Edit/ Piggyback Tuning

[NighEve]

hahah I love your simplified view on this issue rapt. If only things were that easy!

Tonight I installed a 2nd CAI on my ute and did some test driving on all three tunes - factory, 8psi and 10psi.

First thing I will say is that there was water on the road which made my testing of the latter tune interesting

I couldn't believe how nicely the factory tune pepped up with the 2nd CAI - I was very surprised (well until it cut into the standard boost drop flat spot zone again in higher revs).

8psi - I noticed it came on boost even earlier than before. The driving was nice and smooth and responsive without having to push the revs up like before to get it producing boost - I was impressed (this is my general driving map for the moment so I am happy this performed well).

10psi - on a nice private road out here in the sticks I let it unleash. 1st and 2nd gear were useless given the water on the road. 3rd gear just pulled like trojan and yet didn't seem to be getting ahead of itself like before (before you'd hear all this air rushing and it would get to a point at about 130km/h in third where it surged a bit almost like it was choking for intake air). Now it pulled very directly and on changing into 4th at about 160km/h it decided to break traction for a moment (as I said - interesting...). The only downside is that unlike before when you got to about 4500rpm in 4th there was a noticeable but not too drastic drop off in power as the boost tapered off. WIth the addition of the CAI, since it seemed to pull better until this point in the revs, when it hit 4500rpm the drop in boost/power was much more noticeable.

What this says to me in terms of efficiency is that free flowing exhaust and cat, and cold air intake and 10psi mean that you're more likely going reach the limits of the factory fuel earlier in the rev range. Quick fix for the occassional blat or drag racing outting would likely be a rising rate regulator and some custom tuning. Again - unless you were running 10psi all the time or you wanted to go even further, I doubt it would be a concern having this kind of setup. Contemplation...

[Lawsy]

double post, sorry... See below.

[Lawsy]

I still think, like DW, that the injectors aren't actually hitting there 100% DC yet.

I think when these injectors start getting controlled to the utmost enth degree that more power will be seen from these stock engines....... Give it a little more time and I think this will be proven.

[NighEve]

Indeed Lawsy - but as has been said - the EMS controls the injectors in a different way to the factory PCM (Edit or not the way the PCM controls the pulse rate of the injectors I would say remains unchanged and therefore so does the limitations as has been seen with piggyback for a couple of years now and now with the 10psi map for the edit).

I am sure IF the SCT crew could have played with the control of the injectors they would be trying to extract the kind of power DW and the like are speaking of with EMS. Imagine the marketing power they'd have if they could actually do that (In other words they can't because if they could every man and his dog would be CAPA flashed by now).

Food for thought

[JB]

At the expense of this looking like a hijack thread on overboost I would add the following (as I think it is particularly relevant in demonstrating the points we all seem to agree on one way or another). 

If your car was going to suffer from overboost (or had been), adding less restrictive breathing (ie CAI, cat, etc) to it would increase the chances of it occuring.  Remembering an engine is just a big pump and he more air and fuel that its components can allow it to suck through, the more output you will extract (very basic, but for these purposes it will do!!!   So and was said above; if you're running a base tune/component set that was on the conversative side, then ofcourse you have better chances of not having ceiling limit restrictions when introducing a generic map of higher spec performance.  I just didn't think it could be as easily as imaging there was a direct linear relationship between the base and CAPA tunes if the PCM is able to "learn" to a degree.  I suppose it can only "learn" as far as the limits of the componentry will allow when 10psi is trying to be pumped through it (remembering the simple description above).  Unfortunately that is why there's a few people who are not able to run their seemingly more efficient base setups with the higher spec 10psi tune without dramas.  I would be interested if anyone if having trouble with the 8psi map (that would completely shake up my theory). 

I am sure with time and some technical advice from those in the know will see this issue addressed properly. 

I will be adding a CAI this afternoon (should be interesting to see if this brings about any problems or only increases performance).

That's exactly what I am saying, 100%

[RAPHOON]

Unfortunately that is why there's a few people who are not able to run their seemingly more efficient base setups with the higher spec 10psi tune without dramas.  I would be interested if anyone if having trouble with the 8psi map (that would completely shake up my theory). 

I am sure with time and some technical advice from those in the know will see this issue addressed properly. 

I know of at least one car in Brisbane with issues on the 8 PSI map.

[JB]

At the expense of this looking like a hijack thread on overboost I would add the following (as I think it is particularly relevant in demonstrating the points we all seem to agree on one way or another). 

If your car was going to suffer from overboost (or had been), adding less restrictive breathing (ie CAI, cat, etc) to it would increase the chances of it occuring.  Remembering an engine is just a big pump and he more air and fuel that its components can allow it to suck through, the more output you will extract (very basic, but for these purposes it will do!!!   So and was said above; if you're running a base tune/component set that was on the conversative side, then ofcourse you have better chances of not having ceiling limit restrictions when introducing a generic map of higher spec performance.  I just didn't think it could be as easily as imaging there was a direct linear relationship between the base and CAPA tunes if the PCM is able to "learn" to a degree.  I suppose it can only "learn" as far as the limits of the componentry will allow when 10psi is trying to be pumped through it (remembering the simple description above).  Unfortunately that is why there's a few people who are not able to run their seemingly more efficient base setups with the higher spec 10psi tune without dramas.  I would be interested if anyone if having trouble with the 8psi map (that would completely shake up my theory). 

I am sure with time and some technical advice from those in the know will see this issue addressed properly. 

I will be adding a CAI this afternoon (should be interesting to see if this brings about any problems or only increases performance).

Totally agree, 100%