My opinion is 10cm all day long. But thats me. Everyone has thier own ideas.

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Doing it for all the wagons out there

I had the gtpumps s02 which is a td05 -20g .. i had 10cm rear on a 207 was awsome the top end and torque curve far out weighed the lag

using the Perth-WRX mobile app

This was on 98 with a lowly 17psi


using the Perth-WRX mobile app

Is the car going to be street use only or are you going to be at the track/drags regularly?

I have a dom1.5xtr 8cm on my 257 dual avcs sti motor and it's on boost (19 pound) at 3500 rpm and pulls hard to 6000rpm. It is perfect for street and sprint series racing with tight corners and lower speeds etc.

If I was building a track only car I would have gone for a 10cm hot side, as Bram has said to get the the extra poke up top.

Blouch website says the dom1.5 is designed for the 2L engine.

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Bye bye betty blue. Hello F6.

I see absolutely no point in going anything less than a 10cm on ANY Blouch turbo ever built. Case in point. Your car with a DOM 1.5 XTR 8cm on an EJ25. It spools 100rpm earlier than mine did with a DOM 2.5 XTR 10cm a EJ25. And yours is DAVCS isnt it, mine only AVCS? 100rpm is 1% of nothing and i have the next size bigger Dom aswell! In 2nd or 3rd gear, 100rpm is equivelant to a blink of an eye. Doesnt matter if your a race car or a daily driver or even miss daisy doing groceries shopping 100rpm is a poofteenth of fuck all. As i said earlier. I have even seen 8 cms spool SLOWER than 10 cms.

Why anyone would ever bother with a 7 / 8 cm Blouch is beyond me? 7 / 8cm^2 (depending on turbine wheel size) is like a 0.6A/R. Its not even worth it. All you are doing is choking your engine. And there is like no actual benifit in doing it. If it resulted in 500 rpm gain or something, then yeah i can understand. And on a non-billet wheel turbo, it probably would equate to measurably faster spool, but these modern billet turbos spool so ridiculously damn fast as it is. The rpm gains just arent there to justify it. May aswell cash in on some better topend which is actually noticed, as opposed to a theoretical increase in spool which in many case isnt even there.

/rant.

This is nothing against your car Nik. Just trying to find an easy example of why not to go with a smaller A/R on a billet wheel turbo.

And again. There are so many variables in other mods / tuners / exhaust / cams / breathing etc etc etc. So its near impossible to find apple to apple comparison. But my opinion is dont even bother with the smaller turbine housing on a billet turbo.

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Doing it for all the wagons out there

And while im ranting. If you plan on doing a TGV delete and fitting a silicone inlet anyways. Make sure you tick the 3" inlet option. The 3" inlet actually does increase spool. It probably has a bigger effect on spool than the 8 / 10 cm choice. If spool is your concern and you want a turbo like these, go 3" inlet.

Even 3" is probably too small for a DOM sized turbo. Its just its the biggest you will fit on a stock location subaru, and if you want stock location, your limitwd there. Look at Garrett turbos, they start at 4" for turbos that are equivelant to the DOM range and go up from there. Due to area being a squared relationship to diameter, 4" is nearly double 3" cross sectiona area. And 3" is nearly double the CSA of 2.5". Garrett thinks 4" is the size to use for that size turbo. So why limit yourself to a 2.6" stock locatation inlet. Thats like 1/4 the CSA of 4".

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Doing it for all the wagons out there

Kaoself - yes my 20g is the XTR/ball-bearing version.

I'm going to start buying lotto tickets... So Dom 2.5xtr with 10cm hot-side and 3" silicone intake yeh bram?

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[I]trolololol[/I]

Yeah. I have one forsale if you want.

Looking at your graph on the page before i reckon it would spool earlier and make more power up top than the 20g xtr, at the boost your running. But the 20g may be stronger through the mid range. Although the DOMs spool up easy, i think they arent really into thier efficiency range until a bit higher in the RPM range. (More efficient whem moving more air than the 20g).

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Doing it for all the wagons out there

Bramstroker you have nearly every conceivable mod under the sun to make your car breathe better.

I have a tbe...

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Bye bye betty blue. Hello F6.

Realy? I thought your car had a few more goodies than that.

In that case, you should get some EL headers with your new engine.

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Doing it for all the wagons out there