Larger post-intercooler piping

[wintertidenz]

Has anyone had experience with running 3" (rather than 2.5") piping post-intercooler?

I've been noticing lately that the car doesn't seem to want to boost over 8 psi with the larger piping - I've checked all the boost piping etc, and it all seems OK.

I replaced everything post-intercooler including the silicone joiners, and checked that the small BOV return pipe was blocked off... the current BOV also seems OK, but I am looking at replacing that anyway.

I suspect that the larger area of piping is reducing my boost pressure, but before I replace it all again I want to see if anyone else has had similar or the same issues.

[Gly]

yep, had to change my boost controller settings completely when i went to full 2.5 joining to 3inch pipe work,

but most of the probs are caused by pod filters, longer intake pipe in front of the pod helps,
but its still not the best,

[wintertidenz]

So you found a pressure drop when you fitted the larger piping? I'm seeing around 2 psi, but when I install an MBC and adjust it I get no extra pressure. It's possible that the MBC is stuffed though.

I want to design a box that takes a factory filter where the battery is - just haven't gotten around to it yet. I'm thinking that yes the pod could be causing issues, but I couldn't fit the standard air box in with the hard pipe where it is.

[Gly]

it just wouldnt make boost on the original settings. was flat as.

once the setting were changed it was fine, just how it boosted changed,
once the pipe work is pressurized it was about the same.

[wintertidenz]

Sorry what do you mean how it boosted changed? Are you meaning in terms of it taking longer to build boost, or...?

[roryfromnz]

I found this also, i was having major problems trying to get it to boost over standard. For me it was the fact it was opening the actuator earlier? I think it was to do with the setup of the manual boost controller. Once i put the mbc first off the vacuume line and ran it so the secondary line off the t-piece went to the actuator/factory solenoid i was able to get the correct boost pressure again. Took me a bit of playing around as it boost cut afew times in the testing process.. :-)

[swinks]

I used for few years either 70mm or 76mm diameter pipes between ic and td and never experienced any side effects whatsoever, the same I can say on behalf of kochajj.
So, Daniel, rather I'd search for other issues than diameter (i.e boost leak, vacuum pipeing, dv etc.).

[Kenneth]

Make sure you haven't removed/replaced the pipe with the red band on it. It has a restricter in it which, when removed, makes standard boost control not work.

[roryfromnz]

Haha that will be my issue! I replaced all the vac lines when i did this.. oops! ohwell sorted in the end but good to know. Thanks Kenneth :-)

[wintertidenz]

Kenneth - I never had that pipe when I got the car, the car didn't even have the boost or FPR solenoids.
If it's worth replacing it, then I will need to find one from a wreck... unless there is another way I can emulate the small restrictor pill inside? I do have aquarium air line restrictor pieces that I can put in-line and adjust the amount of air going through...

[ersanalamin]

Make sure you haven't removed/replaced the pipe with the red band on it. It has a restricter in it which, when removed, makes standard boost control not work.


I do replace all vaccum line and didnt realize about this. could u plase show me what hose/pipe that should not be replaced? what kinda hose to buy for replacement if its already broken?

[wintertidenz]

I've just put in place a restrictor pill of sorts - I pulled it out of my fish tank parts.

It has a hole through that's about 1.25mm, and it fits nicely inside one of my boost pipes - I've put it in place before the t join and made sure that it can't come out either end.

I'll take the car for a drive when I've replaced the lower arms and see how it goes.

I can also put another piece in place that can restrict how much air flows through (shown in pictures), but I'm not sure if it will hold up to the heat in the engine bay.

52056

52057

[ersanalamin]

I've just put in place a restrictor pill of sorts - I pulled it out of my fish tank parts.

It has a hole through that's about 1.25mm, and it fits nicely inside one of my boost pipes - I've put it in place before the t join and made sure that it can't come out either end.

I'll take the car for a drive when I've replaced the lower arms and see how it goes.

I can also put another piece in place that can restrict how much air flows through (shown in pictures), but I'm not sure if it will hold up to the heat in the engine bay.

52056

52057


So the hose its must one way direction for the wind to come thru? Not two way?

[Davezj]

no,
it is just a restrictor.

[wintertidenz]

As Dave says - it's just a restrictor. It cuts the diameter of the pipe by about half - which should produce the restriction required.

[ersanalamin]

As Dave says - it's just a restrictor. It cuts the diameter of the pipe by about half - which should produce the restriction required.

I see, so its still two way, its just restricted. So hows the performance result? any significance result?

another question is how about if we change the boost solenoid with HKS EVC 5 stepper motor, should oem hosed still used restricted? if we change the hose with colorfull aftermarket silicone hose, should it be still restricted also?

[ersanalamin]

Make sure you haven't removed/replaced the pipe with the red band on it. It has a restricter in it which, when removed, makes standard boost control not work.

Kenneth what do you mean by its makes standard boost control not work? the boost control not limit the turbo boost or is it made the engine not react to turbo boost? made me confuse since i ve replace the hose with aftermarket and the turbo still boost the engine fine. Not notice any difference. so?

[Nick Mann]

Without the restrictor, the solenoid struggles to bleed the air off as fast as it arrives. You need to restrict the flow to the solenoid without changing the pressure.

What you have is a pipe from the pressurised intake to the actuator control line, with a T piece to the boost solenoid. The boost solenoid bleeds pressure in that pipework reducing the pressure seen at the actuators. Therefore if you open up the pipework from the intake system to the actuators, the boost solenoid now has to bleed a large flow of air to change the pressure which it isn't big enough to do. So, the restrictor pill prevents the flow of air into the actuator pipework becoming too large for the solenoid to deal with effectively.

[Davezj]

Perfectly said nick that is a great description of the setup.

So many people ask this question about the restrictor this description should be a simple sticky thread on it's own. Or an entry in the library.

[wintertidenz]

No I haven't tested - still waiting on my lower arms to arrive. Don't want to risk driving the car till then.

[ersanalamin]

Without the restrictor, the solenoid struggles to bleed the air off as fast as it arrives. You need to restrict the flow to the solenoid without changing the pressure.

What you have is a pipe from the pressurised intake to the actuator control line, with a T piece to the boost solenoid. The boost solenoid bleeds pressure in that pipework reducing the pressure seen at the actuators. Therefore if you open up the pipework from the intake system to the actuators, the boost solenoid now has to bleed a large flow of air to change the pressure which it isn't big enough to do. So, the restrictor pill prevents the flow of air into the actuator pipework becoming too large for the solenoid to deal with effectively.

Well thats as clear as sky in sunny weather, you are the mann, and i have to crawl over my tool box looking for a resctrictor as well.

I intend to use HKS EVC 5 next month should i still use restricted hose paired with HKS stepper motor?

[swinks]

I intend to use HKS EVC 5 next month should i still use restricted hose paired with HKS stepper motor?
Nope. EVC selenoid requires open diameter hoses.

[ersanalamin]

Nope. EVC selenoid requires open diameter hoses.

Well I think its already completely clear now. Thanks a Lot for Mr. Nick and Mr. Tomasz

[wintertidenz]

Right - I've had a chance to test now the car is back together.

With the new restrictor in place the car is like a rocket again - builds boost quickly and holds it at 6-7 psi (I suspect 1 psi drop due to the larger piping). It certainly feels better - even my fiance commented that it felt a lot more powerful.

[ersanalamin]

Right - I've had a chance to test now the car is back together.

With the new restrictor in place the car is like a rocket again - builds boost quickly and holds it at 6-7 psi (I suspect 1 psi drop due to the larger piping). It certainly feels better - even my fiance commented that it felt a lot more powerful.

Interesting, i am gonna put restrictor too in this week end. thanks for sharing