ViperBing
Enthusiast
I anyone running any timing advance over stock with a 10 lb pulley on 93 octane?
How about with race fuel?
thanks in advance!
How about with race fuel?
thanks in advance!
VEC timing advance with a 10lb pulley
- Thread starter ViperBing
- Start date
EllowViper
Enthusiast
Pretty ball-z if you are getting away with zero timing adjustments with 10 lbs of boost...but GREAT question that I'd like to find out about too! When I gernaded my #3 on a 6.5 lb with W/M I was running zero retard (stock timing) once the W/M kicked in...and I guess I got enough detonation to kill a ring land on my #3 piston. With my 10 lb forged motor up with a better W/M set-up, I'm still retarding about 6-7 degrees give or take throughout the RPM band. I haven't really tuned it too tightly yet however since I just installed a progressive W/M card from Sean. So to answer your question, I'm still running '"********" on 93 octane with a 10 lb setup.
Russ M
Enthusiast
With 10 psi you should not be running more than 15 degrees total timing under boost, if you are then you should start investing in a new motor. Or driving around on 118 octane fuel or pure ****.
EllowViper
Enthusiast
"Theoretically" timing this beast at WOT isn't too tough of an equation based on the open loop timing curve Sean provides with his VEC instructions. I have not verified this timing curve via logging an ODB-II data stream however. Working off memory here, I recall max WOT timing is "something" like this:
2000 RPM=25 BTDC
3000 RPM=24 BTDC
4000 RPM=22 BTDC
4500 RPM=22 BTDC
5000 RPM= 28 BTDC
5500 RPM=29 BTDC
6000 RPM= 30-31 ?? BTDC
So what is the right approach for retarding the timing?? Depends. Rule of Thumb 1 degree per PSI? This engine loves timing. Like I said, before I "blew" the piston, I was running a very aggresive timing curve and the engine just loved it...but I was mistaken in my plug choice (stock plug). So was it the timing or plug that created my situation. The stock extended reach plug theoretically adds 2 degrees of timing based on the location of the source of ignition..plus the additional electroid heat contributes to pre-ignition. Now that I'm running the NGK two step colder plugs, that factors into the overal timing advance equation as well. Eitherway, retarding the timing at 10 PSI is a must. How much and when is the question to be answered.
2000 RPM=25 BTDC
3000 RPM=24 BTDC
4000 RPM=22 BTDC
4500 RPM=22 BTDC
5000 RPM= 28 BTDC
5500 RPM=29 BTDC
6000 RPM= 30-31 ?? BTDC
So what is the right approach for retarding the timing?? Depends. Rule of Thumb 1 degree per PSI? This engine loves timing. Like I said, before I "blew" the piston, I was running a very aggresive timing curve and the engine just loved it...but I was mistaken in my plug choice (stock plug). So was it the timing or plug that created my situation. The stock extended reach plug theoretically adds 2 degrees of timing based on the location of the source of ignition..plus the additional electroid heat contributes to pre-ignition. Now that I'm running the NGK two step colder plugs, that factors into the overal timing advance equation as well. Eitherway, retarding the timing at 10 PSI is a must. How much and when is the question to be answered.
BOTTLEFED
Enthusiast
good info Eric
I"m guessing that both contributed to your piston failure
too much advanced timing on the cast pistons creates excessive heat and stress on the weak ring lands and causes them to break
I refer to the example settings on this website to get an idea on timing settings
they go from mild to wild
SOME TIPS AND INFORMATION ABOUT VIPER TUNING
I"m guessing that both contributed to your piston failure
too much advanced timing on the cast pistons creates excessive heat and stress on the weak ring lands and causes them to break
I refer to the example settings on this website to get an idea on timing settings
they go from mild to wild
SOME TIPS AND INFORMATION ABOUT VIPER TUNING
EllowViper
Enthusiast
Tim,
Great link...Thanks!! Hadn't seen that before. Gives me some further ideas to mess around with. I pushed the timing up a bit Sunday and messed with my Progressive W/M a bit too and the motor really responded. My W/B is overheating so I have to stop messing around when that goes belly-up. I guess I need a new sensor and the $79 heat sink. My aluminum heat sink isn't enough. Man, I get 12 psi "RIGHT NOW" WHEN
Great link...Thanks!! Hadn't seen that before. Gives me some further ideas to mess around with. I pushed the timing up a bit Sunday and messed with my Progressive W/M a bit too and the motor really responded. My W/B is overheating so I have to stop messing around when that goes belly-up. I guess I need a new sensor and the $79 heat sink. My aluminum heat sink isn't enough. Man, I get 12 psi "RIGHT NOW" WHEN
EllowViper
Enthusiast
...I mash the peddle. A redesigned manifold w/integrated intercooler would sure be nice. I keep designing that in my head...
BOTTLEFED
Enthusiast
the direct-injection water/**** system you made seems like you already accomplished that
sounds like you are having fun with your new setup
too bad we just got 4 new inches of snow so I can't go out and fine tune my setup
EllowViper
Enthusiast
I hear you man...I'm in Colorado Springs this week...28 degrees, chance of snow...grey dreary skies. Makes me appreciate the sunny and 80 degree Tampa weather I left behind...much like San Diego this time of year! Year 'round driving in Florida is priceless. Just need to fix my A/C now!! Always something...plus my drivers window is starting to function very slowly now...doesn't even go down on "cold"days without cycling the switch a few times.
