Turbo Newbie, fuel system ?'s
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SX APPEAL
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95 Maxima SE 5MT - Location: Springfield, MO
Turbo Newbie, fuel system ?'s
Im still new to this whole turbo thing. I've know basically how they work and what the componants are and stuff. But really dont know that much about how they're installed and the tuning required to make them work efficiently. I tried the search but I just cant find the exact info Im looking for. Basically, within the next year or so, if funds allow, I want to turbo my 91 S13 fastback. I dont need a lot of power, 200-250 rwhp would be plenty. My problem is what kit to get and what I need to modify, Ive been looking at that Boost Designs kit mainly. Some kits I look at have bigger injectors and fuel pumps, others dont. Some have the greddy Emanage or similar, others have like a 12:1 FMU or something like that. I know basically what those are but i dont know how they work or how they hook up. So basically my questions amount to: what do I need to make 250 streetable whp and how does all the fuel management crap work? If I missed something in my search please point me in the right direction. Or feel free to just answer, lol.
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nizmo240sx_22
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Re: Turbo Newbie, fuel system ?'s (SX APPEAL)
This kit is your best bet considering it is the best bang for the buckQuote »Some kits I look at have bigger injectors and fuel pumps, others dont. Some have the greddy Emanage or similar, others have like a 12:1 FMU or something like that. I know basically what those are but i dont know how they work or how they hook up.[/quote]An upgraded fuel pump is highly recommended for that power and is considered a must. A FMU adjusts the fuel pressure to increase for each psi you're boosting. These aren't considered the safest but they're cheap. You can also use the stock fuel injectors to 250 hp with this however a FMU is prone to reducing the life of the injectors. As for bigger injectors and an AFC, when you get bigger injectors you will need to modify the fuel map to tune for good a/f ratios. 370cc Injectors will be fine for 250 hp as well as the stock MAFS.Quote » So basically my questions amount to: what do I need to make 250 streetable whp and how does all the fuel management crap work? If I missed something in my search please point me in the right direction. Or feel free to just answer, lol.[/quote]I'd search for FMU for a detailed explanation on how they work. For the power you are looking for you could get away with either a FMU or an AFC and 370cc injectors.SX APPEAL wrote:Im still new to this whole turbo thing. I've know basically how they work and what the componants are and stuff. But really dont know that much about how they're installed and the tuning required to make them work efficiently. I tried the search but I just cant find the exact info Im looking for. Basically, within the next year or so, if funds allow, I want to turbo my 91 S13 fastback. I dont need a lot of power, 200-250 rwhp would be plenty. My problem is what kit to get and what I need to modify, Ive been looking at that Boost Designs kit mainly.
Fuel Pump: This will increase the rate at which fuel can be fed from your tank to the engine. Since you will be needing more fuel per rotation in your engine (due to the increased amount of air from the turbo), you will be taking fuel from the tank faster. The stock pump cant flow fast enough to handle the demands of even lower boost setups. The pump hooks up directly inside the fuel tank on the 240sx, and connects to a line that feeds fuel forward to the engine.
FMU: In order to spray more fuel through the injectors, it is often easier to increase fuel pressure rather then (or in combination with) larger injectors. This will replace the factory fuel pressure regulator that is located at the end of the fuel rail, between the fuel feed line from the fuel filter and the fuel rail, which the injectors connect into. If you increase the pressure in the line, when the injectors open to their normal squirting size, more fuel will come out. Makes sense, eh? The way they work is through a special mechanism involving a valve that is regulated through vaccum pressures. You dont really need to know exactly HOW it works, only why: but you can definetly find that information elsewhere on the net.
Injectors do the same thing more or less: supply extra fuel through larger nozzles (usually listed by cc of fuel they spray in one minute when wide open: stock is just about 250cc (or 25# [25 pounds]). These connect to the fuel rail on one side, and to the intake manifold on the other side, to spray into the cyls.
The Emanage and other fuel managment devices are designed to alter the (or provide a new) signal that is usually sent from the ECU to the injectors and/or timing components. Say the ECU normally requires a certain amount of fuel for a given RPM and load condition. The piggyback or whatever will change that value: adding fuel based on a new "map," a modified list of how much fuel is needed when. Generally this extra fuel is added by increasing the "pulsewidth" of the injectors: basically how long they spray. (note that there is a limited window of oppertunity for an injector to spray: the piston must be in a particular position in a particular stroke: this is why larger injectors are sometimes necessary, because a smaller injector simply cant supply enough fuel through it's small nozzle in the time that it has to spray). Different systems achieve this differently- the E-manage does this by modifying the voltage put out by the mass air flow meter which is then sent to the factory ECU. It's fairly complicated (a reason why some people pefer to avoid the emanage), but it works pretty well. Other systems work differently, each in their own way. (some of these systems control engine timing as well, but I wont get into that here)
250 hp is generally reached around 7-9 psi on the KA24 with stock compression. You can do this with the FMU or lots of different piggyback options. At this level you are JUST on the edge of maxing out the stock injectors, so it really depends on how much you are willing to spend pretty much. There is a lot of argument as far as what you really need and what you dont: what works better and what works not so well. I suggest you look at other people's setups to see what has been tried and proven effective: there is a list of member's KA-T cars in a stickey at the top of this forum.
Ahh ok enough typing. I hope this helps at least a little bit: if you have any more specific questions go ahead and ask (just at least TRY a search first!). There are lots of experienced people here ready and willing to help!
FMU: In order to spray more fuel through the injectors, it is often easier to increase fuel pressure rather then (or in combination with) larger injectors. This will replace the factory fuel pressure regulator that is located at the end of the fuel rail, between the fuel feed line from the fuel filter and the fuel rail, which the injectors connect into. If you increase the pressure in the line, when the injectors open to their normal squirting size, more fuel will come out. Makes sense, eh? The way they work is through a special mechanism involving a valve that is regulated through vaccum pressures. You dont really need to know exactly HOW it works, only why: but you can definetly find that information elsewhere on the net.
Injectors do the same thing more or less: supply extra fuel through larger nozzles (usually listed by cc of fuel they spray in one minute when wide open: stock is just about 250cc (or 25# [25 pounds]). These connect to the fuel rail on one side, and to the intake manifold on the other side, to spray into the cyls.
The Emanage and other fuel managment devices are designed to alter the (or provide a new) signal that is usually sent from the ECU to the injectors and/or timing components. Say the ECU normally requires a certain amount of fuel for a given RPM and load condition. The piggyback or whatever will change that value: adding fuel based on a new "map," a modified list of how much fuel is needed when. Generally this extra fuel is added by increasing the "pulsewidth" of the injectors: basically how long they spray. (note that there is a limited window of oppertunity for an injector to spray: the piston must be in a particular position in a particular stroke: this is why larger injectors are sometimes necessary, because a smaller injector simply cant supply enough fuel through it's small nozzle in the time that it has to spray). Different systems achieve this differently- the E-manage does this by modifying the voltage put out by the mass air flow meter which is then sent to the factory ECU. It's fairly complicated (a reason why some people pefer to avoid the emanage), but it works pretty well. Other systems work differently, each in their own way. (some of these systems control engine timing as well, but I wont get into that here)
250 hp is generally reached around 7-9 psi on the KA24 with stock compression. You can do this with the FMU or lots of different piggyback options. At this level you are JUST on the edge of maxing out the stock injectors, so it really depends on how much you are willing to spend pretty much. There is a lot of argument as far as what you really need and what you dont: what works better and what works not so well. I suggest you look at other people's setups to see what has been tried and proven effective: there is a list of member's KA-T cars in a stickey at the top of this forum.
Ahh ok enough typing. I hope this helps at least a little bit: if you have any more specific questions go ahead and ask (just at least TRY a search first!). There are lots of experienced people here ready and willing to help!
buy a kit that has a very good review on this site ..install it, or get a shop to do it if you have any bad thoughts cheaper to pay them then to pay them to rebuild the engine after you blow it then reinstall kit, a good kit "should" have everything in it to just bolt on and go ... you should be able to get 250 rwhp with a good kit.. but remember this site has a lot of very smart people that know what they are talking about so ask questions about everything, after searching, just look at fiznat post
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IvanAtSPRacing
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Re: Turbo Newbie, fuel system ?'s (SX APPEAL)
Here is my stand on fuel systems and timing control.
fuel pump, upgraded injectors and SAFC + replacing blown motor = more then stand alone engine management system.
Fuel pump and FMU + replacing blown motor = more then stand alone engine management system.
Fuel pump, upgraded injectors and Emanage + replacing blown motor = more then stand alone engine management system.
I am not saying that any of these systems are NOT going to work for 250 whp, but I am saying that all the inexpensive choices come with risks. As long as your willing to accept those risks, then its a good choice for you. I would buy the best system that you can afford. I dont like to do things half assed so I went all out with the kit I developed for the KA and used AEM EMS. We have had NO TUNING ISSUES what so ever. Exelent cold start, no stalling, great gas milage, etc. This car makes more HP at low boost levels then ANY other KA-T I know of. 305 whp @ 10 psi 115k mile stock KA. 404 whp @ 16psi same motor. This system isnt cheap, expect to pay about 2500 for EMS, MAP, IAT, UEGO, FP, FR, FPR, injectors, lines, fittings, and wiring. Add in tuning for about 400 bux and now your pushing the price of a used 89 240sx
The same thing goes for your turbo kit.
Cheap kit + boost creep + blown motor = more then expensive kit that doesnt creep.
Ask around for people that have melted motors down due to boost creep. Ask about how many manifolds have cracked.
Here are some good old sayings that are true about everything.
"You get what you pay for". There is a reason why some kits are really inexpensive.
"When you want something really bad, thats what you usually get... Something REALLY BAD"
Use your best judgment.
fuel pump, upgraded injectors and SAFC + replacing blown motor = more then stand alone engine management system.
Fuel pump and FMU + replacing blown motor = more then stand alone engine management system.
Fuel pump, upgraded injectors and Emanage + replacing blown motor = more then stand alone engine management system.
I am not saying that any of these systems are NOT going to work for 250 whp, but I am saying that all the inexpensive choices come with risks. As long as your willing to accept those risks, then its a good choice for you. I would buy the best system that you can afford. I dont like to do things half assed so I went all out with the kit I developed for the KA and used AEM EMS. We have had NO TUNING ISSUES what so ever. Exelent cold start, no stalling, great gas milage, etc. This car makes more HP at low boost levels then ANY other KA-T I know of. 305 whp @ 10 psi 115k mile stock KA. 404 whp @ 16psi same motor. This system isnt cheap, expect to pay about 2500 for EMS, MAP, IAT, UEGO, FP, FR, FPR, injectors, lines, fittings, and wiring. Add in tuning for about 400 bux and now your pushing the price of a used 89 240sx
The same thing goes for your turbo kit.
Cheap kit + boost creep + blown motor = more then expensive kit that doesnt creep.
Ask around for people that have melted motors down due to boost creep. Ask about how many manifolds have cracked.
Here are some good old sayings that are true about everything.
"You get what you pay for". There is a reason why some kits are really inexpensive.
"When you want something really bad, thats what you usually get... Something REALLY BAD"
Use your best judgment.
lol Ivan, you and your crazy AEM EMS...
Sorry I havnt called ya yet: I'll be settling up with you tomorrow, promise.
As far as getting a $2000 standalone for a 250 hp application I think I'm gonna dissagree with Ivan on this one. Sure, boost creep is sometimes a problem with cheaper systems, and slip ups with fuel delivery or timing do happen, although they arent common. Simply put, you HAVE to be aware of what is happening with your engine, regardless of how much money you pour into controlling it. If you see your air fuel ratios going out of wack (you should have a wideband no matter what you do), you STOP. If you see your boost slowly climbing above what you wanted, you STOP. If you see EGTs suddenly raising above normal levels, you STOP. Nothing excuses anyone from this duty: from having to pay attention to what is going on all the time-- even a standalone.
It is easy to get scared about what might happen to your engine and try to remedy the problem by throwing money at it. Ivan is definetly right: more expensive systems WILL get you better power/gas mileage/peace of mind-- but there are also incredible things you can achive with simple knowledge and awareness as well. Dont think that just because something is cheaper its not going to work, or because something is more expensive it will be flawless: they're both not true. Learn about your engine, understand the potential problems, and then make a decision about how much you want to spend.
That said, I'm going with the AEM EMS (from Ivan at Sound Peformance, no less!) because I have thought about all the things above and I really want the best I can afford, and I feel the need to be able to tinker with the thing to no end. The EMS lets me do that. It all comes down to a balance between what you want and what you can pay for-- the answer is usually pretty much forced on you.
Anyways man good luck!
Sorry I havnt called ya yet: I'll be settling up with you tomorrow, promise.
As far as getting a $2000 standalone for a 250 hp application I think I'm gonna dissagree with Ivan on this one. Sure, boost creep is sometimes a problem with cheaper systems, and slip ups with fuel delivery or timing do happen, although they arent common. Simply put, you HAVE to be aware of what is happening with your engine, regardless of how much money you pour into controlling it. If you see your air fuel ratios going out of wack (you should have a wideband no matter what you do), you STOP. If you see your boost slowly climbing above what you wanted, you STOP. If you see EGTs suddenly raising above normal levels, you STOP. Nothing excuses anyone from this duty: from having to pay attention to what is going on all the time-- even a standalone.
It is easy to get scared about what might happen to your engine and try to remedy the problem by throwing money at it. Ivan is definetly right: more expensive systems WILL get you better power/gas mileage/peace of mind-- but there are also incredible things you can achive with simple knowledge and awareness as well. Dont think that just because something is cheaper its not going to work, or because something is more expensive it will be flawless: they're both not true. Learn about your engine, understand the potential problems, and then make a decision about how much you want to spend.
That said, I'm going with the AEM EMS (from Ivan at Sound Peformance, no less!) because I have thought about all the things above and I really want the best I can afford, and I feel the need to be able to tinker with the thing to no end. The EMS lets me do that. It all comes down to a balance between what you want and what you can pay for-- the answer is usually pretty much forced on you.
Anyways man good luck!
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nizmo240sx_22
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Re: Turbo Newbie, fuel system ?'s (IvanAtSPRacing)
Just wondering, what kind of gas mileage did you see? hard driving?Quote » Add in tuning for about 400 bux and now your pushing the price of a used 89 240sx [/quote]How much do you charge to tune the aem? I have the jwt ecu and was planning on getting a piggyback to lean out the mixture a tad but was thinking the same things. JWT ECU+ AFC + Wideband = standaloneIvanAtSPRacing wrote: Exelent cold start, no stalling, great gas milage, etc.
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SX APPEAL
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95 Maxima SE 5MT - Location: Springfield, MO
Re: Turbo Newbie, fuel system ?'s (nizmo240sx_22)
Wow, thanks for all the gret information. This really helps my understanding of how a lot of the more complicated componants work. Basically before reading this I knew just: exhaust spins tubine half of turbo or goes out waste gate, waste gate is controled somehow... then exits through the exhaust system. turbine spins shaft which drives compressor half which takes in air and forces it through intercooler and into intake. And somewhere along the line the amount of fuel is calculated and pumped in through the injectors. That was my understanding of a tubo system beofre, this thread is helping me with a lot of the details.
Heres another thing I searched about yesterday and couldnt find a conclusive answer to, although there were a lot threads and I didnt have time to read them all. How does an electronic boost controller work as opposed to a manual one. I know that they both control the wastegate to change the amount of boost pressure that goes to the engine, but beyond that I dont really know much.
If there was a good thread on this that I just missed please point me in the right direction, thanks. this thread is great
Heres another thing I searched about yesterday and couldnt find a conclusive answer to, although there were a lot threads and I didnt have time to read them all. How does an electronic boost controller work as opposed to a manual one. I know that they both control the wastegate to change the amount of boost pressure that goes to the engine, but beyond that I dont really know much.
If there was a good thread on this that I just missed please point me in the right direction, thanks. this thread is great
Re: Turbo Newbie, fuel system ?'s (nizmo240sx_22)
With an ideal tune, off boost fuel economy should be at least (if not better) than stock. Hard driving is another matter though-- maybe Ivan can give you better numbers but I wouldnt expect much more than like 15mpg when you're really getting into it.nizmo240sx_22 wrote:Just wondering, what kind of gas mileage did you see? hard driving?
I asked Ivan this last week and I BELEIVE he said $150 an hour (correct me if I'm wrong Ivan). Dyno tuning on a car that is ready to go (meaning no other problems) usually takes an hour or so, maybe 2 I suppose.nizmo240sx_22 wrote:How much do you charge to tune the aem? I have the jwt ecu and was planning on getting a piggyback to lean out the mixture a tad but was thinking the same things. JWT ECU+ AFC + Wideband = standalone
Ivan may not be responding to your questions about prices because his company isnt a sponsor of NICO-- the admins here have some rules limiting how much he can promote his services and products I beleive, so dont take offense that he hasnt responded. If you're really curious you should probably call him-- the website with his phone number is in his signature.
Re: Turbo Newbie, fuel system ?'s (SX APPEAL)
Wastegates work by basically opening up a valve in the exhaust manifold, letting exhaust gas out that would otherwise be routed into the turbo to spin the turbine. When gas isnt spinning the turbine, the boost produced by the turbo is limited.SX APPEAL wrote:How does an electronic boost controller work as opposed to a manual one. I know that they both control the wastegate to change the amount of boost pressure that goes to the engine, but beyond that I dont really know much.
Boost controllers define when a wastegate will open by modifying a vaccum line that is attached to the wastegate itself. I'm not sure of the exact mechanism here, but basically a regular vaccum line (from say the intake manifold or someplace like that) goes into the boost controller, then into the wastegate from there. A manual boost controller modifies that vaccum pressure through a simple mechanical valve-- an electrical boost controller does the same thing except it isnt operated by hand turning a valve, rather through a circut that opens and closes the valve based on preset values.
Like I said, call Ivan to confirm cause this is just from memory: but first of all the SDS uses a MUCH more primative interface- that silly punch screen thing really doesnt even come close to comparing the graphical displays/options/ease that the EMS software offers. On top of that, Ivan (as well as the whole EMS community on the AEM forums) has available to him base maps for turbo KAs that have been tried and tested true. These things make the tuning process much easier (and quicker).
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IvanAtSPRacing
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Re: (fiznat)
Sorry for the delay.
Gas milage is close to 30mpg when driving it normally (not making boost) and drops down into the high teens when beasting on it.
As far as dyno tuning. AEM EMS has datalogging that is second to none. This makes tuning much easier and quicker then a normal stand alone. With easy to reference maps that can be viewed as two dimensional tables (numbers) or three dimensional graphs that alllow you to see peaks and valleys in your timing / fueling maps. Closed loop WB O2 feed back operation. Boost compensation allows you to tune the VE of the motor and then add fuel lineraly with boost. Closed loop knock control. etc, etc etc.................. Its really amazing.
We charge anywhere from $170/hr to $250/hr to tune on our dyno. Our MD 1750 with steady state loading, twin PAUs, simulated inertia, etc makes tuning much easier then with a Dyno Jet. If you setup is simular to our R&D car, then we would just load up our base map and get your car tuned in no time.
Gas milage is close to 30mpg when driving it normally (not making boost) and drops down into the high teens when beasting on it.
As far as dyno tuning. AEM EMS has datalogging that is second to none. This makes tuning much easier and quicker then a normal stand alone. With easy to reference maps that can be viewed as two dimensional tables (numbers) or three dimensional graphs that alllow you to see peaks and valleys in your timing / fueling maps. Closed loop WB O2 feed back operation. Boost compensation allows you to tune the VE of the motor and then add fuel lineraly with boost. Closed loop knock control. etc, etc etc.................. Its really amazing.
We charge anywhere from $170/hr to $250/hr to tune on our dyno. Our MD 1750 with steady state loading, twin PAUs, simulated inertia, etc makes tuning much easier then with a Dyno Jet. If you setup is simular to our R&D car, then we would just load up our base map and get your car tuned in no time.