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Forum nameTurbo/Nitrous Tech
Topic subjectTiming retard with 440's
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=60266
60266, Timing retard with 440's
Posted by mitsudsr, Nov-06-03 05:22 PM
Well this winter I am putting on 440's, profec b, safc, dis-2, and a 2.5" to cat to 3" out exhaust. With this setup I should be able to boost like 17psi or so on 93 octane and not sure how much on 110. I am a little scetchy on the whole timing deal. I searched and read a whole bunch of posts but did not realy leard anything. I am going to get it wide band dyno tuned and just wanted to know what numbers I should have for a base setting before I go. How much retarding is generaly necessary for a set up like this? I basicaly do not want to blow up on the dyno on my first pull. Thanks,
Patrick
96 GS
14.14 @ 96.5 mph on 8psi 8 Nov.02
HRC kit, S20G, FMIC, Howell bottom end 8.6 pistons, S-FMU, Blitz BOV, P&P head, SS valves, lots more little goodies
71095, RE: Timing retard with 440's
Posted by trey1219, May-17-04 01:13 PM
Some people are able to get away with no timing at all. Get a datalogger and find out how much advance you are getting. your car could be different. u might want to go with 550s just tobe safe cuz u might want to run a bit rich. That's what i've learned so far. I am trying to figure parts out as well.

Hope this helps,
Trey
71096, RE: Timing retard with 440's
Posted by MR BLUNT 2gnt, May-17-04 01:36 PM
every time i datalog i see the linear timing line from hell. 17* advance at wot, everytime. i was going to start researching the optimal timing degree recommendations at X psi but haven't as of yet. anyone know of a good link or book that goes in depth w/ timing and boost?
71097, RE: Timing retard with 440's
Posted by XtremeRS, May-17-04 01:46 PM
Originally posted by MR BLUNT 2gnt
every time i datalog i see the linear timing line from hell. 17* advance at wot, everytime. i was going to start researching the optimal timing degree recommendations at X psi but haven't as of yet. anyone know of a good link or book that goes in depth w/ timing and boost?


There are just way too many variables to actually say, you need this much timing with this much boost..Each engine is different, different octane fuels, boost pressure, air temperature, ect..all are factors. The general rule of thumb is, you want as much timing advance as possilbe, with the octane fuel you plan to use, and as much boost as you can run, without knocking. IMO, for our motors, running and average of 17 degrees advance, and lower compression pistons on 92/93 octane fuel, we should be able to run quite a bit of boost without knocking. I know several people who have run over 20-24 psi on the S16g without any timing retard, without getting knock, on 93 octane. Richening the A/F helps a lot, but too much, and you start to loose power. If you are on a dyno, use the wideband, and shoot for around 11.5:1 A/f, and run your boost pressure setting..If it knocks, then you may need to either use higher octane fuel, or cut timing, or lower you boost pressure. You could richen it up a bit, but then power output may come down, past 11.5:1 Fine tuning can be a real balancing act with all the variables like timing, octane, and boost pressure.
71099, RE: Timing retard with 440's
Posted by MR BLUNT 2gnt, May-17-04 02:03 PM
what datalogger shows knock? i wasn't aware of one that does, if there is one i'm buying it yesterday. i have a dis2 programmable to handle the timing retard and i always run 94 octane, usually a cam2 mix on track days. the last time i did this i didnt make to many drastic changes w/ the eic and it actually hurt my car more than it helped, i was way to rich and it fouled my plugs up pretty good. i have a lot of great tuners in my area that know shit tons about 4g63's and can predict pretty much exactly what the timing will do w/ just adjusting the fuel maps but the good old 2gnt isnt as easy to predict.
71102, RE: Timing retard with 440's
Posted by XtremeRS, May-17-04 02:23 PM
Originally posted by MR BLUNT 2gnt
what datalogger shows knock? i wasn't aware of one that does, if there is one i'm buying it yesterday. i have a dis2 programmable to handle the timing retard and i always run 94 octane, usually a cam2 mix on track days. the last time i did this i didnt make to many drastic changes w/ the eic and it actually hurt my car more than it helped, i was way to rich and it fouled my plugs up pretty good. i have a lot of great tuners in my area that know shit tons about 4g63's and can predict pretty much exactly what the timing will do w/ just adjusting the fuel maps but the good old 2gnt isnt as easy to predict.


Its easiest to see knock on a dyno. As of yet, there really is no good way to monitor knock on our motors. There are things you can put together to listen for knock, but it can be heard by your good ol ears most of the time. If you are on a dyno, knock is pretty audible, and any good dyno tuner will know exactly what it is, and it will prob show on the A/f graph, and prob your power graph, since knock will effect both. Knock on our motors sounds like metal balls in a can, a metalic rattlling sound, or spitting sound..You will know it when you hear it..if you are in the car driving, it sounds like its coming from the passenger dash area sort of..One thing to remember about using leaded race gas, is that it tends to make the motor run a bit richer, compared to unleaded pump gas. It has to do with the density of leaded race gas compared to pump.