Chevrolet Corvette Stingray C7 Forum - View Single Post

Dr Jkel · 01-26-2012, 08:20 AM

January 25, 2012

Well tonight was an interesting night.......it is funny how much you learn when you don't really understand everything that goes into doing something.

Matt arrived with new tune in hand...and before we started he said that don't be surprised if it didn't run like I wanted it to. I was like WTF we already had it running correctly at idle...and that is the problem it was all at idle.

Here is where my novice, noob experience comes in. Although it sounded ok to me, although it ran without dying doesn't mean it was running correctly according to the computer. Evidentially the computer learns itself once running. and stores the information in it.

So I basically got a lesson in tuning even though I have nop idea what he is talking about. He tries to relate all this to mean in terms of carberation and some of it transfers but most doesn't....it is basically the same thing except you are not turning screws you are hitting button on a computer to change things.

The BIG problem with all this is really simple.......Matt took all the data we had received and called Street and Performance. Since the wrote the original tune we thought we could give them the data, they could update the tune and all would be good....NOT....Street and Performance tune is a very basic make it start tune, kind of a beginning tune. Based on what we were told we would have to send the chip back and forth about 5 times for them to try and tune it...they would change something, send it back, we would try it and then send the chips back to them....This could take forever.

So now we are going to do it ourselves, really Matt is going to do it and I watch

So after I understood all of that , I realized why it would run rough .

This sytem is not a modern system in the fact that most everyone is running LS motors which are more common nowadays..( years ago when I bought this motor I thought it was the best thing out there...a motor over 400 horses, small block......crate motor with a factory warranty.....all these years later the motor is great but just not up to date....This motor is more for racers who dont run injected systems

Hindsight is a pretty clear thing...it would have been so much easier to put a LS motor in the truck and be done with it, so much more tuning options etc.... Come to find out that Street and Performance and pretty much NO ONE has this motor with this cam and this fuel injection system....so pretty much the base tune from Street and Performance is just that a BASE tune so that the motor will run...BUT if you try and get any performance then you are kinda stuck.

So Matt is making a custome tune for this motor, cam, and injection set up. From what I understand about it you have to make sure the motor and all the other factors are correct at each range in the motor for example timing, vacuum, fuel/air ratio etc.....since it is all computer controlled. So last night we had the idle but that was it.....the 1000 to 2000 rpm range number were not right...vacuum and A/F ratio and timing were off......So as Matt adjusted things it still wasn't right and was really kinda confusing. Pretty much everything Matt entered did not work...................

Well the famous words of " Electrically it is right, MUSt be something mechanically" were uttered

I should have known this was coming, just my luck. The only thing we have not taken apart is the motor on this whole truck so it figures that we would have to fool with it as well.

The first thing we checked were the fuel injectors to see if they were big enough, fortunately they seemed to be the correct ones, problem was they were DIRTY....There was alot of trash in the screens.

Since it was getting late we decided to quit for the night. We will clean the injectors, change the fuel filter ( Again) and Matt said we might as well check the valves to make sure they are adjusted correctly....He said that they were not loose since they didn't rattle but they could be too tight and that would effect things negatively........SURELY the shop didn't tighten the valves up, surely they didn't.

But tomorrow we will check the valve lash, clean the injectors and go back to tuning.......not as simple as I thought.

Matt said it would take four or five times to get the tune right since we have no baseline of data to fall back on......All of his tunes stuff is for LS motors and Honda motors...now he will have a tune for TPI......just takes time.

01-26-2012, 08:20 AM	#336
Dr Jkel Roll Tide Drives: 2010 2SS RJT/BLK 6Spd Man Join Date: May 2009 Location: Talladega, Alabama Posts: 4,378	January 25, 2012 Well tonight was an interesting night.......it is funny how much you learn when you don't really understand everything that goes into doing something. Matt arrived with new tune in hand...and before we started he said that don't be surprised if it didn't run like I wanted it to. I was like WTF we already had it running correctly at idle...and that is the problem it was all at idle. Here is where my novice, noob experience comes in. Although it sounded ok to me, although it ran without dying doesn't mean it was running correctly according to the computer. Evidentially the computer learns itself once running. and stores the information in it. So I basically got a lesson in tuning even though I have nop idea what he is talking about. He tries to relate all this to mean in terms of carberation and some of it transfers but most doesn't....it is basically the same thing except you are not turning screws you are hitting button on a computer to change things. The BIG problem with all this is really simple.......Matt took all the data we had received and called Street and Performance. Since the wrote the original tune we thought we could give them the data, they could update the tune and all would be good....NOT....Street and Performance tune is a very basic make it start tune, kind of a beginning tune. Based on what we were told we would have to send the chip back and forth about 5 times for them to try and tune it...they would change something, send it back, we would try it and then send the chips back to them....This could take forever. So now we are going to do it ourselves, really Matt is going to do it and I watch So after I understood all of that , I realized why it would run rough . This sytem is not a modern system in the fact that most everyone is running LS motors which are more common nowadays..( years ago when I bought this motor I thought it was the best thing out there...a motor over 400 horses, small block......crate motor with a factory warranty.....all these years later the motor is great but just not up to date....This motor is more for racers who dont run injected systems Hindsight is a pretty clear thing...it would have been so much easier to put a LS motor in the truck and be done with it, so much more tuning options etc.... Come to find out that Street and Performance and pretty much NO ONE has this motor with this cam and this fuel injection system....so pretty much the base tune from Street and Performance is just that a BASE tune so that the motor will run...BUT if you try and get any performance then you are kinda stuck. So Matt is making a custome tune for this motor, cam, and injection set up. From what I understand about it you have to make sure the motor and all the other factors are correct at each range in the motor for example timing, vacuum, fuel/air ratio etc.....since it is all computer controlled. So last night we had the idle but that was it.....the 1000 to 2000 rpm range number were not right...vacuum and A/F ratio and timing were off......So as Matt adjusted things it still wasn't right and was really kinda confusing. Pretty much everything Matt entered did not work................... Well the famous words of " Electrically it is right, MUSt be something mechanically" were uttered I should have known this was coming, just my luck. The only thing we have not taken apart is the motor on this whole truck so it figures that we would have to fool with it as well. The first thing we checked were the fuel injectors to see if they were big enough, fortunately they seemed to be the correct ones, problem was they were DIRTY....There was alot of trash in the screens. Since it was getting late we decided to quit for the night. We will clean the injectors, change the fuel filter ( Again) and Matt said we might as well check the valves to make sure they are adjusted correctly....He said that they were not loose since they didn't rattle but they could be too tight and that would effect things negatively........SURELY the shop didn't tighten the valves up, surely they didn't. But tomorrow we will check the valve lash, clean the injectors and go back to tuning.......not as simple as I thought. Matt said it would take four or five times to get the tune right since we have no baseline of data to fall back on......All of his tunes stuff is for LS motors and Honda motors...now he will have a tune for TPI......just takes time. __________________ MUSTANG...Like Bringing a Hot Dog to a Steak Dinner....There is no comparison.