Mixed reactions. I was hoping the AFR would be more level as a result of all the SD tuning I did, and it read leaner than on the street (expected). So can I base any street AFR tuning off these dyno pulls, or do I need to risk sitting the night in jail to get a 4th gear WOT pull to 7000RPM? I had my PE multipler set to request 12.6 until 4800, then gradually lean out to 13:1 at 6800.
http://www.musclecarsoforlando.100me...MSCC/JMZ28.jpg
Why run the car to 7000 RPM when the power drops off at 6300?
Looks like your CAM and setup are not good to 7000 so you are more than likely just abusing the valvetrain past peak power... to each his own though.
I will tell you with my C5 I just take the chance .. I do ALL of my tuning on the street... then just use the Dyno to check power.. everyone always asks about numbers... so that is why I run it.
I see that I get about as good of readings in 3rd on the highway as I do in 4th... I try to get it very close in 3rd gear pulls and then do a 3-4 pull once it is right. 4th gear for me is about 145 MPH at redline .. ;D
Nick Steffens&&2002 Z06&&
I run the car to 7000 because the drive power to the rear wheels in first gear exceeds any point in second gear. It doesn't matter that I'm past the power curve, I'm still in a better position due to gearing. I want to insure the tuning is correct the entire RPM range.
So you're saying that the AFR between 3rd and 4th is minimally different? Which is leaner, and by how much?
Do you have a wideband for the street that you used to dial in the 12.6?
I did an SD tune with MAF attached (but disabled) and a LM-1, did some basic MAF curve tweaking, and set the PE to where I wanted it. I don't have a 'street' run because they're a bit finicky about my driving record ;D
if you make peak hp at 6300 it doesnt mean you should shift there for best times...to figure out your shift points you'd want to pull to around 6800 to figure out how much it drops off after your peak hp.Originally Posted by BLOWNZ06
You can open a support ticket here https://support.hptuners.com/
I made a pair of WOT runs in 4th gear this evening. On the first one, my LTFT's were positive and the AFR was in the mid 12's (same tune as the posted dyno sheet above). I then reset the LT's and the AFR was in the upper 13's, but the LT's locked at zero even though some of the idle cells were creeping from +5 to +10. A wee bit of KR around 3000.
I also notice that all through the run there were spurious cell 15's mixed in with the cell 22's, even though TPS was at 100%. That's not right, is it?
Anyone care to take a look at the logs? They're in:
http://www.musclecarsoforlando.100megs25.com/MSCC
I modified the bin to take out the necessary KR, and based my PE adjustments on Run2 - althought I haven't written it yet.
I also had some coolant burp up from the passenger side of the engine, it's splattered all over by the battery, top of wheelwell, etc. I guess it came from the overflow?
MAF on or MAF off? May need to fine tune your WOT VE just a tad. And also I'd say richen up a bit! There's more tq down low to be had!Good pull though!
2002 Quicksilver Corvette Z06
And then...
MAF on. I'm confused by the switching between cells 15 & 22 while at WOT in the logs. Take a look and tell me your opinion
Check your LTFT upper RPM boundary. Could be on the upshift you are crossing that at WOT hence cycling between 22 and 15.
No shifts. The sections in question were 4th gear pulls from 2-3K all the way to 7000. It appears the 15/22 switching occurs about the same time as KR was detected during the run. My LTFT RPM boundaries are 1000, 2000, 4000, and the first KR instance was ~5200RPM.
I get some switching now also from 15 to 22. It didn't do it before the cam. It's all in the same gear as well.
98 M6 TA, mods: tsp torquer(233/233 .589 112), Patriot golds, ls6 oil pump, ls6 intake, tsp lid, pacesetter LT\'s and ORY, magnaflow, fra, HPTUNER!
I read on another forum that it may be related to the Evap solenoid. No time to do logging yet though.
why are you tuning your Air fuel on the street in 4th gear???
can you hit 145mph at the drag strip??? probably not in that car....
try tuning it in 2nd gear...like when you need to accelerate on to the highway....
wont piss off the cops....will still get accurate...and will be better at the track because you will be tuning in the engine load range that you are in on the track....
-Scott -
Well, I'll consider when the engine gets puts back together. I acquired a head gasket leak in the two week span between when I last dynoed the car and two weekends ago. Without knowing about the leak, I made a high-RPM pass on the interstate, and it gradually overheated. I'm considering lowering the fuel cutoff temp from 258* to something more sane.
Warped driver side head 4-5/1000th's and the passenger side head has a valve guide which is moving with the stem. Both heads at a local machine shop now - last I heard my performance shop hasn't received word back from them on whether they can do the valve job.
Reply With Quote