What is VVT exactly and is it ok in a resto mod

[chally426]

Looking at a 6.4 that says "has VVT", I know it is variable valve timing, but is this on all 6.4's and is it o.k. for a resto-mode application
or is it the same as MDS..??

Thanks

[7212Mopar]

See Allpar

http://www.allpar.com/mopar/SRT-V8.html

No one care for MDS but VVT and long and short runners you might want to retain. Give Arrington a call.

[jimynick]

V V T is a power and emissions play used on all cylinders; MDs or displacement on demand is primarily a fuel mileage thing. If memory serves, the average car needs about 40 HP to run down the road, so why feed all those extra cylinders for no gain? V V T allows for the best of both cam phasing worlds with better bottom AND top end power, courtesy of advancing/retarding the cam through the power cycle. If you're going the EFI route, why quibble about one more electronic device, especially one that'll pay you back in increased power and gas mileage? Just sayin'   

[chally426]

So,...Do all 6.4's have VVT and the VVT is okay as far as putting in an older car with a 6-speed

[jimynick]

I don't honestly know if ALL 6.4's have V V T and I don't understand the issue about putting one in an older car with a 6 speed. None of the older cars had 6 speeds, let alone EFI or V V T or D O D, so why would it matter? Why hamstring yourself if you're going the resto-mod route by worrying about it- just do it if it makes you happy! 

[chally426]

I don't care one way or another if the VVT is there, I really don't know what it does,  I just want to check if its going to cause any problems that its compatible with all the aftermarket stand alone ECM systems

[7212Mopar]

The 392 crate engine does not have VVT or MDS. Not sure about the truck version. All 6.4L for Challenger, Charger and Grand Cherokee have VVT for auto and manual. Probably would not work with aftermarket ECM.

[jimynick]

I'd bring the subject up with some of the aftermarket suppliers and see what they say. We're right now in the middle of overhauling my son's 5.4 Ford Triton and it has V V T. The thing with that, is that if the system isn't functional, it reverts to full advance and that not only affects performance, but fuel mileage- in a significant way, and I dare say the Mopar system may have similar default parameters. It also seems to me that there was a supplier who used tweaked oem ecms and perhaps some of the more knowledgeable gentlemen here could elaborate?

[cjd automotive]

Yes, all 6.4's have VVT.  You want it.  It allows the cam to mechanically retard and advance.  Really helps low rpm torque without affecting upper RPM horsepower.

I know the Holley controller cannot control the VVT yet.  It can be locked out with a Comp Cams kit, but if your leaving the engine relatively stock, I'd run the factory controller. 

BTW, the shop truck.  VVT and MDS Hemi with factory controller.  Not pretty, but very fast!!

[jimynick]

That's cool, that truck is! That's also the old school hotrodding spirit as well. You can't go wrong sticking a bigger engine in it, can ya?!

[GCCUDA]

you will need a factory pcm . no one has an aftermarket unit.  YET. and will take some time before its mastered as well .

[Modern Muscle]

All Factory 6.4L have VVT and we and our stand alone can control it in any resto mod conversion.

[jimynick]

All Factory 6.4L have VVT and we and our stand alone can control it in any resto mod conversion.

There ya go! Nice to see that someone's finally managed that. 

[teemu]

 Hi all,
 I have 6.4 Hemi in my Challenger, first I had 5.7 Hemi and aftermarket ECM, it works perfectly, but now, VVT is a problem.

 I know that I could buy original ECM, but the price, if box cost in USA $3000 when I get it,  it cost to me over $4000, I live in Finland.


 Can anybody tell, is VVT solenoid and intakesolenoid 12v or 5v, and what kind of pulse going in, only two wires going in to VVT solenoid.
 
  And how VVTsolenoid works. I know it works 0%, 50% and 100%, but what determines  when the solenoids open, is it RPM, pressure or what.

 Is it dangerous running the engine without VVT, if I use Comp cams locked kit, or what happen If I not lock it?

I drove this car at the last summer, and it works fine,  we keep the RPM under 3500

  Thanks, and sorry about my English
      -Teemu

[Modern Muscle]

Hi all,
 I have 6.4 Hemi in my Challenger, first I had 5.7 Hemi and aftermarket ECM, it works perfectly, but now, VVT is a problem.

 I know that I could buy original ECM, but the price, if box cost in USA $3000 when I get it,  it cost to me over $4000, I live in Finland.


 Can anybody tell, is VVT solenoid and intakesolenoid 12v or 5v, and what kind of pulse going in, only two wires going in to VVT solenoid.
 
  And how VVTsolenoid works. I know it works 0%, 50% and 100%, but what determines  when the solenoids open, is it RPM, pressure or what.

 Is it dangerous running the engine without VVT, if I use Comp cams locked kit, or what happen If I not lock it?

I drove this car at the last summer, and it works fine,  we keep the RPM under 3500

  Thanks, and sorry about my English
      -Teemu

VVT is controlled by the ECU.  A new ECU flased for your application is only 649.00 USD  that would be your cheapest alternative