# B12 GA16DE(T) queries



## BeyondBiscuits2 (Jan 18, 2006)

As some members here know, I have a 1990 Nissan Sentra B12 with a GA16DE engine that is on and off being turbocharged. Being a student and always finding less and less time to work on things and getting my designs up to specs, I thought it best to ask fellow members what they would do in my shoes with my parts lists. Here it goes:

Turbo setup:
-- GA16DE engine
a) 1999 cylinder head and crankcase (less than 35,000 miles)
b) 1995 manifolds, ECU, and engine wiring
c) no emissions (EGR valve, tubing)
d) stock fuel injectors (185cc or 195cc, not sure)
e) stock fuel rail (no fmu or adjustable fpr)
f) NGK G-power platinum spark plugs (gapped at .048)
-- Borg-Warner KKK K03 turbocharger
-- miscellaneous turbo piping (from SR20DET kit)
-- 3-inch exhaust pipe from turbo exiting to front of bumper
-- stock B12 GA16i fuel pump (not sure on flow rate)

Pictures:









First turbocharger... currently dead and disassembled for rebuild.









First turbocharger with custom adapter plate to attach to stock manifold.









First turbocharger with overview.









Standard K03 turbocharger, most likely brand new.









K03 turbocharger cut-away showing internals and all that fun stuff.









K03 turbocharger map... sorry for low quality it was all I could find.

I have pictures of the setup on my B12... but there are on my camera phone and I have no cable to hook it up to my computer. I am currently at university, and my turbo and setup are back home. Once I head home for Fall Break... I will hook everything up and take pictures them.

Results:

There is no sort of management on my turbo setup at the moment. I am using stock GA16DE fuel injectors and fuel pressure regulator, as well as the stock GA16i fuel pump that originally came with my B12. My friends and I have pieced together piping to connect the compressor outlet to my intake manifold, with a blow-off valve and boost gauge hooked up as well. We ran the wastegate pressure line off the piping rather than the compressor housing itself, mainly because the stock fitting was unavailable as well as a possible increase in the wastegate shut-off. I am also running NGK G-power platinum plugs gapped at .048 over the standard .045 since the car was initially running rich on 93 octane fuel, but has now leaned out.

At first pass, I was able to achieve 4 lbs of boost almost instantly with no turbo lag or spool time. This is no doubt due to the small size of the turbo itself. Boost is instant, the minute I open up the throttle it comes to life. This comes as quite a shock to anyone driving a normally-aspirated GA16DE that basically has no low-end power. The K03 turbo without a doubt solves that problem. In an eighth mile run, I was able to sustain 4 lbs through all gears attempted (up to 3rd gear) with no drop off or ill-effects. As a matter of fact, my Sentra kept asking for more, it seemed. Unfortunately... I can give no actual run time as the dragstrip had a malfunctioning timing system (it said I ran a 12:08, which is absurd since my single cam GA16i ran faster and it was the best pass my B12 had ever made!). Once, while out on the streets (yes I know... bad me) I was able to hit 5 lbs without trouble (around 5300-5400 rpms) and even to 7lbs (around 6000-6300 rpms) before I decided not to push it any harder. That was at full open throttle with full VTC on 93 octane fuel.

The question is... what do I need to do to get my car running anywhere from 5 - 7 lbs of boost without any ill side-effects?

List of parts available:
-- KA24DE fuel injectors (275cc)
-- KA24DE stock fuel pump (not sure on flow rate)
-- Apex'i S-AFC controller (old knob type)
-- Nissan T25 turbocharger (SR20DET, decent shape)
-- Mitsubishi 14b turbocharger (4G63T, bad bearings)

Obviously, fuel management is the biggest issue. What sort of setup should I run? I have access to a complete KA24DE fuel system, as well as a Vortech fmu (a Mustang friend has one he is willing to part with for a small fee). I also have the S-AFC I am planning on hooking up regardless... but will that give me enough control over the air-to-fuel mixture ratios to be effective? Or should I just give up on the K03... have a turbo manifold built and step up to a T25 or 14b? Your thoughts would be greatly appreciated.


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## BeyondBiscuits2 (Jan 18, 2006)

Here are the pictures of my new K03 turbocharger, right off the production line with no mileage. Cost me close to $200, but I think it will be worth it if I can pull some real boost from it. I know of owners of 1.8T Jettas and 1.8T A4s that have gone in excess of 15 lbs of boost using the stock K03 turbocharger through simple computer programming.


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## bestb12injersey (Sep 11, 2007)

this is my next step. i need to know more. how did you not get detonation? the engine cant hold to much i put a mazda turbo on my first engine and it blew. the new engine i have is a 94 trans is a95 200sx. what was the psi were you using? i put 8lb/psi. maybe you did something different. not trying to sound like an ass so dont take it that way


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## BeyondBiscuits2 (Jan 18, 2006)

No detonation... but I am only at 4 lbs of boost normally. It has spiked as high as 7 lbs before, but still no detonation. I have done nothing to the internals, and have the stock compression ratio of the GA16DE, no modification or thicker head gasket. Do you still have the GA16i fuel pump or the GA16DE fuel pump? I think the GA16i fuel pump pushes more fuel than the GA16DE due to a higher psi setting in TBFI vs. MPFI, so maybe my engine is just pushing a little more fuel than your's? I also have no coolant temperature sensor hooked up or wired in, so my engine thinks it is running below freezing and sprays more fuel accordingly. Maybe that might also be factor?

Once I get my setup down here to Chattanooga, I am going to hook up an adjustable fuel pressure regulator and see if I can up the boost to around 7 or 8 lbs standard. If that doesn't work, I will get an fmu or hook up the S-AFC I have sitting around. I also have a set of 275cc injectors from the KA24DE and a KA24DE fuel pump I can use if fuel is the limiting factor.


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## bestb12injersey (Sep 11, 2007)

BeyondBiscuits2 said:


> No detonation... but I am only at 4 lbs of boost normally. It has spiked as high as 7 lbs before, but still no detonation. I have done nothing to the internals, and have the stock compression ratio of the GA16DE, no modification or thicker head gasket. Do you still have the GA16i fuel pump or the GA16DE fuel pump? I think the GA16i fuel pump pushes more fuel than the GA16DE due to a higher psi setting in TBFI vs. MPFI, so maybe my engine is just pushing a little more fuel than your's? I also have no coolant temperature sensor hooked up or wired in, so my engine thinks it is running below freezing and sprays more fuel accordingly. Maybe that might also be factor?
> 
> Once I get my setup down here to Chattanooga, I am going to hook up an adjustable fuel pressure regulator and see if I can up the boost to around 7 or 8 lbs standard. If that doesn't work, I will get an fmu or hook up the S-AFC I have sitting around. I also have a set of 275cc injectors from the KA24DE and a KA24DE fuel pump I can use if fuel is the limiting factor.


i have the ga16i fuel pump. now i understand, im running the coolant sensor. does your car get hard to start in the cold? mine does and how can you tell if your car is over heating? dont you need a jwt computer to run different injectors and fuel pump? also you would need the mass air flow meter too? while your there mighta as well change the throttle body. im not saying im a genious im just curious to know more about turboing this type of engine.i did it once and i failed. now i need to learne more before i try to do it again. from your previous posts i see you know what your talking about.


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## bestb12injersey (Sep 11, 2007)

can ka24de injectors and fuel pump be used off the altima? or the 240?


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## BeyondBiscuits2 (Jan 18, 2006)

bestb12injersey said:


> i have the ga16i fuel pump. now i understand, im running the coolant sensor. does your car get hard to start in the cold? mine does and how can you tell if your car is over heating? dont you need a jwt computer to run different injectors and fuel pump? also you would need the mass air flow meter too? while your there mighta as well change the throttle body. im not saying im a genious im just curious to know more about turboing this type of engine.i did it once and i failed. now i need to learne more before i try to do it again. from your previous posts i see you know what your talking about.


My car is not difficult to start at all... it fires up basically first crank (unless it is really cold outside and it takes a little tap on the accelerator to get things moving). I really can't tell if my engine is overheating, but I have never had any problems in terms of that since I always check my coolant level regularly and have a good water pump and hoses.

In regards to running different injectors, you really don't have to have a different ECU to run them. Basically, your engine just needs to have enough fuel to spray them. Hence an adjustable fuel pressure regulator or S-AFC. As far as your ECU will know, they are just the stock injectors, but are spraying a lot more. In terms of the air flow meter, once you get a new one of those, you have to have the JWT ECU, and that is quite the amount of money to fork over at once. I would seriously consider getting a JWT tuned ECU or Megasquirt system if I was planning on running 10+ lbs of boost, but for under 10 lbs, I don't think it is a real necessity. My car is by no means a drag car, and I just like having a little extra "something" if some Honda decides it wants to pull on me.

At the moment, my B12 runs a slight bit lean with the K03 turbo, stock injectors, stock fuel pump, and 93 octane fuel. That reading is courtesy of my friend's wideband. If I hook up the 275cc injectors, my car will run incredibly rich without the fuel pressure tuned down or an S-AFC to manage the spray. I can also get a fuel pressure regulator or fmu that adjusts fuel pressure per pound of boost, which helps end the lean on your fuel. But, at the moment, my car gets incredibly fuel efficiency while running only the slightest bit lean. Hopefully, no detonation (I haven't heard or felt any so far), it runs as smooth as it did without the turbo.

In terms of which models of Altimas and 240SXs, it doesn't really matter. My engine is OBDII, but I have OBDI injectors from my friend's S13 240SX KA24DE. I also have the fuel pump from that. Since the ECU doesn't really do anything in terms of the injectors or fuel pump, I am pretty sure they'll work. After all, if you can slap DSM 4G63T top-mount injectors on a Subaru or Honda, I think they'll work. I am pretty sure both the OBDI and OBDII injectors on the GA16DE are the same injectors, with no changes whatsoever, but I could be wrong. We'll see if I ever put them on. In terms of choice of injectors, there should be no difference between the 240SX and Altima injectors. I suggest you get an Altima fuel pump, since they are cheaper and easier to get out of a junked car (if you take the scrapyard acquisition approach).


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## bestb12injersey (Sep 11, 2007)

BeyondBiscuits2 said:


> My car is not difficult to start at all... it fires up basically first crank (unless it is really cold outside and it takes a little tap on the accelerator to get things moving). I really can't tell if my engine is overheating, but I have never had any problems in terms of that since I always check my coolant level regularly and have a good water pump and hoses.
> 
> In regards to running different injectors, you really don't have to have a different ECU to run them. Basically, your engine just needs to have enough fuel to spray them. Hence an adjustable fuel pressure regulator or S-AFC. As far as your ECU will know, they are just the stock injectors, but are spraying a lot more. In terms of the air flow meter, once you get a new one of those, you have to have the JWT ECU, and that is quite the amount of money to fork over at once. I would seriously consider getting a JWT tuned ECU or Megasquirt system if I was planning on running 10+ lbs of boost, but for under 10 lbs, I don't think it is a real necessity. My car is by no means a drag car, and I just like having a little extra "something" if some Honda decides it wants to pull on me.
> 
> ...


so your saying i can put the injectors from an altima in with just an ajustable fuel pressure regulator and a fuel pump from an altima and i dont need an ecu? awsome! are the connectors the same on the injectors and fuel pump? do i have to use that fuel rail or the ga16de fuel rail?


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## BeyondBiscuits2 (Jan 18, 2006)

The KA24DE injectors use the same connector as the GA16DE injectors. As for the fuel pump, it should be the same as well. You will need a GA16DE fuel rail, though. Also, make sure you have either an fmu (which raises fuel pressure per pound of boost) or an adjustable fuel pressure regulator to have everything run smoothly. I would also suggest some form of fuel management system (A'pexi S-AFC or even a Megasquirt piggyback system) to ensure you don't overfuel your engine. I would highly suggest you run something like an S-AFC if you are going to use higher spray injectors on your GA16DE without any sort of ECU modification. If you don't, and even if you turn down the fuel pressure, your engine is still going to run rather rich, and that means horrendous fuel economy. A step up from 185cc or 195cc injectors to 275cc is a big jump, and I honestly don't know how the GA16DE will handle it, most likely not well without proper adjustment.

What I was trying to say about the injectors and the ECU is that the ECU simply tells the injectors when the spray, and according to the coolant temperature sensor and rpms, how much to spray. Theoretically, if you place KA24DE injectors in place of the GA16DE injectors without any adaptation to the programme, the injectors should spray at the proper time but at 275cc rather than the stock amount. Without some way to either tune down the spray or a big enough turbo to require that much fuel, you will have problems. I am not honestly sure an fmu will help you tune down spray, I think it works only to increase fuel pressure. That means it is most likely going to be of no help in a car with larger injectors as it is. An adjustable fuel pressure regulator should work by which you can tone down the fuel pressure so it doesn't spray as much. I think an S-AFC is the best bet, though, but you an experiment without one if you want too. You can get one on eBay for around $100 or so, give or take. It is probably just more advantageous to get one and not be sorry than try without one and end up ruining something.


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## bestb12injersey (Sep 11, 2007)

i think im going to go with the regulator and the apex'i setup. the cheapest i found one for $200 off a friend. does it matter that it belongs to an evo? i dont think so cuz he put it on his civic too. but tell me what you think. i saw your car on car domain. you dont have amber corners?you can paint them with a paint called vans lens paint. i did it and it looks awsome. and you could paint over theyellow part of the light it is the same color. i have an intercooler from a eagle talon that i might use when i put the turbo on. what intercooler did you run on yours?


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## BeyondBiscuits2 (Jan 18, 2006)

At the moment I am not using an intercooler, 4 lbs of boost is not worth it. Also, if I were to run those pounds through an intercooler, I would lose at least half of the boost by the time it reached the throttle-body. I would run either a side-mount DSM intercooler (you can get them dirt cheap) or an SR20DET side-mount (I have one I can sell you for cheap). They look to be the best fits, though have fun finding where to put them.


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## bestb12injersey (Sep 11, 2007)

check out my car at http://www.cardomain.com/ride/2931585


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