383_Stroker Returning To Dyno 11/23 -- Timing Experiments - Big Picts
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Joined: 09-17-05
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From: Pittsburgh, PA
Everyone has their own way.
Technically your timing curve should look almost like a horse shoe. At peak cylinder pressure you run the most amount of timing you can before knock (which will also be your lowest amount of timing) then ramp up from there to redline.
But E85 kinda screws with that, because I ran run the same amount of timing at redline that I can at peak cylinder pressure. I can not for the life of me get the car to knock.
This was an old school way I was taught.
Technically your timing curve should look almost like a horse shoe. At peak cylinder pressure you run the most amount of timing you can before knock (which will also be your lowest amount of timing) then ramp up from there to redline.
But E85 kinda screws with that, because I ran run the same amount of timing at redline that I can at peak cylinder pressure. I can not for the life of me get the car to knock.
This was an old school way I was taught.
Last edited by WSFrazier; Nov 24, 2010 at 07:08 PM.
I should have stated it clearer. Its not flat across the board. only from .80g/cyl and higher airmass, from 3k up. the graph curve does look similar to OP's below this.
It put down half decent #s on the dyno dispite my rough tune, stock catback, and lack of any cooling mods. but I know it will do more now with a good exhaust and some tuning.
thx for the info
I follow a theory called Max Torque Timing. I think it results in the best street tune.
Basically, you should be commanding your peak timing just before your engine makes peak tq. On the TVS, that is right around 4750. So if your peak timing is 25 degrees, you should be commanded 25 degrees in the cell before 4750. Whatever that is.
And ramp that timing a little harder and you will have much better TQ. Your HP numbers are right inline with most people on that setup. But your TQ is still behind.
If you are running 50/50 gasoline/E85 that should be plenty of octane to push the timing even harder.
I know there are going to be some people who will jump in this thread and say things like, "you could make a lot more blah, blah, blah..." Some people want you think that tuning the LSJ is rocket science. But it is not.
I would rather help you get there then criticize.
It looks like you have a pretty good street tune. The car must feel pretty good.
Basically, you should be commanding your peak timing just before your engine makes peak tq. On the TVS, that is right around 4750. So if your peak timing is 25 degrees, you should be commanded 25 degrees in the cell before 4750. Whatever that is.
And ramp that timing a little harder and you will have much better TQ. Your HP numbers are right inline with most people on that setup. But your TQ is still behind.
If you are running 50/50 gasoline/E85 that should be plenty of octane to push the timing even harder.
I know there are going to be some people who will jump in this thread and say things like, "you could make a lot more blah, blah, blah..." Some people want you think that tuning the LSJ is rocket science. But it is not.
I would rather help you get there then criticize.
It looks like you have a pretty good street tune. The car must feel pretty good.
Are you running a TVS? I believe the torque is going to peak much earlier than 4700rpm on the M62. What you are describing sounds more suited for M62, but I'd bring in PE much earlier. like 2800 and 4-5 psi
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From: Still fixing others mistakes.
You always say people dont run lean enough to take advantage of over 25.5*, but if I am correct (again this is me trying to figure you out) you like to run E85 at 11.5 tapering to 11.8 AFR since you said you have found over 11.8 is losing power on E, which is similar to what he is running. So do you not go past that much timing as well?
Which leads me to believe that maybe when you were on race gas or meth that you leaned the car out more and pumped more timing into it.
Am I close? Or maybe way off
Rent me! per hour
Joined: 03-22-07
Posts: 24,161
Likes: 20
From: Still fixing others mistakes.
.. My mind... its blownI'm running Methanol injection on top of the e85 mix currently. It's not just a 50/50 e85 mix.
..I do appreciate your input on this though.. feel free to keep talkin ;-)
Let me try to comprehend some things here based off some hints or "puzzle pieces" you have left in multiple threads lol.
You always say people dont run lean enough to take advantage of over 25.5*, but if I am correct (again this is me trying to figure you out) you like to run E85 at 11.5 tapering to 11.8 AFR since you said you have found over 11.8 is losing power on E, which is similar to what he is running. So do you not go past that much timing as well?
Which leads me to believe that maybe when you were on race gas or meth that you leaned the car out more and pumped more timing into it.
Am I close? Or maybe way off
You always say people dont run lean enough to take advantage of over 25.5*, but if I am correct (again this is me trying to figure you out) you like to run E85 at 11.5 tapering to 11.8 AFR since you said you have found over 11.8 is losing power on E, which is similar to what he is running. So do you not go past that much timing as well?
Which leads me to believe that maybe when you were on race gas or meth that you leaned the car out more and pumped more timing into it.
Am I close? Or maybe way off
Interestingly enough, at one point i moved from a flat 11.8 to a flat 12.0.. and lost 1 horsepower .. My mind... its blown
I'm running Methanol injection on top of the e85 mix currently. It's not just a 50/50 e85 mix...
I do appreciate your input on this though.. feel free to keep talkin ;-)
haha.. i see you've been paying close attention too
.. My mind... its blownI'm running Methanol injection on top of the e85 mix currently. It's not just a 50/50 e85 mix.
..I do appreciate your input on this though.. feel free to keep talkin ;-)
haha.. i see you've been paying close attention too
I forgot to compare it to the timing table that I had on before the fail table I have on now. This one similar to the one I was explaining last night, but has 25* max instead of 25.5 from the stock pulley. Our cruising area is way different but cheack out the similarities at WOT
You got a litte more in the 3800-4300 cells
You got a litte more in the 3800-4300 cells
I forgot to compare it to the timing table that I had on before the fail table I have on now. This one similar to the one I was explaining last night, but has 25* max instead of 25.5 from the stock pulley. Our cruising area is way different but cheack out the similarities at WOT
You got a litte more in the 3800-4300 cells
You got a litte more in the 3800-4300 cells
Side note... higher cruise timing is good for mileage..
.. and on e85.. you should rape it..lol