On the Mustang dyno it just flatlined at ~6000 rpm (and stayed into 7K + )...These graphs were done using DLL and my guess is that the RPM range was not great enough / caused the issue with DLL.

 

hmm...I don't understand what you mean "the rpm range was not great enough"

the only time I've seen a dive like that in DLL is when the car is knocking or if I started going up a hill while the log was being recorded, slowing the transition to the next RPM. Sorry to bug you about it, it just seems odd.

 

The car was not knocking...I may have been going up a slight incline...On the Mustang dyno it was flat after 6K (until 7k)...Thanks for the help. I'll do another 3rd gear pull on perfectly flat road and see if it differs. Thanks again!

 

that's probably a good idea, maybe it was a fluke

 

A lot of good suggestions, I wanted to share my observation on STI/WRX with limited experience:

Fact I've seen while tuning: STI/WRX does well with aggressive timing.
1 BOOST increase = 15 WHP.
1 degree timing Advance = 8 WHP.

Based on some reading on this board, EVO seems to flow nicely and support increased boost. Hence, I will say that BOOST might be better option in your case (based on mods on your sig).

By the way, I noticed that alot of members change head stud if they are running beyond 23 PSI max boost. You might want to consider changing it as it might be a weak link based on some reading. It is not that expensive any way and it does make sense to me to replace them.

My personal opinion on your car based on what you said:

1. I would not increase timing unless WI is added.
2. I would lower the peak boost a little down as I prefer to trade a few WHP for the flatened curve. I love a feel of top-end rush with EVO. This was the reason why I got rid of mid range torque monster, STI , for an EVO.

Just my 2 cents.

 

We both run very similar setups, tunes ( I was surprised that his A/F at various points were identical to mine even...maybe not too surprised), the same boost curve more or less, and similar MIVEC. We both have admitted at various times that 25psi at peak torque is doable with reasonable amounts of timing still left on the grid. I have tried more but cant be consistent on it knocking or not so I leave it where it is. The IX head is just absolutely a marvel for what you can get away with versus the VIII. I wouldnt be shocked if there were additional differences between the two other than water passages. Contours of the combustion chamber, piston design, lobecenters, and other details go along way to make things like this achievable.

It seems to me that alot of shops are tuning for 23-24 theses days as a rule and not the exception.

 

My Vishnu tune is similar to yours also. A little leaner, more boost (as high as 25 psi), and a little less timing advance. I seem to have less timing advance than either you or cij911. Up to about 6000 rpm, I have no knock, but I do get a few knock counts every so often above 6000 rpm. I'm wondering if maybe I can fix that with a little more fuel.

Maybe next time I'm planning a trip to Portland, I'll stop in your shop for a custom tune.

 

After reading this thread, I am really curious about the safe boost level that IX's can handle. Currently, my car is tuned for 21.5 psi, using stock BCS. Would you guys say that these 24~26 psi boost settings are safe for even a car that is primarily set up for road-racing? Or am I just leaving a lot of power on the table, not taking advantage of IX's improvements? Thanks.

 

23 psi on a 9 running 93 octane is easy and should yield you a little power in the mid range...may not really do anything for a road course circuit if you are always above 5K....

 

I reread this thread again. There seems to be much talk about more advanced or more retarded timing vs boost and afr, but I haven't seen any examples of what people consider to be more conservative (retarded) timing vs advanced timing for a given boost/afr/rpm. e.g., if boost = 23 psi and afr =12.0 at 3000 rpm, what is considered conservative and aggressive timing?

 

to put it simply, it's hard to give a definitive answer because every car is slightly different. I've seen some cars that like 8* of timing down there and others that couldn't handle more than 2* for example. Also octane makes a big difference. 91 octane in some places seems to be much better than say California's oxygenated fuel aka "camel ****"

The key is to get the AFR where you want it and play with timing to see what your car likes the best. That low rpm range is critical because once it starts knocking down there it can ruin the entire pull. Then go back when you get the AFR and Timing right and add some boost, rinse and repeat. You really need some way to measure the performance to see what's working. Dyno, G-tech, Datalog Lab etc..

28 psi at 1* of timing down there could be much less powerful than say 24psi and 5*

 

use a g-suite?

 

stock cams

 

yes

 

AFAIK, the boost is set FIRST, then the AFR and then the Timing. If you set the boost AFTER the AFR and timing then the boost might change your AFR readings.