[Turbo_RORO]

Originally Posted by toohighpsi

He is referring to the water flow settings on the AEM controller (where the water flow hits max) not the actual boost settings. He was running 11 psi boost on both pulls (175 kpa).

Fuel is the limiting factor, Greg wants to run the 75mm pulley (same that I used to run a 9.9 pass), but with the LT1 injectors it's exactly on the limit of the fuel system...

As for the boost system, the 2300 is good for over 900 RWHP if you have the engine and fuel for it.

Thanks. But I'm asking about spark timing. Was there a point where adding more timing did not add more power? I thought I read that he is running 26°. Was wondering what the power difference was between say 18 and 22 or 22 and 26?

[Turbo_RORO]

Originally Posted by toohighpsi

The water slows combustion, so you normally run a couple more degrees with it than without, but it does amazing things for preventing knock and keeping IATs and EGTs in line.
You probably have more in yours if you are only at 18, but watch for the point of diminishing returns with that E - don't add more timing than you absolutely need (even without knock). Ethanol has a really bad tendency to step right from controlled combustion to pre-ignition without ever going through knock (like gas does). I don't think I need to say that bad things happen quickly when that occurs.

Sorry, I did not see this post until now. I know that you guys understand what I was asking. I am just interested in the results that you have found. Thanks. Don't want to be pushy. Just interested.

[parish8]

I haven't spent much time on the dyno with mine. Pretty much basing my timing on my LS experience. I remember creeping timing up on a higher boost set up and picking up ~5hp/deg going from 15 to 18 deg. At just 18deg of timing we started pushing water. The heads were actually weeping on the dyno. We decided at that point to not go over 15deg and just add boost when we want more power. I plan on lowering the timing from 18 down to 15 as the boost goes up.

I can say I have made quite a few runs at my current hp level, so far so good and it is making great power with "low" timing.

Never messed with water.

[Turbo_RORO]

Originally Posted by parish8

I haven't spent much time on the dyno with mine. Pretty much basing my timing on my LS experience. I remember creeping timing up on a higher boost set up and picking up ~5hp/deg going from 15 to 18 deg. At just 18deg of timing we started pushing water. The heads were actually weeping on the dyno. We decided at that point to not go over 15deg and just add boost when we want more power. I plan on lowering the timing from 18 down to 15 as the boost goes up.

I can say I have made quite a few runs at my current hp level, so far so good and it is making great power with "low" timing.

Never messed with water.

I agree I use the tables in HP Tuners to add or subtract timing both with ethanol and methanol. For example
93 only= 15°
93+ meth= 20° max (iat based)
e85 only= 20° max ( ethanol content based, all off the way to 99%)
e85 + meth= 22 ° ( iat and e content based)
e85 +meth + nitrous=??? Still working it out. Probably 17-19°
Ms109 + meth + nitrous = next to test!

[toohighpsi]

17 degrees is the minimum I would run on an LT, if you're down to 15, you'll probably find more power by lowering boost a bit and raising timing. On the other end of the range, 22-23 degrees is the most I would run before going to a smaller pulley and running more boost - if the fuel is available. It is important to note that my experience on LTs is with PD SCs, your results with a centrifugal could be different since you're running less boost across most of the operating range.

My LT4 Z06 for example was running 91 pump, 1600cc/min of 50/50 water/meth (2 large nozzles), 15psi boost and 27 degrees of timing to make 712rwhp, it still gained 8hp going from 25 degrees to 27 degrees with no knock so I left it. I couldn't raise boost any more as it is the smallest SC pulley available.

Unfortunately I guess I drive the car harder than I though and was using 1-2 gallons a week of meth - wayyy too much grief for a daily driver. I have since switched to straight water in the tank, dropped the water flow to 600cc/min and re-tuned. It's much easier to just pull in a gas station or grocery store and buy a gallon of Reverse Osmosis or Distilled water than find methanol and mix (we can't buy the blue -20 washer fluid here, plus distilled water is only $0.99/gal).

I'm right on the edge of the fuel system without the meth, but still running 15 psi boost and 21 degrees of timing on 91 pump. Power? I'd guess about 670-680 RWHP. Maybe have time to get it back on the dyno sometime soon.

[Turbo_RORO]

Originally Posted by toohighpsi

17 degrees is the minimum I would run on an LT, if you're down to 15, you'll probably find more power by lowering boost a bit and raising timing. On the other end of the range, 22-23 degrees is the most I would run before going to a smaller pulley and running more boost - if the fuel is available. It is important to note that my experience on LTs is with PD SCs, your results with a centrifugal could be different since you're running less boost across most of the operating range.

My LT4 Z06 for example was running 91 pump, 1600cc/min of 50/50 water/meth (2 large nozzles), 15psi boost and 27 degrees of timing to make 712rwhp, it still gained 8hp going from 25 degrees to 27 degrees with no knock so I left it. I couldn't raise boost any more as it is the smallest SC pulley available.

Unfortunately I guess I drive the car harder than I though and was using 1-2 gallons a week of meth - wayyy too much grief for a daily driver. I have since switched to straight water in the tank, dropped the water flow to 600cc/min and re-tuned. It's much easier to just pull in a gas station or grocery store and buy a gallon of Reverse Osmosis or Distilled water than find methanol and mix (we can't buy the blue -20 washer fluid here, plus distilled water is only $0.99/gal).

I'm right on the edge of the fuel system without the meth, but still running 15 psi boost and 21 degrees of timing on 91 pump. Power? I'd guess about 670-680 RWHP. Maybe have time to get it back on the dyno sometime soon.

Thanks for the info. I have a dyno rental coming up so I am looking for This kind of info just to keep in the back of my mind. I have a Plan but I don't know it all. I will bring my larger pulleys as well. See how that pays off. Also may play around with some of the M1 I have sitting in the corner. Shit I have too many fuels.

[laynlo15]

Mike is right but I will have the bigger injectors this winter along with a few goodys we also have planned. All that know me have seen I go through with my plans in a timely manner as I did with my Magnuson SC G8 and now my Gen6. It will be a wicked ride when I'm done, its in my DNA, can't leave it alone. Good thing or bad thing?

[DFW1LE]

Originally Posted by laynlo15

Good thing or bad thing?

Old Chinese proverb, "Behold the turtle, he makes no progress unless he sticks his neck out."

[laynlo15]

My neck is way out and won't go back in the shell till I take my last shit.