Hitting fuel cut?

[BlueRB240]

So let me start with the good news. I figured out the problem I had a while back with my Rom. The maf wouldn't read right no matter what boost and I could never get a clean pull at low boost. It turns out it was a user problem on my part that happened to me on my other nistuned car. I had always forget to hit the burn to rom button when I was done messing with the car. So arg to me. I got a few pulls on the dyno tonight @14psi to 8k. It was good I was happy, I got my EVC4 to control the boost right and the Lightning maf wasn't fubared like I thought it was. So I bring the boost to 18psi which is what I dynoed with last time on a manual boost controller. The car wouldn't pull past 7k, it hit the limiter everytime! . I also noticed that I wasn't running as much timing in the cells as I did when I made my last dyno pull because I'm using the whole map now lol. Sad and happy at the same time. Best it could do was 389@18psi a few more degrees and I should be back where I was and over 400whp if I can get it rev past 7k.

[BlueRB240]

http://www.youtube.com/watch?v=i0jHULAWZWQ

low boost 8k pulls my bov sucks.

http://www.youtube.com/watch?v=jblPjWzIerU

hitting a wall @ 7k even tho the limiter is set to 8k getting there.

[TM_S13]

Well... I'm no expert.. but from what I saw on the log, the maf seems to be pretty maxed out since it goes to over 5 Volts right after 5500rpm.

Then, if you're doing 8000rpm, I believe you should adjust the RPM scales, both fuel and timing, because they only go to 7000rpm, and like so you're loosing resolution on the map.
And right after 6700rpm the AFR's go way too lean and the RPM's are still rising wich can't be good and might lead to some serious det... timing also seems to be a bit too advanced...

But hey, I'm no expert whatsoever hehe. With a boost level lower than 18psi that doesn't happen right ? If so it might be the MAF maxing out...

[BlueRB240]

Well... I'm no expert.. but from what I saw on the log, the maf seems to be pretty maxed out since it goes to over 5 Volts right after 5500rpm.

Then, if you're doing 8000rpm, I believe you should adjust the RPM scales, both fuel and timing, because they only go to 7000rpm, and like so you're loosing resolution on the map.
And right after 6700rpm the AFR's go way too lean and the RPM's are still rising wich can't be good and might lead to some serious det... timing also seems to be a bit too advanced...

But hey, I'm no expert whatsoever hehe. With a boost level lower than 18psi that doesn't happen right ? If so it might be the MAF maxing out...

The timing been reported isn't right it's off a few degrees from what I have noticed. I might have to go to a bigger cold side intercooler pipe if the maf is maxing out already tho it shouldn't be. I did have a map set for 8k but I had all sort of problems with this so I redid the map and never rescaled it because I didn't think it was going to work.

[TM_S13]

IIRC Nistune had a few issues regarding the 8000 rpm limit not being 100% right yet...
perhaps you can try and run an rpm limit of 7800rpm, re-scale and go from there.

as for the maf... I'm talking based on the log... it passes 5volts way too fast, and if I'm not mistaken that's the voltage that indicated the maf is on it's limits.

[BlueRB240]

IIRC Nistune had a few issues regarding the 8000 rpm limit not being 100% right yet...
perhaps you can try and run an rpm limit of 7800rpm, re-scale and go from there.

as for the maf... I'm talking based on the log... it passes 5volts way too fast, and if I'm not mistaken that's the voltage that indicated the maf is on it's limits.

I'm running blow through on the maf but the piping is only 2.75. I was told to run at least 3" piping but now I know for sure.

Matt how does nistune read the EGT's from the Zetronixs wideband controler? is in celsius or fahrenheit?

[Matt]

Celsius I believe is the default. I think they have made it configurable, but we just read what it sends us

[BlueRB240]

Celsius I believe is the default. I think they have made it configurable, but we just read what it sends us

Ok I have the box checked for temps in fahrenheit but not sure if that would cover the EGT or not.

[PL]

Just had a quick look at your log. Things that stand out are firstly that your battery voltage is flapping around all over the place - varying between 12.2 and 13.4V. This would definitely be worth sorting out.

The other thing is your lack of speed signal. Like many Nissan ECU's the RB20 will cut once it's been run at WOT for a certain time. This may or may not be the problem...

PL

[BlueRB240]

Just had a quick look at your log. Things that stand out are firstly that your battery voltage is flapping around all over the place - varying between 12.2 and 13.4V. This would definitely be worth sorting out.

The other thing is your lack of speed signal. Like many Nissan ECU's the RB20 will cut once it's been run at WOT for a certain time. This may or may not be the problem...

PL

it's not been reported right either, it's one of the things I saw a long time ago. I put a volt meter on the battery and got 14v. I wired up the spedo but it was reading wrong on the speedometer lol. I was pegging it in 2nd gear running it up on the dyno. I have to change the gas tank and put in new subframe bushings so I'll be under the car and see if I can remember how the wiring goes for it.

[PL]

You won't see battery voltage at the ECU because of voltage drops through the wiring, earths, etc.

PL

[Matt]

Agreed - ECU reports exactly the voltage that it sees at the terminals going in

[nissangts]

BlueRB240 did you sort your issue out? From what I have read it seemed as if you may even have grounding issues. As it concerns the MAF however isn't it rated at 600-700 in the stock housing it comes in?

[BlueRB240]

No haven't sorted it out yet. The maf is blow through so it's in a 2.75" intercooler pipe. I'm going to step it up to 3" and check the grounds again next time I make it out to my car.

[nissangts]

Any reason why you have it as blow thru though? Grounding issues are the worst though, almost every car I have worked on has a grounding problem.