I don't argue with a MBC.
This is just more for the hell of it. See what is possible.
But at the same time, the increase is still under stock boost control. It is not really spiking (like unwanted), that is just the normal peak under stock boost control. But really it is also unknow to anyone. Dealer wouldn't know it was enlarged and you wouldn't have to take it apart just to go to the dealer.
Either way, I don't think I'll be going back anyway unless I have a serious problem. I never said there was anything wrong with a MBC. I came across the pill and decided to do some testing.

 

Interesting... I paid the $17 to Mitsu for an extra turbo vac. line set...since I have an extra set, I might see what I come up with also... I'll use my peak and hold function on my Blitz TT. It won't be any time soon with my schedule though...

 

Could someone post a pic of where the hose is?

 

I noticed the restrictors when adding a MBC. There are two of them in that line: one near the BCS and the other near the T that splits between the wastegate and the pipe coming off the turbo.

 

That's interesting. I didn't see the other one, but the car was hot when I checked.
Is it in the same line, just at the other end?

 

Well, upon further inspection, I must retract my last statement I only have one restrictor as well. It was a late night during the install and I must have looked at the same end twice Please disregard the above and I'll make a note to myself to refrain from posting during periods of sleep deprevation.

 

Now that is funny because I am fairly certain there is a second restrictor on the short line between the turbo outlet and the waste gate. In fact I have the hose with three way Tee in my hand and,,, yup there it is. Taking this restrictor out looks like it would decrease boost though, since it is limiting air from the turbo to waste gate.
I believe these restrictors are there to keep the BC selonoid within its normal operating air flow range, or for smoother transitions.

 

Don't know what the metal is the restrictor is made out of, but you could try filling the hole back up with solder ( if it will adhere to it ) and then you can drill it out again to any size you want.

 

OK, I just did this mod, not too hard but some stuff was hard to remove and DON'T rush or you will break something.


Anyway I get to the lines, just kept squeezing them until I felt the restrictor in the closer of the two vaccume tubes. It was A PAIN IN THE *** TO GET THAT TUBE OFF THE NIPPLE, I eventuallyt cut it off.

Using a wood screw to get that little fitting out is a must and quite easy if you do it right. I don't think you understand HOW SMALL this fitting is, tiny, very, and ant could literally grab it and run off with it, I picked larger things outa my teeth.

Anyways I pull it out and start the car up. It is a little cold so when you hit the gas the car falls right on its face, SO I let it warm up.

The most noticable gain is the boost response, WAY faster spoolup, WAY faster. I hit 1.4 bar now, a full bar higher, you can really see the ECU yank it back faster, sometimes it holds 1.2 to redline, sometimes it holds 1.1 bar. Either way their certainly is a boost increase.

I tried an AWD launch, somehow I nailed a perfect one and spun all 4 wheels for a good 2 seconds, then took off, hit 60 MPH really fast and then 100MPH. Bost is higher all over, but there is an agressive pull back of boost, instead of a gradual pull back, the car is like "OH ****" and then drops it from 20 to 16PSI or 17PSI.


Its good enough for now, I will probably go with a MBC a little later on.

ZGood mod, If I can do it, anyone can, really.

 

Can I get a pic or good description of the location of the hose? I pulled off the air scoop thingy and poked around, but I can't identify any of the parts under there you guys are talking about because I don't know turbos. Or anything for that matter. Little help?

 

Under the air box is the boost control Solenoid with 2 hoses coming off of it. (mounted to the bracket that holds the airbox).
The hose towards the front of the car, it is the one with a clamp holding it on to the BCS. About 1 inch or so ffrom where it is attatched to the BCS the is a small lump in the hose. This is the brass restrictor in the hose.

An ant could run off with it.
Just don't drop it when it comes out! I worked it out with a pick and I dropped it. Doh! Can't believe I found it.

 

So, there are 2 restrictors in the US Evo. In the UK, the one that is modified for boost control is the one in the line from the turbo to the wastegate actuator. A new restrictor with a smaller hole in it is used to keep the wastegate closed for longer. Cowboy, can you elaborate on this restrictor? Hole size etc.? Also, Vishnu has a restrictor mod as part of their stage 0.5 mod. Anyone know the details on this piece? It's supposed to keep the stock boost from dropping off as much at high rpm's.
Cheers,

 

Yes, there are two restrictors. If you remove the restrictor by the wastegate, you won't be able to go over 11-12psi. I unfortunately found this out when I accidentally ripped mine and tried to replace it with a regular hose (no restrictor).

 

Um, never mind what I said about the second restrictor, turns out I was just seeing the end of the tee connector inside the short hose . I broke my original tee pulling the hoses off from the wastegate/turbo and replaced it with a little brass tee. Anyway there is definetely just the one restrictor and it is on the hose end near the selonoid.
I had done this mod a while back but have since switched to a MBC. This mod works as advertised but a MBC/EBC works much better, more consistent, faster spool.
With this mod, if the boost goes much over 1.4 Bar, the ECU gets excited and quickly drops the boost .1 Bar. This is still higher than stock but you can really feel that abrubt boost change happening at random, it gets annoying.

 

So this explains why my car is in limp mode. When I removed my MBC, I replaced the hoses on the turbo side (wastegate & turbo nipple) with new vacuum hoses. I ripped the old ones. Anyone have a part number for these?