Intake plenum question?

james_gt · Post by **james_gt** » Sun Mar 07, 2004 3:52 pm

First off I would like to know what this part does, is it needed for the car to run properly. I have seen people replace them with aftermarket ones and what I was wondring is, is there anything special inside the aftermarket ones like the stock one, or is it just straight tube. Sorry, Im just looking to get rid of that box and i was just wondering if a normal bent metal tube with metal fittings welded on would work. Thanks

james

vrg3 · Post by **vrg3** » Sun Mar 07, 2004 5:56 pm

It should work... Have you seen legazee's design?

http://bbs.legacycentral.org/viewtopic.php?t=1040
http://bbs.legacycentral.org/viewtopic.php?t=1352

I don't know if the resonating chambers and positions of the fittings matter too much for functionality of the canister purge, the IAC valve, and wastegate bleed, but it seems to work for him.

Canister purge only happens when you're on boost. At this point the turbo's pulling air in fast so there'll be a partial vacuum throughout the intake just because your air filter and tubing doesn't flow 100% perfectly. So as long as you don't create a zero-restriction intake purge should work in my opinion.

The IAC valve's only in use at idle and so it shouldn't matter too much since air isn't moving very fast or turbulently. Also, the ECU can compensate for some changes in IAC behavior. So that shouldn't be a problem...

The wastegate bleed is the only one I'd be at all concerned about. The electronic boost control in the ECU is calibrated for the dynamics of the stock setup: 5.5mm line coming from the compressor outlet, going to 4mm line into the solenoid, with 5.5mm line going back to the wastegate actuator and 5.5mm line with a 2mm restrictor carrying bled air to the resonator.

I know that removing that 2mm restrictor caused boost to be a little unstable and unpredictable on my car. In a sense it changed how easily the boost was bled. Changing where the bled air goes in the resonator may change boost dynamics.

I don't think legazee ever said if he was using aftermarket boost control or not, or whether boost control was at all affected or not.

If you are using aftermarket boost control, it's a non-issue, and you could even leave off that extra nipple.

createnew · Post by **createnew** » Mon Mar 08, 2004 12:19 pm

wow. I read both of those threads. Did legazee ever get those done and try to distribute them? I'd be interested in one of those, but probably have to make them myself because of the low cash flow problem. Thanks for brining those back VRG. Theres a lot of things you guys have covered. If I didn't have to go to a friends house just to use the computer, I would try to read everything.

vrg3 · Post by **vrg3** » Mon Mar 08, 2004 4:19 pm

He talked about making a bunch and bringing them to meets and such but I don't know if he ever found time. You could always try dropping him a line.

The trickiest part is of course finding an appopriately sized piece of pipe. The inlet of the stock piece is about 80mm outer diameter and the outlet is about 65mm outer diameter. legazee found a fortuitously-sized piece.

mTk · Post by **mTk** » Tue Mar 09, 2004 8:18 am

I made one of legazee's intakes today.

It is really VERY simple to do. here is the price breakdown:

-stainless coffee mug: $4
-1/8 mpt x 1/4 barb: .89
-3/8 mpt x 1/4 barb: .89
-3/4 mpt x 3/4 barb (elb): $1.19
- Permapoxy: $2.49

Total w/ tax: $10.14

MK

vrg3 · Post by **vrg3** » Tue Mar 09, 2004 3:37 pm

I think a 3/8" hose barb might be closer to the stock size for the auxiliary purge hose. The stock size is 7.5mm.

legacy92ej22t · Post by **legacy92ej22t** » Fri Mar 12, 2004 4:31 am

mTk wrote:I made one of legazee's intakes today.

It is really VERY simple to do. here is the price breakdown:
-stainless coffee mug: $4
-1/8 mpt x 1/4 barb: .89
-3/8 mpt x 1/4 barb: .89
-3/4 mpt x 3/4 barb (elb): $1.19
- Permapoxy: $2.49

Total w/ tax: $10.14
MK

Was there a noticeable difference? Do you feel it was worth doing?

I've been wanting to rid myself of that resonator for a long time but haven't addressed it yet. Maybe I'll add it to my spring to do list.

azn2nr · Post by **azn2nr** » Fri Mar 12, 2004 4:41 am

is there just a way to close off the gap between the two sides where the air swirls around without affecting anything?

vrg3 · Post by **vrg3** » Fri Mar 12, 2004 5:03 am

Actually, I thought before about taking some gaffer's tape or something and using four or five strips to close off the rest of the resonator from the airflow. Kind of like putting a piece of pipe inside the resonator. As long as it didn't make a perfect seal, the three accessories connecting to it should still work okay.

Haven't tried it though. I'd need to be really sure that the tape wasn't gonna come loose or disintegrate. It'd suck to have a piece of tape stuck in my compressor wheel. Or in my valvetrain.

legacy92ej22t · Post by **legacy92ej22t** » Fri Mar 12, 2004 5:08 am

I wonder if we could gut the resonator? That would be cool. It would probably be hard to do without destroying the whole box though.

boostjunkie · Post by **boostjunkie** » Fri Mar 12, 2004 5:13 am

I was under the impression that that resonator was completely hollow.

legacy92ej22t · Post by **legacy92ej22t** » Fri Mar 12, 2004 5:17 am

Hmm... maybe it is. I was thinking there was a little plastic wall inside but now that I think about it maybe it doesn't.

vrg3 · Post by **vrg3** » Fri Mar 12, 2004 6:00 am

It's not quite hollow, but it doesn't exactly have a wall inside either. The inlet and outlet tubes protrude inside the chamber, if that makes any sense.

My gaffer's tape concept is the only thing I can think of that would be akin to gutting.

THAWA · Post by **THAWA** » Fri Mar 12, 2004 6:02 am

what about just geiing a piece of pcv pipe about the same damiter but a lil shorter than thinside and securing it to the inside?

vrg3 · Post by **vrg3** » Fri Mar 12, 2004 6:35 am

I thought about that too. The inlet and outlet aren't quite lined up. And, the pipe would reduce the channel's diameter. Like I said earlier in the thread, the inlet and outlet are different sizes.

THAWA · Post by **THAWA** » Fri Mar 12, 2004 6:38 am

i say just do the coffe mug thing

try to get dave to sell cafepress.com mugs with legacycentral on em

createnew · Post by **createnew** » Fri Mar 12, 2004 12:54 pm

Yeah, sounds like the next best thing to fabing up a hole new intake.

QuickDrive · Post by **QuickDrive** » Fri Mar 12, 2004 5:55 pm

THAWA wrote:i say just do the coffe mug thing

try to get dave to sell cafepress.com mugs with legacycentral on em[/color][/size]

Well Here's a shopping list I fabbed up for anyone attempting this coffee mug mod and has short term memory loss or something.

legacy92ej22t · Post by **legacy92ej22t** » Fri Mar 12, 2004 6:40 pm

QuickDrive wrote:

Priceless, hahaha, nice!

vrg3 · Post by **vrg3** » Fri Mar 12, 2004 7:22 pm

I disagree with one of those fitting sizes. I think you'd be better off with a 1/4" barb for wastegate bleed, 3/8" for canister purge, and 3/4" for IAC.

DOA · Post by **DOA** » Wed Apr 07, 2004 10:19 pm

Small point on something someone mentioned, when I started to do the mod i put just the mug inline with no hoses connected and the engine wouldnt start at all so you definately need one or more of em connected.
Btw, big up to the guy who came up with the thought, top modsmanship

.

vrg3 · Post by **vrg3** » Wed Apr 07, 2004 10:48 pm

The idle air hose (the big one) definitely needs to have metered air coming through it, yes.

And, yes, another cheer for legazee! (Where is he these days anyway?)

BAC5.2 · Post by **BAC5.2** » Wed Apr 07, 2004 11:04 pm

I seem to be the only one who has put the purge canister line right next to the breather line, rather than under the mug.

azn2nr · Post by **azn2nr** » Thu Apr 15, 2004 4:28 am

na i put mine inline too. on a side note my gas mileage jumped 4-6 mpgs. and with gas being 2 bucks a gallon it helps alot

BAC5.2 · Post by **BAC5.2** » Thu Apr 15, 2004 4:31 am

Really!? 4 whole miles to the gallon!?

DAMN!

Did a flyby on my buddy, and you can't hear it from outside the car... yet...

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Intake plenum question?

Intake plenum question?