[SalEsh]

hello everyone, im very new to this car and have some questions.

im in the midst of dyno tuning my 300c and want to know what type of A/F do these engines like? as well as timing? i got a predator and was playing with it on my dyno the other night.

right now with the K&N CAI and the tuner i put down 301rwhp and 340ftlbs/t, i dont know what these are suppose to put down does that sound right?. i had our wide band on the car while testing and was messing around with the a/f, now i dont know what these engines like for a/f so i have it set right now at 12.0-11.8 ranging in there at WOT.

i had my tuner set on the 93 oct and CAI, then just modified the tune.


suggestions any one please. or tips or even settings lolol


thanks in advance!!!


Brandon

 

[joey]

I don't know about A/F ratios but 301hp and 340lbs is much better than the average 5.7. I doubt you will find much more with the Predator. I believe 290hp and 305lbs is around average for a stock 5.7.
Your 39 difference between HP and torque looks odd. 10-20 is more typical for a stock set-up. Some folks have blown their engines running too lean after messing with the a/f and timing. The blown engines were highly modified, but you still need to be careful. For a stock 5.7 with a drop in filter like yours, I think Diablo's canned tune is probably the best for your car.

 

[joey]

You might try posting your question in the Diablo forum here.
Diablo often pipes in.

DiabloSport Inc - LX Forums Modern Mopar Muscle

I looked around and found this thread that says under WOT 12.5-12.8 is a good range.
But you need to be using a Wideband for A/F and not the Predator.
Also monitor the knock retard with the Predator.

Air/Fuel, what should it read?? - LX Forums Modern Mopar Muscle

 

[SalEsh]

i was monitoring my a/f on our dyno, i just didnt know what a good range was, and this is a mustang dyno just a little fyi, dont know if that means anything to my question hehe.

as for my mixtures as of now i didnt go to crazy but i leaned out the 4kto 4800k range 3% and from 5k on i up'd the fuel 5%. again i didnt want to go to crazy as i dont know what they like. this made my a/f at WOT at the ranges i spoke of.


thanks very much for the info ill have a look see.


Brandon

 

[SalEsh]

forgot to mention about the other night when i was dyno'in.

i couldnt get a proper tach signal. i tryed the inductive pick up by straping it on a spark plug wire and it would not work, just jumped around. i tryed every single freaking wire and same results each time. does this have anything to do with the MDS? i dont recall turning this off...

we had dynoed a SRT-8 couple weeks back and all we did was strapped the inductive pick up on a spark plug wire and it got a good tach signal..

i had to use the optic eye to get a proper tach signal on my crank pully, the default in that was we had to put it on a long rod and had to hold it there by hand. not exactly alot of room down there to zap strap it too, and or use our electro mag to hold it properly.


any one have any suggestions?



Brandon

 

[SalEsh]

any one know????


Brandon

 

[Keithyhome]

you are correct re 5.7 Dyno

I don't know about A/F ratios but 301hp and 340lbs is much better than the average 5.7. I doubt you will find much more with the Predator. I believe 290hp and 305lbs is around average for a stock 5.7.
Your 39 difference between HP and torque looks odd. 10-20 is more typical for a stock set-up. Some folks have blown their engines running too lean after messing with the a/f and timing. The blown engines were highly modified, but you still need to be careful. For a stock 5.7 with a drop in filter like yours, I think Diablo's canned tune is probably the best for your car.

Joey,

you are spot on for the stock dyno on a 300C (290 / 300+ at the wheels). With a tuner, cat back, and intake together mine now pulls closer to 300/330 on a good day....the dyno don't lie. One has to remember the bolt-on power does not stack.

Barry Kluczyk wrote a detailed book called "High-Performance HEMI Builder's Guide 2003-Present" which provides a great bit of detail regarding bolt-ons for the HEMI. It also describes the differences between the 5.7 and 6.1 blocks and specification.

www.cartechbooks.com

 

[Keithyhome]

AF ratio for 5.7

a ration of 13 across the RPM range is great. Most tuners will alter this a bit and some will lean out close to 14 on the top end (5500rpm) which is getting dangerous.

My 3rd gear dyno pulls ran a flat 13:1 up to around 4700rpm then starts to go lean on the top end...this is using a SuperChips programer.

My 4th gear dyno pulls with the same tuner ran rich after 5,000 rpm and by 5500 reach 12:1...otherwise 13 across the rest of the rpm range.

Has anyone done 5.7 dyno runs with the Predator or Hypertech units?

 

[SalEsh]

a ration of 13 across the RPM range is great. Most tuners will alter this a bit and some will lean out close to 14 on the top end (5500rpm) which is getting dangerous.

My 3rd gear dyno pulls ran a flat 13:1 up to around 4700rpm then starts to go lean on the top end...this is using a SuperChips programer.

My 4th gear dyno pulls with the same tuner ran rich after 5,000 rpm and by 5500 reach 12:1...otherwise 13 across the rest of the rpm range.

Has anyone done 5.7 dyno runs with the Predator or Hypertech units?

i am using the diablo, and i will post all my numbers and ratios now that i know what the engine likes.



but as for the tach signal im still clueless, and my searching has brought me nothing.


Brandon

 

[ubeenbit]

I know this is an old thread, but I just experienced this tach issue tonight on my dyno. With wheel spinning in drive the tach signal was erratic and never real steady, in park or neutral stable and steady upto max rpm in park.

Has this issue ever been resolved or anyone else came across it?

Jason

 

[SalEsh]

I found that I just used our optic eye with a reflective tape on the crank works best

Brandon

 

[ubeenbit]

Thanks, I do not have the ability to use an optic eye right now.

So do all 300C have a problem with a steady tach signal with the wheels turning? It is a very strange issue, park or nuetral no problems at all.

I wonder how the cigarette lighter tach pickup works. I need to get one of those to try and avoid cutting back insulation.

 

[Eather]

I have a question for you all. My 5.7 has run great (k&n intake, cat back Magnaflow, programmable superchip.), until I changed the spark plugs. Now I am having a major miss in the timing I believe, it even stalls out when given quick bursts if throttle. Any suggestions?

so so confused!!

 

[joey]

I have a question for you all. My 5.7 has run great (k&n intake, cat back Magnaflow, programmable superchip.), until I changed the spark plugs. Now I am having a major miss in the timing I believe, it even stalls out when given quick bursts if throttle. Any suggestions?

so so confused!!

If dealer changed the plugs then I would take it back.

Not sure about Superchips logging, but see if there is anything you can log for each cylinder/spark plug. Maybe you will be able to log the spark miss, or some other cause.