Originally Posted by
freemaSSon
alot of the nitrous has to do with the amount of COMPRESSION.....many of the truck engines have very LOW C/R's in the high 9's and very very low 10's....
if you have an LQ4 or the LQ9 then the cylinder wall flex is reduced with a more ridgid bloack and the LQ4 has like 9.7ish C/R or something really stupid low and the piston are so deep in the block, it has like damn near a .100 "QUENCH" which is you piston to deck height clearance distance.....and anything over a .075 will permit you to run MORE of any power adder.....even if you deck the heads to 58 or smaller CC's to get the compression up and a .045 gasket you will get like an high 10 to 11 flat C/R and that DEEP SUNK piston will hold more timing, more NO2 more boost with lower octane.....
IMHO any truck with the LQ4 has the building blocks for more power than EVERY OTHER STOCK LSx bottom end PERIOD.....if you keep the RPM's to more than 6000 rpm's that stock bottom will handle 700 at the crank for more miles than the bushing that support the body.....HANDS DOWN the best STOCK BOTTOM.....
the 4.8's and 5.3's all have good starting points as well, the piston are sunk VERY deep in the bores "QUENCH" is one of the biggest power making secrets in the LSx generation motors......i am working with one of my brothers to build a 4-bolt 350 with the same technology edges in the LSx series in his dirt car, he is the lead tech in an old school machine shop in Houston and i have been trying to get him and the shop owner to experiment with some of my input and a roller setup in his dirt car to make MORE power with 93 octane......
so my long way to what i'm saying is it is MY THEORY that the rods botls are most effected from the ABOVE 6000 RPM power adding......and -HIC- it is not the timing that will get you it is the OCTANE.....if you use 100/101/104 whatever that range Unleaded race gas at your local track is buy 5 gallons add it to the tank at about 1/8th when you get to the track.....then leave the line on 10 degress of timing at 1800 rpms make all the KPA 10 degrees of timing then interpolate a LINEAR line from the ENTIRE COLUMN to about 4500-4600 rpms to 25 degrees and run the 25 degrees to the end of the table.....this will allow you to have a real FLAT hit then the shot will be at full strength at about the end of the 60' and it should run out the back door like you have never felt......
****BUT DO NOT EVER RUN MORE THAN 20 DEG. with 93 and that much nitrous.....with an additive try 22 but that is PUSHING your luck......5 gallons of 100 added to about 1/8th of a tank will net about 97-98 which is SUPER safe and it will make MORE POWER with a SUPER COLD plug.....TR7 minimum part #7317 and a TR8 may be best to be the SAFEST with the STOCK hyperuteptic pistons.....the colder the plug the cooler it should power not by much but at that amount of nitrous COOLEST is always best......i'm running the TR7 #7317 with a LOOSE .030 gap on my 200 shot.....
i am no authority just sharing my education and experience with nitrous......i have had to educte myself and i have been exposed to some of the most successful nitrous guys and i have become a sponge after all i have a 15G+ ENGINE at stake.....
as far as AFR i have found that the learner the shot DOES NOT ALWAYS MAKE THE MOST POWER.....my research with my truck has found about 11.6-11.9 is the sweet spot for me......put the NO2 pill in and leave it then toy with leaning the fuel pill until you feel it or see it begin to nose over......ANYTHING in the 11's is safe the 12's are only risky if you are on pump gas but with octane 12.5 is not unheard of.....but for me i have taken it all the way to 12.3ish and it started falling off at around the 11.9 range......anything leaner and i lost power.....the 11.9 as the shot gets going and mine settles in at 11.6-11.7 and drives out the back door.........200 shot PILLED at .78 and .41
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