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2011 Forester 2.5X Manual w/ Ko'2
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Discussion Starter · #1 ·
Hello Forester owners :smile2:

I just installed a complete short ram intake kit. Cobb ram air w/box and Perrin turbo inlet. First of all I am no professional mechanic, simply amateur. Let me say the inlet is the worst job I can remember doing so far, what a pita! So I stop complaining, now the job is done.

My concern and the true reason of this post is about the intake manifold. To be able to complete the job, I loosen the 6 long bolts that attach the aluminium part of the manifold to the engine block. I did not remove it entirely because this is another crazy job, just enough to give me some room. I did not replaced the manifold gaskets because like I said removing it completely is kind out of my league. I just torqued back the screws to 20 ft-lbs, but now I fear the worst. This engine is boosted, 9 years old, the perfectionist in me think it was a bad idea...

So now, my question is, will I notice right away if a leak is present?
My best idea was to watch out for the boost gauge value, see if its solid, if its not probably a leak?

Let me know what you guys think.

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2012 XT Touring 4EAT
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I just installed a complete short ram intake kit. Cobb ram air w/box and Perrin turbo inlet. First of all I am no professional mechanic, simply amateur. Let me say the inlet is the worst job I can remember doing so far, what a pita! So I stop complaining, now the job is done.
Okay, the PITA part was the intake - not the Cobb ram air w/box. Yes, the intake is difficult job . . . I did this on my '06 FXT. And, by the 2011 models, Subaru's OEM intake is quite nice - better than earlier models - so there will be little benefit from doing this. With all due respects to Perrin, it's an unnecessary mod. Your suffering was [probably] for naught.

My concern and the true reason of this post is about the intake manifold. To be able to complete the job, I loosen the 6 long bolts that attach the aluminium part of the manifold to the engine block. I did not remove it entirely because this is another crazy job, just enough to give me some room. I did not replaced the manifold gaskets because like I said removing it completely is kind out of my league. I just torqued back the screws to 20 ft-lbs, but now I fear the worst. This engine is boosted, 9 years old, the perfectionist in me think it was a bad idea...
I can't imagine why the gaskets would leak. Replacing them would be nice, but I would be surprised at a leak. Look at our boost gauge - any changes? Any codes? With the engine running, any strange 'hissing' noises under the hood?

If there was a leak, it would be a vacuum leak, right? The nice thing about vacuum leaks is that they tend to suck the surfaces together under load. Criminy, I managed to miss-install the intercooler-to-throttle-body duct. The car ran fine except when boosting - then the leak was obvious and boost was lost. As soon as I was off boost, it started working again. But, I digress.

With the engine running, preferably above idle, spray around the manifold joint with brake cleaner or WD-40. Does the engine speed up? Any smoke coming out the tail pipe? This is an old-time method for checking for vacuum leaks but it should work fine on the EJ engine.

FWIW, I recently did a similar mod on my '12 FXT - almost identical vehicle to yours, even the color. I used the Mishimoto MMAI-STI long ram. It really did affect the vehicles running (to be expected, but sometimes mods being sold are more hype than reality). I reflashed the ECU with Cobb's OTS stage 1 tune and that made a world of difference - for the better! I've got one more mod in the works before doing a real tune.

 

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As I suggested above, I don't think the new turbo intake will make much difference (maybe build your character ;-) but the Cobb short ram will change things. Specifically it will make your engine run lean - not a good thing.

This lean condition may be caused by an inadequate 'map' within the factory ECU firmware, or it could be caused by a badly positioned MAF relative to the new intake duct, or maybe just the fact that the MAF is in a bigger tube, so that unmeasured air is passing the MAF. There's a thread on this forum about this topic, with varying opinions on the cause of the lean conditions after this mod.

Regardless of the cause, the fix for this lean condition is a tune. The Cobb Stage 1 will fix that problem, at least until you can get a real chassis dyno tune. You might want to make this (Cobb Stage 1 or 'real tune') a high priority.
 

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Discussion Starter · #4 · (Edited)
Thanks for inputs Dave!
Btw is that a Oil Catch Can you got there passenger side firewall?

So how do I put the stage 1? Purchase a Cobb Tuning Accessport? Is that something I can do myself? Once I had a Suzuki GSXR with a power commander (piggy back ecu), I just downloaded the new map and plug onto the bike. Is the Accessport the same?
 

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Btw is that a Oil Catch Can you got there passenger side firewall?
No, it's an upper cylinder oiler. There is a Grimmspeed AOS mounted on top of the oil filler tube. Does anyone really want to be emptying a catch can? Really?

So how do I put the stage 1? Purchase a Cobb Tuning Accessport? Is that something I can do myself?
You need a Cobb Accessport (pricey) which should come with the correct maps for your vehicle/year. Next, you 'marry' your Accessport to your vehicle. This is a reversible action, if you decide to sell the vehicle. But if you were to sell the vehicle with the Cobb short ram installed, you might still have some 'running' issues.

At that point, it's pretty easy to put on the new map - definitely a DIY activity. Problem is, the Cobb OTS maps are not _that good_ - a tune would be better. But if you have the Cobb short ram (or the Mishi long ram), then the Cobb Stage 1 map is a lot better than the factory map. Plus, it should reduce or eliminate the 'running lean' issue. My oiler doesn't solve the 'running lean' issue either, but it does put a band-aide on it ;-}
 

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Discussion Starter · #6 ·
Just to give a heads up, I finally test drove the car and so far everything looks fine.
Vacuum looks the same value as before and boost too, but I didn't really boost over 4 psi because I want to be gentle with it until I get the Accessport.
My first impression was awesome, I don't regret every penny. What a change in the sound of the turbo spool, on my god. This is really the kind of sound I was looking for with that mod and Im glad I got it... After all what's the point of having a snail when you don't even notice?

... on a different subject, I did my rear sway bar and that is a great improvement too! I can't wait to put the Coilovers on. Here's a teaser;

 

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<snip>... on a different subject, I did my rear sway bar and that is a great improvement too! I can't wait to put the Coilovers on. Here's a teaser
Are you sure the rear sway bar is an improvement? Over three Foresters, my conclusion is to leave the rear sway bar alone and beef up the front. The overall effect of the stiffer front bar is is to stiffen the whole car.

Adding a bigger sway bar in the rear makes everything strange. Lowering the vehicle helps by reducing the tendency to roll, but lower all 4 corners. There are other threads on this, and varying opinions, so do some reading.
 

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Discussion Starter · #8 ·
Yes I am sure of the improvement. The Rear Sway bar is only a tiny 16mm where the front is already beef to 21mm. That 16mm in the rear makes the car under-steer in a corner (even more noticeable when slippy) and makes the rear end handle like a floating boat on water.
Increasing the size of the rear closer to the front has improved a lot the rear handling even with stock suspension. The rear end is way more flatter during cornering, you can definitely notice this.
I will have to put more mileage on before commenting about the under/over -steer.
The car is now just overall more stable on the road. Steering response is improved too.
The only very small cons I can think of would be the feeling of harder to turn steering wheel. But hey, that could be just me, and also I have no idea about the actual alignment specs at the moment. I am waiting for the coilovers drop to take it to the alignment shop.

That is my feedback so far... Only 100+km done yet.

Edit: I think I will open a specific thread for that sway bar subject so people can chime in.
 

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Discussion Starter · #9 ·
New CEL p0021

Update: Today I have the check engine light stored code p0021 , I am wondering if it could be because of the intake? Maybe a side effect of the lean fuel value people are experiencing?

Engine idle just fine and looks perfect under low/med load. But I am unsure if power seems unstable when going in boost values since this code. Like I said before I am not pushing the car... But I recall having a feeling of fluctuation in torque while engaging on highway.
 
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