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View Full Version : 2003 silverado 8.1 w/5 speed allison and whipple intercooled supercharger



djv86
January 29th, 2015, 03:51 PM
a customer brought his truck into the shop with a detonation issue.. whatever tuning has been done to the engine and or the incorrect spark plugs have managed to blow up 3 engines the past 7 months.. engine is bone stock minus the carb approved whipple supercharger kit including the intercooler.. engine did have the incorrect heat range spark plugs.. correct plugs are in now and test drive will be tomorrow. I'm here to ask if anybody has performed a speed density tune on one of these engines..

I've got a few different methods of tuning and here to see what anybody here has done or found best results. i under stand the whipple ecu adds extra fuel once boost kicks in the only problem is the gm ecu NEVER goes into open loop and takes fuel away from the stock injectors under boost to maintain 14.7 afr causing horrible knock and piston damage.

is it possible to make a custom map using the CALC.VE method and during the copy and pasting to buy the new map the original map only goes up to 105kpa and this engine under boost makes almost 150kpa can i just increase the map reading to 160 and put a boost sensitive map sensor in or is the custom OS a MUST for controlling boost.. only thinking this since the moment i create the custom os is changes the os part number and here in california I'm unaware upon if the new smog machine will catch the diff os part number.

steps I've done so far

1. fuel pressure does what its supposed to per. whipple
2.boost doesnt excess whipples spec
3.monitored AFR using my wideband on bank 2 sensor 1 location and the AFR is between 10-11.1 under WOT and still "pings" while at WOT watching knock retard on the TECH2 it only see a maximum of 4 degrees retard

any help or information would be amazing.

hopefully there isn't already a thread on this exact configuration.

in the attachment is the current tune file before any custom stuff have been done minus tire and fuel tank parameters

djv86
January 30th, 2015, 05:22 AM
whoops sorry noticed its in the wrong area please delete if needed moderators..