Heresy - Interceptors and HHO

[BennVenn]

Considering nearly all new engines have turbulence plates in the intake manifolds I'd say there is some merit to a turbulent Air charge. I know the AU does and I could probably do a back to back run with the control solenoid disconnected to see how it affects low end torque.

Turbulent air into the carb though... I don't think that'll do the venturi's any favors but it would probably help mixing the LPG which is mounted just above.

As for resonators in the intake path - It's not just for MAF based intakes. We've got a great wall 4x4 here with a 4g69 in it with a bunch of resonators and its MAP based.

On the instagram I did dyno runs with the stock airbox vs a pod filter. Wasn't expecting the results we saw - a huge flat spot with the pod filter with no changes to the tune. It turns out the flat spot isn't related to the Pod filter itself, there's some magic going on in the stock intake pipe / resonator. Stock intake hose with no pod or factory filter gives the same result as stock intake with pod. A 3" aluminium pipe and pod direct to the throttle body gives the flat spot. See here: https://www.instagram.com/p/CssaWAnP-oP/

And the main reason I think a pod filter is a complete waste of money here: (Pod vs stock with the bonnet closed) https://www.instagram.com/p/Cssa-99sz6w/

[vlad01]

The resonance chambers are primarily for NVH reasons but they can offset dips in VE as a side benefit, although gains are usually minuscule.

[Charlescrown]

To my knowledge that solenoid on the Ford is for a variable length intake manfold to get a wider torque curve. I agree Vlad that their primary design is to reduce NVH and they wouldnt put them on if they could make a saving but I havent noticed any difference with or without them. NVH can be a very difficult thing to determine and without very expensive sound equipment probably impossible to resolve. I do remember the VN rough idle kit that involved a plastic insert behind the throttle body which was added after a customer complained but I'm not sure just what it did.

[immortality]

I believe that was the bellmouth fitted into the intake manifold to even out air distribution? Became standard fitment on later model 3800 engines.

POD filters have their place if done right.

[BennVenn]

There's no way you can fit the same amount of filter material / surface area in a pod vs a factory filter. It's going to be a compromise of filtration for flow, and if you're going to put the pod in an airbox for the benefits of cold air induction then you might as well just leave the stock filter in there... Just my opinion!

This puslar had that 3" elbow and pod when I got it and the amount of fine dust coating the intake pipe suggests there was no filtration occurring at all. It also explains the state of the bores when I had it apart last... Can't really expect much from what looks like a $10 ebay pod though.

[vlad01]

Nah, it was to reduce output and mainly to dampen throttle response as the early VN customers complained about touchiness and wheel spin off the line. I also heard it was also an attempt to segment the 5L and the 3.8L as the early VN V6 was virtually the same in acceleration in practice to the 5L. I don't know if this last point is true or not but doesn't surprise me with holden's marketing. But I think it's likely as a well tuned early VN goes like a cut cat, while the 5L has more power on paper, it's quite lazy for the size of the engine in stock form.

They actually make air distribution quite bad and removing it fixes that issue. I've confirmed these 2 things on the dyno and pretty obvious when you pull the plugs on engines with and without the insert. Without they are all the same appearance and color, with it installed, the middle look normal, the front white and the rear are black. There is about 10Nm of torque lost across the entire curve with the insert installed and everything optimized in the tune for both scenarios, so that the best case and the difference can be more than that in not ideal tunes because of the bad distribution.

[immortality]

Yeah, the early VN's were definitely good down low. More fun than my VS Senator in many ways but the auto sucks out a lot of the fun

There's no way you can fit the same amount of filter material / surface area in a pod vs a factory filter. It's going to be a compromise of filtration for flow, and if you're going to put the pod in an airbox for the benefits of cold air induction then you might as well just leave the stock filter in there... Just my opinion!

This puslar had that 3" elbow and pod when I got it and the amount of fine dust coating the intake pipe suggests there was no filtration occurring at all. It also explains the state of the bores when I had it apart last... Can't really expect much from what looks like a $10 ebay pod though.

I guess that depends on the size of the POD filter and quality.

[Charlescrown]

Hey Vlad that reminds me about the Morris Marina. A friend of mine was a development engineer at the time and they found the 1.6L produced more power than the 1.8 so they put a restrictor under the carbie to reduce power. Easy upgrade for more power. Yea the VN V6 was a lively beast but they shound have done something about the driveline vibration. Boy was it bad. I think it got fixed with the VP but not sure on that. I can't believe the misalignment of the uni joints and that was how you had to assemble the shaft. I have no idea why they did it.

[vlad01]

My VP vacationer vibrated bad, especially when going up hill and it was auto. Once I changed it to manual that shuddering went away. I'm not entirety sure but I suspect it's the lack of rotating mass having a flex plate instead of a heavy flywheel and the shudder felt like power pulses from the engine vibrating the drive line. In ecotec they made the flywheel even heavier and they feel really smooth but you can feel the loss of rpm acceleration and flywheel effect.

My VP vacationer had it manual conversion from a 90 VN donor that I bought so the tailshaft wasn't a factor as the vibration went going to the VN drive line.

[Charlescrown]

The weight of the torque convertor makes up for the flex plate so that wouldn't have been the issue. I just remember teaching drivelines and we had 2 VP and 1 VT and the alignment specs for the VP defied all logic the VT they had to be in straight alignment or you got a bad vibration caused by velocity fluctuations so I would love to know the GM logic.