How Big Of A Cam In A 5.7 with Full Accessories Including Conditioning
10-13-2017, 03:00 PM
#3
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And to be clear -- a 5.7 LS1, not a 5.7 Hemi?
Just going off your username and making sure...
Just going off your username and making sure...
10-13-2017, 03:04 PM
#4
Yea we don’t like those kind around in these parts. Lmao! Look ma it has a Hemi. Naw just fooling around. What you got Bro?
Btw just had my ole Lsx tattoo redone. Now covers my entire right fore arm. Lsx 4 Life!
Btw just had my ole Lsx tattoo redone. Now covers my entire right fore arm. Lsx 4 Life!
10-13-2017, 03:42 PM
#5
Tell us what cylinder heads stock, ported stock, after market etc, what intake LS6, LSXR MSD etc and what RPM range.
Personally 227/235 to 231/236 is about as far as I would go on a stock cube LS1. Many other will go way bigger. My stock cube LS1 had a 224/224
Texas Speed Magic Stick 3 or 4 with specs like 239/242 .649"/.600 are toward the upper end of range.
Personally 227/235 to 231/236 is about as far as I would go on a stock cube LS1. Many other will go way bigger. My stock cube LS1 had a 224/224
Texas Speed Magic Stick 3 or 4 with specs like 239/242 .649"/.600 are toward the upper end of range.
10-13-2017, 05:22 PM
#7
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Ahhh.....16°or less overlap. That a great answer. Thanks JakeFusion!
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10-14-2017, 10:31 AM
#10
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10-14-2017, 11:46 AM
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Originally Posted by Stampede4ever
I bought a 220/224 .575 lift, for my 6.0l, and I don't know how guys are running over 0.600" of lift.
Thanks.
Thanks.
10-16-2017, 05:29 PM
#13
Compression always helps those larger valve ticklers too
Those who used to stay 10.1:1 stock had great success with the old 224/224 stuff
plenty on here can achieve "streetable" manners with a 228-236 range cam when the static compression ratio gets to that 11-11.4:1 range
Heck even 12:1 is attainable with .040" Cometics and those 58cc TFS 205s
which then would open up that 238-244 size cam range
All requiring a tuner capable of working their magic
So the blanket question of "size cam" and "drive-able" are really quite dependent on a host of varying factors
Those who used to stay 10.1:1 stock had great success with the old 224/224 stuff
plenty on here can achieve "streetable" manners with a 228-236 range cam when the static compression ratio gets to that 11-11.4:1 range
Heck even 12:1 is attainable with .040" Cometics and those 58cc TFS 205s
which then would open up that 238-244 size cam range
All requiring a tuner capable of working their magic
So the blanket question of "size cam" and "drive-able" are really quite dependent on a host of varying factors
10-16-2017, 07:22 PM
#14
I've never had an issue with big cams and A/C because usually the additional load and extra fuel provided when the A/C kicks on smooths the engine out. An engine will lope more when the load is very light and the fuel is not so rich.
The only thing you can't "tune out" easily or much at all sometimes is the waste of fuel that using a large cam often carries. My last engine used 50% additional fuel at idle when the duration of the camshaft increased from approx 20* over stock on intake and exhaust. I was able to smooth it out for A/C, but the additional fuel use was still there. As a side note, fuel use during cruise did not notable increase between the cams, which is why I specifically mentioned idle fuel use, basically this is the worst time to get miles per gallon since the car isnt even moving and you are burning gas.
So car A and car B may get identical fuel economy but car A sits in traffic lights stopped for 2 to 3 times longer than car B so it will look like its getting "worse MPG" when they are getting the same, and this is compounded by the camshaft type of mods that lovably trash low rpm cylinder consistency/efficiency for the sake of higher rpm performance.
The only thing you can't "tune out" easily or much at all sometimes is the waste of fuel that using a large cam often carries. My last engine used 50% additional fuel at idle when the duration of the camshaft increased from approx 20* over stock on intake and exhaust. I was able to smooth it out for A/C, but the additional fuel use was still there. As a side note, fuel use during cruise did not notable increase between the cams, which is why I specifically mentioned idle fuel use, basically this is the worst time to get miles per gallon since the car isnt even moving and you are burning gas.
So car A and car B may get identical fuel economy but car A sits in traffic lights stopped for 2 to 3 times longer than car B so it will look like its getting "worse MPG" when they are getting the same, and this is compounded by the camshaft type of mods that lovably trash low rpm cylinder consistency/efficiency for the sake of higher rpm performance.
Last edited by kingtal0n; 10-16-2017 at 07:28 PM.
10-16-2017, 09:30 PM
#15
Idling with a big cam is no worse for fuel if you tune the EOIT.
My VE table is in the 20s and 30s upto 1200 RPM... and no gas smell. I get 20mpg in city driving with a 4000 stall and 3.73 gears. By delaying when the injector fires, you spray a lot less fuel out of the open exhaust valve. It helps tremendously with idle, off-idle, and low RPM cruising.
Also, pull back timing when you do that. You can idle a huge cam with 16-20 degrees with proper injection timing. Lopes like a son of a bitch and doesn't have the toxic NOx smell (which is much stronger than raw gas - it's what clings to your clothes).
My VE table is in the 20s and 30s upto 1200 RPM... and no gas smell. I get 20mpg in city driving with a 4000 stall and 3.73 gears. By delaying when the injector fires, you spray a lot less fuel out of the open exhaust valve. It helps tremendously with idle, off-idle, and low RPM cruising.
Also, pull back timing when you do that. You can idle a huge cam with 16-20 degrees with proper injection timing. Lopes like a son of a bitch and doesn't have the toxic NOx smell (which is much stronger than raw gas - it's what clings to your clothes).
10-17-2017, 08:18 PM
#16
Idling with a big cam is no worse for fuel if you tune the EOIT.
My VE table is in the 20s and 30s upto 1200 RPM... and no gas smell. I get 20mpg in city driving with a 4000 stall and 3.73 gears. By delaying when the injector fires, you spray a lot less fuel out of the open exhaust valve. It helps tremendously with idle, off-idle, and low RPM cruising.
Also, pull back timing when you do that. You can idle a huge cam with 16-20 degrees with proper injection timing. Lopes like a son of a bitch and doesn't have the toxic NOx smell (which is much stronger than raw gas - it's what clings to your clothes).
My VE table is in the 20s and 30s upto 1200 RPM... and no gas smell. I get 20mpg in city driving with a 4000 stall and 3.73 gears. By delaying when the injector fires, you spray a lot less fuel out of the open exhaust valve. It helps tremendously with idle, off-idle, and low RPM cruising.
Also, pull back timing when you do that. You can idle a huge cam with 16-20 degrees with proper injection timing. Lopes like a son of a bitch and doesn't have the toxic NOx smell (which is much stronger than raw gas - it's what clings to your clothes).
I also just figured out the airmass is used to calculate torque which affects all shifting characteristic. My trans was a completely different animal when I sync'd up the engine's actual torque with the predicted torque numbers that made sense. <3ing HPtuners so far.
Also I understand you are saying injecting fuel after overlap period would conserve fuel that would have left through overlap and I agree. However, the energy produced by combustion in an engine with an aggressive camshaft near idle may be reduced, which in and of itself means it will use more fuel to maintain the same RPM regardless of when we spray that fuel (due to thermodynamic laws) In other words, the engine is even less efficient when the cam timing is optimized for higher rpm performance. If you had a generator, for example, and needed it to run with optimal fuel conservation, you would be very careful with the valve timing such that at the exact RPM(s) the generator will generate power the event would be most efficient. We optimize the engine for higher rpm, it sort of screws up the idle region where we idle and don't care about output.
10-17-2017, 09:42 PM
#17
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Ok... thanks
10-18-2017, 02:06 PM
#18
From what I just learned, the VE table controls what the ECU thinks the cylinder airmass is in Speed density. So if you had 600 horsepower but told the computer you had 50% size of actual injectors (for scaling since you couldn't input, say, 120lb/hr), your VE table would be half of actual. So it wouldn't really matter what the VE table "says" a 20 is my 40 or his 60
I also just figured out the airmass is used to calculate torque which affects all shifting characteristic. My trans was a completely different animal when I sync'd up the engine's actual torque with the predicted torque numbers that made sense. <3ing HPtuners so far.
Also I understand you are saying injecting fuel after overlap period would conserve fuel that would have left through overlap and I agree. However, the energy produced by combustion in an engine with an aggressive camshaft near idle may be reduced, which in and of itself means it will use more fuel to maintain the same RPM regardless of when we spray that fuel (due to thermodynamic laws) In other words, the engine is even less efficient when the cam timing is optimized for higher rpm performance. If you had a generator, for example, and needed it to run with optimal fuel conservation, you would be very careful with the valve timing such that at the exact RPM(s) the generator will generate power the event would be most efficient. We optimize the engine for higher rpm, it sort of screws up the idle region where we idle and don't care about output.
I also just figured out the airmass is used to calculate torque which affects all shifting characteristic. My trans was a completely different animal when I sync'd up the engine's actual torque with the predicted torque numbers that made sense. <3ing HPtuners so far.
Also I understand you are saying injecting fuel after overlap period would conserve fuel that would have left through overlap and I agree. However, the energy produced by combustion in an engine with an aggressive camshaft near idle may be reduced, which in and of itself means it will use more fuel to maintain the same RPM regardless of when we spray that fuel (due to thermodynamic laws) In other words, the engine is even less efficient when the cam timing is optimized for higher rpm performance. If you had a generator, for example, and needed it to run with optimal fuel conservation, you would be very careful with the valve timing such that at the exact RPM(s) the generator will generate power the event would be most efficient. We optimize the engine for higher rpm, it sort of screws up the idle region where we idle and don't care about output.
10-18-2017, 03:25 PM
#19
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Ignore him. He's off on one of his usual tangents.....
10-18-2017, 05:14 PM
#20
short answer is, if you bought a gas-powered electric generator and *EDIT* Add 20degrees of intake duration it wouldn't get the same economy per electrical energy power output. The same goes for an engine in a car, it doesn't even matter if you spray the fuel after overlap.
Last edited by kingtal0n; 10-21-2017 at 11:01 PM. Reason: meant to say 20* of intake duration sorry