Been reading through some threads and all say there should be a 2mm restrictor in the bottom (or waste) hose from solenoid to intake pipe.

I've read this stated a lot and also everyone says that is the only restrictor in the pipework (pre 96 3 port)

Now..

I've just picked up a 95 STI V2 which is only making 0.7bar on WOT (hence me coming on here searching threads)

I've had a squeeze of the pipework to solenoid and the bottom restrictor appears to be missing (there is a white mark where the restrictor should be) which I know should = more boost spike

Also this car appears to have a restrictor fitted in the pipe to the actuator (again where the white mark is)

What I'm interested in is why everyone says there is no other restrictors when mine has the white mark and what feels like a restrictor in the actuator line. Also see the pic below (not my car) and it has the white mark on the actuator pipe too which I would of thought indicates restrictor?



Or is the white mark not relevant to restrictor on that pipe? and someones taken it from waste pipe and put it in actuator line?


Also does anyone know peak boost on std STI V2 95? I can't blumin find the info... 0.9bar?

 

white marks mean nothing.
restrictor should be in the hose from the very bottom of the boost control solenoid iie the hose coming out of the base of the solenoid and not the hose coming out of the side of the solenoid.
This is a brass restrictor inserted inside the pipe and should not be confused with white plastic pipe adaptors which step down/step up between 3mm and 5mm mbore pipes.

Edited to say : 13.64psi and a 6K ECU

 

Thanks Scott.

After having a look today there was actually no restrictor in the actuator line (just felt like a hard part in the pipe)

There was no restrictor in the bottom hose either...

There was however a bolt in the bottom hose completely blocking off the pipe. I can only assume the restrictor was removed at some point and overboost issues caused someone to block the pipe.

Now, I made my own restrictor using the end of a pen, drilled it to 2mm and took the car out. Boost was now too high, didn't give the car WOT but saw 1.2bar on part load and backed off.

Stuck another restrictor in drilled to 1.5mm and now have 1bar. I have 2 restrictors in line, one 2mm and one 1.5mm. I'm wondering if it's because I used a plastic lid (which is obviously thin) that it wasn't right at 2mm.

Also it could be that drilling thin plastic allways ends up a larger hole as it's so soft. I was in a rush (as was off out) and grabbed the 1st things I could find. I think I'll make a circa 5mm long one out of metal starting with 1.5mm.

 

Glad you found the problem i.e the bolt in the pipe.
If you do a search on my name and the word 'Restrictor' you'll probably find the Pt.No you require.

I'm not 100% sure size the hole should be as never measured it, some people have posted saying it's 2mm, but I don't think it's that big TBH. The VF28 and TD04 use 0.9mm and 1.1mm IIRC.

 

Give the solenoid a good check over and clean, someone could have put the bolt in cos the solenoid is bust

 

Made another restrictor tonight out of a bit of metal, started with 1.5mm..

Took car out and getting 1.3bar easy not on WOT, had a little stab at WOT and saw 1.4bar peak!

Suddenly hit me.. module! Whipped the ecu out and there is a chip in the ecu with 52R 1,2 in big white print on a black sticker.

Removed chip, soldered a bit of bell wire in to re-connect J1 and..


Just been out for a play and it's hitting fuel cut now ffs

At first it seemed perfect, hit just under 1bar on WOT through all the gears then it started fuel cutting in 3rd, gauge would read a tiny bit over 1bar and it cuts now!

Would an induction kit make it do this?

The car is otherwise a standard sti v2, std exhaust, std downpipe.

And I'm only running a 1.5mm restrictor (should be 2mm iirc) With 2mm restrictor it'd be even worse.

 

Ah, sorry Scott. Just seen this

So maybe the STI isn't even 1.5mm? That's interesting..

I'm wondering if those part no's relate to an sti too.

 

Buy the kit from Subaru..

 

AFAIK all the Pre96 use the same restrictor as they all use the TD05 (except for WRX Wagon).

Fuel cut in a 7K is 15.96psi so 1.1bar. sounds like you found that with your tests.

Drop the restrictor down to 1.2mm, thats what I reckon they are.

 

Dan, thanks but my main concern is whether my 95 sti would have this exact part.

For example, an old post I found through google..

 

hmm, it didn't seem like 1.1bar to be honest..

Also you say 6k and 7k ecu poss, but I'm sure it was a w6 or something (knew I should have written it down) maybe someones used that because of the module being in there (if it's the wrong ecu)

 

If pre 96 models all had different size restrictors then all pre 96 ECU's wouldn't be interchangeable.

This is a very high possibility. Don't know how you would find out which it is without the label on the top. The serial numbers inside must correspond to something eh???

 

Well after a search.. it's an early wrx ecu. Seems someone's used the w6 as a vessel for this chip in Japan (presume they bought the whole ecu done)

 

W6 fuel cut ia around 14.5psi and should boost to 11.47psi as standard.
Re: you PM, yes I can supply either a chip or a bespoke remap using the new live mappable adaptor and software....depends how much you want to spend.

Get the restrictor down in size so it's around 0.8/0.9bar and we can work from there....

 

If you see post #3 I explained that there wasn't actually a restrictor in the actuator line in the end.