ryan91rs

iTrader: (1)

sorry guys if it's a stupid question but i need some reference. I'm getting a dual duct air cleaner. it's built for a carb and has a "thermometer" piece in it that when gets warm it opens the heat riser flap . anyway the tbi does not have one (it has a sensor which I'll retro fit in) does that sensor control the riser, i thought it was the maf. as you can see I'm confused. i only run it in summer (going in the garage in two weeks b/c cold weather) so is it that important? should i use the piece in the h.o. air cleaner? thanks for the help!

Apeiron

It's called a Thermac valve, and it's to take warmed air from the heat stove on the exhaust manifold when the engine is cold to allow it to warm up faster. If you leave the vacuum line to it disconnected, it will stay open all the time.

ryan91rs

iTrader: (1)

no i think you misunderstood me. the tbi air cleaner does not have "one" and just has a vacuum line to the "valve" to move the flapper. but the same line in the h.o. cleaner goes to the piece that is built into the air cleaner next to the filter then it goes over to the valve that allows warm air in. should i just hook it up direct like the tbi or run it in to the small temp piece next to the air filter in the base?

coolram62

iTrader: (2)

Connect it the same as the stock TBI air cleaner vacuum line.This way the valve(I believe the dual snorkel has to thermac valves).This way you will get the faster warmup but then i don't believe fuel injection would suffer from icing(cold condensation forming)like a carb.

Jproz1167

iTrader: (3)

It wont fit a TBI engine if the air injection diverter valve is in place.

Jproz1167

iTrader: (3)

here is what I mean to get the air cleaner to sit like its supposed to. You would have to drop the air injection diverter valve about 2-3 inches even then you couldn't get the snorkel tubes to fit because the A/C lines would be in place and interfer .... Of course your car may not have this stuff either LOL

ryan91rs

iTrader: (1)

wow thanks for the picture! well i have the ac set up but the compressor and lines are not on, it has a bad clutch. so i just put on an ac delete pulley. so then if i can modify the way a.i.r. sits i can fit it on. which is what i figured i would have to do. thanks for the help! and no there is only one Thermac valve on the h.o. ait cleaner. and if it still does not fit then i'll get a 2" tbi spacer from summit, but that's a last resort.

THANKS FOR THE HELP!!

do i also have to put the yellow tape around parts of my ac? just wondering if that was a fitment thing? lol.

Jproz1167

iTrader: (3)

to mod the diverter valve you'de probably have to cut the metal line and shorten it, but then it will probably hit your valve covers LOL but then you could probably bend the pipe maybe LOL. Eith way it's going to take work to make it fit LOL ... The HO air cleaner has 2 thermac valves but only draws hot air from the drivers side exhaust manifold like your stock air cleaner. The passenger side thermac valve only closes a flapper door there no opening for the heat stove pipe like on the drivers side.the yellow tape was cause my air injection pipe to my cat converter broke on way home a rattled beyond belif and annoyed the crap outta me is all LOL

Apeiron

Are you talking about the thermal vacuum switch that lies in the base of the air cleaner? Not the thermac motors that are in the inlets?

ryan91rs

iTrader: (1)

yes there is a "switch" and on carb camaro you have to use it to open them or you will bne sucking hot air all the time. how is this different on tbi was really the question. i don't want to suck hot air all day. that kill mpg and power.

thanks for clarifying!

Apeiron

There are two types of thermal vaccum switch used with the thermac system. The one in the air cleaner measures the intake air temperature. Some applications used a TVS in the waterneck to measure the coolant temperature instead.

With either one, you wouldn't really have hot air all the time. The thermac valve is only closed while vacuum is applied, so going WOT or leaving the vacuum lines disconnected will open the valves.

DLV555

iTrader: (1)

Connect the switch to ported vacuum on one side and then to the thermac motors on the other side. The TBI engine should have been hooked up that way. I would swear mine was.