Guest Jason Posted February 17, 2004 Share Posted February 17, 2004 I've heard of people handling fuel enrichment by adding an EIC and extra injector(s) before the throttle body -perhaps on a charge pipe. How successful is this arrangement? Since air is always flowing quickly through the charge pipe while the engine is under boost, wouldn't the extra injector cause an uneaven fuel mixture? I could see this happening especially at low duty cycles. -Jason Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted February 18, 2004 Share Posted February 18, 2004 Perusing prior posts by some of the turbo guys with stock ECU system, they'r rich to ~4500 RPM and then go lean. If you REALLY want more power and boost, you need to upgrade the Fuel management computer. At the least the 300ZX unit next step would be the JWT 440cc/Ford Mass AIR system. My money will be on either MegaSquirt or UltraMegaSquirt or SDS - preferably the UMS. (I like to do it myself) Quote Link to comment Share on other sites More sharing options...
Guest Jason Posted February 18, 2004 Share Posted February 18, 2004 I was thinking of using Megasquirt to drive extra injectors under boost. It would be a simple install compared to a full Megasquirt operation because you'd only need tach, pressure, and air temp inputs. If you're not under boost, the stock computer would handle everything. I just wonder how effective extra injectors would be if they were installed in a charge pipe instead of the intake runner. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 18, 2004 Share Posted February 18, 2004 EIC is a viable option for extra fuel. As Brad said, stock EFI will run pretty rich on boost, from about 2500 to 4500 rpm, more than rich enough to support any boost the stock T3 can throw at it, for sure, and probably more than that. With a stock T3 at 10psi I was running about 10:1 air/fuel ratio until 4000rpm which is super rich. But they start to lean out past 5000rpm. So you would only need the EIC to start supplying fuel past that point. Not sure how much EIC's cost but I'm sure it'd be less money and easier to install and setup than going full programmable. Guys stop being so one-track-minded. Sure standalones are definately the best way to go but some people just want a little extra tune-ability or performance on a budget and w/o having to install a whole new system. Alternately, depending on how much boost you want to run you can easily get the extra fuel you need by installing either an adjustable fuel pressure regulator and upping the pressure, or larger injectors. Either one will cause you to richen the mixture thru the whole rev range, which many people have had no problems tuning out the low and mid range richness by simply adjusting the stock factory air flow meter. However, since adjusting the afm seems to only affect fuel mixture up to 4000rpm the extra fuel or fuel pressure will still supply enough fuel where you need at the top end. JerseyZ from these boards is one really good example... bone stock EFI on his turbo motor, running 370cc injectors, tightened up the AFM spring a bit, and his car runs great and runs low 13's all day long with a best of like a 12.8. And you can do this for much less than either an EIC or standalone. Guys really should spend more time seeing what CAN be done with stock stuff before just moving on to more expensive, complicated alternatives Quote Link to comment Share on other sites More sharing options...
Guest Phil1934 Posted February 18, 2004 Share Posted February 18, 2004 Cheapest supplemental ECU I've seen is aquamist MF2 at $300. Quote Link to comment Share on other sites More sharing options...
Clifton Posted February 18, 2004 Share Posted February 18, 2004 I use this on my truck and did use it on my Z before the full SDS. SDS makes an affordable one. I picked up an HKS AIC on Ebay for cheap. Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted February 19, 2004 Share Posted February 19, 2004 If he was gonna do the MS to control extra injectors - which will have distribution problems, he might as well use it to replace the ECU and upgrade his injectors. Quote Link to comment Share on other sites More sharing options...
Afshin Posted February 19, 2004 Share Posted February 19, 2004 In general EIC does work and has been used succesfully in many turbo application and aftermarket kits (specially in the 80's). I think having it before the throttle body in high velocity conditions should improve the atomization of the fuel. However, this will also increase the chance for the fuel to deposit on the intake sooner causing droplets.. I guess this is pretty much like a carburator/single port EFI set up. Considering the amount of aftermarket fuel systems, from stand alones to cheaper piggy back systems (which cost about the same a a EIC system) it makes more sense to me to get the piggy back system and use larger injectors to provide more even and accurate fuel delivery). Also, the piggy back system will allow fine tunning of the fuel delivery thru out the power band. Jason, do you have a specific application in mind, l28et, V8 turbo.. ? Quote Link to comment Share on other sites More sharing options...
Guest Jason Posted February 19, 2004 Share Posted February 19, 2004 Actually, I want to turbo my daily driver: a Quad 4 powered Olds Achieva SCX. My car has 182k miles now, leaks oil, and will need a new clutch soon. My LT1 ZX should be on the road by spring, allowing me a new project. Ive been inspired by those Quad 4 pictures in "Maximum Boost" and some impressive results by other boosted Quad 4's. My current thought is to plumb each runner with an additional injector powered by Megasquirt so I won't have distribution problems from injecting before the throttle body. I can't get rid of the stock computer completely because I need it to handle ignition timing and air conditioning. I'll need to get something to retard timing under boost like a MSD programmable DIS-2. By piggyback, do you mean something like the SAFC? I like that idea, but I think they'll only modify the air signal +/- 50%, and I have doubts about idle quality once you've modified the signal by that much. You might be off the stock fuel map, and compensation for injector opening times would be off. It would also be less expensive to buy another fuel rail + injectors from a junkyard, than get some 40#ers (I believe stock Q4 is 28lbs). -Jason Quote Link to comment Share on other sites More sharing options...
mobythevan Posted February 19, 2004 Share Posted February 19, 2004 just to make sure you know, the megasquirt can do the ignition and will give you the functionality of the boost timing retard module. So now you are only keeping the stock ECU to run AC. What exactly does it control for the AC system. Maybe that can be handled by MS or something simpler. If that is the only reason to keep the stock ECU we may be able to come up with a better solution for you. From the outside I don't see why you can't use MS for fuel and ignition and something else for AC control. MS has a couple programmble outputs so maybe it can do the AC control you need. Let me know some more specifics. Quote Link to comment Share on other sites More sharing options...
Guest Jason Posted February 20, 2004 Share Posted February 20, 2004 I'm sure I could get the AC running without the computer. I believe the computer just checks a pressure sensor to stop the compressor from running if the pressure is too high or low. I don't really want to buy a boost retard module, especially since it'll cost as much as another running Quad. I don't think there's a easier choice however. My Quad has a distributorless ignition. Megaspark has some addon that will run a Ford DIS, but not the GM system. I'd have to change over to Ford parts. To determine when to fire, I believe my system uses a tooth wheel on the cam with variable gap spacing, while Ford has a balancer mounted wheel with 36 equal spaces. I'm sure Megasquirt could be taylored to run my DIS, but I don't have the electronics backround or equipment to figure that out. I'll look into switching over to the Ford system, but to me, it seems easier to keep the stock system and run Megasquirt as an EIC for boost. Other than the work of adding extra injectors to the intake runners, I can't see any downside. Using Megasquirt as an EIC will require less rewiring, and will cost less since I can get junkyard injectors cheaply. The stock computer already handles ignition and fuel nicely, so I'd only have to tune the system for boost. Quote Link to comment Share on other sites More sharing options...
Clifton Posted February 20, 2004 Share Posted February 20, 2004 I don't think an SAFC will work as your EFI is design for N/A and while it may notice some increased airflow it won't be able to account for it all. This is assuming it uses a hot wire sensor, if it's map then it's 1 bar and it won't pick up 1 psi. If you don't plan on much boost you could get by with out the MSD dis as they are pricey. Just retard a few degrees off the base at first to see if you can get by like that. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted February 20, 2004 Share Posted February 20, 2004 What year quad 4 is that? I believe the ecu can be reprogrammed to work with boost quite easily. You should visit diy-ef.orgi and check into that. Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 20, 2004 Share Posted February 20, 2004 The only thing the ECCS does in relation to the A/C is to increase the idle speed via the AAC so the engine doesn't stall when the clutch on the compressor engages. You don't need to control this through the Megasquirt, all you need is a solenoid, and bypass bleed circuit with a needle valve hooked in parallell withthe compressor clutch power wire. Why do I know this? Because my 74 260Z is having the compressor installed tomorrow afternoon, and that's how I'm controlling it! Basically all you need is a variable circuit so you can fine tune the speed when the compressor is loaded up. Once you have it set, barring dirt contamination you should be good. You could also simply grab the vacuum pulloff from a 280Z, and hook an old EGR solenoid in the clutch circuit, for an old-school vacuum pulloff opening the throttle incrementally while it's engaged. No need to involve the ECu at all for the A/C! Quote Link to comment Share on other sites More sharing options...
mobythevan Posted February 20, 2004 Share Posted February 20, 2004 My Quad has a distributorless ignition. yep, forgot about that one. Like you say the MS really only supports ford EDIS easily. Well, it was worth the thought. Quote Link to comment Share on other sites More sharing options...
Afshin Posted February 26, 2004 Share Posted February 26, 2004 3 popular piggy back main air-fuel controllers are the Apexi S-AFC, the HKS S-AFR, and the greddy e-manage. They all can change the airflow signal from the MAF sensor, and hence adjust fuel delivery. However the e-manage does much more, it allows for larger injector or AMS setting, adjustement of ignition timing, 3D mapping, datalogging and pretty much most of what a standalone does. Many of these functions will require a laptop, but since you are still using your original ECU and are not MAP based, it requires very little tunning and you maintain original functions such as AC, idle control , emisions.... The system sells for only $250 on ebay new, which is much cheaper than a SDS at $1000.oo. Also you would maintain your direct ignition system which would cost even more with the SDS (I'm not saying that it is better than a full standalone like SDS, just much much cheaper with many of the same key important functions) Here is a site with some info: http://www.boostsolutionsinc.net/technical-AFCcomp.htm This was their conclusion: Choose Greddy e-manage: If you do not care about using a laptop once in a while, and you want full air, fuel, and ignition control, with 3D maps, just like a standalone. With basic datalogging capabilities. Also great for you if you are planning on a bigger turbo and bigger injectors. Monitors the injector duty cycle as well. Choose Apexi S-AFC: If you like playing with many displays, and like the big electronics screen, or want the show stuff for you car, the S-AFC is for you. Choose HKS AFR: If you do not care that the HKS unit looks simple, and that you really will need the BOV correction function, along with the increased throttle response. Also, the HKS gives you more control over the curve. But you do not have the 2 maps, the knock display, and the other cool stuff from Apexi. The HKS is great for tuning though. The best price of all, as well. Quote Link to comment Share on other sites More sharing options...
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