VCT Vs Non-VCT???

bubbagump308 · 07-12-2006, 08:23 PM

Hey can anyone tell me if a VCT Head will bolt onto a standard AU2 Block? Is there any advantages? I can get a Head from an AU3 XR6, just want to know if it worth me getting it?

AU2PWR · 07-12-2006, 08:36 PM

pfft , Casper will brainwash you lol !!

I assume VCT would be Better , but thats alot of Farting around , wouldnt you need new Computers and CAI Plumbing ?

smiley · 07-12-2006, 08:37 PM

It should bolt straight on however wouldn't provide any benefit unless you were able to get the VCT working through the ECU somehow.

AU2PWR · 07-12-2006, 08:42 PM

Quote:

Originally Posted by SR_AU

pfft , Casper will brainwash you lol !!

I assume VCT would be Better , but thats alot of Farting around , wouldnt you need new Computers and CAI Plumbing ?

Thought So....

TwistedEL · 07-12-2006, 10:09 PM

Not sure why but VCT engine has got different engine mounts... not sure if that means there is a difference in the blocks as well?

Sapper · 07-12-2006, 10:10 PM

What are you trying to achieve by bolting in a VCT head?

AU2PWR · 07-12-2006, 10:16 PM

Quote:

Originally Posted by hot xr6

What are you trying to achieve by bolting in a VCT head?

An Extra 1 RWKW

Dark Horse · 08-12-2006, 12:00 AM

Quote:

Originally Posted by TwistedEL

Not sure why but VCT engine has got different engine mounts... not sure if that means there is a difference in the blocks as well?

All the VCT gear is in the head. Why would they need a different block?

TwistedEL · 08-12-2006, 09:48 AM

NFI but like I said they have different mounts

Casper · 08-12-2006, 10:25 AM

Its an identical block and bottom end so yes, the VCT head would bolt straight on.
That said.. why would you want to do it? To make it even remotely worth while you would need a VCT ECU or something to trigger the VCT mechanism, along with all the wiring to get it done. Then you get stuck with a head that has had almost no development work done on it in the last 7 years and is only now beginning to get aftermarket cams and mods avaliable... at a premium cost.

Seriously, as I keep saying, unless the car came with VCT then the conversion has more bad points then good.

jonbays · 08-12-2006, 10:28 AM

The VCT head will bolt up and should work fine. Without the VCT switch enabled in the ecu the would have the same power as a VCT engine peak 172rwkw.

The difference is the VCT solenoid advances the cam from 1200-3800rpm giving more mid range. it runs retsred for idle and for high rom power. This means the idle is crap without an ecu (XR6, Ghia) that compensates for this with a higher idle speed and differentr mixture.

Make sure you get the oil supply pipes for the VCT with the head and then a simple jaycar rpm switch can be built and installed to make it work wit the std ecu not having to know about it.

Gianz · 08-12-2006, 11:46 AM

Quote:

Originally Posted by Casper

Its an identical block and bottom end so yes, the VCT head would bolt straight on.
That said.. why would you want to do it? To make it even remotely worth while you would need a VCT ECU or something to trigger the VCT mechanism, along with all the wiring to get it done. Then you get stuck with a head that has had almost no development work done on it in the last 7 years and is only now beginning to get aftermarket cams and mods avaliable... at a premium cost.

Seriously, as I keep saying, unless the car came with VCT then the conversion has more bad points then good.

Casper.... who do you know of that has done any development work for a vct head and cam? i have been looking around for months but am suspect of every performance shop i have talked to. i dont want to be the ginea pig, i want whats going to work with the vct operational. its not rocket science as variable cam timing has been around for many years. so why are tuners so affraid of it?

Casper · 08-12-2006, 11:51 AM

Quote:

Originally Posted by Gianz

Casper.... who do you know of that has done any development work for a vct head and cam? i have been looking around for months but am suspect of every performance shop i have talked to. i dont want to be the ginea pig, i want whats going to work with the vct operational. its not rocket science as variable cam timing has been around for many years. so why are tuners so affraid of it?

G&D have been doing some development using my car however we have not got the head/cam past a design/concept stage yet (it all costs money). The VCT is not rocket science however it is also something that reacts very different to a std head, good and bad.
Sometime next year we should take concept to actual for the head and cam and we will see how it goes. My personal opinion is it will be a large step forward however only time will tell.
The good thing is that G&D have a lot of experiance in custom design for heads and cams so they have the knowledge to do this, its just me getting the funds to turn that knowledge into something that can be measured. Until then I would rather not speculate what the results would be as I simply dont know.