Formula934

iTrader: (4)

Been research different timing combinations for the past few months. What i want to do is get a list of everyones setup that is specific to high compression, boost level (turbo or supercharger), pump gas/E85 or methanol and the most important part what timing your running, also include if its stock bottom end or not. Obviously this is a reference but would give me an idea where to set my timing tables. Im sitting at 16 degrees at peak torque and 18 up top with 11.7 afr and the motor is loving it. I just ordered a 4.25 pulley for the d1sc and hoping for 8-11 psi up top.

Just so i am clear, ive researched every ls1 tech post relating to high compression and timing and most threads leave out the timing part and are not specific to what i want to know. What this thread is designed to do is be very specific to only High compression setups only and meth + pump gas and most importantly the timing / AFR /boost level.

Heres my setup:
Stock 346 ci bottom end ls1
-Cnc ported 243 heads milled 11.1 CR
-TSP 228R cam
-Kooks headers into magnaflow cb (no cats)
-Ported fast 92/92
-hardened pushrods & dual valve springs
-100 % meth injection (alky control) single 15 g nozzle
-D1sc twin intercoolers 4.5" with 4.5" pulley

Last dyno was 600rwhp/515rwtq. Timing was erratic due to spark smoothing turn on and ltft were not disabled at the time. Should be closer to 630/550 at this point.

Old Geezer

iTrader: (3)

Obviously, the timing u are running, didn't result in a melt down. So,rerun the test w/ the smooth/ltft turned off, back down a few degrees, to start with. Read the plugs, data logs, and see where you are, & sneak up on it.
Using others tune info is a good way to join the "DOTC" club....

JoeNova

15 PSI on a 10.5:1 5.3 with 11 degrees of timing on straight pump gas.
I hear afterwards he was running 20 lbs with 93 and water/meth and 9 degrees.

Denmah ran an almost identical combo, flat top 5.3 with 706(or 862) heads, pump gas, 23 PSI and 9 degrees.

Formula934

iTrader: (4)

I agree there is no substitution for a systematic approach to tuning like you suggest and believe me, im not implying anyone should copy and paste timing off of someone elses setup but its nice to have a reference for people with high compression setups because believe it or not, theres not a whole lot of data out there. From all the reading ive done, theres too much variation from setup to setup to even get a ball park estimate as to what would be remotely close to start with timing. I think this thread could help some guys considering a high compression combination which is not as unpopular as it used to be 10-15 years ago.