rudypoochris Posted November 22, 2006 Share Posted November 22, 2006 This is not necessarily Z related. Assuming the car is a mass air flow based car, what can be done using the stock computer as far as turbo charging. 1. Will the computer realize there is a turbo and compensate with more injector time? 2. Can the injectors be substituted for larger ones with out reprogramming the computer (as in will it learn through what the o2 sensors are saying, that the fuel mixture is rich)? 3. Do injectors use a univeral.standard harness type or would injectors from a different brand car need to be rewired to fit another. Thanks! Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted November 22, 2006 Share Posted November 22, 2006 1. Yes, as the turbo (should) draw air through the MAF/AFM, the engine will be aware of the increased air being ingested. The trick is that the MAF/AFM will have a limited resolution, after which it is `maxed out', and it cannot measure increased flow. E.g, say your AFM can only measure up to 10lb/min of air, if you are actually ingesting 15lb/min, you are going to have a problem. 2. You can substitute different injectors assuming they are the same impedance, plug and shape. How well the standard ECU adjusts is very much dependent on how old it is. I wouldn't be expecting miracles. The std nb O2 sensor is not good for much aside from saying `right/wrong'. 3. Don't use a universal harness as far as I know, but then I have only seen ones that use a Bosch type plug: 2 pin female - 9 122 067 011 New Part Number Now 1 287 013 003 Dave Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted November 22, 2006 Author Share Posted November 22, 2006 Is the MAF usually already maxed out at stock? If so, can a resistor simply be put inbetween it and the computer. Then the computer sends lean for a couple seconds and compensates at the o2 sensor, or does it not work that way? Thanks! This is all in reference to modifying a 1988 central fuel injection Audi 80 Quattro. I was wondering if it could be turboed using the stock computer or simply ported, cam change, and larger injectors. Quote Link to comment Share on other sites More sharing options...
240hoke Posted November 22, 2006 Share Posted November 22, 2006 They can also be affected by backflow due to the turbo. this is particularly true with KA setups. The air coming back out of the turbo on decel messes with the MAS and causes the motor to shut down Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted November 23, 2006 Author Share Posted November 23, 2006 I see. Apparently the setup is some kind of mechanical electronic mix. It is a central injection where some kind of restrictor plate blocks off air. When you accelerate, it opens the plate more and the injectors spray more I do believe. How they know how much to spray I am not sure, it may be mechanically linked to the throttle opening. Quote Link to comment Share on other sites More sharing options...
510six Posted November 30, 2006 Share Posted November 30, 2006 You have an older CIS or Constant Injection System.I have had several Volvos with CIS and even converted a 510 4cyl and an L series 6 to CIS.You can activate the cold start injector under boost to gain a bit more fuel.I am not sure how to do the wiring for the Audi , but it`s possible. http://www.turbobricks.com/mods.php?content=art0021 Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted December 16, 2006 Share Posted December 16, 2006 You may get the MAF to read the extra air for turbo, but it won't enrich properly, NOR will it retard properly. You can change injectors (assuming same impedance and plug and body type) only if you can rescale the signal through some means or reflash your computer. NEVER rely on the O2 to somehow "adjust" for different sized injectors. More recent computers will have to drastically adjust with their long term adjustments stored in memory. Not a good idea, even though I have seen one or two peeps do it with small changes in injector size. If your MAF is maxed and your injectors are maxed, do something to increase both at teh same time. Then, the only issue you will still have is ignition timing being higher for the same amount of air for the reduced signal to the ECU. You can usually get away with leaving the ignition timing issue along IF the car was already turbocharged from teh factory. Mark Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted December 16, 2006 Share Posted December 16, 2006 They can also be affected by backflow due to the turbo. this is particularly true with KA setups. The air coming back out of the turbo on decel messes with the MAS and causes the motor to shut down You need a BOV upstream of the MAF, but obviously this only works with blowthrough. If the MAF is pullthrough, you will need a recirc valve (BOV being recirculated). Quote Link to comment Share on other sites More sharing options...
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