6A12 Mivec 2ltr V6 Performance

[fuel]

I only assumed Q was putting the mivec 6a12 heads onto a 6a13 block because I couldn't see the point of putting a mivec 6a12 into a legnum.

I guess it would sound amazing.... while it's struggling to haul the 1500kgs body around haha. 200hp sounds impressive but it's all at 7500rpm and the peak torque of 200Nm is at 6000rpm. The 6A13 SOHC is only 25hp down on power of the MIVEC but is well up on torque and more importantly most of the torque is down low.

[scott.mohekey]

Oh right it's been a while since I've had a chat with him for some reason I thought he was doing a MIVEC 6A13TT hybrid, although he was being quite secretive with his engine build.

He posted up pics on ozvr4, and maybe here. Ive seen it in the flesh and it is well shiny.

[fuel]

hah I've just had a read of the 2.4 GDI performance thread...

[wintertidenz]

How rare are those Gen-1 engines with the cambelts on the passenger's side? If they aren't that rare, then my old project might make a comeback...
V6 1600cc Lancer, rip the engine out and go MIVEC

[scott.mohekey]

Do you mean the 6A12s in the 7G galants?

[wintertidenz]

Yeah

[scott.mohekey]

Goku might have one for sale.

[fuel]

nah I think he means the MIVEC 6A12's in the 7th gen Galants, they're only in the VX-R from 1993 til 1996. Prefacelift autos are 190hp while manuals and facelift autos are 200hp. Available in either MIVEC or MIVEC-MD.

I happen to have a whole VX-R for sale, suitable for parts as its uneconomical to put back on the road.

[VR4WGN]

Thats another fantasy island project he mentioned

if theres nothing nice you can say then maby refrain from posting in this thread,youv said what you wanted now maby just leave it alone ok!!

whilst i DO take in what everyone has said i AM however learning and how do you learn? Not from smartarse comments and querky lil sayings but from experience from others or own ok!!

i like to ask alot of questions but if this is not acceptable then by all means let me know and i WONT!

[VR4WGN]

I had it in my head that Q was planning on putting the mivec heads on an NA 6A13 block. Is this not the case?

nope lol

[VR4WGN]

I guess it would sound amazing.... while it's struggling to haul the 1500kgs body around haha. 200hp sounds impressive but it's all at 7500rpm and the peak torque of 200Nm is at 6000rpm. The 6A13 SOHC is only 25hp down on power of the MIVEC but is well up on torque and more importantly most of the torque is down low.

lol you bursting my bubble now lol...
um the reason for wanting to put th Mivec 6A12 into a Legnum is for economy from a VR4 and then the knowing of the high revving capabilities (if im right??)

this thread is REALLY interesting and i REALLY Apreciate Evryones input(including some of the bad ones).

if im wrong for wanting to install the Mivec on the grounds of economy with a bit of a change(mivec) please let me know guy

as for 2wd vs 4wd what do you think is best?
im going for a 4wd shell and a vr4 8G gearbox and transfer case

by what im taking in on this thread is that the better choice would have been the SOHC 6A13 correct? then how does that shape up in comparison on fuel usage to the Mivec 12'r?? and surely id get SOME pull when mivec kicks in correctover the 13??

thnx guys

[bradc]

If you want economy then 2wd and a 2.0 engine is going to be better every time.

Have you driven a V6 2.0 EA4W or EC4W Legnum? The performance will be just the same as that, but instead of changing gear at 6000rpm it will keep on going to 8000rpm. Compared to the 6A13 SOHC, the 6A13 will have about 20-25% more torque from idle up to 5000rpm. At 5500rpm the two engines will have about the same amount of torque and at 6000rpm in a 6A13 it will slow down, whereas the 6A12 will keep revving.

[Turbo_Steve]

IF you want economy, build a manual, 2WD VR4 with bigger turbos and ECU.
It should pretty much trounce the rest of the range for economy if you don't drive it like you stole it, and will also happen to have ooooodles of power too.

For the ultimate, make it RWD

[VR4WGN]

lol Steve........ budgets lol.... i cant bend over far enuf to pull out enough $$ lol

[Kenneth]

If you want economy, get the heads skimmed and up the compression to decent level.
You will also need a fuel and boost re-map to avoid detonation and make the most of your new compression ratio. NOTE: You WILL be lowering boost and committing to using the best fuel you can buy


The #1 problem you face is that the cost of doing any of this requires the car to be used for a long time (or lots of kilometres) to repay your investment in returns on fuel.

You would probably get as good continued return on investment if you make your other consumables last much longer (oil coolers, amsoil @ 25,000km etc)


I say this a lot, but here goes again... If you are concerned with the fuel economy to the point you will spend a couple of thousand dollars to improve it, you need to think about getting a cheap run-around.

That said, I am sure fuel economy is not your driving concern, in which case you might still find it a worth-while idea. Just ditch the fuel economy reasons, because that goat has had enough abuse

[fuel]

I would highly advise against upping the compression ratio on a 6A12, especially if the bottom end is not new. The damage caused to one of my 6A12s which grenaded itself had just had its heads reconditioned and skimmed as it blew a head gasket - less than two weeks later numbers 3 and 4 big end bearings let go therefore allowing the pistons to hit on the head which caused one of the rods to snap and the other rod to come free from the small end as the piston shattered.

I cannot stress enough how fragile the 6A12s are in the bearing department. Talk to any reputable engine builder who has had experience with the 6A12 and they will agree.

[fuel]

lol you bursting my bubble now lol...
um the reason for wanting to put th Mivec 6A12 into a Legnum is for economy from a VR4 and then the knowing of the high revving capabilities (if im right??)

this thread is REALLY interesting and i REALLY Apreciate Evryones input(including some of the bad ones).

if im wrong for wanting to install the Mivec on the grounds of economy with a bit of a change(mivec) please let me know guy

as for 2wd vs 4wd what do you think is best?
im going for a 4wd shell and a vr4 8G gearbox and transfer case

by what im taking in on this thread is that the better choice would have been the SOHC 6A13 correct? then how does that shape up in comparison on fuel usage to the Mivec 12'r?? and surely id get SOME pull when mivec kicks in correctover the 13??

thnx guys

The MIVEC-MD in my manual VX-R can pull some impressive fuel economy numbers on the open road, the best I got was 6.9L/100km but that was driving 90km/h and trying to get MD to kick in as often as possible. However once you start loading the car up with people and gear etc MD kicks in less often, sometimes not at all, and I find I have to push the engine more to get going and therefore fuel economy drops considerably.

Your Legnum un-laden is going to be the same weight as my Galant fully laden with passengers, then imagine your Legnum with passengers and gear in the boot. If I push mine hard enough it can drain the tank almost at the same rate as my VR-4.

For fuel economy, you want an engine which is going to be the most efficient with power delivery, ie something which delivers torque down low and is going to be reasonably un-stressed lugging the heavy body around.

There are plenty of cars out there which lower spec smaller engined models actually use MORE fuel than the upper spec bigger engined variants, simply because they are having to work harder to get the car moving.

[fuel]

Also VR4WGN I don't know where in NZ you are but if you are close to Hamilton you are welcome to drive both my manual and auto VX-Rs, you'll see a huge difference in speed between the two and how the auto just feels like such a slug compared to the manual. The auto VX-R would still be considerably quicker than a manual MIVEC Legnum.

[Kenneth]

Just to be clear (sorry if I made a bad assumption) my post was pertaining to the use of a 6a13 engine rather than 6a12. In my mind, you might as well have the 2.5L engine if you are not intending to be revving the nuts off it.

It did occur to me that perhaps the crank/rods etc could be taken from a NA 6a13 and put into a DOHC 6a13 to increase the compression a little.

[fuel]

and also I agree with Kenneth, if you are worried so much about fuel economy go buy a $1000 ****ter like a 3cyl Daihatsu Charade. The VR-4 (or any Legnum for that matter) is what it is, in its fuel sucking manor - but you get satisfaction out of it.

To me my VR-4 is appalling on fuel, but I drive it only a few times a week, although there was a period I was driving it daily, but even then I didn't really care about the fuel economy because it gave me more smiles per gallon than it does miles per gallon.