups aren't having issues yet.

I haven't had much issue tuning my returnless system up until I put the F1A on. For me the switch to return is more for convenience. I'm tired of having to upgrade so I'm going big one last time and I'll be done for good. Or so I tell my wife.



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[jodadejss06gt]

Josh, more than you if i can!

I just shot the moon when I got this setup from the guy that had the homebuilt twin turbo setup from like NYC, badhorse or something. I just think its too much pump for returnless and being a street driven car. Anyone else that is capable of tuning is more than welcome to grab the whole fuel hat, fpdm, setup from me when I pick it up from the builder.

I just hope there isn't too much heat going back into my tank. With the setup I'm running it shouldn't be bad. Its one E-85 AEM 320 running constant and then the walbro 465 activated on boost.

 

[isthatguy]

nice! I just finished mine up, have a few odds and ends to tinker with before tune.

 

[BruceH]

It looks like you didn't trim the ears off of the alternator. I've been hoping that is just a cosmetic step because my alternator is a parts store replacement with a lifetime warranty. I purchased it over a stock one for the lifetime warranty and I'm sure that grinding on it wouldn't be good if it had to go back.

nice! I just finished mine up, have a few odds and ends to tinker with before tune.

 

[Dubstep Shep]

It looks like you didn't trim the ears off of the alternator. I've been hoping that is just a cosmetic step because my alternator is a parts store replacement with a lifetime warranty. I purchased it over a stock one for the lifetime warranty and I'm sure that grinding on it wouldn't be good if it had to go back.

What brand alternator is it?

If it's one that my old company sold (51% of the Orielley's, autozone, and advance market) then it doesn't matter why it broke, they take it back.

 

[99horsey]

Unfortunately grinding the ears off is not a cosmetic step. He did grind them off because they would be at 12:00 and 6:00 if they were left on. Even with the ears ground down as close as possible, there is not a whole lot of clearance between the alternator and the hood.

 

[Dubstep Shep]

You can always buy a Roush alternator. They come without those two tabs