[Eric_Oz_S2]

By the way - were you able to get anything richer than stoich (14.7) on the PT maps?

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[flash]

apparently they changed the ECU quite a bit from the S2. there is no memory that affects running condition when you disconnect power or the ECU itself. you can swap out a chip as fast as you can, and you're good to go. no waiting for it to "learn"



tuner pro doesn't have the 3D WOT maps in the module. like i said, there are 142 OEM maps in the 968 ECU



and yes, my PT maps take the mixture wherever i want it and keep it there for as long as i want it, and only where i want it to, dependent on the condition. i had code written specifically to allow me to do that.

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[flash]

the car is now just about buttoned up and ready for tomorrow's dyno date. the new parts are being finished this afternoon. i think i'll have enough stuff tomorrow to figure out which way to go and resolve the "issues". i booked 3 hours this time, and reserved a session saturday afternoon if i don't get everything done that i want to.



lol - i may have to take a cab home tomorrow though, and leave the car there. depends on where we are and how much work it will be to finish.

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[DaveN]

What, a cab! Aren't you worried about Industrial Espionage? <img src="/forum/images/smilies/968/ohmy.png" class="smilie" alt="" /> <img src="/forum/images/smilies/968/laugh.png" class="smilie" alt="" />

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[bombfactory]

If you're using the dyno at MD Automotive, say hi to Mark for me!

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[flash]

nope

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[flash]

lol - my car got jealous of all the time i have been spending on the test car, and decided to have its battery die. ok - i was a dummy and left the hood open and killed it



anyway, the test car is all ready for tomorrow.

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[tamathumper]

lol - yes, mine is disconnected at the light fixture for just that reason.

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[flash]

not sure, but i think that disables the alarm.



i'm installing a switch in the next few days

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[DaveN]

Mine has always been disconnected at the hood just for that reason. But, then again, my alarm has never gone off, Hmmmm.

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[MB968]

I keep taking the connector off. Would be nice to have an under the hood in line switch

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[bombfactory]

Wish I had known it was that easy to defeat the alarm. I had my mechanic disconnect it after it started going off for no apparent reason after I locked the car.



I now also keep my under-hood light disconnected after a few dead battery episodes.

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[flash]

well, i think we're dead in the water



i made 20 more horsepower up top, but gave it up everywhere else. it was also scary lean up there. the injectors just aren't big enough



i'm going to spend the weekend scratching my head, but i think i'm screwed. i think i got it right the first time.



i'll explain more in detail later. right now i'm headed for a drink.

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[gbarrier]

Thanks for trying.

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[flash]

Ok. Time to fill in the details.



I have always said that an intercooler was not needed in a 5lb system. I said the restriction would be such that the net power, even after factoring in the gains from cooling, would be less than what you started out with.



I have always said that the injectors were maxxed out at 4.9lbs. I even went on further to say that the mixture was not what I would like way up top, but for a street system, it was fine, but that it would not likely do well on the track, given the increased heat, and the likelihood of detonation due to that and the mixture.



In an effort to provide something for the guys who insist on taking the kit to the track, even though it is NOT designed for it, I attempted to come up with a "Stage 2" setup that would make it safer to run, and hopefully provide a bit more power.



The good news is that I know as much as I thought I did.



The bad news is that I know as much as I thought I did.



After extensive testing, and multiple attempts, I have come to the same conclusion as before. The injectors are too small, and an intercooler does not work.



I started out by making a small intercooler. Space is a very real issue, as you cannot put one in front of the radiator or it will negatively affect the cooling system. You can't put it behind the bumper, as it results in heating up the intake air and washing out the gains of the intercooler.



I got the intake temps to drop almost 60 degrees at redline, which is huge, but the parasitic restriction cost me 2 lbs of boost. That equated to about 20 hp down across the board.



So, I built a bigger intercooler, maxxing out the space available. This one was 75% bigger than the first. This picked up a bit over a half pound of boost, putting it right in the hunt for any other intercooler, but still the power was down.



This led me to start letting more air into the supercharger. I opened up the venturi. This picked the boost back up to the same 4.9psi as before, but the only at peak. The rest of the curve was still down everywhere. The mixture was also very lean.



I tried a 10:1 rising rate regulator to increase fueling. No dice. It's too slow to keep up. I tried pumping up the pressure with an AFPR. It got a bit better, but not nearly good enough.



In the end, I was able to gain a good amount of power above 6k rpm, but it was down at least 10 everywhere else. Torque was off too. Everything that the kit did so well was gone. All that was left was power way up top where nobody really uses it anyway.



I've gone back and forth over this. I have come back full circle to where I started. 3 weeks and a few thousand dollars later, and I'm no better off. There is no more power to be had without major changes. It would require bigger injectors, and AFPR, a bigger fuel pump, a smaller supercharger pulley, a different belt, different idler pulley, different belt adjuster, and some way of tweaking the low end of the mixture to clean up the over-fueling the bigger injectors cause that the ECU cannot adjust out. To overcome the parasitic loss, boost would have to come up to 7 lbs, which would require even more fuel. That would bring you back to a net of 5. Power would come up about 25hp. But even if I did go through all of that, and manage to get it, the engine couldn't handle it. I've blown up one, and there are 2 popped head gaskets already. I'm not inclined to kill another motor figuring this out.



I'm fiddling around with some tuning, and have improved a few areas, but there are not really any power gains. The kit is as good as it gets, unless you want to rip into your motor, and develop something on your own. I have some suggestions for those who insist on tracking the kit, but I repeat that I think this is a BAD idea.



When I finish the chip, I'll let everybody know, but that's as far as I'm going.



Sorry guys.

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[Dimma]

[quote name='flash' timestamp='1349485203' post='133425']



I started out by making a small intercooler. Space is a very real issue, as you cannot put one in front of the radiator or it will negatively affect the cooling system. You can't put it behind the bumper, as it results in heating up the intake air and washing out the gains of the intercooler. [/quote]

That's why I chose a water to air intercooler with it's own water-system and pump ; could that be an option for you too ?



Edit : answer to my own question ; not really, the maxed out fuel injectors means : stop here ! ( or change injectors ). Indeed, starting to alter your Sc setting brings more trouble then gain ( as it often does in my experience )

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[Eric_Oz_S2]

I don't see what the big deal is about changing injectors. As long as you don't go crazy with injector sizes the ECU should cope with the change. May no longer be CARB certified, but for the track it won't matter. The fuel pump can handle a lot more fuel than just the stock injector load. You wouldn't need an AFPR, and the other changes you list seem trivial. I get the impression that it was really just the constraint of keeping the injectors that is limiting further development. Your tuner should have been able to sort the code changes with the larger injectors.



10/10 for effort though <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

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[Gotter]

I love that after $Ks of his own money, countless hours, and endless rants from the wife...



he ends with 'Sorry'.



No, sir.



Thank you. We owe a thank you, you don't owe a sorry!

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[tamathumper]

I am at once disappointed and relieved, if you know what I mean. <img src="/forum/images/smilies/968/biggrin.png" class="smilie" alt="" />

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[flash]

i do



eric. the pump CANNOT keep up. i ran out of pump as well as injector. when i cranked up pressure, it would fall off under load. that meant the pump could not maintain the flow. the pump is only rated at 58lbs, and only puts out 98 liters/hr. it is barely larger than the stock requirement.



the big problem is that i would have to raise the boost too far to make up for the restriction. that means even more fuel needed. the stock 28lb injectors cannot flow enough, no matter what i do to pressure. i need volume, not pressure, and then i need to be able to get it into the engine. so, i would need a pump and a set of injectors.



changing injectors IS a big deal. the problem i am having is that regardless of what i do to the mapping, the ECU will not let me lean out the very bottom end. it is WAY too rich at startup (in the 9:1 range) and even after the warmup, it is in the 12:1 range. this is way too rich for longevity. until i figure out what to do about that, bigger injectors are a track only item.



i already know the rods can't handle the load. i've seen the results of 2 motors now that went too far. i already know the valves float under higher boost. that one is a no brainer. i don't know yet what else is not up to the task. i'm not going to be the guy who finds out either.



the bottom line is that this is a kit for street cars. it was always designed that way. i always said it is not for the track. there aren't enough people who would take this to the track to justify the amount of time needed to work out this stuff. also, as it always goes with track guys, there is no end. even if i did work it all out, they would want more. then we get into the limitations of the MAF and the manifold. in the end, it would probably cost about $2.5k per car to do it, and you would only gain a very minimal amount of power. yes, it would be safer to run, but who would spend that much money? this is no new news to track guys, but in the 968 market, i just don't see it.



i'm going to leave the track development up to somebody else. after the weekend, i'm going to see what i can do to make the setup a little safer, but i'm not going to chase something that is just not wise.

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