[Carlos Garza]

Predator - knocks Retard - Custom CMR Tune

I live Mexico and have been a Charger SRT8 owner for the past 6 months and I love my car. In Mexico, the best gasoline we get is 92 octane, at least that's what they advertise. I've been trying to get a custom tune for my car but there is only one dyno at my home town and I don't think the guys that runs it knows much about toning cars, so I'm not letting him touch my baby.

What I would like to do is to buy an email tune from the guys at ProMotion tunes. For that I need to get my laptop fixed before I can datalog my diablo tuner using the Data Viewer and send them the results.

So for know, what I ended up doing is using the hand held to see what results I could get, and here they are:

I ran the car on third gear from a roll starting at 2000 RMP until the car shifted to forth gear. I did this using the Stock Tune first and then ran it using the 91 CAI tune with raised shift points and RPM.

Original Stock Tune.

RPM........2080......2528......3000.....3520.....4000.....4576....5056.....5504.....6144
Knocks.....0,00......2,50.......2,50......3,00......2,50.....1,00.....1,50.....1,50......1,50
MPH.......40,50.....47,00.....58,00....67,50.....75,50....88,00...97,50..106,00...118,50


91 CAI tune r17

RPM........2016......2528......3008......3520.....4000.....4512....5088....5504......6080......6400
Knocks.....0,00.......3,50......3,00.......2,00.....3,50......2,50....4,00.....3,50.......4,50..... 3,00
MPH.......37,50.....48,00.....57,50.....67,50....77,00....87,00...97,50..106,50...117,00... 123,50

I've read that it's hard to tune a car that has knocks retard with the original stock tune, but I've definitely notice more power, better ETs at the track and better 0-60 times since I got my Diablo toner. So after all this I have a few questions...

1. Are the knocks retard that I'm getting fixable? and if they are, What do I do to fix them?

2. Could this be doing any damage to my car?

3. With the fuel we got here in Mexico, Can I increase my cars performance with a custom CMR tune?

Thanks guys

 

[Hemi_charger]

I live Mexico and have been a Charger SRT8 owner for the past 6 months and I love my car. In Mexico, the best gasoline we get is 92 octane, at least that's what they advertise. I've been trying to get a custom tune for my car but there is only one dyno at my home town and I don't think the guys that runs it knows much about toning cars, so I'm not letting him touch my baby.

What I would like to do is to buy an email tune from the guys at ProMotion tunes. For that I need to get my laptop fixed before I can datalog my diablo tuner using the Data Viewer and send them the results.

So for know, what I ended up doing is using the hand held to see what results I could get, and here they are:

I ran the car on third gear from a roll starting at 2000 RMP until the car shifted to forth gear. I did this using the Stock Tune first and then ran it using the 91 CAI tune with raised shift points and RPM.

Original Stock Tune.

RPM........2080......2528......3000.....3520.....4000.....4576....5056.....5504.....6144
Knocks.....0,00......2,50.......2,50......3,00......2,50.....1,00.....1,50.....1,50......1,50
MPH.......40,50.....47,00.....58,00....67,50.....75,50....88,00...97,50..106,00...118,50


91 CAI tune r17

RPM........2016......2528......3008......3520.....4000.....4512....5088....5504......6080......6400
Knocks.....0,00.......3,50......3,00.......2,00.....3,50......2,50....4,00.....3,50.......4,50..... 3,00
MPH.......37,50.....48,00.....57,50.....67,50....77,00....87,00...97,50..106,50...117,00... 123,50

I've read that it's hard to tune a car that has knocks retard with the original stock tune, but I've definitely notice more power, better ETs at the track and better 0-60 times since I got my Diablo toner. So after all this I have a few questions...

1. Are the knocks retard that I'm getting fixable? and if they are, What do I do to fix them?

2. Could this be doing any damage to my car?

3. With the fuel we got here in Mexico, Can I increase my cars performance with a custom CMR tune?

Thanks guys

Carlso try different gas stations I know there probably mostly pmex right?? so maybe an octane booster or find some race gas that you can mix in to bring up the quality of the gas

 

[metgo]

To fix the knock just pull a little timing out.

 

[Carlos Garza]

To fix the knock just pull a little timing out.

Should I pull about 2 degrees all across the board?

 

[metgo]

I would just do 1 degree at a time across the board until you don't get knock.

 

[Vagabond]

Be very careful with messing with the timing. Small steps are best, big ones can lead to big damage.

 

[Hemi_charger]

Be very careful with messing with the timing. Small steps are best, big ones can lead to big damage.

Not with retarding Metgo is right start to pull timing out

 

[Carlos Garza]

What if I Give it 3% more fuel... that would keep me from messing with the timing...

 

[Hemi_charger]

What if I Give it 3% more fuel... that would keep me from messing with the timing...

yeah you could add fuel till the knock goes away you might have to do both

 

[Carlos Garza]

yeah you could add fuel till the knock goes away you might have to do both

I just hope this helps mi car get more power

 

[Hemi_charger]

I just hope this helps mi car get more power

once you get rid of the knock then you can start tuning for even more. did you have any results yet?

 

[Carlos Garza]

once you get rid of the knock then you can start tuning for even more. did you have any results yet?

yes... I modified the tune by adding 3% more fuel, here are the results:

91 CAI Tune with raised shift points, RPM and +3% fuel all across the board.

First Run with the Car Temp at 185 degrees
RPM......2016......2560.......3072.......3520.......4000......4512......5056......5472......5536........6016......6336.......6368
NK.........0.00.......0.00.......0.00.......0.50........1.50.......0.50......2.00.......1.00.......0.50........3.00.......1.50.......0.00
MPH.....40.00......48.00.....58.50......67.50......77.00.....86.50.....97.00....105.50....106.50....116.00....122.50....123.00

Second Run with the Car Temp at 190 degrees
RPM.......2016.......2560.......2688......3008......3520.......3872......4000.......4512.......5024.......5568.......6016.......6408
NK.........0.00........0.00........2.00......0.50.......1.50........3.50.......3.00.......2.00.......1.50........0.50........0.50.......3.00
MPH.....39.00.......48.00......51.00.....57.50.....67.50......74.00......77.00.....86.50......96.50....107.00.....116.00....125.00

 

[Hemi_charger]

hmm crank up the fuel some more and see what happen like to 6 to 8 %

yes... I modified the tune by adding 3% more fuel, here are the results:

91 CAI Tune with raised shift points, RPM and +3% fuel all across the board.

First Run with the Car Temp at 185 degrees
RPM......2016......2560.......3072.......3520.......4000......4512......5056......5472......5536........6016......6336.......6368
NK.........0.00.......0.00.......0.00.......0.50........1.50.......0.50......2.00.......1.00.......0.50........3.00.......1.50.......0.00
MPH.....40.00......48.00.....58.50......67.50......77.00.....86.50.....97.00....105.50....106.50....116.00....122.50....123.00

Second Run with the Car Temp at 190 degrees
RPM.......2016.......2560.......2688......3008......3520.......3872......4000.......4512.......5024.......5568.......6016.......6408
NK.........0.00........0.00........2.00......0.50.......1.50........3.50.......3.00.......2.00.......1.50........0.50........0.50.......3.00
MPH.....39.00.......48.00......51.00.....57.50.....67.50......74.00......77.00.....86.50......96.50....107.00.....116.00....125.00

 

[PPP-Tech]

Just take one persons advice and run with it. If you do a little of everybodies recomendation, you will never know what is fixing it and/or what is making it worse. We are a cmr tuner and do this on a regular basis, I would just add 2-3% more fuel in the range where knock still exists and if that doesnt fix it, retard 2 degrees of timing where it is knocking at.

 

[TBYDaytona40]

Yall are far braver than me. No WAY would I even consider doing this myself.

 

[PPP-Tech]

adding fuel and removing timing is actually making it a safer tune. You could do it easily.

 

[TBYDaytona40]

Probably, but I would be afraid to. Somethings I think I'd rather pay pros for.

 

[Hemi_charger]

adding fuel and removing timing is actually making it a safer tune. You could do it easily.

yeah you cant hurt it by adding fuel and pulling timing. Just don't lean them out thats when things go bad

 

[Carlos Garza]

I’m confused now…. I found 2 different KNK measurements. KNK FUEL RETARD and KNK LT RETARD, witch one is the one I should be monitoring?

 

[mnunes]

Mine says "KNOCK TOTAL RETARD" - that's the one that they've been referring to many times in the Q&A thread.