Turbo Dodge Forums banner

limits of stock air box

1038 Views 19 Replies 6 Participants Last post by  Turbo3IROC
Has anyone tested the limits of the stock air box? What I'm looking for is basically How much HP you have made on the dyno or your best ET. Also give your mods that you made it with. More to come.....
1 - 20 of 20 Posts
I would assume the biggest problem with the TIII airbox is that it sits over that cookstove known as a turbo :D If you could keep the airbox cool (yeah, right) and have a K&N in it, it'd probably have decent flow.
Anyone have any input?
Thanks iTurbo.
If I recall, the GLHS air box doesn't sit directly above the turbine.

Even with the stock turbo, mine got so hot that the rubber around the K&N filter was starting to deform.

Maybe a reflective shield on the underside of the air box could eliminate this.
GLHS airbox? Post #4 of that thread has to do with the TIII setup, which is why I posted the link.
Post #4 was about Larry 4sfed4. I thought the same thing at first when I went to the link though.

JayLo, what was your power level when that happened?
ahh sorry about the confusion. The GLHS and R/T airbox setups are quite a lot different of course.
Hey I just remembered something....Just after I bought my Spirit R/T, I was disassembling the airbox setup to clean it out. I found a homemade heatshield made out of an old Wyoming license plate bolted to the underside of the airbox. Seemed to work pretty darn well and was hardly noticeable.
Sounds like a great example of TurboDodger ingenuity. :thumb:
Hey Kelly,

My red R/T had a stock airbox with a K&N drop in. It's last time at the track before it met it's maker was 12.4 @ 110. I didn't have the snorkel on it that day though, so I don't have any back to back numbers there. I did run it with the snorkel other times at the track (while working out tuning issues) and was easily knocking back 13.0's and maybe even a few high 12's.
Mods for that car were intercooler, +20's, exhaust and boost. No balance shafts and the valves were supposedly back cut. Stock SBEC, stock turbo.

Pat
Pat, thanks! That's exactly what I was looking to hear. I had a K&N in my car and I didn't think it was flowing enough air. It would fall on its face by the top of 2nd and was pig rich. Pulled the filter out and made one pass where I missed a couple shifts but I was able to tach 2nd & 3rd more that way. Then I made a clean pass after with no bog.

I got the car back here and put a paper (purolater) filter in it and it still bogs top of 2nd. A friend that I work with has a new filter on the way and offered to let me use his cone filter that he just dynoed 286 hp so I know it flows enough air for me.

So I'm kind of dumbounded again because I didn't think the stock filter was flowing enough air. Doesn't seem to do it until it's warmed up also. You guys have any ideas?
Is the hose from the turbo inlet to the box getting soft and sucking shut a bit?
Turbo3IROC said:
Pat, thanks! That's exactly what I was looking to hear. I had a K&N in my car and I didn't think it was flowing enough air. It would fall on its face by the top of 2nd and was pig rich. Pulled the filter out and made one pass where I missed a couple shifts but I was able to tach 2nd & 3rd more that way. Then I made a clean pass after with no bog.

I got the car back here and put a paper (purolater) filter in it and it still bogs top of 2nd. A friend that I work with has a new filter on the way and offered to let me use his cone filter that he just dynoed 286 hp so I know it flows enough air for me.

So I'm kind of dumbounded again because I didn't think the stock filter was flowing enough air. Doesn't seem to do it until it's warmed up also. You guys have any ideas?
Sounds like there's more to it than the air filter. Does it follow the same pattern EVERY time, or does it do it on an intermittent basis?
Turbo3IROC said:
Pat, thanks! That's exactly what I was looking to hear. I had a K&N in my car and I didn't think it was flowing enough air. It would fall on its face by the top of 2nd and was pig rich. Pulled the filter out and made one pass where I missed a couple shifts but I was able to tach 2nd & 3rd more that way. Then I made a clean pass after with no bog.

I got the car back here and put a paper (purolater) filter in it and it still bogs top of 2nd. A friend that I work with has a new filter on the way and offered to let me use his cone filter that he just dynoed 286 hp so I know it flows enough air for me.

So I'm kind of dumbounded again because I didn't think the stock filter was flowing enough air. Doesn't seem to do it until it's warmed up also. You guys have any ideas?
I agree with Scottmon. This sounds like more than just the air filter. I’m running a ricer APC piece of crap air filter right now, and I don’t get any bogging. I didn’t bog with my stock air box and K&N either.

Perhaps having the air filter in place is causing the airbox-to-compressor-hose to cavitate as Pat suggested. If the hose were too soft, not having the air filter would remove an otherwise normal pressure drop in the system, which would reduce the amount of vacuum the hose normally sees. Remove the air filter, and the problem would “appear” to go away.

With that said, does it bog when the engine is cold (and the hoses are nice and stiff)?

A really dirty air filter or trying to move way more air than was intended (say a hybrid or larger turbo with a lot of boost) through a filter could induce enough vacuum to suck a normal hose shut. Could either of these be the case? What else have you changed on the engine?
JayLo said:
I agree with Scottmon. This sounds like more than just the air filter. I’m running a ricer APC piece of crap air filter right now, and I don’t get any bogging. I didn’t bog with my stock air box and K&N either.

Perhaps having the air filter in place is causing the airbox-to-compressor-hose to cavitate as Pat suggested. If the hose were too soft, not having the air filter would remove an otherwise normal pressure drop in the system, which would reduce the amount of vacuum the hose normally sees. Remove the air filter, and the problem would “appear” to go away.

With that said, does it bog when the engine is cold (and the hoses are nice and stiff)?

A really dirty air filter or trying to move way more air than was intended (say a hybrid or larger turbo with a lot of boost) through a filter could induce enough vacuum to suck a normal hose shut. Could either of these be the case? What else have you changed on the engine?
I have thought about the inlet hose sucking shut. It only does it after it's warmed up pretty good, so it's probably pretty soft then. But as you mentioned it is somewhat intermittant. I clean the K&N before each season and that seemed to help from last year. Then I started experimenting with the spring on the WG and it started coming back. The boost still falls off up top but it does hold up a bit better now.
How much can be gained from going to an after market cold air set up? Does anyone make one that fits a t3?
darktone said:
How much can be gained from going to an after market cold air set up? Does anyone make one that fits a t3?
Well, what I'm going to try on my IROC R/T is to put a K&N cone filter (more the straight type, not really a cone) on the computer intake behind the driver's side headlight, then run the output from the computer straight to the turbo inlet. Looks like I'll have to make the hole in the radiator bracing bigger to fit the filter, but should definitely pick up some cold air! Looks like this'll only work on Daytonas though. Filter I have is approx. 5" tall, 5" dia, w/ 3" inlet. I'll have to double check the box to be sure though, I haven't looked at it in a while.
I swapped out the inlet hose and the old one felt pretty soft. Took it for a ride today and got it plenty hot and it didn't bog down. So I am finally confident that I found my problem. Thanks guys.
1 - 20 of 20 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top