AFM (aka DOD) functionality after swap

[chvy=power]

Tow mode requires a BCM in the loop. If you want DOD, VVT and tap shifting, that also requires a BCM. Guys are using a Corvette tune to get tap shifting without a BCM, but that kills DOD and VVT. BTW, VVT is killer to have, just look at the torque curves of the motors with it. DOD would be nice to have as well. It's not all that hard to get the BCM in the mix if you wire your own harness. There seems to be some trick to get DOD to work though. The Motech harness does it all, but I just found a problem with their basic harness. The ECM plugs are wired about two feet too short to use on our rig with the ECM on the fenderwell, and the fuse box is about one foot too short. If you get a Motech harness have them do it custom and get those lengthened. BTW, the Motech accelerator bracket is easily modified to use in our trucks. Absolutely use one if you go with DBW. See my swap thread for pictures.

Do you have any links or dyno graphs showing a vvt motor with a better torque curve than a non vvt motor? Iv never been impressed with vvt as far as performance or driveablity. Iv talked to several guys, one being Geoff skinner of engine power systems, who claims that the vvt is purely gm's way of trying to pick up fuel economy and has no effect on performance.

On a stock motor I can see trying to keep it, but if it's performance your after...in my opinion it's a waste of time trying to keep it

[Nak]

Do you have any links or dyno graphs showing a vvt motor with a better torque curve than a non vvt motor? Iv never been impressed with vvt as far as performance or driveablity. Iv talked to several guys, one being Geoff skinner of engine power systems, who claims that the vvt is purely gm's way of trying to pick up fuel economy and has no effect on performance.

On a stock motor I can see trying to keep it, but if it's performance your after...in my opinion it's a waste of time trying to keep it

Built 454ss dyno.jpgL94 Torque Curve.jpg

I guess it depends on your definition of "performance". For the track, sure you'r better off with the extra RPM available without VVT. For day to day driving and towing? Around 300 Lb-Ft just off an idle with a stock engine and torque converter is damn nice to have. Look at the graphs, a built 454 has higher peak torque, but nowhere near the area under the curve that the L94 with VVT has. If my 6.2 ends up anywhere near as nice as my buddy's totally stock Denali I'll be thrilled to death. Quiet, great gas mileage, reliable, loads of torque from idle to redline and 0-60 in the mid 5's. No need whatsoever for a high stall speed torque converter. Yeah, I'll take VVT for a daily driver, for a tow rig, for the kind of off roading I do, for manageable on road traction in winter conditions.

Everyone's needs are different. For some, VVT is not the way to go. I'll easily agree that if you're looking for minimum 1/4 mile times, skip the VVT. But the truck that does great at 1/4 miles is not going to do as well towing in 6th gear at 60 MPH. Again, it all depends on what your definition of performance is.

That's just my opinion of course.

Just looked at your build thread, very nice! It totally sucks you had to lose the blower... Anyways, from the feel of your thread I'd agree that what you're after is better achieved without VVT or DOD. What I'm after in my build I believe is better with the VVT and DOD. (At least I'm hoping that my precautions will prevent the issues associated with DOD.)

[chvy=power]

Gm's vvt system retards timing, it does not advance timing any greater than it would be on a non vvt engine. Advancing the timing is how more power is made. So I don't understand, on a stock vvt vs a non vvt engine, how the vvt engine would make more power anywhere in the rpm range. The vvt simply retards cam timing in hope to improve fuel economy. And trust me, based on the 3 different LY6s Iv owned, fuel economy isn't all that great on them with or without the Vvt. All it does when the vvt kicks in, is make you have to press the pedal further to the floor to maintain the same speed and power as you had before it kicked in. So in my opinion, what a pain in the A$$!

On another note, I do find it quite neat that your trying to keep it on your swap and hope all goes well!

[chvy=power]

In reference to the 454 vs the vvt engine....the 454 probably has some cylinder heads, with hogged out runners that require high rpm to make any power, and same goes for the camshaft. Obviously a big donkey dick cam is gonna be a terd down low in the rpm. Mate the hogged out heads and a big cam in the 454, and a stock 5.3 will make more power down low

[Nak]

This is a pretty good article about VVT, complete with dyno comparisons:

http://www.hotrod.com/how-to/engine/...formance-test/

[Nak]

In reference to the 454 vs the vvt engine....the 454 probably has some cylinder heads, with hogged out runners that require high rpm to make any power, and same goes for the camshaft. Obviously a big donkey dick cam is gonna be a terd down low in the rpm. Mate the hogged out heads and a big cam in the 454, and a stock 5.3 will make more power down low

What I like about the L94 is that it isn't just making more power down low, it's also making more power up high. The graphs show the 454 only has a torque advantage within a very narrow RPM band, just a couple of hundred RPM.