[banditsc]

Looks like a trip to your parts car is in order.

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[flash]

lol - now knock that off - i have a real hard time thinking of a very clean 20k mile car as a parts car



pretty sure i still have the coil - i'll look tomorrow

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[MB968]

[quote name='flash' timestamp='1354922180' post='135958']

i am hoping that i have not discovered a hiccup that would affect people running the 18lb flywheel.



in my car, with both of the larger sets of injectors, i have an odd glitch. on decel, coming down from about 3400rpm, when i chop the throttle, it "hunts" for a map, and the mixture is all over the place, until it gets down to about 2500rpm. it doesn't do anything weird on the way up, or anywhere else, but you can feel that it is doing something. the instant you even tickle the throttle, it settles in. it's only on full chop decel. it's worse in taller gears than in lower ones. it isn't horrible, and i have to work to make it really happen, but it's definitely there. i thought i felt a hint of this kind of thing with the OEM injectors, but it became more evident with the bigger ones.



i have 2 theories:



1. the flywheel is too light, and the load is uneven on the way down.

2. the <acronym title='throttle position sensor'>TPS</acronym> is not right somehow



i'll be testing these over the weekend.



this was not a problem in bva's car with the <acronym title='dual mass flywheel'>DMF</acronym>. not sure if it was the flywheel, the <acronym title='throttle position sensor'>TPS</acronym>, or something else different about my car.

[/quote]



Will the factory ecu allow it to run in a limp mode if it looses the signal from the crank positon sensor. If so, you could loose this signal and see if you still have the glitch. My reasoning for this test: If the light flywheel is part of the issue, I'd expect to see it significantly reduced if the engine is just running off the cam position sensor as this sensor signal shouldn't see nearly as much of any oscillation due to the single direction nature of the cam belt (i.e. won't easily backdrive due to tensioning mech on this side).

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[flash]

i've done some fiddling, and i'm pretty sure i know what the problem is, and that it is probably limited to my car. i'll know for sure on wednesday.

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[flash]

problem found. i was right on all counts.



first and foremost, the problem is limited to my car. it's because of a mod i did a long time ago. nobody else is going to have this problem.



second, the light flywheel is not the "cause" of the problem. it only exacerbated it.



the issue was the Throttle Position Sensor. it was not properly set so the ECU thought the throttle was partially open, when i fact it was closed. hence, when i chopped the throttle, the injectors did not shut off. i had the plate set cracked just a bit, so it was letting just a touch of air in there, but not enough to mix with the fuel. consequently it was confused. i close the plate farther, and the problem got worse.



where the flywheel comes into play is that due to its reduced mass, it takes longer during coast down for the rpms to drop, and so more fuel is dumped in there. the taller the gear, the longer it takes.



i swapped out to OEM parts and bingo! no problem at all.



i can now proceed with Stage 3. i will be done on thursday. i plan to be shipping on the following tuesday.



woohoo!!!

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[MB968]

Great, glad you found it, and that it was only a single souce problem with a simple solution.



Out of curiosity, are you able to change the closed throttle, <acronym title='throttle position sensor'>TPS</acronym> voltage in the ECU to indicate when it is actually closed? Or is this something we don't have access to?

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[flash]

yup - me too - very happy to have resolved it, and it be limited to my car. i am not one to make excuses with my products. if they don't work right, i pull them.



i'm going to look again, but i think it's something we don't have access to.

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[flash]

we're all set for the final in-car tuning tomorrow. dyno on thursday.

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[flash]

in car tuning went very nicely.



dyno tomorrow.

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[flash]

dyno went well, and as expected. mix is MUCH better, and down around 11:1 way up top, so very nice and no detonation.



we did the runs on a car with an original untouched motor with 100k on it.



i made what i expected to make, pretty much the same as stage 2 across the board, with a little more torque here and there, but nothing much, and with an upper end gain of about 3hp. this would probably be a bit more on a motor with a fresh head, but not a whole bunch.



i'll post the charts soon. they sent me home with the wrong ones.

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[Eric_Oz_S2]

[quote name='flash' timestamp='1354753111' post='135827']most of the kits out there are out of warranty on he hardware portion of the kit now, so this does not apply to those people, but something that i am reconsidering is honoring the warranty for both stage 2 and 3. obviously the head unit itself, and its warranty are at the discretion of Rotrex. as long as it doesn't run out of oil, isn't overheated, or opened up, they are very good about the warranty. i can't guarantee that the unit won't overheat though, as i have no idea how hard somebody will drive it on the track. so, you can pretty much figure that if you take it on the track, you're on your [/quote]



All I can say is that around 15 track days later with an 85mm pulley and 6600 rpm cutout, I have had no problems with my rotrex. And this is in a hot climate including track days with temps sometimes over 30 degrees C.

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[flash]

yeah - they are pretty tough units, which is why there are not a lot of exclusionary issues with the warranty. pretty much, if you install it like you should, keep it full of fluid, and don't overheat it, you're good.

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[gbarrier]

I had sent my stock injectors out to Marren before I heard about Stage 3 so even though I have bought into Stage 3 I decided to go ahead and let them clean the injectors and see how they flowed. They came back today and they flowed 320 ccpm at 3 bar. Guess I'll save them back in case I decide to detune later or perhaps sell them later if I decide there is no chance. Was just glad to know that some of our stock units are still flowing adequate volume after cleaning.



Now, where's those big old injectors I'm waiting for.

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[flash]

that's crazy - i've never seen the OEM injectors flow that much. they aren't even specced that good brand new



sell them, quick!!!

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[flash]

so, i'm going back because, after studying the data, i think i can improve on a couple of spots. we are set for wednesday morning. i may or may not be able to make improvement, and it's really only clean up on curve shape, but i'm being anal again, and want to give it a shot.



in the meantime, here are some charts from the other day. ignore the red trace line. that was just something from an early run that didn't get deleted.



as you can see, the curves are very similar to stage 2. there are a couple of spots that are better, and we made a touch more at peak, and it might be even better, since stage 2 was done on a pretty fresh motor, and stage 3 was done on a 100k mile motor.



peak hp is now just over 274 at the hubs, and peak torque is 264 at the hubs. that crunches to about 310 flywheel hp and 300 torque. not bad on 91 octane.



the real story is the mixture up top. now we are way down into the safe zone, and not pushing the limits of anything. i'm very happy with this.



   

   

   

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[vliegwielolaf1234]

I am in .

Looks very nice . especially the afr .



Top

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[flash]

thanks - yeah - much safer.



like i said, i'm going back on wednesday to see if i can pretty up a couple of spots, but really it's just polishing at this point. i don't expect to make any significant gains over where i am. i'm just looking to see if i can smooth out a couple of things.



i am picking up the injectors monday, and setting up all of the packages. i'll be burning chips wednesday night, and shipping everything out on thursday.

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[tamathumper]

Hmmm, mix gets wonky right where I spend most of my time driving? High 2's?

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[kzem1]

Nice looking charts. I'd like to see that chart matched up to stock. I bet it is scary. A completely different car.

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[flash]

tama - i doubt very seriously that you are spending more than about a second at WOT in the high 2's. remember that this is WOT.



this is NOT what the mix looks like at cruise, or even part throttle. at cruise, it will be stoich. at part throttle, it will depend on the load level.



there is no need for it to be any richer there WOT though, as you are not on boost yet. in fact, i'm going back to see if i can get it leaner below that point, or if it's just a characteristic of nailing it for the dyno run, and not really what the mix is.



kzem - i'll see what i can do about making a chart that would show that.

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