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Shawn_Mc

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10:1 compression seems a little bit high for boost dont you think? I’d hate to restrict the car to just race gas or e85
If he kept the boost to a reasonable level (5-6) and the timing to mid 20's, he'd probably be ok on 93 pump if the water temps were under control.
 

Hoytster

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Drivetrain loss is not static, it's a percentage which is typically calculated at 15% for a manual (on the high side). That gets us to 430. Typical total accessory lose is usually 15-25HP. These are on the high end, assuming the alternator is putting out 100 amps plus, full RPM on the water pump and power steering pump, ect.
 

Hoytster

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The 11r head design allows you to run more comp with boost. My engine with the 9.3 comp is planned for 20+ pounds once I change chargers. With your comp, you could go well into the 10's on pump, keeping your intake temps down.
 
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Cclaro

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If he kept the boost to a reasonable level (5-6) and the timing to mid 20's, he'd probably be ok on 93 pump if the water temps were under control.
I keep it at around 180 without ac around town. With ac depending on how hot the day is it’ll creep to the low 200s
 

Shawn_Mc

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I just updated my DynoSim6, so I'll get that info back tonight. Ive got some stuff to do.

As a side question, what ECU are you running?
 
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Shawn_Mc

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Drivetrain loss is not static, it's a percentage which is typically calculated at 15% for a manual (on the high side). That gets us to 430. Typical total accessory lose is usually 15-25HP. These are on the high end, assuming the alternator is putting out 100 amps plus, full RPM on the water pump and power steering pump, ect.
you can work the loss as a percentage, but it wont be the same for each engine. An alternator that requires 15-20hp at RPM X is going to require that HP regardless of how many Gross HP are turning it. IE a 1000 hp engine is still going to suffer the 20hp loss, just like a 400hp engine was, turning the same alternator at the same speed. Does that make sense?
 

Hoytster

I don't dare do that to my Knob
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you can work the loss as a percentage, but it wont be the same for each engine. An alternator that requires 15-20hp at RPM X is going to require that HP regardless of how many Gross HP are turning it. IE a 1000 hp engine is still going to suffer the 20hp loss, just like a 400hp engine was, turning the same alternator at the same speed. Does that make sense?
I think you might have misunderstood me, only the driveline is a percentage. Driveline loses are primarily frictional losses which increase as power output through the driveline increased. The accessory loss I stated of 15-25HP is the typical measured accessory loss of the alternator, ect on a Foxbody, which is static. Basically the same thing you just said, I think.
 
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Shawn_Mc

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What I found using a Comp XFI236HR-14 236/248 Hydraulic Roller Cam ( https://www.compcams.com/xfi-computer-controlled-236_248-hydraulic-roller-cam-for-ford-351w.html ). The Comp grind is only .579 lift. I stretched it to .608 for these tests.
The first one is at straight up degrees. The second is -4 from suggested. Also, note the ignition timing...I wish the simulator would let you pick a better combustion chamber. They give you 3 to choose from from each (flat, wedge and a Hemi/Pentroof) The ignition timing setting is on auto in the Sim. Your results obviously varied. I entered the flow numbers at each point of lift off the TFS spec. Spec'd a high performance open plenum manifold with a 1000cfm throttle.

The last one is advanced 4 degrees. Look at the meat in the middle. That's got street car written all over it.

Looks like this page is reversing the order of the pics as I post them. Highest number is -4, middle number is 0 and lowest peak is +4, but the middle of the power is the best at +4, by far.
357FW Advanced 4.JPG


Straight up 357FW HP graph.JPG
4 degrees retarded 357FW HP graph.JPG
 
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Cclaro

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What I found using a Comp XFI236HR-14 236/248 Hydraulic Roller Cam ( https://www.compcams.com/xfi-computer-controlled-236_248-hydraulic-roller-cam-for-ford-351w.html ). The Comp grind is only .579 lift. I stretched it to .608 for these tests.
The first one is at straight up degrees. The second is -4 from suggested. Also, note the ignition timing...I wish the simulator would let you pick a better combustion chamber. They give you 3 to choose from from each (flat, wedge and a Hemi/Pentroof) The ignition timing setting is on auto in the Sim. Your results obviously varied. I entered the flow numbers at each point of lift off the TFS spec. Spec'd a high performance open plenum manifold with a 1000cfm throttle.

The last one is advanced 4 degrees. Look at the meat in the middle. That's got street car written all over it.

Looks like this page is reversing the order of the pics as I post them. Highest number is -4, middle number is 0 and lowest peak is +4, but the middle of the power is the best at +4, by far.
357FW Advanced 4.JPG


Straight up 357FW HP graph.JPG
4 degrees retarded 357FW HP graph.JPG
Yeah the ign timing is way off from what it realistically would be, lost like 15 horse bumping up the timing to 31 if I remember correctly.
 

Cclaro

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Aug 1, 2020
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What I found using a Comp XFI236HR-14 236/248 Hydraulic Roller Cam ( https://www.compcams.com/xfi-computer-controlled-236_248-hydraulic-roller-cam-for-ford-351w.html ). The Comp grind is only .579 lift. I stretched it to .608 for these tests.
The first one is at straight up degrees. The second is -4 from suggested. Also, note the ignition timing...I wish the simulator would let you pick a better combustion chamber. They give you 3 to choose from from each (flat, wedge and a Hemi/Pentroof) The ignition timing setting is on auto in the Sim. Your results obviously varied. I entered the flow numbers at each point of lift off the TFS spec. Spec'd a high performance open plenum manifold with a 1000cfm throttle.

The last one is advanced 4 degrees. Look at the meat in the middle. That's got street car written all over it.

Looks like this page is reversing the order of the pics as I post them. Highest number is -4, middle number is 0 and lowest peak is +4, but the middle of the power is the best at +4, by far.
357FW Advanced 4.JPG


Straight up 357FW HP graph.JPG
4 degrees retarded 357FW HP graph.JPG
Wouldnt advancing or regarding the cam just change where the car makes power and not necessarily how much power The car makes?
 

Shawn_Mc

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Oct 1, 2021
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Wouldnt advancing or regarding the cam just change where the car makes power and not necessarily how much power The car makes?

You can make a litte more peak, assuming the heads are capable of flowing the air, but for the most part, you're correct. Really what youre doing by adjusting the cam timing fore and aft is trying to find the meat of the power band in the most likely used portion of the RPM range. That's why I suggested advancing the timing a little for the street. Even if its a street strip car, if its a daily driver, it'll be more fun to drive with that beefy mid range than wringing it's neck for top end giggle time. This comes from a guy that built an N/A Bug engine (early 80's) that ran almost like a two stroke, made almost no power until 4500 rpm, then would literally rip the front wheels off the ground in 2nd gear, or smoke the tires to the 9000rpm shift point. That car was fun, wide open. But driving away from a red light with a cop behind you...trying to behave yourself, not a lot of fun. My Turbo Charged 355 in a 66' C10 was way more fun.
 

Shawn_Mc

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Oct 1, 2021
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Anahiem
The ignition timing is a function of the flame front from the kernel hatching out to full cylinder diameter. With a flat top piston and a small chamber, you simply dont need that much timing. If youve got a nice small CC, that still flows on the exhaust stroke, some of those "fast burn fuels" are worth even more power with less timing. But if youve got a giant chamber, like that Dart I built, that has giant domes 48.5cc, It kept making power the more timing I threw at it. I stopped at 40. But ever time I added timing, the HC's would come down and the CO2 would go up (more complete burn)