Air Intake Duct

[someotherguy]

This intake setup goes through '95 model year. The 96 and on Vortec engines have the air filter on the right wheel well just aft of battery.

The piece inside the fender was omitted beginning 1994 model year. The duct from core support to fender existed throughout the entire life of the gmt400 body style.

Richard

 

[Nad_Yvalhosert]

The piece inside the fender was omitted beginning 1994 model year.

Weird. There was one in my '00 Yukon Denali. I removed it when I installed my K&N box assy on the fender

 

[Supercharged111]

Weird. There was one in my '00 Yukon Denali. I removed it when I installed my K&N box assy on the fender

Did you get any before/after airflow data?

 

[Nad_Yvalhosert]

Did you get any before/after airflow data?

Data? Not really. Just a "seat of the pants" dyno that says it was an improvement. One that gets undone by a lead foot listening to a throatier, noisy air intake!

 

[L31MaxExpress]

Weird. There was one in my '00 Yukon Denali. I removed it when I installed my K&N box assy on the fender

My 99 Tahoe had one as well. I removed it about the time I added the Volant. At ~280 gms/sec max airflow it did not change airflow much. It was already removed when I put the 8.1L style air box in for the 8.1L. The 8.1L would have taxed that duct more than the cammed 305 did.

 

[someotherguy]

My 99 Tahoe had one as well. I removed it about the time I added the Volant. At ~280 gms/sec max airflow it did not change airflow much. It was already removed when I put the 8.1L style air box in for the 8.1L. The 8.1L would have taxed that duct more than the cammed 305 did.

If you're talking about the piece that runs through the fender to the filter housing, that's surprising. I've only ever seen them in the pre-1994 trucks, and I've taken apart a LOT of gmt400's of all years. Hell there was a while I didn't even know this part existed until I'd taken apart some older trucks.

I agree with removing it under all circumstances, though..!

Richard

 

[L31MaxExpress]

If you're talking about the piece that runs through the fender to the filter housing, that's surprising. I've only ever seen them in the pre-1994 trucks, and I've taken apart a LOT of gmt400's of all years. Hell there was a while I didn't even know this part existed until I'd taken apart some older trucks.

I agree with removing it under all circumstances, though..!

Richard

Yep the duct that runs to the filter housing. It looked restrictive so I pulled it out. Nad also stated his 2000 Yukon had one. So maybe it was put back into place in later years.

My brother and I parted out a 99 K1500 Suburban. It had one as well.

 

[someotherguy]

Yep the duct that runs to the filter housing. It looked restrictive so I pulled it out. Nad also stated his 2000 Yukon had one. So maybe it was put back into place in later years.

My brother and I parted out a 99 K1500 Suburban. It had one as well.

Bizarre. Who knows why GM does some stuff. Of all the trucks I parted, none of the 1994-up vehicles had it. If it had just been one example I'd start to wonder if it was a boneyard fender from an older truck installed on a later model, but more than a few examples makes that less likely of a possibility.

Richard

 

[LVJJJ]

As such I run a 3" duct to the driver's side of the air cleaner. I cut into it with an oval hole and fit the ribbed adaptor from the other side, then run a 3" ribbed hose down into the fender well for a second cold air intake. Cut hole in splash guard.

I have been concerned about the passenger side intake as being too restrictive. Long ago I replaced the stupid air restricting box with a straight 4" pipe directly into the air cleaner. Removed all of the restrictions in the air cleaner neck for an unimpeded flow of air. This post provides good info to figure out a better passenger side intake.

 

[CNRED]

These engines never have moved much air. Not making 200 hp. If you take the air cleaner off and listen, you will find the heads are the choke point.