Because I feel like the more information that is available, more informed a decision people can make! Also I have a sick desire for more information..(Ask Brad..)
In any event, I wanted to see what the LMS Alky tune looks like without spraying. Since they add no additional timing or boost I decided to give it a whirl. Plus I know they use throttle control for boost spikes (thus saving you from running too lean)...
The controller is set to spray at 7.5 PSI reading from the 3BAR at the manifold, initial is set at about 12o'clock (I had dialed this in last year but forget the volts on it) and usually I run the gain at 6. These test were done with just manipulating the gain.
Running the LMS 4X Alky tune without meth results in a small mount of fuel rail pressure drop, down to around 12Mpa at the boost spikes, but more importantly, even without ANY meth this tune did not develop any knock retard. Thus I can conclude that the advantage with Alky kits on the LMS tune is to assist in fuel pressure and lower IAT's. However, LMS doesn't seem to pull timing at the same thresholds as other tuners.. they are not as aggressive on pulling timing due to higher IAT's from what I can see. Due to amount of boost, timing, and how they implement throttle closures, you would NOT blow your motor if the pump fails or your run out of meth in the middle of a run. Silly safe.. Also, if you are running meth, there is no reason to purchase the HPFP unless you are looking to run HEAVY (+40% or more) Eblends, or running ATP's (guessing but I suspect even then, you dont need it as Mike B runs the bigger turbos with meth without issues.)
Running this with the gain set at 4 was interesting.. fuel pressure didn't get impacted as much, IATS dropped SOME but started to climb in 3rd gear, which means I am not spraying enough to offset the heat, again, no KR to speak off.
Running with the gain set at 6 resulted in what I normally see.. no fuel pressure drop, and the IATS drop through the whole run. HOWEVER, due to the throttle closures being used at the boost spikes air volume is being cut back significantly, and because you are still spraying you run stupid rich for a second. I believe this does have an impact on the amount of power being produced running that rich. Especially out of the whole where that first boost spike at 4500rpms has a huge throttle closure...
I would like to see the meth hit without causing the engine to run that rich off the line but still maintain the cooling effects on the IAT's through the run... I think this would net a better MPH and better ET at the track...
I think it would be good to increase the PSI when the meth hits, and dropping the initial amount of spray, but leaving a nice ramp up on the meth would be beneficial. I would be interested to see a datalog from a dyno tuned meth setup from LMS.. curious how they are handling it.
Couple of Notes:
1: The Boost in PSI PID is INACCURATE for some reason, I am actually running about 1/2 psi more than its reading. This was validated, the manifold absolute pressure PID is indeed accurate.
2: My car can take an UNREAL amount of timing without knock, so YMMV. IE: I run 28 degrees starting at around 4000 RPMS with 16PSI desired on Brads tune and never see more than +1 KR once in a blue moon.
3: The LMS 4+X Race Tune (non-meth) does not have any pressure drop at the rail. However, they are much more aggressive with the throttle controlling load on that tune. Boost and timing are the same however.
