[jhein]

I have all the parts to restore my functional shaker. The question is should I?

The way I understand it with the factory setup it will open only under WOT. Is that correct?

I'm wondering if that is best or not. Would there be any condition of partial throttle that would benefit from having it open? Right now, I have taken out the linkage from the solenoids to the flap so it's hanging free and opens under vacuum alone.

If I could figure out a way to modify the factory system to get it to open at the same time as the secondaries that seems like it would be better.

[98 SNAKE EATER]

I've driven with mine fully closed and wide open and honestly can't tell a lick of difference in power either way

Pretty cool to watch though

https://www.youtube.com/watch?v=VwCz3wg81aQ

[Norwood]

Originally Posted by 98 SNAKE EATER

I've driven with mine fully closed and wide open and honestly can't tell a lick of difference in power either way

Pretty cool to watch though

https://www.youtube.com/watch?v=VwCz3wg81aQ

Agree 100% it a neat gimmick for sure.

[Formulabruce]

/^^^^^^/ I agree.

[jhein]

When I first got the car, the carb brackets and switch were missing. The solenoids and the rod connecting them to the flap were in place. That held the flap closed until you opened the secondaries. But, the flap never opened all the way due to the resistance from the solenoids. So it was a semi functional system. Right now, I have the rod from the solenoids to the flap removed so the flap is just hanging loosely. I guess I'm just gonna leave it that way. It opens when it needs to and that's it.

[jhein]

Originally Posted by 98 SNAKE EATER

I've driven with mine fully closed and wide open and honestly can't tell a lick of difference in power either way

Pretty cool to watch though

https://www.youtube.com/watch?v=VwCz3wg81aQ

Do you know what cam you have in that motor? It doesn't sound like an 068. Sounds good.

[PAUL K]

I thought one of the magazines opened the hood scoop for a 73 SD455 TA during a road test and gained close to two tenths ET in the quarter mile.... Maybe I'm remembering wrong. With out a doubt one should go faster with the hood scoop open. If they don't something else is wrong.

[unruhjonny]

even if it's a gimmic, it's cool - I'd have it all in place if I were in your shoes.

[jhein]

Originally Posted by unruhjonny

even if it's a gimmic, it's cool - I'd have it all in place if I were in your shoes.

That's about what I thought you'd say.

[kingbuzzo]

I have a somewhat functional one on my '74 I just purchased - it is so cool compared to my old '74 that had it blocked off.

Sounds like a mf at WoT too.

My th400 down-shift doesn't seem to be working properly but I still have to work that out.

[jhein]

Does anyone know how many CFM the 70 single snorkel air cleaner flows? As I said elsewhere, I've been taking it relatively easy on the new drivetrain. But, just before I started having my electrical problems I did open it up through 2nd and 3rd gears (it was awesome, BTW...). That flap opened right up! The point is that if air will flow through the path of least resistance, it wanted to go through the shaker, not the snorkel. That's with my flap just dangling, disconnected from the solenoids.

[PAUL K]

IDK what a single snorkel flows but it's not enough. I also know the shaker opening by itself doesn't flow enough for a high horsepower engine. I've driven my 70 a few times after it had been rained on and it had drops of water on top of the shaker. When you'd floor it the scoop door would open and it was fascinating to watch the droplets slide over the scoop and get sucked in the open door.

[necdb3]

Originally Posted by PAUL K

IDK what a single snorkel flows but it's not enough. I also know the shaker opening by itself doesn't flow enough for a high horsepower engine. I've driven my 70 a few times after it had been rained on and it had drops of water on top of the shaker. When you'd floor it the scoop door would open and it was fascinating to watch the droplets slide over the scoop and get sucked in the open door.

So there's a method to the madness of the old game of flipping the air cleaner upside down? A friend in the 70's told me it added 10HP to his car. LOL

[PAUL K]

Originally Posted by necdb3

So there's a method to the madness of the old game of flipping the air cleaner upside down? A friend in the 70's told me it added 10HP to his car. LOL

Yes definetly. Ten horse seems realistic but it probably sounds like a fifty horsepower gain.

[keith k]

The biggest benefit of the shaker is that it's pulling in cooler air (that hasn't been heated up by passing through the radiator on its way into the snorkel).

To maximize that benefit, I would use a 73-76 shaker with the entire vertical block-off plate removed.... and put the stock '70 unit with flapper on a shelf in the garage.

[necdb3]

Originally Posted by PAUL K

Yes definetly. Ten horse seems realistic but it probably sounds like a fifty horsepower gain.

Would be a good show for "Engine Masters" to run. With and without air cleaners or different air cleaners.

[jhein]

Originally Posted by keith k

The biggest benefit of the shaker is that it's pulling in cooler air (that hasn't been heated up by passing through the radiator on its way into the snorkel).

To maximize that benefit, I would use a 73-76 shaker with the entire vertical block-off plate removed.... and put the stock '70 unit with flapper on a shelf in the garage.

I agree. If anything it's the cool air not any ram-effect, especially for the shaker.

What's the reason for using a different shaker, to preserve the original or or just better flow without the flap?

[fbody_mike]

Originally Posted by necdb3

Would be a good show for "Engine Masters" to run. With and without air cleaners or different air cleaners.

Salad Bowl for the win! Check out Engine Masters Season 2, episode 27 "Air Filter Horsepower Shootout!" They tested 19 types of air filters, it was a good episode. I will have to rewatch it. Spoiler...but a salad bowl will work the best.

[poncho-mike]

If you look at a Firebird air cleaner, the base is dropped relative to where the base is on the GTO. This restricts air flow, so flipping the lid upside down would help a bunch.

At steady state cruising, an engine only puts out as much horsepower as it takes to maintain a constant speed. So if you improve air flow to the engine, it probably doesn't make much difference at part throttle. At full throttle, you need the extra air. In theory, the area in front of the windshield is a high pressure area, and pressure increases the faster you go. So if the shaker opens up, it's letting in cooler (and denser) outside air into the aircleaner, bypassing the single snorkel that's bringing in hot air. So I would expect a difference would only be noticeable at higher speeds.

[keith k]

Originally Posted by jhein

What's the reason for using a different shaker, to preserve the original or or just better flow without the flap?

Because the flap opening on a '70-'72 shaker isn't the size of the full potential opening. You're probably losing 25-30% of the total air that could flow through if the entire area was opened up. That's a lot of air. And the more that comes through the shaker vs. the snorkel, the lower the average inlet air temperature.