Old 06-09-2011, 09:23 AM
  #26  
Rob_DOHC
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Originally Posted by BRAM
How are you going to measure the afr ratio of each cylinder with egt probes?
Yes mate, an EGT probe on each cylinder. Bit of a faff and takes a while to sort but it should be worth while in the end. My aim is to have a car that drives/starts/idles/cruises like an OEM mapped would. I'll do it on some rollers i think.

At a guess the leaner cylinders will be hotter?
Yes mate, its a bit weird but the cylinder will get hotter the leaner it gets up until a certain point when it gets cooler. I'll never get each cylinder exactly the same but i'll probably get them within 50deg C. Eventually i want to run pretty high boost so i think this will be important to me.

fantastic thread!!

i thing stu has some competition with his technical guides lol

great stuff
Lol cheers mate, don't think stu has anything to worry about though

If people are interested i'll do the same when i sort the EGT/sequential?


Roger, yep semi sequential still uses 2 banks of injectors (on a 4cyl) but it injects half the fuel twice as often. So at the moment 1&2 get a full squirt, cylinder 1 can use it, but cylinder 2 is on its compression stroke so can't.... so it has to sit in the port until the valve opens, similar to wasted spark.

But with semi sequential half the fuel is injected into a port that can't use it, where it stays until the exhaust stroke (hopefully nicely atomised) when the other half is injected as a timed event. Some engines like fuel to be injected at a different time to others but generally we will inject on a closed inlet valve. TBH i may not see any improvement with semi or even full sequential, but im up for a good trial

Rob,