Recirculation gear on 7mgte.

[kemicalx]

G'day guys,

My new 7m is basically ready to go back in the car, I'm just at the stage of putting back all the vacuum hoses and bits of piping. As I’m going with a standalone computer and don’t want to use 3 of my 4 aux outs for the ISCV I’ve removed it and the connecting hoses. This has led me to wonder what other vacuum/EGR hoses I could remove or block off. Bits in question are highlighted below,





So what I'd like to know is,

What is the line running from the bypass valve to the plenum for? Does it trigger anything? Can it be removed?

What is the VSV for and how is it triggered? I see it has a line from the FPR, and a line from the bypass valve, but don't understand what it does. Could this be removed as well?

A little explanation on these systems would be greatly appreciated guys,

Cheers all

[kemicalx]

anyone ?

[thechuckster]

The TSRM for Mk3 Supra should have piping diagrams.

am at work otherwise i'd find you a URL

[kemicalx]

Cheers mate, but I have the diagrams, just really want to know what it actually does, and if it can be removed without any dire consequences

[thechuckster]

bypass valve = BoV? in which case, it needs to see manifold vacuum/pressure post throttle to work

The VSV valve could be the VSV for EGR control, in which case it's managed by the ECU.

Personally, i'd trace out piping from this section <www.cygnusx1.net/supra/library/TSRM/ec/EC_01.html>, you'll need:
-cankcase ventilation (PCV)
-charcoal cannister (EVAP)
-Dashpot (DP)
and if you do it neat enough, they wont notice the missing EGR system.

If the power steering pump supports it, an air-control valve to increase the idle when at full lock <www.cygnusx1.net/supra/library/TSRM/sr/SR_48.html>.

chees,
charles.

[JustCallMeOrlando]

There should be crankcase ventilation, fuel pressure regulator, the charcoal cannister, BOV , power steering and possibly factory boost gauge all coming off the inlet manifold. There will also be a fatter line for the brake booster. Provided the charcoal cannister is all hooked up correctly, I doubt they'd notice anything missing, just as Charles said.

My engineer just looked and saw my charcoal cannister was there with the vacuum lines all connected and then marked it on the engineers report which was enough to satisfy the guys at the pits.

[1200det]

What are you using for your Idle Speed Control ? Nothing ?

[EldarO]

taking this EGR stuff off, what kind of gains can be gained from it..?

fuel efficiency, power etc..?

Eldar.O.

[kemicalx]

Shouldn't be any gains. Just want to get rid of stuff that won't be needed, as was said the VSV is controlled by the ecu which won't be in the car anymore.

ISCV won't be used anymore, found out they are worth $1000 from Toyota though

[thechuckster]

taking this EGR stuff off, what kind of gains can be gained from it..?

the only gain is less plumbing under the bonnet

fuel efficiency, power etc..?

none, just slightly worse emissions compared to factory settings.

[tooch]

Not to mention less carbon and crap getting in your throttle body. The throttle body from my old motor was caked with it, there was a little bypass type port thingy that you couldn't see even existed as there was that much carbon on and in it!

[Disturbed1]

What are you using for your Idle Speed Control ? Nothing ?

aftermarket ecu - dont need it

[EldarO]

the only gain is less plumbing under the bonnet

none, just slightly worse emissions compared to factory settings.

so basically, taking it off is a way to get rid of clutter in the bay, save the tiniest margin of weight, and kick nature in the nuts...?

i dont think mine is hooked up at all, in fact, i think its completely missing (import engine, didnt look like it had any of that stuff) but if it was there, id keep it...

Eldar.O.

[1200det]

I understand the need that you wouldnt need it with aftermarket ECU , I dunno how much the 7M relies on it , But i know my 1UZFE had a faulty stepper motor in the ISC and geeez it wouldnt idle for shit when cold in canberra weather

[kemicalx]

soooo can i ditch it all? I’ll be replacing the standard bypass valve with a higher rated bosch unit, presuming it still has the same output on the top should i just block this off or does it have to go to the intake plenum for pressure?