In a nutshell, boost can be progressively increased, while ignition timing is proportionally retarded, and there will be increases in power. However, the one piece of information which we never see is where EGTs are when this is done to what we consider to be extremes. If the ignition is retarded too far, we still have burning fuel when the exhaust valve opens, and that is not a good thing. IMO, retarding ignition timing should be limited such that EGT is kept to a maximum of 900C before the turbo and 800 afterward.



So, just what IS in Room 237 Mr. O'Halloran. . . ?

 

I think Ignition Timing is over rated, yet every motor is diffrent, both my 35R and 42R motors have made LOTS of power with no timing, in fact adding timing added no power. Looking back at my 35R map 27psi@6000rpm= 7degrees. and i made 609whp@35psi with C16

 

I've pushed EVO's from 26lbs to 32lbs on 93 octane pump gas with no issues. Those cars all had worked (ported, polished, valve job, etc) heads though. I've not had a chance nor really cared about pushing a stock head EVO far on pump gas. Some people prefer to play it very safe when it comes to straight pump gas. Other makes. In the Supra/2JZ world it was unheard of to run over 16lbs through a single on pump gas. Nothing wrong with that or running 22lbs on a fully built EVO with pump gas. I've had Supra owners jaws drop or walk away shaking their heads when I have tuned other's cars to 680whp through a 6-speed or 600whp through a 2-speed Powerglide on 93 octane pump gas. Then when I tell them inline four cylinder EVO's are doing that on 93 octane pump gas It's pretty funny but a lot of money spent for anything to happen. In the end it is all up to the owner and tuner to figure out where they want the car to be

 

So true.

 

but fun!

 

I'll say only one thing and quickly. When looking at Knock Voltage on the AEM you are basically looking into the sky. You can make the clouds take whatever shape your imagination wants.
Reality is in Knock RAW. Datalog some raw voltage in fourth gear and then decide what your boost and timing threshold should be.

To the OP good job on your trial and for the record, the timing values you used are not that conservative. You did a good job incrimenting and learning what the engine can and cannot accomplish with your particular setup.

 

Another guy that has owners jaws drop or walk away shaking their heads

 

Good post!

 

What timing did you have when you made 609whp@35psi? If you only ran 7 degrees @ 27psi then you must have been running somewhere in the 3 degree range @35 psi.
You must have a very fast burning mixture the be making good power with that little timing.

 

Yeah I agree 7 degrees advance on C-16 seems odd.

High compression motor maybe?

 

quite interesting post...

however on C16 i would imagine that the car even at 30psi would be able to handle timing advance even close to 20 degrees... I am not expecting to continue to get ~20awhp for each increment but maybe a little bit more power...

i hope you would continue the test from where you left it...

 

I have run 22 degrees with water/meth at 32psi over 6500rpm making 553 at Sporty Dyno with hks 272 cams.After hard driving in the street for a couple months i spun a rod bearing.Pistons and head gasket was new. Another evo stock engine with 20g i ran 20degress at 22psi over 6500rpm and as low as 8 at 3000 with water/meth and still running 11.3 in the 1/4,i open the engine to fully built it with a gt35r and stock pistons was still new.With c16 i will not run so low timing as you do.

 

running anymore than 12Degrees MAX timing on C16, 35R, 8.5:1, HKS 272 and stock intakmanifold was pointless as it just increased knock and made Zero power diffrance on a AWD dynoject. But thats just my motor. And my new setup makes power on no timing as well.

 

allthough my friends 1G DSM on pump gas is at 22psi and 17 degree max timing. I also made the most power with a 1G DSM on DSM Link, 3065, 24degrees max timing 33psi on C16. So maybe my car is just very odd.

 

The 1G ECU doesn't really account for timing belt stretch if I recall correctly. Seemed like 22 degrees at 7000 RPM equated to about 16 degrees actual advance. Or at least some where in that neighborhood.

Every motor is different. But my personal opinion is I like to mess with fuel and find the fuel that will get the best mph with the lowest timing advance for a given boost level. I like to mess with the stock block though and it is my opinion that the best way to keep a stock block in one piece is low timing advance and a stockish rev limiter. You can still go very quick with those limitations.