I've considered about every turbo on the market. I finally settled on the set of KO3s coors has based on price and being a close enough size to what I was looking for. I've gotta thank the guy, he's giving me a hell of a deal in the name of science.

 

Ok, so here's what I've come up with. I'll do larger 24lb injectors first and foremost. Then I'll replace the factory fuel pump with this one from Summit which says it's good up to 500 horsepower which is about 200 more than I'm going for and I'll tie it into this return style regulator using this which threads into the regulator (which also has a boost reference point which increases fueling on a 1:1 ratio). Then I'll tie the regulator right back into the factory fuel line using one of these.

So, how's this sound to everyone now?

 

dont change injectors. all youll accomplish with that is screwing up your fuel mapping for vacuum to ambient pressure. stock injectors will be fine up to 5psig. Itll be a minor miracle if you can get it reliable enough at 5psi so set the bar low before you go build blowzilla

Ive used that regulator before with the low pressure spring for a dual tbi vehicle. it had very inconsistent pressure and I thought it was a POS. maybe its more suited to the high pressure spring.

the return has to be before the pump, as long as you do that youll be fine.

I think this is a horrible idea, and fueling and turbo selection are just the tip of the iceberg. If you are committed to doing this and having any kind of reliability I predict at least a couple grand in parts.

you should probably read this front to back before buying anything. http://www.amazon.com/Modify-Management-Systems-Motorbooks-Workshop/dp/0760315825
Ive read a lot of efi and turbo books and that one is by far the best

 

I'm definitely setting the bar low. I don't have plans to ever go over 5 psi. I just figured some larger injectors would be a kind of "better safe than sorry" kind of deal, but you seem to know what you're talking about. That's what I'll have the wide-band O2s for anyway to make sure I'm not leaning out and to dial in the fuel pressure.

Good tip. I found this one which seems to have good reviews and is only a few dollars more.

I'm planning to dump the return directly into the tank. Is that a good plan or should I plan to return it into the actual fuel line before the pump?

I've been fully expecting a couple grand in parts. There's been a few people come by saying it's a bad idea, but I appreciate the help you're giving despite that.

I'll try to take some of my Christmas money and buy that unless I can find the PDF online by some miracle.

Thanks again, you're being very helpful.

 

I it only costs two thousand to make my Disco a biturbo I'm in NOW.

 

Plus the cost of turbos I'm afraid! Probably cost another $500-$1500 for those.

 

returning directly to the tank would be idea for cooling purposes, maybe a d1 pump will work. Never compared the 2 to know for sure.

For everything below boost you should be running stock fuel pressure and injectors. Your engine is basically stock at that point and the MAF, fuel injectors, and timing will be fine. It'll either get slightly worse fuel mileage or behave like you are at a lower sea level depending on your turbo specs.

You need the fuel pressure to rise only when under boost since the manifold pressure will be fighting the injectors and the factory ECM is not setup to handle this. Its kind of a rig doing it this way, but realistically you have to keep the stock ECM. The aftermarket stuff won't work with your transmission or gauges or possible emissions testing. You could throw money at those problems, but having something switch over to manifold pressure when under boost is probably the cleanest way to go. I don't know what devices are on the market for that, I'm sure jegs sells a bunch.

And keep in mind you have a rev limiter around 5200 RPM that you cannot change, so don't pick a top fuel dragster turbo, it'll never build pressure.

 

Good deal. I think I've got it figured out pump wise. I'm going to try to use that external pump that I posted along with the different regulator. I'm going to make a plate to go over the factory fuel pump hole with 5/16" fitting for both the return and the pump. I'll have to figure out the fuel pick up situation as well as the fuel gauge situation, but those shouldn't be too complicated since there are several universal aftermarket options for both.

I would guess it will act like I'm at a lower sea level because the KO3s are pretty small. I'm not really worried about worse fuel mileage anyway. I came to terms with the Discos fuel mileage long ago and I really don't care much any more.

Luckily emissions testing is not a worry. I wouldn't pass if it were as it is now. Cats are getting burned out and I'll be deleting them when I go through my exhaust soon. That said, stuck with the stock ECU for a while because it will be some time before I can do my transmission swap. Isn't that what the fuel regulator I posted does (the second one) since it has the boost/vacuum reference port

 

So I did the math again since I made some more major modifications to my plans. Looking at around $2,250. I'll bump that to around $2,750 to be safe and hopefully we'll land somewhere in the middle.

 

A D2 fuel pressure is referenced to atmospheric pressure so it always measures the same on a gauge. I think its 37, but check RAVE. You'll set your pressure regulator to whatever RAVE says and not touch it again.

A D1 is referenced to manifold pressure, so the gauge reading is something like 37 - engine vacuum. Engine vacuum is represented in a bunch of units, depending on who you talk to. I use negative psi(g). its unconventional, but it makes the math easy. So if a D1 is at -10psi (approx 30% engine load at sea level) the gauge will read 27. When the engine is off or at full throttle the vacuum is 0 so the gauge will read at 37.

So your D2 that is referenced to atmospheric pressure needs that vacuum/boost port open to the atmosphere.... until you hit boost and the manifold is now positive pressure and is limiting your fuel injectors. That is why you need some time of electrical device that has a pressure sensor (typically a MAP sensor off a boosted GM vehicle like a grand national) and a shuttle valve to change the port to vent to atmosphere or connect to the engine manifold. There may be a mechanical solution, I'm unaware of one. The electrical solution will have a controler that will filter out noise and control hysteresis so the valve will not bounce open and shut at 0 manifold pressure as it oscillates above and below boost. Read the books, they cover this.


I see you are looking at using headman headers for the basis of your manifold. Don't. They are junk and way too thin for a turbo. Get some 3/8" thick manifold flanges made, and use cast iron pipe chopped and welded to an off the shelf turbo flange. cast iron pipe welds easily with a MIG and this is what people normally use for low budget one off turbo builds. You will probably need to learn CAD and draw up the flange and have it either laser or waterjet cut. Plasma is too rough and you'll spend forever smoothing it. I've never seen a buick/rover 3/8" thick flange commercially available, but I've never looked so it may be out there.