5th and 6th port mod
12-27-07, 11:02 AM
#30
I just sold my old actuators or I'd get some pineapple sleeves and put them back on to test them out...hmm nah too much work cuz I don't have any back pressure or other things that might be needed. Funny how everyone used to rave about removing them, now people say keep them.
12-27-07, 11:15 AM
#31
well, removing actuators does net a gain up top because it cleans up the turbulence that was there before. Most ITS racecars will remove the actuators, since they spend the bulk of their time in 6 port territory anyway. Of course, the tradeoff is a very crappy low end.
12-27-07, 11:46 AM
#32
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I just sold my old actuators or I'd get some pineapple sleeves and put them back on to test them out...hmm nah too much work cuz I don't have any back pressure or other things that might be needed. Funny how everyone used to rave about removing them, now people say keep them.
12-27-07, 09:05 PM
#33
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For any given set-up there will be one (and only one) ideal point to open them. Doing one dyno run with them closed and one run with them open will give you two curves that cross over. The rpm point where they cross is the point the ports should be set to open at. Any other opening point will result in a loss of potential power in between the ideal and actual opening points.
12-27-07, 10:59 PM
#34
the Rtek has a limited range of controlling the opening of the 6PI. At the latest setting, power kept climbing in the low end of the dyno curve. The optimal point is probably past where I have the point set to now, but I can't get there, because the Rtek can't open them any later.
12-28-07, 12:29 AM
#36
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the Rtek has a limited range of controlling the opening of the 6PI. At the latest setting, power kept climbing in the low end of the dyno curve. The optimal point is probably past where I have the point set to now, but I can't get there, because the Rtek can't open them any later.
I don't have a series five na, only a series four, but reading the RTEK manual I can see where if you wanted, you could use the AWS output to control the 6PI solenoid with a little wire swapping. You could just swap the wire from the AWS to the 6PI solenoid. I forget the wire colors, but it'd be the wire NOT colored black/white.
I had no idea the 6PI was that limited in the series five RTEK2.0. They ought to correct that in the future.
I use the RTEK EGR for triggering the aux ports on the series four na. Used to use a SummitRacing RPM switch prior to that. In conjunction with a couple of vacuum hose and a extra emissions type solenoid. Like I say, series four are diff than S5.
12-28-07, 07:52 AM
#37
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12-28-07, 08:15 AM
#38
I did do the 2 run method.....it was 5 runs of progressively opening them at a later rpm, and the power kept climbing. At no time did the graphs of any two runs cross each other. It's like a monotonic sequence, if you consider the range to the limited range of the Rtek. It's like saying, look at line A (4P) and line B (6P). Find where they intersect over the range X1->X2. Well, they intersect at X3 where X3>X2. However, over the range X1->X2, A>B for all points in the range X1->X2. Understand?
12-28-07, 05:37 PM
#39
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That's not the method I described, and it's far from the best way to determine the optimum opening point. You had the system opening the ports during the runs, which you don't want. Obviously the curves will never cross over doing it that way. You have to do one run with the auxiliary ports closed, and one run with them open (wired open if need be). When you overlay the two power curves, they will cross over each other, because the ports-closed curve will peak before the ports-open curve. That crossover point is when the ports should be opened to get the most out of the engine.
12-29-07, 03:27 AM
#41
That's why I said almost the entire run. Besides, that's a very low launch rpm...
That's not the method I described, and it's far from the best way to determine the optimum opening point. You had the system opening the ports during the runs, which you don't want. Obviously the curves will never cross over doing it that way. You have to do one run with the auxiliary ports closed, and one run with them open (wired open if need be). When you overlay the two power curves, they will cross over each other, because the ports-closed curve will peak before the ports-open curve. That crossover point is when the ports should be opened to get the most out of the engine.
That's not the method I described, and it's far from the best way to determine the optimum opening point. You had the system opening the ports during the runs, which you don't want. Obviously the curves will never cross over doing it that way. You have to do one run with the auxiliary ports closed, and one run with them open (wired open if need be). When you overlay the two power curves, they will cross over each other, because the ports-closed curve will peak before the ports-open curve. That crossover point is when the ports should be opened to get the most out of the engine.
Entertain me, if you will.
Let A1(R) = power based off the power curve of 4PI defined at RPM point R
A2(R) = power based off the power curve of 6PI defined at RPM point R
Ri = RPM where the two curves cross.
R* = 5th and 6th port opening RPM
Ideally, you want to set R* (5th and 6th ports opening) at Ri, so that
A1(Ri) = A2(Ri)
Correct?
Furthermore, let the Rtek's adjustment range be defined as
R0:Rm, where R0 denotes 0 rpm and Rm denotes the maximum RPM of the adjustment range
Also, observe the relationship that Ri > Rm and that (1) A1(R0:Rm) > A2(R0:Rm) for all R0:Rm.
let A0(R) = A1(R) - A2(R)
A0(Ri) = 0
(2)d(A0)/dR = (-) and d2(A0)/dR2 = (-) for all R as observed from the dyno graph.
(btw, (2) implies (1))
Solve for optimal value of R* with the constraint R* element of R0:Rm so that it maximises power on the dyno.
Show your work. Partial credit will be awarded.
Last edited by Roen; 12-29-07 at 03:36 AM.
12-29-07, 03:36 AM
#42
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Could you find a more complex way to describe something so simple? 
The point is you never found where the two curves crossed over, because you never produced the two curves. The method you used isn't the best way to optimise the 6PI system. And if the Rtek isn't able to open the ports at the ideal point then I'd find a better way to control them. A simple rpm switch would do a better job in this case.
Out of curiosity, how modified is your engine? How extensive is any porting? If the ideal auxiliary port opening point really is above 4300rpm on your engine, I'm curious to know why it's so much higher than stock (3850rpm on S5's, probably similar in S4's). I would guess porting would change the ideal opening point, I'm just not sure how.
The point is you never found where the two curves crossed over, because you never produced the two curves. The method you used isn't the best way to optimise the 6PI system. And if the Rtek isn't able to open the ports at the ideal point then I'd find a better way to control them. A simple rpm switch would do a better job in this case.
Out of curiosity, how modified is your engine? How extensive is any porting? If the ideal auxiliary port opening point really is above 4300rpm on your engine, I'm curious to know why it's so much higher than stock (3850rpm on S5's, probably similar in S4's). I would guess porting would change the ideal opening point, I'm just not sure how.
12-29-07, 03:45 AM
#43
Haha, that is one of my biggest problems, but at least it's explicit!
My assumption is (with 95% confidence, standard statistics assumption) that Ri is indeed outside the range of R0:Rm. R0 is in effect, wiring the ports open. Rm is closing them as late as possible. I did do intermediate tests of points within the range, and it supported my relationship as described above, hence I didn't bother closing the ports by removing an actuator, for example.
A simple RPM switch would be ideal, but it adds to the complexity of an otherwise simple install job.
I was surprised at the results, since my engine is stock, as claimed by the PO (It's a Mazda reman installed at the dealership, damn bastards left a nylon rag in the manifold, which I found when I changed injectors!). I made multiple dyno runs up and down the range to establish the relationship I saw. It could be the fuel and timing tuning that alters the ideal crossover point, but fuel tuning in that range is stock, only timing was changed. I am almost positive (95%
) that the crossover point is above 4300 on my setup.
My assumption is (with 95% confidence, standard statistics assumption) that Ri is indeed outside the range of R0:Rm. R0 is in effect, wiring the ports open. Rm is closing them as late as possible. I did do intermediate tests of points within the range, and it supported my relationship as described above, hence I didn't bother closing the ports by removing an actuator, for example.
A simple RPM switch would be ideal, but it adds to the complexity of an otherwise simple install job.
I was surprised at the results, since my engine is stock, as claimed by the PO (It's a Mazda reman installed at the dealership, damn bastards left a nylon rag in the manifold, which I found when I changed injectors!). I made multiple dyno runs up and down the range to establish the relationship I saw. It could be the fuel and timing tuning that alters the ideal crossover point, but fuel tuning in that range is stock, only timing was changed. I am almost positive (95%
) that the crossover point is above 4300 on my setup.
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