brrgrr

Here is a recent (simulated, of course 3rd gear WOT run at 16 psi. The data was imported into excel to produce the graph below. Your thoughts on the AF ??

Bri Bro

Too lean between 3-5K. It should be slopping down from 14.7 at 2K to 11.8-11.5 by 3.5K, then flat at 11.8-11.5 to 6.5K. Running +13 at 4K is begging for detonation. All my answers are of course, simulated

gt37vgt

Show off

Rogue_Ant

Peak torque (when boost first hits ~16psi), is where your richest spot should be. That is where you are most likely to knock...
I would shoot for mid/low 11's at peak torque, then hold 11.5-11.8 for the remainder of RPM.


-Rogue

Van

Neat stuff!

toddk911

As I have learned from Rogue, it is more boost incumbent than rpm.

Think about it, an NA motor runs about 14.7 at idle and at 6K and no issues because there is no boost.

So a super quick spool would need to be in the 11-12's maybe by 2,500 and a laggy turbo maybe not till 4K.

How much room is there to lean it up to aid in spool up? I assume you would still want to be under 13 even for spool up?

brrgrr

The car has a Kokeln stage V turbo, 3" exhaust, MAF, LR Stage II head and intercooler, 65 lb injectors, MBC, LR DP wastegate, Tech edge WB, and a few other things.

This run was a 2500 rpm "roll on" to WOT - boost builds progressively starting at 2800 or so and hits 16 psi by 3400.

I will be adding a little fuel in the 3500 - 5000 rpm range to get into the low 12's. You actually tune using the MAF Voltage as a reference, so this is the graph I use to actually make adjustments......

Van

Can you datalog boost levels, too?

Makes me want to get a wideband and log it with my traqmate!

JohnKoaWood

That is exactly why I went Zetronix.. I log boost, EGT, AFR, Throttle Position, MAF V, RPM, can export the raw data or use the interface for graphs of all side by side or individual traces... it has been indespensable for tuning IMHO... but that is just me..

Daily use I am only displaying boost, AFR, and Knock counts on the dash so I can see when something blows up...

Bri Bro

That what I do, works well.

Ziff951

I've been tuning my AFR on mine (LR 340 kit) with my laptop in the car with me. It seems that it's boost, or load, that dictates the AFR more than rpm. Is that correct? I can be running in 3rd at 4k rpms and be fairly lean (14 ish) since I'm under no boost, then when I dip into the throttle and boost builds, the AFR adds fuel in a nice curve towards 11-11.5 at WOT.
I say all this not as a pro, I'm learning too and just wanted to put some more info in the pot, but it seems like when we're off boost it's basically like an N/A car... right? So, higher rpms without load wouldn't necessitate a rich condition..

And yes, it is nice having all the gadgets to monitor and adjust everything... ;-)

951_RS

Yes, high rpm no boost would be fine at 14.7

brrgrr

It is total mass - airflow through the MAF that dictates fuel. As the total mass-air goes up, the voltage output from the MAF goes up, and it dictates a different spot on your "fuel curve" At high rpm and no boost - you are not pumping nearly as much air as high rpm and full boost.

To answer the earlier question on boost - No, I don't have the ability to log it - I know about where it falls on the fuel curve but it would be nice to see it exactly.

Rogue_Ant

But down on power. NA tunes for 12.8-13.0 for max power.


-Rogue

toddk911

http://www.dsmtuners.com/forums/tuni...boost-psi.html