BOV's are cheaper, FULLIIIIIIIIIIII!

The external gate is a great mod if you want:
unique sound at high revs,
scare pedestrians/cyclists/GTR's,
Rock solid boost control
Higher hp and torque especially down low and when trying to get to high boost levels. My gate only opens when the gizmo shows 22psi and not before...not 1mm. An internal gate will crack open and your losing power ant torque.

So on my car the 3 inch pipe is just for gas coming out of the turbine blades... 2 inch of screamer pipe vents as well at high revs... so do the maths.... 2 inch of gas getting vented is a fair bit of extra exhaust size at high revs vs just a 3 inch pipe with turbulent wastegate air right at the start.

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PS my torque went up by 50 and then 70nm from 3000-6000 because my internal gate must have been farked and pissing boost. So for me the mod was well worth while. If your turbo is old your gate might be losing as much as mine was.... 2-3psi at low revs and about 5psi at high revs. (15psi max vs 20psi max now at same revs)

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So what do the sizes mean when you can get a 44mm or 48mm and so on?

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Balls.

you gained 70nm of torque between 3000 and 6000 just by fitting an external gate (+ tune obviously)

far out! what did the mod cost? bout 1000-1500$ all up? that is one of the better Nm/$ mods out there..If It's directly attributed to that.

Can I put your claim on REXNET? Jus there's a bigger pool of people with gates over there that could back this up.

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K.E.R.S!!!1

its not the fact that the external gate created extra torque, it was that the original internal gate would have been leaking.

the same results can be acheived with the trampoline spring modification to the internal gate.

an external gate will have little performance gain under 1.6 bar. as a standard p15 housing can still maintain 1.6bar with an internal gate at 8000 rpm.

i am in the process of testing an external gate @ 2bar with no other modifications, dyno plots to be made available soon once ive finished tweaking the boost curve. a previous plot with internal gate @ 2bar netted 330hp/480nm, first impressions are that i wont improve torque all that much over what ive got, but i may edge out a little more horse power up top now that the turbine housing isnt being over-worked.

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Long live the WRC

Don't forget it also changes your gear ratios pete, plus bipolarbear is running 20psi now instead of 16, plus there are no before & after dyno plots to prove it. you know, just putting that out there

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MY93 Impreza GX 1.8L, 0hp, 0nm

As I stated, the gain for me was large because my internal gate was farked. If yours is 50% as farked as mine you might get 50% of my gain 10% , 10% gain. But I think that almost all internal gates will be leaking even if its just a smidge.

Gate closed until boost level is reached = free power and torque.

I just feel that the car is much more stable, no spikes, no overboost on cold days etc.... boost controller can always flow as much air as it wants to control boost. So you can tune better.

If you look at the boost graph below (2nd graph)... I now hear the screamer and see the 22psi on the Gizzmo at about 6000rpm...and I have 15psi at 4200 so u can see how the external gate has given me heaps of extra boost at each rev point. AT peak revs I now have 22psi which is 12psi more than I had before at 6000.

By the way, the super spikey old Boost chart is how the car was when I first had it as the boost signal to the LINK computer was plumbed into like 8 other lines of various things.

I need to do another run on the Wok dyno so I can overlay the new power and torque and boost curves over these old ones. 342@15psi aint too shabby.

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