16 valve throttle body size. 3sgte recirc blow off valve?

[RedMist]

How big is the stock 4age throttle body? I'm interested in placing a couple of these in my VQ35 race engine.

I'm also interested in using two recirc blow off valve as I dont want anything venting to atmosphere in a dirt and rock encrusted atmosphere.
Anyone know of a stock recirc valve that would suit? The 3sgte ones are plastic and wouldnt take a rock impact, however are the stock WRX ones any good?

[IH8TEC]

mine is 58mm on my 4age one also gtr skyline bov's like i have on my car, the only reason i can't plumb mine back is becuase the turbo is in the low right front of my car, and the piping would be stupidly long.

[no_8wire]

How big is the stock 4age throttle body? I'm interested in placing a couple of these in my VQ35 race engine.

I'm also interested in using two recirc blow off valve as I dont want anything venting to atmosphere in a dirt and rock encrusted atmosphere.
Anyone know of a stsock recirc valve that would suit? The 3sgte ones are plastic and wouldnt take a rock impact, however are the stock WRX ones any good?

Arent SW20 BOV metal?

[Trls250s]

A common upgrade on the 4ages is to use Supra ones.

I also know that 3sgte throttle bodies are the same size as 4age ones at 55mm.

Supra ones are 60mm.

[fivebob]

The 3sgte ones are plastic and wouldnt take a rock impact

The SW20 ones are metal They need to be because they bolt to the intake piping directly after the turbo and have to withstand high temperatures. It's the ST215 (and probably the ST205) that are plastic.

[RedMist]

The 3sgte ones are plastic and wouldnt take a rock impact

The SW20 ones are metal They need to be because they bolt to the intake piping directly after the turbo and have to withstand high temperatures. It's the ST215 (and probably the ST205) that are plastic.

Most certainly is plastic on the ST205.
The MR2 ones sound like a great choice... so long as I can adjust them to suit the boost I'm running....which is where it gets interesting.
I'm running two boost maps, one 7psi (actuator pressure) for club events. And then 11-12psi (depending on how it ends up tuned) for Nationals.
So are the MR2 ones suitable?

[RedMist]

A common upgrade on the 4ages is to use Supra ones.

I also know that 3sgte throttle bodies are the same size as 4age ones at 55mm.

Supra ones are 60mm.

Years of self poisoning in my youth have destroyed to many brain cells.

I have a spare ST205 TB sitting in my garage. The Garrett turbo's have a disgustingly small intake side exhaust. I'll see how the ST205 TB matches up on Monday. Then purchase a second.

[fivebob]

Most certainly is plastic on the ST205.
The MR2 ones sound like a great choice... so long as I can adjust them to suit the boost I'm running....which is where it gets interesting.
I'm running two boost maps, one 7psi (actuator pressure) for club events. And then 11-12psi (depending on how it ends up tuned) for Nationals.
So are the MR2 ones suitable?

The SW20 ones will work fine.

Boost maps make no difference to Bypass Valve operation. BOV and Bypass valves work by pressure differential between the inlet manifold (after the Throttle body) and the pressure side of the BOV.

When you close the throttle the inlet manifold goes into vacuum, or at the very least much reduced boost, whilst the rest of the intake piping is still pressurised. The vacuum is applied to the diaphragm on top of the of the B(O)V piston, and the other side is still pressurised so the valve opens.

The Toyota valves also use another device to speed up the opening and closing of the valve, and also keep it open under bypass conditions which is why it is essential that you make sure you get the piping with the SW20 BOV, at least the first part of it which contains the "Vacuum Transmitting" Valve

[RedMist]

Thanks Fivebob.
One would gather then, that in a majority of cases, an aftermarket BOV is purely bling.
Placement of the BOV should be close to the turbo then? I would have thought that because the pressure wave was generated at the TB it would have been prudent to place it there.

I've also contemplated using two Chinese manufactured MR2 intercoolers. This is purely a packaging exercise as I dont have a tonne of room within the confines of the cage to allow for largish intercoolers.
http://www.trademe.co.nz/Browse/Listing ... =138565534
Are these acceptable? Or am I wasting money on a half hearted solution?

[flygt4]

i gained significant power (dyno proven) by using an elcheapo trademe intercooler over my old rusty bent evo one.
the brand name ones are more efficient, but i reckon it only matters if you are chasing every last hp. in most applications they are fine.

i don't even run a BOV atm. i used to, but it caused more problems than it was worth, i meant to invest in a decent one but never really got round to it.

hint: stock gtr skyline bov's are very good, and i think they come in pairs

[fivebob]

One would gather then, that in a majority of cases, an aftermarket BOV is purely bling.

Exactly. Replacing the stock valve with an aftermarket item is not a performace mod, it's purely about ignorance and noise

Placement of the BOV should be close to the turbo then? I would have thought that because the pressure wave was generated at the TB it would have been prudent to place it there.

There's quite a lot of debate about this, personally I don't think it matters as the pressure wave moves at local acoustic velocity. Proponents of the "close to the throttle" school of thought think it's better because to their way of thinking it keeps the air moving in the same direction. I doubt this is the case as the pressure wave and direction of flow are not that closely related. IMO the pressure wave will still make it to the turbo albeit at a reduced amplitude.

I've also contemplated using two Chinese manufactured MR2 intercoolers. This is purely a packaging exercise as I dont have a tonne of room within the confines of the cage to allow for largish intercoolers.
http://www.trademe.co.nz/Browse/Listing ... =138565534
Are these acceptable? Or am I wasting money on a half hearted solution?

Not sure about their performance, they look like they're stainless steel in which case they would be as efficient as aluminium items. But given that the cost of brand name I/C's is rather high, and SW20 ones are becoming a lot harder to find, I would suggest trying these first and monitor intake air temp.

[RedMist]

Sorry forgot to key the last pic... the yellow circle is the turbo. The red square is the intercooler. It will be fed air through two side pods.