I don't think there are 2 restrictors. I did not see another and as he posted above, he was mistaken and also agrees there is only one.

On an totally off topic note, I just notice your avatar Option2.
Never paid attention before, just realized what it was. That's kewl.

 

I just tried this and saw something a little different that what is described here.

I pulled out the little brass restrictor as described in this thread.

I loved the "an ant could run off with it". That would be one big ant!

Anyway, mine was cone shaped and had different sizes that mentioned by timzcat.

On the large end: OD--5/32; ID--7/64.
On the small end: OD--7/64: ID--1/16/

So the restricive size was 1/16. There is now way I could have drilled it to the size mentioned.

I test drove it and didn't feel much of a difference. I don't have a boost gauge yet, so I can't give any real numbers with it out. I put it back in for now, until I get a boost gauge.

Can anyone confirm my numbers?

 

More boost accross the board, car is faster, for me.

 

Yes, I meant 5/64 drill bit.
Yes it is cone shaped as you say, the important part is the restriction size.

Oh, and remember an ant can carry like 10 times his weight.

 

Ok, I'll say it again. There are 2 restrictors. One in the hose going to the boost control solenoid and also one in the hose off of the turbo compressor housing. I have a brand new hose set sitting here in front of me and can plainly see and feel the restrictor in the hose coming off of the turbo compressor housing. If you remove the restrictor in the hose coming off of the compressor housing, you will only be able to boost to 11-12psi as stated before.

 

Right, and if you remove the one at the BS you will gain 2psi...

 

OK, so can we get confirmation on this please...

Turbo to restrictor to T
T to restrictor to BCS
T to WG

Is this the correct description?
Peter

 

Dude, if you have a 958 RWHP Supra, you should be able to figure this out, you can also use a Boost controller too.

 

I don't actually understand the question but you can feel the restrictors in the lines.

 

Thank you for the technically informative and helpful response. The confusion stems from the lack of understanding and clarity on this thread. I do NOT want to use a boost controller b/c I do NOT want to void my warranty, and yes, having a 958 rwhp car satisfies my urge for modification. Yes, I did build that car myself, and yes, I do know a little bit about cars. All i'm doing is going on a fact finding mission to learn the EVO and to try to understand how the car is built from the factory. Obviously you are NOT going to be one of the sources that can provide me with anything useful. Thanks...
Peter

 

There are 2 restrictors. Decreasing the size of the hole in the restrictor that comes off the turbo housing will increase boost. They have been doing it this way in the UK for years. From what I understand, this method is more accurate than enlarging the solenoid restrictor. The idea is to reduce pressure to the wastegate actuator causing the wastegate to open later.
Cheers,

 

Thanks for the response wtz, I understand how restrictors work, I was just trying to get clarification as to where the restrictors are located and how many of them there are... That's all...
Peter

 

There is one restrictor and it is near the selonoid end, I have the original hoses in my hand. It's not like every person on this forum cannot verify this fact for themselves. The hose going from the waste gate to the turbo outlet is glued to the nipples on both ends, I broke the Tee connector pulling them off, so be carefull.

The theory for a restrictor in the short line going from the turbo outlet to the waste gate sounds reasonable, but on a US EVO VIII it's just not there.
If some one says they have a factory replacement hose with two restrictors, well that's wrong, because the original hose does not.

Removing the selonoid restrictor or trying to add one in the short line will tend to make the boost a little unstable. IMO, get a real boost controller or just leave it alone. If your worried about warranty just take it out before going to the dealer.

If some one actually got less boost after removing the restrictor, they probably reconnected it wrong.

 

WOW, sombodys a little insecure, argue on the internet much? Need to proclaim your happiness and angst to complete strangers?


Seriously, you can hook up a BC in 2 mins, and you can also remove it in 2 mins before your trip to mitsu.


Never Did I say that...


That I doubted your other rides...
That I doubted that you built your own ride...


You seemed to read all that in my little statement, need to work on that.


Thanks

umiami80

 

Can someone post a TXT file in timzcat FTP stating the step by step directions for this. It'll also be nice if it had afew pics, this will help alot more people that dont know where anything is, thanks