Tuning out afm and cam swap question

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iamdub

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I have read over on the Performance Trucks forum of guys adding the VVT wiring to their older harnesses but I think they used the donor's computer; not 100% sure anymore.

VVT does more for gas mileage than AFM or even the 6-speed. My 2006 Pontiac Montana had a 240 horsepower V6 with VVT and that thing got 23 mpg @ 77 mph and 21 mpg @ 90 mph and 21 mph @ 72 mph. This was essentially the same mileage as the older engine which made 180 horsepower and did not have VVT. However, the 2004 got its best mileage at 72 mph whereas the other one was more efficient a higher speeds.

I never considered improved mileage from VVT. I've just focused on the flatter power curve. I'll dig around on PT for the conversion info. Thank you.
 

swathdiver

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I never considered improved mileage from VVT. I've just focused on the flatter power curve. I'll dig around on PT for the conversion info. Thank you.

Me neither until I was making a chart of the mileage of the various years and noticed when the mileage increased. The 2WD '07-'08 Tahoes were rated for 14/20 and with 4WD 14/19. In 2009 both drives were rated for 14/20 which was the first year of the 6-speed. VVT was introduced in 2010 and used throughout and both drives were now rated for 15/21.

Power wise, VVT brought peak horsepower up 200 rpms and lowered peak torque 200-400 rpms depending on the model without VVT.

Your 2008s LMG = 320 HP @ 5200 / 340 TQ @ 4200
My 2009s LC9 = 310 HP @ 5200 / 335 TQ @ 4400

But both motors from 2010-2014 now make = 320 HP @ 5400 / 335 TQ @ 4000

These are SUV numbers, the pickups were slightly different, must be programming, as they are all mechanically identical.
 

tst1212

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My 2011 Z71 has 40K miles, do I really need to switch out the cam and lifters or could I just do the afm delete and wait? At the rate I'm going +100K will take me another decade.
 

swathdiver

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My 2011 Z71 has 40K miles, do I really need to switch out the cam and lifters or could I just do the afm delete and wait? At the rate I'm going +100K will take me another decade.

Sometime in 2011 newer, more reliable AFM parts were introduced. Most guys "turn it off" rather than physically delete it. Keeping clean oil in the motor goes a long way towards longevity. Consider limiting your oil changes to 5000 miles or 1 year, whichever comes first.
 

tst1212

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Sometime in 2011 newer, more reliable AFM parts were introduced. Most guys "turn it off" rather than physically delete it. Keeping clean oil in the motor goes a long way towards longevity. Consider limiting your oil changes to 5000 miles or 1 year, whichever comes first.

Thanks, will do.
 

sfc_jones

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I am going to finish my project by going to either a whipple or pro charger. add 45 injectors, long tube headers, 4l80 Tranny. So far I have replaced the oil pump, did the DOD/AFM delete, Added a Low Lift Cam. And used ARP Bolts. My Goal is 450 HP at the wheels.
 

sfc_jones

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My Engine Builder told me that if you tune out the AFM you still have the parts to fail and at 240k miles on my Tahoe I didn't want any issues.
On my wifes 2010 Suburban I am going to do a AFM Delete with LS& Lifters and a LS7 Cam and replace the oil pump while I am in it. I might as well use ARP Bolts as well.
 

sfc_jones

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A 427s cam in a 325? That'll surely move the powerband up real high and kill the low end needed to get her moving.
IIRC a LS7 cam has the same values as a stock 5.3 Cam. the difference is the LS7 never had AFM.
 

swathdiver

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IIRC a LS7 cam has the same values as a stock 5.3 Cam. the difference is the LS7 never had AFM.

LS7: 12638426 - 211-230 .593-.589 120.5
LMG: 12625436 - 196-201 .481-.481 116
LMG: 12593207 - 193-193 .482-.482 116

And of course what we don't see with cam specs is the shape of the lobe which is just as important for determining the motor's manners. There's a guy over on Performance Trucks yanking the cam out of his LQ4, it is smaller than the LS7 and it killed his torque and horsepower. It's better to go too small than too big.
 

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