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DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
The other day I was out with the vette data logging. Has anybody noticed that the SA you put in TunerPro is not the same as the data log output using EBL? Example, my tune is pretty good and the car hauls ***, but I have been data logging for another issue (IAC) and saw that under WOT my SA at 100% TPS was a solid 39* until I let off and said...Huh?! I looked back at my current tune and it should be 36.2*. Checking, I also noticed that my knock counts were rather sky high, but didn't hear anything odd.
Today, concerned about the SA issue I changed the SA 95/100 MAP at 3000RPM and up to redline to 35.85* and took it out for more data logging to see what was going on with the timing. Now at WOT the SA is a solid 38* until I let off and the car still hauls ***, but no real noticeable bad knock counts. There were a few, but nothing like where a degree higher setting was showing.
So, just wondering if anyone else has seen something like that? I'm using EBL FLASH II, 7747 and TunerPro R/T BTW. Thanks
There is a lot more to the final at-crank SA then the main & extended SA tables. The main item to look at is the PE SA adder. Then followed by the coolant comp SA table.
There is a lot more to the final at-crank SA then the main & extended SA tables. The main item to look at is the PE SA adder. Then followed by the coolant comp SA table.
RBob.
Thanks Bob, I'll another look at those, but I should mention I did that already and didn't notice any real significant values, but maybe I missed that. Thanks again.
If you have everything set right, the at crank SA will match what is on the WUD and any data log file.
If the at crank SA does not match what is displayed on the WUD or data log, you need to check the initial SA value, which should be set to whatever your base timing is on the dizzy (with the esc wire disconnected). You'll have to verify that with a timing light.
Then there's the SA latency table. That's a can of worms I'm not gonna begin to open. Plenty of info on that on this forum though.
If you have everything set right, the at crank SA will match what is on the WUD and any data log file.
If the at crank SA does not match what is displayed on the WUD or data log, you need to check the initial SA value, which should be set to whatever your base timing is on the dizzy (with the esc wire disconnected). You'll have to verify that with a timing light.
Then there's the SA latency table. That's a can of worms I'm not gonna begin to open. Plenty of info on that on this forum though.
My Inital SA matches what my timing is set to. I looked at my SA-PE adder vs gear/rpm table was already zeroed out and I'm not even going to mess with the latency at all. Thanks
First thing I would do is check the timing with a timing gun at idle and verify it is what is shown in the ebl. You'll want to use a non-adjustable timing gun because the adjustable guns also have built in latency. Then check the timing 3000 rpm in the ebl and with the gun--hold the throttle as steady as possible or set a block of cells at the same value to keep the timing from moving. Do this and you'll know if your latency value is off as well as knowing which readout is correct and go from there.
I'm not far from you, are you the shop in Havasu that has the dyno? Is it an engine or chassis dyno?
First thing I would do is check the timing with a timing gun at idle and verify it is what is shown in the ebl. You'll want to use a non-adjustable timing gun because the adjustable guns also have built in latency. Then check the timing 3000 rpm in the ebl and with the gun--hold the throttle as steady as possible or set a block of cells at the same value to keep the timing from moving. Do this and you'll know if your latency value is off as well as knowing which readout is correct and go from there.
I'm not far from you, are you the shop in Havasu that has the dyno? Is it an engine or chassis dyno?
No, I'm not in Lake Havasu, AZ, but the shop and chassis dyno that I use to tune the car is at Horsepower Connection in Lake Havasu. Not sure if you know it, but Brian the owner is a great guy and is a well known tuner across the country in the racing circuit. He used to teach EFI tuning at EFI University in Temecula CA until they moved the school to Lake Havasu. He doesn't teach there anymore from what I understand, but does hols classes in his own shop on tuning. He also has a nice engine dyno room. He does a lot of big HP boats as well.
No, I'm not in Lake Havasu, AZ, but the shop and chassis dyno that I use to tune the car is at Horsepower Connection in Lake Havasu. Not sure if you know it, but Brian the owner is a great guy and is a well known tuner across the country in the racing circuit. He used to teach EFI tuning at EFI University in Temecula CA until they moved the school to Lake Havasu. He doesn't teach there anymore from what I understand, but does hols classes in his own shop on tuning. He also has a nice engine dyno room. He does a lot of big HP boats as well.
That's welcome news about that shop, the majority of the shops out here seem to be run by guys who's real knowledge and interest never goes beyond carbuerated engines or desert racers.. I'll reach out to them when I'm ready to dyno the car. I've enjoyed doing dynos with knowledgeable efi guys and thought I'd have to drive to Vegas to do another dyno session.
Just for your benefit I posted the link below the pic. The Nova on the home page is one of his car he races. It's a SBC, single turbo car that runs 7.50s 1/4 mile. He has a new DART billet block going in it with twin turbo's the last time I was at the shop back in Sept.
Anyway, I'm starting to think I may be using the wrong SA Latency table. Here is my current table. Isn't that a small cap GM module table? I have a large cap GM dizzy, with an ACCEL module.
OK, yeah that's significantly different and I thought after looking at mine closer that it didn't look right. Started digging a bit and said that looks like a small cap table. UGH! Thanks again for the help.
Last edited by Buccaneer; Mar 10, 2019 at 12:17 PM.
UPDATE: uploaded the new large cap table and went to the track Friday night. Motor was running well and the launch was good @ 1.75 60ft, but since I had done some rearend work, I wasn't sure how it would react so I was a little easy on the launch. Launched straight as an arrow and felt like a great run and pulling like a freight train and on the way to at least a 12.60 pass. At 6200, it didn't want to shift into 3rd so I had to get out of it until it shifted and then back into it. Still ran a 12.90 @ 107mph, I lost two tenths or more with that little maneuver. I think I have the governor weights a little too light now and will have to play with that a bit and hope to get another blast in before the heat fires up here in AZ. Other than that, the motor was hauling *** and since I didn't want to chance anything on a new motor, I only made one pass and called it quiets. Maybe next time.
Last edited by Buccaneer; Apr 2, 2019 at 06:33 PM.
