SpeedFreakGT

i just bought a hood to put on my 91 firebird. The hood i bought is the one with the scoop set off to the drivers side and has a solenoid to open a flap. Is there a somewhere i can tap into to make the flap functional at wide open throttle?

also i was wondering if there is a place that carries the breather top that has the hole in the top to actually make it functional?

OrangeBird

iTrader: (1)

Here is a very well detailed thread about the scoop that has all of the info your looking for..........

https://www.thirdgen.org/forums/hist...-trans-am.html

SpeedFreakGT

That is a awesome amount of detail.
Thanks for the link. now to try to wrap my head around the wiring.

T.L.

That's a Trans Am hood. The Formula didn't have the solenoid with the flap. I intend to wire mine with some sort of W.O.T. switch instead of all that complicated factory wiring...

SpeedFreakGT

I need to do some research to just figure out the easiest way at WOT like you said.

T.L.

I assume a custom bracket for the switch would have to be made...

OrangeBird

iTrader: (1)

If you mount a switch that gets activated at WOT, don't use the switch to directly control the solenoid, using a relay between the switch & solenoid will ensure the switch lives a good long life, VS having it's contacts quickly fried by the current the solenoid will draw

PS, didn't certain THM400 transmissions have an electric kickdown that had a carb mounted switch? Maybe that switch could be found and repurposed for use here?

T.L.

Oh I had every intention of using a relay. I just haven't figured out how to mount a W.O.T. switch to a Quadrajet. The bracket that comes with it is made for a Holley.
It's kind of a low priority at the moment...

vorteciroc

I think you will have to fabricate a bracket for a common Micro-Switch.

Unfortunately, most of the Micro-Switches/ Brackets that are produced for Carburetors/ Throttle-Bodies...
are for Nitrous-Oxide usage.
It is unsafe to spray/ inject Nitrous-Oxide above or below a Vacuum-Seconday Carburetor...
I.E. a Rochester Quadra-Jet.

It is important to have a relatively consistent amount of Atmosphere entering the Engine, as Nitrous-Oxide and Fuel are also mixed into the equation...
in attempt the keep a safe and appropriate/ stoichiometric mixture.
So Nitous-Oxide and Fuel is injected at Full-Throttle ONLY...
Vacuum-Secondaries do not open to the same amount consistently enough, to be reliable for Nitrous-Oxide use.

If you and the other Members, have the same kind of "Luck" that I do...
Everyone will be blowing apart Intake and Induction, via Nitrous-Oxide "Back-Fire".

Good luck; the fab-work should not be too involved...
I would reach-out to a Quadra-Jet Specialist, and see if they have anything that you could work with.

Drew

iTrader: (58)

GM used a vacuum switch on carbed cars. Hit the gas, vacuum drops, air cleaner opens.

vorteciroc

An adjustable Vacuum-Switch would work.

See what the average Vacuum Reading is under heavy-load Full Throttle.
With Vacuum secondaries... the vacuum is not normally going to drop to 1" Hg (or less) like a mechanical-secondary Carb.

dmccain

iTrader: (2)

Had one of those old style setups but long since removed it. Had a switch wired to activate it but when it failed I removed the flapper for more air all the time. Had zero problems with water getting in and still dont. I now just have the block off plate drilled/cut out so fresh air comes in all the time.