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Today I went for a quick drive in my 91 RS 305 5 speed.
Has been sitting for at least ten years following a crash before I bought it.
It had no air dam
i went for a ~3 mile drive 50-60 mph
With no air dam coolants temps were 220-225
I then installed the air dam without changing anything.
I went for the exact same drive and the coolant temps were ~165
Just sharing in case any noobs don’t have an air dam but want confirmation that it makes a pretty big difference.
I learned last summer how big of a deal an airdam is on my LS376/480, Tremec T56 Magnum swapped, 1991 Foxbody Mustang coupe. I wasn't running the plastic airdam and my coolant temperatures would climb to 220F going down the highway with the AC on in the Houston heat. When I would slow down below 40 mph and my new, OEM, C7 Corvette, brushless PWM fan would kick on, the coolant temperatures would come down to 205-210F. Usually it's the other way around; the fans are the "weak link."
I posted this issure in a thread on LS1tech.com and a forum member asked me if I had my airdam installed on the Mustang. I told him I had the plastic airdam but it wasn't on the car. I installed it and boy did that plastic piece make a huge cooling difference going down the road at highway speeds. Now with the airdam in place, the car cools much better than the C7 Corvette fan. Everyone, make sure you install your car's airdam!!!!
There's a reason why, in every, "My 3rd gen overheats!" thread posted here, that usually the first question asked of the OP is if the factory air dam is actually on the car, in the original factory location.
Turns out, directing air through the radiator, rather than it passing under it, cools the engine.
Who knew?
Last edited by ironwill; Mar 19, 2026 at 11:55 AM.
There's a reason why, in every, "My 3rd gen overheats!" thread posted here, that usually the first question asked of the OP is if the factory air dam is actually on the car, in the original factory location.
Turns out, directing air through the radiator, rather than it passing under it, cools the engine.
Does anyone know it the side pieces have any effect on the firebirds? Like the pieces that go in front of the front wheels.
my 82 started running a little hotter w the blower and intercooler. I had the stock 82 style air dam and swapped the larger 85-up one and it got me down to 185-190 on hot days. Prior in "spirited" bursts I was getting to 200. The larger one totally scoops up more air.
Does anyone know it the side pieces have any effect on the firebirds? Like the pieces that go in front of the front wheels.
my 82 started running a little hotter w the blower and intercooler. I had the stock 82 style air dam and swapped the larger 85-up one and it got me down to 185-190 on hot days. Prior in "spirited" bursts I was getting to 200. The larger one totally scoops up more air.
I recently read a thread where someone mentioned the side pieces near the front wheels. I know you have a Firebird, but my IROC didn't have them but maybe a previous owner removed them.
My Foxbody, Mustang coupe has them. I did install them. I ***assumed*** they were to keep excessive rain water from splashing into the engine compartment but I read that they actually help cooling. If the factory installed them, then they are needed.
I have heard from some people smarter than I am that the air dam not only helps build air pressure to go through the radiator, but that it also is instrumental in creating vacuum behind it as well to help pull air through. Not sure of the accuracy but sounds legit.
I've also found if your car is lowered and the air dam is new or mostly there if it's too close to the ground or won't do much at all and needs a slight trim
