I'm going to redo the test tonight if i have a chance.

I will use 4th gear, which is 1:1, and begin 100% TPS at 2,500 RPM.

In this test, I think I was already going way too fast to accurately gauge when boost kicks in, since I floored it at 3,000 RPM.

 

how much boost spike are you experiencing when you shift?

 

I've not measured the boost spike yet, but i haven't noticed any significant or alarming boost changes when shifting. I can try to take a closer look tonight. Are you more interested in upshifting of downshifting?

 

2-3 3-4 shifts mainly I'm seeing like a 1.5 psi spike between 3 & 4

 

Ok.
I will try to do some upshift logging for you tonight.

 

awesome.. . thanks for your help

 

I wasn't able to get log screens of this, but at 0 PSI, with moderate throttle position, the 2 to 3 and 3 to 4 upshifts are each accompanied by a 1 psi increase. I guess this is somewhat consistent with what is going on in your car?

 

exatly. So did julian tune you to where you're already as lean as you should be when you hit boost or did he tune it a little rich so that when you hit that one pount increase at 6k rpms that you wouldn't go too lean? I'm just trying to get an idea if this is how the automatic needs to be tuned or if its for such a short period of time that its ok for it to lean out for a split second

 

I believe julian tuned it to be safely rich. I have not yet had a wideband AFR installed, but will soon. According to the utec logs, I am almost always running rich at any load.

 

what kind of A/F are you reading at WOT?

 

I tune most of my stock motor F/I cars safely at 11.3 A/F never leaner than 11.5 with 7-9 psi, usually...

 

cause Julian said so... thast why




and +1 11.3 is quite safe

 

good to know. What else besides A/F is taken into consideration when tuning our cars just out of curiousity.

 

AF and Timing are two most improtant part on tuning...

 

forgive the newb question, I've heard of timing and pulling timing and adding timing but what exactly is it?

 

nothing else at all.

 

I have a feeling you're being sarcastic

 

This what I was told by a reputable shop in this forum in term of Timing Profile.

"A good timing profile should have the lowest timing values near the trq peak, and throughout the midrange where trq is very high, and then gradually layer in more timing as trq falls off, and redline approaches. "

 

lol... I don't know if you'll fully understand but I'll explain it...

There's a term called TDC, or Top Dead Center and refers to where the piston is in the cycle. It can be BTDC (Before) which means the piston is RISING, or it can be ATDC (After) which means the piston has already reached its peak and is heading back down after the combustion.

The spark is ignited BTDC, so that the flame front of the combustion will finally hit the piston just after reaching TDC. If the spark were fired AT TDC, the flame front would hit the piston several degrees after peak since these timing degrees are such small fractions of a second that the time it takes for the flame to travel that tiny distance is actually factored in.

I believe stock timing at base (idle) is 15 degrees BTDC (you can see it on a plate somewhere in the engine bay). "Pulling" or "retarding" timing means you're starting the combustion process later than the ECU was planning on it.

MAX efficiency puts the flame front hitting the piston at TDC, but that is extremely dangerous as the simple fact that if detonation occurs BTDC, that is a TON OF STRESS on your rods and piston. Even regular combustion will put undue stress on this combo if hitting BTDC. Need any further explanation of it?

(oh, and this is the reason why when you put in crap-grade gas and the engine detects knock, it'll pull timing and you'll feel a power loss with this more conservative map because your combustion flame front is hitting your piston even further ATDC, which hurts efficiency)