So when I got the car I notice the plenum was really hot compared to my TA, but that car was more stripped when I got it and had better under hood air flow. Last year I did lots of normal stuff, egr delete, TB coolant bypass and it got a bit less hot. This year I started out with wrapping the exhaust some and removing the rest of the AC and other stuff to open more area under the hood and it was just a lil warm. Recently I did several things to help cool my intake while it was off and now it's cool after a drive. Just now I set the pedal to keep rpm up to about 1500 and sprayed some water to try and break up any carbon if some(I've done it with carbs and can't believe I didn't think of it sooner if you've read my other detonation thread) and the back 2/3 actually got cold(kinda like cold water, but not ice or nothing). I admit I didn't touch the plenum after my 20min drive to test out my changed shift points or even shut it off when I got back, I just let it idle in the garage while I got the water & spray bottle. Really need to get a heat gun, outside temp is 70's, oil temp was 210 and coolant 180's with the fan running(new t-stat and fan program are kinda conflicting atm but that's another thread).

Anyways I was just curious how others are doing with their modded plenum temps. I do some of the same stuff to cool a carb intake and the carb will always feel cool as well.

edit: I only put may a few oz of water and it was luke warm, just a spray here n there.

edit2: TPI

 

The engine will take a lot more water than you would think it could. I watched a mechanic POUR water into a carburetor with a radiator fill hose (high RPM). Lots of black smoke came out the exhaust pipe and then it cleared up and ran fine.

 

Gotta be careful to not hydro lock it. I've seen some pour slowly from a glass and I normally use a bottle myself and just rev it up some and give it a stdy drizzle(both sides if a dual plane). For the tpi I just unhooked the brake booster line and it's hard to say how much the spray gave, so I figured better safe than sry.

 

Install a catch can and you should lower plenum temps and stop getting oil buildup in the intake.

 

I deleted the smog/egr/pvc/cs so no more junk, just air and fuel.

 

On the lt1 coolant bypass, what would happen if you ran the a/c coolant return line through the plenum bypass line?

 

Cool/cold is one thing but frozen throttle blades are why they had the coolant lines. Not that I think it could really happen unless you maybe did something like that.

 

Where do the blowby gases and crankcase oil fumes go?

Do you have breather valves on the valve covers?

 

Yup

 

I would think that Freon returning from the evaporator would be in a liquid state than to flow by diverting it through the inlet-outlet lines of the throttle body and the loop thru the plenum itself would not freeze as it has already lost most of its cooling capabilities as it returns to the condenser to be cooled before going back to the pump to recirculate. The problem I see would be greater heat buildup going to the condenser to cool the Freon as it removes additional heat from the plenum loop. Of course this is in theory. Making new lines for a crowded area could be a problem too!

 

I don't have a clue bout AC stuff And I didn't think their would be any flow freeze/obstruction, I'm talking about frost forming and locking the throttle blades in the right circumstances. IE some of the really big drag cars that use the scoop on top of the blowers gotta oil down the butterflies or they will stick the throttle. If you did the AC thing and you went max rpm for a bit and it was cold out, you could have that happen maybe. Someone reading this someday may end up in that scenario.

 

Throttle icing is possible in certain conditions...but pretty unlikely, and the consequences are pretty low.

So is AC'ing the TB worth it? No. The HP required to run the AC will NEVER be recovered by the very, very slightly cooler inlet air temps created by cooling the TB. Even if you cooled the entire air filter housing, TB, plenum, runners, and base w/AC, I doubt that you'd have a net gain in power. Only time I've heard of where AC cooling intake pays off was in a supercharged application, where AC cooling the intake charge resulted in 100+ degree drop in intake temps....something not possible w/an NA car.

 

Tom makes a good point on the hp used vs gained.