1st run with Direct Scan : tuning help?

[1 quik6]

Was pretty excited to try out the new data logging tool. I just got in my stall converter and have no traction until I get my drag radial so my results were somewhat screwed up. I had turned down the boost to around 17psi even though I usually run more just to get some easy baseline runs. Now I have some questions to ask.

What should I be looking for under the Inj. PW. I found a chart of expected values on GNTTYPE.org but had no Inj. PW value to look for. Mine was over 26 (more than 100%) at wot. Does that mean I'm running out of injector?

I just put in a heated 02 sensor just before making my run. The direct scan shows a trouble code for an 02 sensor but I just assumed it was because I hadn't cleared the code with our tech 1 yet. At idle was getting 02 volts as low as 71mV but keeps bouncing around up to just over 700mV. Is that normal? At WOT it is hanging pretty close to the 800mV mark which I think is normal.

What is generally accepted for the knock cnt? Evidently I had a knock count of 2 before I even started my fun. On my time slip it shows 2/0 giving me a total of 4 for the day. I was expecting 0/0 because I had the boost turned so low this time. I actually still had some race gas mixed with my 92 so with 17psi is this normal? How much can I turn up the boost and not worry? My peak knock Rtd was 4.4 as the knock was occuring. GNTTYPE.org says that <6 is o.k. Any advice?

Thanks for any input you can lend. I'd really like to get all of this stuff figured out so I know I'm not hurting anything.

Eric Malmsten
Ishpeming, MI

 

[TurboDave]

Was pretty excited to try out the new data logging tool. I just got in my stall converter and have no traction until I get my drag radial so my results were somewhat screwed up. I had turned down the boost to around 17psi even though I usually run more just to get some easy baseline runs. Now I have some questions to ask.

What should I be looking for under the Inj. PW. I found a chart of expected values on GNTTYPE.org but had no Inj. PW value to look for. Mine was over 26 (more than 100%) at wot. Does that mean I'm running out of injector?

Normally I'd say no, but since you were only running 17# of boost the demands on the system shouldn't have been that great, so with that said, it may be time to start thinking about an injector upgrade.

I just put in a heated 02 sensor just before making my run. The direct scan shows a trouble code for an 02 sensor but I just assumed it was because I hadn't cleared the code with our tech 1 yet. At idle was getting 02 volts as low as 71mV but keeps bouncing around up to just over 700mV. Is that normal? At WOT it is hanging pretty close to the 800mV mark which I think is normal.

Everything there looks perfectly normal. Just a tiny bit rich on the WOT side, but that directly attributable to the lower boost. Trouble code might be a left-over.

What is generally accepted for the knock cnt? Evidently I had a knock count of 2 before I even started my fun. On my time slip it shows 2/0 giving me a total of 4 for the day. I was expecting 0/0 because I had the boost turned so low this time. I actually still had some race gas mixed with my 92 so with 17psi is this normal? How much can I turn up the boost and not worry? My peak knock Rtd was 4.4 as the knock was occuring. GNTTYPE.org says that <6 is o.k. Any advice?

knock counts can occur during starter cranking so don't worry about knock counts, you're more concerned with knock retard. Knock retard of 4.4 is a little higher than i would consider safe. And as you run higher boost levels approaching 20#, never accept any knock retard much over .5

Thanks for any input you can lend. I'd really like to get all of this stuff figured out so I know I'm not hurting anything.

Eric Malmsten
Ishpeming, MI

 

[1 quik6]

Normally I'd say no, but since you were only running 17# of boost the demands on the system shouldn't have been that great, so with that said, it may be time to start thinking about an injector upgrade.

I already have a set of 50#'s sitting on the shelf. Just thought I'd wait until I got my new turbo if I could. I was hoping to only buy a new chip once instead of twice. O-well. I guess I'll go ahead and order the new chip for 50# and stock turbo.

knock counts can occur during starter cranking so don't worry about knock counts, you're more concerned with knock retard. Knock retard of 4.4 is a little higher than i would consider safe. And as you run higher boost levels approaching 20#, never accept any knock retard much over .5

Why do you suppose I have the 4.4 knock retard at 17psi? What should I do to fix it? This was my only chance to log data before my 3" downpipe and exhaust was getting installed. With the higher flowing exhaust the problems will likely get worse won't they?

 

[TurboDave]

As to why the 4.4, when did it occur? At the 2/3 shift point is the most common place for the most serious knock because of the sudden load.
Why? to many variables. Maybe there wasn't enough race gas left. Maybe your chip has too much timing, etc. To hard to say exactly why

 

[1 quik6]

As to why the 4.4, when did it occur? At the 2/3 shift point is the most common place for the most serious knock because of the sudden load.

It looks like it hit 3rd gear at 59mph and the 4.4 of knock rtd occured at 71mph in 3rd gear. It also hit a high of 2.5 of knock rtd at 36 mph before hitting 3rd gear.

Why? to many variables. Maybe there wasn't enough race gas left. Maybe your chip has too much timing, etc. To hard to say exactly why

What I don't understand is that my car is pretty much stock right now (look at my sig). Stock turbo, injectors, exhaust, motor. The only things I've really done to affect the knock is cone filter (not likely making any difference), chip, and boost controller. I suppose the chip could be causing my problem by having too much timing but that won't improve with race gas if I'm trying to run 22psi, right? I got the chip from my brother at Precision T&E a few years ago. I beleive Joe was doing the chips there at that time. My brother said that it would be better than a stock chip even because they had way too much timing in the other chips I was using. I guess what I am trying to say is that I should not need ANY race gas right now to run 17psi of boost. That chip was designed for 92 octane and 19psi of boost.

One thing I did notice is that the Flags/Sensors section has the PE mode and Boost are highlighted. When we hooked up the AEM boost controler we took out the factory boost sensor. Shortly after that, a check engine light came on so we re-plugged in the boost sensor (although the light was probably actually caused by a bad 02 sensor) that is just going along for the ride not hooked to vacuum or boost. Since that is the sensor feeding the ECM (and not the aem that is actually controlling the boost) the Direct scan is not showing any boost. Could that be causing some other problems?

Another interesting thing I noticed but unrelated. I had recently installed the 3000 stall converter. I could foot brake without a problem right after I got it to 2800 rpms. It seems to be more loose now that I've been driving it for a while. Now with my 1 logged run I noticed that at launch for 1 frame I had 3350 rpms at 0mph. No wonder I'm having traction problems! It all just happens so fast when making a pass this Direct scan is really cool to look back on.

Thanks again Turbo Dave for all of your help!

 

[1 quik6]

Another goofy question. What modification have I done so far to require more injector? Aren't stock injectors normally capable of running 23psi on race gas with a stock turbo? I had concerns with an open 3" down pipe but that isn't even on the car yet.

I would normally have attributed any problems occured during this run as too much boost so I'm glad I turned it down for tuning purposes.:smile:

 

[TurboDave]

Another goofy question. What modification have I done so far to require more injector? Aren't stock injectors normally capable of running 23psi on race gas with a stock turbo? I had concerns with an open 3" down pipe but that isn't even on the car yet.

I would normally have attributed any problems occured during this run as too much boost so I'm glad I turned it down for tuning purposes.:smile:

Stock injectors were never designed to be pushed that hard!!
That's not to say folks don't do it regularly. I'm not at all surprised they're trying to exceed 100% duty cycle even at 17#

 

[1 quik6]

One thing I did notice is that the Flags/Sensors section has the PE mode and Boost are highlighted. When we hooked up the AEM boost controler we took out the factory boost sensor. Shortly after that, a check engine light came on so we re-plugged in the boost sensor (although the light was probably actually caused by a bad 02 sensor) that is just going along for the ride not hooked to vacuum or boost. Since that is the sensor feeding the ECM (and not the aem that is actually controlling the boost) the Direct scan is not showing any boost. Could that be causing some other problem.

Maybe I spoke too quickly, I looked at the screen again and found boost DC approx 85% at WOT. What does that mean? I guess I should really look how my factory boost sensor is hooked up when I get my car back from the exhaust shop.

 

[Madcat455]

Maybe I spoke too quickly, I looked at the screen again and found boost DC approx 85% at WOT. What does that mean? I guess I should really look how my factory boost sensor is hooked up when I get my car back from the exhaust shop.

I asked that question too on my first run with DS

It's just telling you how hard the ECM is cycling the Solonoid. Since you don't have the solonoid hook up, it's meaningless.

 

[1 quik6]

In the dial mode of the Direct scan it seems like it should have a boost guage. Does the ECM have the boost pressure being fed back to it on a stock car or does it only provide the DC output and hope the psi turns out to be right?

 

[Madcat455]

In the dial mode of the Direct scan it seems like it should have a boost guage. Does the ECM have the boost pressure being fed back to it on a stock car or does it only provide the DC output and hope the psi turns out to be right?

No boost pressure feedback, It's only triggering the solonoid to bleed off pressure. I don't know where it gets it's info from as most here say that the MAP isn't connected to the ECM. So I don't know how it determines when to trigger the Solonoid(maybe RPM/MAF scaling?)