Question about S2 tuning?

[TommyMardon]

I've scavenged the net and there doesn't appear to be any decat mods? Are these available some where?

Also with dump valves, what are S2s like running fully atmospheric? I know the 1.8Ts run on a recirc system, but I see people running atmospheric on those.

What would a twin piston collins/baileys be like on an S2? Any videos of the sound?

[rxl]

I've scavenged the net and there doesn't appear to be any decat mods? Are these available some where?

Also with dump valves, what are S2s like running fully atmospheric? I know the 1.8Ts run on a recirc system, but I see people running atmospheric on those.

What would a twin piston collins/baileys be like on an S2? Any videos of the sound?

http://www.ebay.de/itm/BN-PIPES-Kat-...item5ae46074ff
decat mod

s2 runs also recirc system and i also got atmospheric ones... sound good but seems i lost some power.. so gonna sell it and go back to stock...

[TommyMardon]

http://www.ebay.de/itm/BN-PIPES-Kat-...item5ae46074ff
decat mod

s2 runs also recirc system and i also got atmospheric ones... sound good but seems i lost some power.. so gonna sell it and go back to stock...

How about an uprated recirc valve or?

[Rusty]

You don't need an upgraged recirc valve for stock turbo. You can run APR R1, which is a diaphragm type or something like a Forge 006 or 007, which are piston type. Don't go atmospheric on a stock MAF setup, it'll ruin the response. You can get DVs which split open air and recirc but they don't work that well. Anyway, with a modified airbox or cane filter, you'll get plenty of woosh noise

Unless it's a 3B, you're better off getting a 3" DP and sports cat on there and then removing one or both of the silencers.

[GazzaG60]

I ran a gfb atmospheric no issues.

I would avoid Collins/baileys forge myself.

go for best you can afford.

[Rusty]

Where was the MAF?

[GazzaG60]

at first on the car. standard location. fine. I did use a boost controller though. maybe that had an effect. I set to 1 bar and that was it on stock software. af was good. I know not the best solution but worked fine.

after that the maf was moved still not pressure side...to the boot. I fitted vems and the big turbo. when I fitted the turbo I limped it home on the maf but it stalled lots on setting off. thin too much air for the mix.

if you like recirc I thought the best I saw was the gfb twist to hybrid valve. not cheap though.

I understand the logic of metered air etc but in reality it was fine. as were the hundreds of subarus ive seen done before with blitz,gfb,hks valves. maf no pressure side.

[prj]

Fitting a vent-to-air BOV on a S2 with standard turbo will add between 0.5 to 1 second to your 0-60 time.

If you don't care about making your car slower for some noise, then go for it. I personally have little regard for such things, but it's not my car.

[GazzaG60]

from the man who knows. no need for the attitude though the guys just asking a question.

maybe my boost control negated the effect. I think so. it was a lot more pokey than a stock s2.

[prj]

The point is, your car would be quicker without the BOV.
As are all the Subaru's and Evo's, unless you run speed density on them.

[TommyMardon]

I'm guessing (Like all turbos) having an atmospheric valve will cause more lag?

[UrS4boy]

I'm guessing (Like all turbos) having an atmospheric valve will cause more lag?

Yes. That is what prj was saying, especially between shifts.

Here is some By-pass Valve info to read (if you are running Google Chrome, you might get a warning, otherwise, its fine):

http://forums.quattroworld.com/s4s6/msgs/20994.phtml

[prj]

A simple Google search will tell you this:

In the case where a mass airflow sensor (MAF) is used and is located upstream from the blowoff valve, the engine control unit (ECU) will inject excess fuel because the atmospherically vented air is not subtracted from the intake charge measurements. The engine then briefly operates with a fuel-rich mixture after each valve actuation.
The rich mixing can lead to hesitation or even stalling of the engine when the throttle is closed, a situation that worsens with higher boost pressures. Occasional events of this type may be only a nuisance, but frequent events can eventually foul the spark plugs and destroy the catalytic converter, as the inefficiently combusted fuel produces soot (excess carbon) and unburned fuel in the exhaust flow can produce soot in the converter and drive the converter beyond its normal operating temperature range.

From:

http://en.wikipedia.org/wiki/Blowoff_valve

[TommyMardon]

A simple Google search will tell you this:



From:
http://en.wikipedia.org/wiki/Blowoff_valve

Understood! I'm assuming ALL turbo cars run on recircs standard? Never got my head round Atmospheric dump valves, what cars can run them properly?

[GazzaG60]

I understand that as it is. in reality though I felt no adverse effects but like I say maybe because of the changes in other areas such as boost control.

subarus the same. although they were in the end demaffed using linkecu for the bigger ones.

at the end of the day you take your choices but the experience of PRJ in these areas is greater that that of most of the rest of us.

ill stick to my bov and take the hit on performance when I get the engine back in.