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Old 02-17-2018, 07:22 PM   #1
PDXREALTOR
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Default 2.5 to 3" turbo inlet adapter

I don't know if this will help anyone, but I thought I'd share.

This part can be found here : https://www.amazon.com/Spectre-Perfo.../dp/B0008G5G4G

or at a lot of auto parts stores. I got mine at Advanced Auto.

I'm not sure if a straight 3 -> 2.5" would fit, even with TGV deletes, and the offset Agency Power 3 -> 2.5" looks more restrictive than their 3" -> 3" offset coupler.

My Perrin 2.4" inlet is already kinked a bit at the turbo because of the TGV housing. So.... I really wanted that bit of offset the AP offers.

Keep in mind I've deleted the PCV, Air pump, and OEM fuel rails.... so.... I have a lot of room under the intake.

I also like the velocity stack flow. So, I made this for my AP 3" inlet going onto my 2.4" FP Green




After a little dremel work -



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Old 02-18-2018, 02:59 PM   #2
PDXREALTOR
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Here it is installed on the turbo inlet. I did re-adjust the coupler to get rid of the pinch from the TGV/Manifold flange. I didn't snap an updated picture because well, it took some time and I wanted to get the pipe part installed while everything was lining up and I seemed to be on a roll.

This 3" intake install is no joke. It would have been nice to have a velocity stack that went all the way back to the base of the turbo. I would suggest that anyone going this route make or buy a second 2.5" round piece and trim it to sit on the turbo's input from the housing forward just to the point where it sits the velocity stack perfectly at the beginning of the turbos intake.

With all the twisting and maneuvering that is required to get this positioned at it's best it would be a bit easier this way. Never the less as you can see it's not impossible to do without that spacer.

The only reason the intake came off was so that I could get the coupler aligned perfectly so as to not create any pinch points.






Last edited by PDXREALTOR; 02-18-2018 at 03:21 PM.
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Old 03-06-2018, 07:14 PM   #3
PDXREALTOR
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So I finally got a chance to do some pulls with boost back at normal numbers and, with the 3" tube I'm not able to hold boost up top. I'm down 1 lb using an MBC.

I'm really hoping it's because the 2.5" cold air intake is choking things up. We'll soon find out - look what I just got - a 6" filter with velocity stack that goes to a 3" pipe. It's going to fit perfect right down next to the FMIC piping.



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Old 03-06-2018, 07:23 PM   #4
Delphi
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Not surprising. Tuner local to me came across this that some did to a car he was tuning. Mind you it wasn't transitioned but still, proof is in the pudding.

http://www.westernsubaruclub.com/smf...?topic=39669.0
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Old 03-06-2018, 07:33 PM   #5
PDXREALTOR
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I created a velocity stack reducer at the inlet. It lines up and is clamped perfectly. It's in no way a hack job like the pic in the link you posted. Are you saying I should have used this instead? Or are you suggesting 2.4" inlets should stick with 2.4" intakes? The compressor is only 2.4" regardless of the turbo housing. I'm sure you know that though....

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Old 03-06-2018, 08:03 PM   #6
PDXREALTOR
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What you linked to is a picture of a complete hack job. The accompanying chart resembles results expected by looking at the picture.

Here's a before and after road dyno taken on the same road. You can see the drop is nothing like what you linked to. Neither is my way of adapting the 3" pipe to the 2.4" turbo.

I used to play with supercharged jet skis... a lot. The first, and one of the best dollar for reward mods, was to get a 4" composite velocity stack just like the one I pictured above and put it on the 3" supercharger inlet. Then, we'd use a 4" duct with large filter. The improvement was night and day.

I don't think it's possible the method I used caused the drop off.

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Old 03-07-2018, 04:50 AM   #7
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I couldn't wait for the CAI pipe to show up, so I put this b*tch on short ram style and went and did some pulls. This map has 2* timing pulled out as I'm tuning VE table and need to tweak the ignition.

I really just wanted to focus on the boost after putting on the large air intake. This is a before and after. I gained .4-.5 lbs down low, and lost .4 - .5 up top.

I should be able to get it back up top with a little timing as I know I have headroom up there whereas at PT I am at my limit.



This is going down in the fender when my pipe gets here. The car is much more free flowing with this intake and filter vs. the 2.5" Perrin setup.

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Old 03-07-2018, 10:44 AM   #8
Delphi
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That part you put in there looked like a silicon ring. Is it hard plastic? If it is hard plastic then it shouldn't cause an issue. If it is silicon then it could be folding over. Something changed because your boost fell due to a pre turbo change.
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Old 03-07-2018, 01:46 PM   #9
PDXREALTOR
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Quote:
Originally Posted by Delphi View Post
That part you put in there looked like a silicon ring. Is it hard plastic? If it is hard plastic then it shouldn't cause an issue. If it is silicon then it could be folding over. Something changed because your boost fell due to a pre turbo change.
It's not a solid, but it's firm. Not soft like silicone.

I think what happened is the straw affect. Sucking threw a bigger straw flows freer and is harder to keep the air stacked.

I think FP told me their 3.3" intake would do the same thing. I know all the reading I did said better spool, less boost.
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Old 03-07-2018, 09:48 PM   #10
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Nice work man. Love custom stuff looks like you put a lot of time into it but it worked out for ya ***128077;***127995; Also it's a clean looking setup. Doesn't fp make a 3" inlet how would that fit if you had to do all this custom work?
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Old 03-07-2018, 10:27 PM   #11
PDXREALTOR
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Quote:
Originally Posted by CSC_Customs View Post
Nice work man. Love custom stuff looks like you put a lot of time into it but it worked out for ya ***55357;***56397;***55356;***57339; Also it's a clean looking setup. Doesn't fp make a 3" inlet how would that fit if you had to do all this custom work?
Thanks. I actually just got back from putting on the pipe to get the air filter in the fender. I like the ram intake look, but IATs are higher even with a FMIC and IAT sensor on the cold side.

The FP inlet on the turbo has anti surge ports, is 3.3 inches. When I put the turbo on I was doing forged pistons and tons of other parts/motor upgrades so I stayed with the 2.4" piping as I read the 3.3" wasn't much difference.

However, after I turned up the boost I felt it running out of breath around 27 PSI. With this newer setup, 3" piping from mega filter to turbo, at 27.99 PSI in 4th it just feels like it's ready for another pound. Unfortunately my engine is built up for more than 28 psi, otherwise I'd up the boost to 29 or 30.

Once I get this all tuned in I think I will end up in the 510-540 range and 450 flat torque.

Here's some pics of the final setup.





Last edited by PDXREALTOR; 03-18-2018 at 07:29 PM.
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