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scanmaster

TTA 1077

TTA 1077

Well-Known Member
Just installed a scanmaster with my new turbo tweak chip.(thanks Eric, so far so good)What i need to know is it normal for the O2 reading to drop into the 100s even the 40s & 50s when you let your foot off? It will go back to the 780s even 800 when cruising on the gas. It also drops a little during gear shifts but stays in the 600s. whats up with this?
 
Only worry about 02's underboost. Idle and cruising they are worthless. Use BLM's and INT's for idle and cruising.


Post up your idle numbers.

Jason
 
Thank's, not used to the scanmaster. When you hook up the OTC you see all the info a little different, not constantly running in front of you. What should the #'s look like for our cars? 1077 is basically stock, the only thing that might change this week will be the addition of an RJC plate.
 
I will post some #'s tomarow. I'm at work until Wed. on the 2-10 shift and am not driving the car. I'll take it out early and get some readings.
 
Ok! here are the #'s. I didn't know if you guys wanted them at idle, under boost, or cruising, so I did all of them. These were derived form driving a 14.4 mile loop, some city some express way.

IDLE- AF=05 L8=34 BAT=13.3 INT=128 BL=130 MPH=0 CLT=167 ATS=121 RPM=925 TPS=.46 IAC=0 CC=23-294


40 MPH- AF=50 L8=? BAT=13.5 INT=134 BL=128 MPH=45 CLT=164 ATS=97 IAC=37 CC=255 RPM=1775 TPS=.74

60 MPH- AF=25 L8=87 BAT=13.7 INT=127 BL=130 MPH=63 CLT=167 ATS=73 IAC=44 CC=248 RPM=1925 TPS=1.00

60-100 MPH (boost=17.5psi) O2=714 mv /knock retard=19.4
0-60 (boost=17.5psi) O2=820mv / knock=0.0

WTF is up with my 60-100 run??? I'm running 93/100 oct. mix, and really no mods except for the turbotweak. No RJC yet either. I have a week pas. side motor mount and my A/C compressor has a noisy bearing, can those 2 things cause that much false Knock???
 
TTA 1077 said:
Ok! here are the #'s. I didn't know if you guys wanted them at idle, under boost, or cruising, so I did all of them. These were derived form driving a 14.4 mile loop, some city some express way.

IDLE- AF=05 L8=34 BAT=13.3 INT=128 BL=130 MPH=0 CLT=167 ATS=121 RPM=925 TPS=.46 IAC=0 CC=23-294


40 MPH- AF=50 L8=? BAT=13.5 INT=134 BL=128 MPH=45 CLT=164 ATS=97 IAC=37 CC=255 RPM=1775 TPS=.74

60 MPH- AF=25 L8=87 BAT=13.7 INT=127 BL=130 MPH=63 CLT=167 ATS=73 IAC=44 CC=248 RPM=1925 TPS=1.00

60-100 MPH (boost=17.5psi) O2=714 mv /knock retard=19.4
0-60 (boost=17.5psi) O2=820mv / knock=0.0

WTF is up with my 60-100 run??? I'm running 93/100 oct. mix, and really no mods except for the turbotweak. No RJC yet either. I have a week pas. side motor mount and my A/C compressor has a noisy bearing, can those 2 things cause that much false Knock???
Click to expand...


Your 60 to 100 run...
Maybe a bit lean, 714. Car is under more load at this mph. Was the car in overdrive at 60? Did it shift down?, I've noticed knock when a gradual roll at speed if it stays in overdrive. Just a guess.
 
All your numbers look great. Your IAC is at zero but if your car is idling fine leave it alone.

The knock would scare me....19.4 is headgasket zone.
 
Well if the car seems to be in tune what would be causing that much Knock? I thaught that looked extream! What mechanical issues might there be?
 
No mechanical issues. If you can do a 0-100 and see where the knock starts. If you lugged the motor in OD at full boost it will knock.

Jason
 
Just a thaught, when I looked down at the scanner a few seconds after I started that run it was at 5* retard. Now the scanmaster records the highest O2 and knock that you can recall later. Well could it have recorded the point at which I let off at 100mph therefor cutting fuel and leaning out the motor? It would seem to me that if I was really getting 19.4* retard the car would falling on it's face. That's alot of timing to be pulling out with out feeling it. The car was pulling awsome! I need to ride with another person to record some of this stuff, these cars do their magic in seconds, so trying to watch the road,a boost guage and a scanmaster at 100+mph is crazy!!!
 
Sounds like the powerlogger would be easier to use in getting the car figured out.........and to see how driving conditions change the cars behavior.
 
TTA 1077 said:
Just a thaught, when I looked down at the scanner a few seconds after I started that run it was at 5* retard. Now the scanmaster records the highest O2 and knock that you can recall later. Well could it have recorded the point at which I let off at 100mph therefor cutting fuel and leaning out the motor? It would seem to me that if I was really getting 19.4* retard the car would falling on it's face. That's alot of timing to be pulling out with out feeling it. The car was pulling awsome! I need to ride with another person to record some of this stuff, these cars do their magic in seconds, so trying to watch the road,a boost guage and a scanmaster at 100+mph is crazy!!!
Click to expand...
Just because you knock doesn't mean it actually pulls timing.

When I was tuning the alcohol I had like 1.9 degrees of knock at the top of third yet the timing never changed. I do not think it is immediate.

Jason
 
I went through the TTA repair manual and looked at the diagnosis for spark Knock the only thing in the list that was out of norm was my coolant temp. I'm going to make another run tonight or tomorrow and check the boost #'s again. This time I will try in Drive with 3/4 tank of fuel. I noticed I was a little under 1/4 tank when I made that run and I know these cars lean out when low on fuel. There is a list out there (I've read it) that shows all the things that cause false knock, like a check list, for turbo buicks, I'll try and find that and go through it as well. What are some other things that would cause that much knock? Could 19.4 be false? Or is it to high to be false?
 
Here are some new #'s 60-100MPH O2 mv= 722/ knock 4.7 that was in drive. Next was at some highway speed to 137mph racing a c6 vette:) O2=764/ knock was 6.2:( Much better #'sthan what I first posted, but still lean. Should I bring the fuel up on the Turbotweak? or just wait and see what the RJC plate does for me? Some of that might be the weak motor mount. Anyway I can't believe how well I did against that vette. We were even on launch and I pulled away until about 120 then he started to catch me, at 135 or so he was pulling away. The second go I had the drop on him and pulled way away, he must have been doing 160 to catch pass me, well after I was slowing down! My girlfriend was riding shotgun and got a pic. on her cell phone, will try and download and post:):):)
 
TTA 1077 said:
Here are some new #'s 60-100MPH O2 mv= 722/ knock 4.7 that was in drive. Next was at some highway speed to 137mph racing a c6 vette:) O2=764/ knock was 6.2:( Much better #'sthan what I first posted, but still lean. Should I bring the fuel up on the Turbotweak? or just wait and see what the RJC plate does for me? Some of that might be the weak motor mount. Anyway I can't believe how well I did against that vette. We were even on launch and I pulled away until about 120 then he started to catch me, at 135 or so he was pulling away. The second go I had the drop on him and pulled way away, he must have been doing 160 to catch pass me, well after I was slowing down! My girlfriend was riding shotgun and got a pic. on her cell phone, will try and download and post:):):)
Click to expand...


Cool, what mods have you done? Was your speedo pegged when the vettes past you? I guess it was if you said he was going 160. excellant. Post pics or video.
 
Not much in the way of mods, 100# springs, Turbotweak, ATR 3" exhaust running a test pipe, ATR MAF pipe with a 9" K&N, ported stock elbow and what looks to be a good tune with the exception of that lean condition. I was beating the crap out of the TTA to run that vette, those C6's are definitely a world class sports car, Chevy finally got it right. If we can get that cell phone pic downloaded, I'll post it in the chat section:) meanwhile, anyone know what might be causing me to be on the lean side? I double checked the fuel, it's running 43 psi.
 
The RJC plate will help deffinately. I'd try it first and run pure 100 octane.
Then if it's still lean, I'd fatten up the chip, maybe then fatten up the reg itself to 44psi. Sounds like it's running good with stock turbo and Injectors.
 
sverble said:
The RJC plate will help deffinately. I'd try it first and run pure 100 octane.
Then if it's still lean, I'd fatten up the chip, maybe then fatten up the reg itself to 44psi. Sounds like it's running good with stock turbo and Injectors.
Click to expand...

I'll try the RJC plate then, I hesitated installing it because I like to get the car running right before each mod. There has to be something causing me to lean out? I know these cars ran a little lean with the factory tune and 6* knock is still acceptable, but would like to see it at 2 or below. I live in NY, could our higher ethanol additive be a culprit? Asfalse knock, how about that weak passenger side mount?
 
TTA 1077 said:
I'll try the RJC plate then, I hesitated installing it because I like to get the car running right before each mod. There has to be something causing me to lean out? I know these cars ran a little lean with the factory tune and 6* knock is still acceptable, but would like to see it at 2 or below. I live in NY, could our higher ethanol additive be a culprit? Asfalse knock, how about that weak passenger side mount?
Click to expand...

no a higher ethanol content is going to effect your knock ratings, the fuel is still rated to 92 or 93 octane. The higher ethanol content will decrease your gas mileage and your power output by a very little bit.
 
When you bought the chip did you have the intake pipes, exhaust, and valve springs or did you tell Eric about the mods at the time? If not then you're going to be flowing a little more air than I car would stock with those mods so it's going to cause the car to run lean since it's still providing the amount of fuel that was needed when it was getting less air. For what the numbers look like it's just running a little lean at the top end so I would add a little fuel in the 3-4 fuel settings on the chip. Going off your 0-60 mph scan with O2s around 800 and no knock it looks like you should be doing just fine through 1st and 2nd, if you feel uncomfortable with them then you could add just a little bit more fuel in 1st and 2nd but liek I said the numbers look good.

Oh and another thing if you're locking the converter at WOT that's going to put a lot of load on the motor which may be causing the extra lean condition, again just compensate with some fuel. I think my chip is set to lock at 80 or 100 I don't remember.
 
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Ok, I'll install the RJC plate this afternoon then try and see what the #'s are. Could it be something with my fuel delivery such as the pump going bad or dirty injectors? Just trying to cover all basses.
 
You are going to have to fatten it up. The RJC plate wont magically raise the fueling. It might supress knock but not 6 degrees...

No...your car is fine just up the fueling. Erics chips arent dyno tuned but they are very close.
 
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