Tearing down the Cabriolet

[trav1856]

So as I've been pulling parts of the Cabriolet, I discovered that the idiot I bought it off of, took all the bolts out of the motor mounts, except for the rear one. (The one the transmission bolts to), so I'd have had a fun time getting that out without making the engine hit the floor. I was removing the strut and control arm from the driver's side. (basically I'm completely dismantling the thing, so see if there is anything that would prevent a rebuild, in the event I decide to restore it, though it's pretty much gutted on the interior, so I may just use what I can and sell off the rest).

Starter looks new. alternator looks like the original. A/C compressor won't fit so that's going in the sell pile (diesel one on mine is rotary)...and I think it may be locked up anyway so it'll have to be rebuilt, then again it could just be the clutch locked up. Distributor is good, going into the sell pile. (along with the block and head).

I'm considering using the intake on my diesel and using a remote air filter...perhaps a 3" setup (maybe 4"?) to give it a better breathe on the intake, and then drilling out the donut on the exhaust to 3" and running a 3" exhaust. Between that and the governor mod, without running a turbo, what do you think I can get HP wise? (R.O.R. feel free to chime in)

[vanagonturbo]

removing backpressure from an NA diesel is not such a good idea..

[trav1856]

I was under the impression that's what you were supposed to do to a point...or do you just increase the exhaust size if you're running turbo? I've read a lot of conflicting info.

[8v-of-fury]

removing backpressure from an NA diesel is not such a good idea..

Why? There is absolutely no need for back pressure on a diesel. I am running my N/A through a 2" straight pipe, with a Cherry Bomb glass-pack in the tunnel in front of the shifter. Sounds BEAST.

[vanagonturbo]

A 2" system still creates backpressure. the op indicated he wanted to use 3".  although your 2" might sound 'beast' that does not equate to power. a 3" exhaust will cost the OP power. Just because it is a diesel does not mean that EVERYTHING is opposite

[maxfax]

3" is a bit much for a NA..   However the 2" will equate to some power gain over the stock straws they used..  Much over 2" is just gonna make more noise and nothing else, unless you're planning on some crazy mufflers in the mix...

[8v-of-fury]

A 2" system still creates backpressure. the op indicated he wanted to use 3".  although your 2" might sound 'beast' that does not equate to power. a 3" exhaust will cost the OP power. Just because it is a diesel does not mean that EVERYTHING is opposite

Yes a 2" straight system will still have some back-pressure. Compared to the 1.5" system with a resonator and a muffler however it is pretty much none. 3" might be much, I wasn't appraising the 3".. merely the straight pipe idea. I am not just making an assumption here or a wildass guess that because its diesel it is a complete 180 different than gas, therefore requiring no back pressure.. There is virtually no valve overlap. If one is open, the other is closed. They are fully open at BTDC, and fully closed at TDC.. resulting in absolutely no need for back pressure.

3" is a bit much for a NA..   However the 2" will equate to some power gain over the stock straws they used..  Much over 2" is just gonna make more noise and nothing else, unless you're planning on some crazy mufflers in the mix...

Yes i wouldn't say 3" would hurt anything more than your wallet or your ears.

[trav1856]

Thanks for the input....

Now about the gasser intake...good idea? bad idea?

[vanagonturbo]

Ok, so lets assume that an NA diesel doesnt need any backpressure at all, why is the exhaust smaller on an NA diesel than its gas counterpart? One would think that a design change in manufacturing would be more expensive than using both exhaust systems for gas and diesel alike...

[maxfax]

The smaller exhaust was a noise reduction measure..  We Americans were skerd of them big bad new fangled diesels back then..

Trav, as far as the gasser intake goes there really isn't much gain on an NA other than the ability to plumb a cone filter wherever you'd like..  Take a close look at a MK1 NA intake, not gonna get much more flow than one of those....

 For a TD however, they are an upgrade from the stock TD manifold..

[vanagonturbo]

The smaller exhaust was a noise reduction measure..  We Americans were skerd of them big bad new fangled diesels back then..

Ahh, interesting! Damn 'Murricans

[R.O.R-2.0]

The smaller exhaust was a noise reduction measure..  We Americans were skerd of them big bad new fangled diesels back then..

Trav, as far as the gasser intake goes there really isn't much gain on an NA other than the ability to plumb a cone filter wherever you'd like..  Take a close look at a MK1 NA intake, not gonna get much more flow than one of those....

 For a TD however, they are an upgrade from the stock TD manifold..

if you add 3" or larger piping to your air box, instead of the 1.5" snorkel its got, that will help more than a different intake manifold..

usually the only ones running the gasser intakes, are us guys with low mounted turbos.. i just didnt think that the stock TD manifold was that good of a design. sure, it works, but it has right angle ports, and the outside cylinders dont get much air flow..

[maxfax]

Damn 'Murricans indeed Vanagon..  I had convinced a customer to put 2" pipe on his Jetta Coupe..  We actually used a decent muffler and the damned thing was still rather loud, but darn did that bugger run and sound good... It was too loud for his tastes unfortunately..  The addition of a resonator made it tolerable but at a noticeable loss of power..

if you add 3" or larger piping to your air box, instead of the 1.5" snorkel its got, that will help more than a different intake manifold..

Right on!!!  Plumb it right up beside the radiator beside the grill and you'll have faux ram air!  However you'll want to not do that in very cold temps...

[R.O.R-2.0]

Damn 'Murricans indeed Vanagon..  I had convinced a customer to put 2" pipe on his Jetta Coupe..  We actually used a decent muffler and the damned thing was still rather loud, but darn did that bugger run and sound good... It was too loud for his tastes unfortunately..  The addition of a resonator made it tolerable but at a noticeable loss of power..

if you add 3" or larger piping to your air box, instead of the 1.5" snorkel its got, that will help more than a different intake manifold..

Right on!!!  Plumb it right up beside the radiator beside the grill and you'll have faux ram air!  However you'll want to not do that in very cold temps...

cold temps and moist air may make some condensation on your air filter, and that wouldnt be good. frozen air filters do not flow very well..

[maxfax]

cold temps and moist air may make some condensation on your air filter, and that wouldnt be good. frozen air filters do not flow very well..

I never even gave that a thought..  My experience with the faux ram air was a 3 day wait for heat last winter...