Guest |260| Posted February 10, 2009 Report Share Posted February 10, 2009 Hey Everyone, Have another question for all of those who have gone before down the road of stand alone engine mgt, or for our engine tuners out there. Q: Has anyone found a quantifiable "A-B" benefit on an 4 cylinder, 16V, RACE only car (trailered, dedicated race car) for going full sequential on injection and spark vs. batch fire and wasted spark? Meaning this car has to be able to start, idle, warm up, drive in and out of a trailer, to the tech line, then pretty much run WFOT for ~30-ish minutes at a time. I'd be into going the extra work of adding the cam sensor for sequential if it will provide a quantifiable power or driveability benefit,,,, but,,,, if not I dont want to waste the resources of installation time, parts, tuning time, and money doing it unless there is good reason. The engine is question is a BMW S14 4 cylinder, NA, running on a ViPec V44. It will have a COP setup. Injectors are rated at 300cc @ 3 Bar, rev to 8000ish RPM. 1) Implementing sequential on our BMW S14 motors is readily available via a parts bin raid of E34 M5 cam sensor parts, and physically not difficult to implement. 2) Through much internet searching, many people seem to say (or think) that going full sequential has most of its benefits part throttle and for fuel economy & emissions? True - False? 3) I'm not a techy kind of guy, so if I do not need to do this for a race car,,, I wont bother. I just want to make my cars run as good as they can given the mechanicals involved. Meaning, I dont want to add any science projects to my list that will not make my cars go faster. The V44 "can" do it, but I dont want to climb that mountain just because its there if you get my drift... Any proven experiences as they relate to 4 cylinder race engines is greatly appreciated. Thanks in advance jimmy p Quote Link to comment Share on other sites More sharing options...
rayhall Posted February 10, 2009 Report Share Posted February 10, 2009 Jimmy, As far as firing the plugs on the exhaust stoke, this will not cause problem, but there can be spark power and coil temperature problems doing this in some cases. If the engine is to run very high boost, then sequential ignition should be used, so you get a powerful spark. As far as batch fire fuel, it depends a lot on intake runner length and camshaft overlap. Long runners with low overlap will start and run very much the same as full sequential. Often you cannot tell the difference. Exhaust emissions is another thing. Sequential is the only option for this. On a race engine I would recommend you use sequential fuel. The Ignition will depend on a whole lot of factors. Quote Link to comment Share on other sites More sharing options...
Apex Speed Tech Posted February 11, 2009 Report Share Posted February 11, 2009 Jimmy, I agree with Ray 100%. In practice, I have seen improved drivability, response and fuel consumption. Also, if you have individual EGTs or Lambdas, you can tune individual cylinder mixtures which often results in power improvements and more robust operation. Regards, Neel Quote Link to comment Share on other sites More sharing options...
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