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WOT timing retard with DISC 95 383

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Old Aug 27, 2011 | 04:03 PM
  #1  
chief455's Avatar
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From: Winsted, CT 06098
WOT timing retard with DISC 95 383

tune is awesome, AFR is 12.3-12.8:1 during boost 10lb / WOT
at 5000 rpm's I get timing retard, max allowed by setpoint - until up near 6000 rpm the retard gets less.
Ded stop / convertor flash launch is worst, hits around 4500 rpm.
retard is instant as soon as I hit 5000 rpm. Sometimes it will retard at lower rpms also after convertor flash = WOT.
RPM MAP-95 100
4000 = 24 24
4500 = 24 24
5000 = 24 24 RETARDS 5 DEGREES
5500 = 22 22 RETARDS 4-3 DEGREES
6000 = 20 20 NO DATA
6500 = 19 19
7000 = 19 19

should I subtract the amount retarded from my set points? and smooth the transition..

How low is this - should I be looking for another reason for the timing being retarded?

Last edited by chief455; Aug 27, 2011 at 04:16 PM.
Old Aug 28, 2011 | 09:29 AM
  #2  
onefastmx5's Avatar
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Joined: Dec 2008
Posts: 437
From: ABQ, NM
Re: WOT timing retard with DISC 95 383

12.3-12.8 is on the lean side for a boosted motor WOT, i'm running 11.5:1

I would try setting 5k to 22, and 5.5k to 20. Keep in mind the PCM will run an extra few degrees to those numbers automatically.

On my "max timing retard setpoint", i have it maxed out to pull like 13deg in all zones if it needs to (i've gotten bad gas before and this saved me)
Old Sep 6, 2011 | 11:24 PM
  #3  
dookie454's Avatar
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Posts: 573
Re: WOT timing retard with DISC 95 383

Originally Posted by chief455
tune is awesome, AFR is 12.3-12.8:1 during boost 10lb / WOT
at 5000 rpm's I get timing retard, max allowed by setpoint - until up near 6000 rpm the retard gets less.
Ded stop / convertor flash launch is worst, hits around 4500 rpm.
retard is instant as soon as I hit 5000 rpm. Sometimes it will retard at lower rpms also after convertor flash = WOT.
RPM MAP-95 100
4000 = 24 24
4500 = 24 24
5000 = 24 24 RETARDS 5 DEGREES
5500 = 22 22 RETARDS 4-3 DEGREES
6000 = 20 20 NO DATA
6500 = 19 19
7000 = 19 19

should I subtract the amount retarded from my set points? and smooth the transition..

How low is this - should I be looking for another reason for the timing being retarded?
Im having the same problem and I have the same 24 degrees entered and am probably around the same boost at that RPM. I added some 104 octane and it seemed to go away, so I'm also wondering what would make it go away without pulling more timing since I want to keep the power.. I'm thinking Meth Injection? With Meth do you think timing could be increased?

Last edited by dookie454; Sep 6, 2011 at 11:27 PM.
Old Sep 7, 2011 | 12:26 PM
  #4  
Kevin Blown 95 TA's Avatar
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Joined: Oct 2001
Posts: 2,684
Re: WOT timing retard with DISC 95 383

You guys should get a boost retard setup or 2 bar tune - anything besides taking all the timing out at 95 & 100 KPA which is 0 pounds of boost. Why leave all that power on the table?

And by all means get Meth/h2o injection and bring a lot of your timing back in.
Old Sep 7, 2011 | 12:52 PM
  #5  
RealQuick's Avatar
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Posts: 5,645
From: Bridgewater, MA
Re: WOT timing retard with DISC 95 383

Originally Posted by Kevin Blown 95 TA
You guys should get a boost retard setup or 2 bar tune - anything besides taking all the timing out at 95 & 100 KPA which is 0 pounds of boost. Why leave all that power on the table?

And by all means get Meth/h2o injection and bring a lot of your timing back in.
This...
Old Sep 8, 2011 | 04:56 PM
  #6  
roguedriver's Avatar
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Joined: Oct 2002
Posts: 1,194
From: Albuquerque, NM.
Re: WOT timing retard with DISC 95 383

I've run all the way up to 32deg with 100% meth on the dyno up to 12psi with no retard at all. I was scared to add anymore! With my fast xfi, i also had it up to 32deg before the HP increases finally started slowing down. I knew anymore timing at that point wouldn't gain much and i was reaching the limit. Without meth though, i wouldn't set the 95 and 100kpa cells much past 22 to 23deg.

Ken R.
Old Sep 10, 2011 | 10:25 AM
  #7  
dizwiz24's Avatar
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Posts: 125
Re: WOT timing retard with DISC 95 383

What compression ratio is your motor?

On my stock bottom end hotcaam/ported stock heads/lt headers lt1 motor w/ meth/water injection, I drop my timing back to 20 degrees by 5000 rpm. I'm at 11 psi boost at 5500 by the way. This is on a 1200 cfm p600b blower.

My timing curve (on '93 stock computer) looks likes this:

3600: 27
4000: 23
4500: 21
5000: 20
5500: 20
6000: 19

I have no idea if I can run more aggressive than this, but I believe so in cool temps.

Sometimes I will get some knock retard in 1st gear around torque peak. Its annoying bc I'll feel a loss of pull due to timing retard. Btw I have a dash mounted casper knock gage (its orig designed for a buick gn) so this makes it very clear whenefer the computer is doing knock retard.

If this happens, then I turn the dial on my msd6btm to allow a small amt of additional retard w boost. Usually I wont add more than about .3333 degrees addl retard per psi boost.

This only seems to happen on 80f+ days. Below that temp and the thing runs without a hitch.

Btw wideband afrs around 11.5:1 on my setup.

Last edited by dizwiz24; Sep 10, 2011 at 10:27 AM.
Old Oct 10, 2011 | 04:06 PM
  #8  
blown94's Avatar
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Joined: Oct 2004
Posts: 1,228
From: Florida
Re: WOT timing retard with DISC 95 383

[QUOTE=dizwiz24;6779667]This only seems to happen on 80f+ days. Below that temp and the thing runs without a hitch.
QUOTE]

LOL @ 80* days. Try running one of these cars in florida in the, well, anytime other than winter! Its like night and day when you run the car in the early morning even on a hot day vs in the middle of the day when the pavement temps are enormous and humidity unbarable. Feels like 50hp loss. The meth inj helps, but this time around im adding an intercooler cause by the time you compress 98* air i can only imagine what the intake temp sensor is reading, i never did check.
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