DIY - GrimmSpeed Intake Installation Guide

[Apoc]

One pro tip from me. Assemble the tube and filter and clamp it down exactly 1 inch from MAF flange before you slip it into the box. Much less fuxing around to get the exact distance you need between the filter and MAF sensor flange while it's still out of the box.

[Flow]

I'm more of a 'mod by numbers' guy than real mechanic, and this was easier than I expected. Some pictures that might help.

1. Where the sound generator tube goes into the footwell. I just muscled it out.

2. This is one of the sound generator tube clip. If you squeeze from the sides with pliers, you can pull it out easily. I couldn't get access to do so on the first one (moving away from the firewall) though, so I ended up muscling it out as well, which was fine, but broke the clip a bit.

3. My intake tube (the stock piece we connect to) isn't rectangular... not sure if it deformed from heat, or what, but this was the biggest challenge to me to getting a 'snug' fit.... this is where I ended up. The gasket touches the foam, but its not a tight seal. Didn't notice any nvh or impact, though.

4. No picture, but I also had to bend the 2nd screw hole piece (the one that attaches lower down, and away from the bumper), as as it came from GS, it didn't seat with the stock intake tube.

Conclusion - after driving on it for ~4 hrs: got rid of the washing machine sound I hated. This might have been just due to getting rid of the sound generator. My mpg went up by ~2. Butt dyno says more power. Love it.

[toeout]

Originally Posted by Apoc

One pro tip from me. Assemble the tube and filter and clamp it down exactly 1 inch from MAF flange before you slip it into the box. Much less fuxing around to get the exact distance you need between the filter and MAF sensor flange while it's still out of the box.

This made it a lot easier, plus it's easier to check that the filter is on the pipe evenly and not tilted.


I have this little "hungry mouth" thing between the lid and the front wall. Tried tightening the bolts in different sequences, but it didn't help. I wonder how much it really matters, since the box is not completely airtight anyway. I could put a strip of tape over it if it's important, it just wouldn't look as good.

[anewprelusion]

Originally Posted by toeout

This made it a lot easier, plus it's easier to check that the filter is on the pipe evenly and not tilted.


I have this little "hungry mouth" thing between the lid and the front wall. Tried tightening the bolts in different sequences, but it didn't help. I wonder how much it really matters, since the box is not completely airtight anyway. I could put a strip of tape over it if it's important, it just wouldn't look as good.

I have the same "hungry mouth". I'm wondering if something got warped while wrestiling with the gasket. I too want to know if this affects the performance. Ideally we would want the air to be sucked in through the snorkel rather than the engine bay. With that gap, it's almost making it a Short Ram instead of Cold Air intake. = /. In any case, I doubt it makes that much of a difference in performance.

[nyfries]

I have the same hungry mouth. Try to contact grimmspeed about it no response yet =\

[nyfries]

Got an response back from grimmspeed. They confirm that the hungry mouth thing is fine. The box isn't airtight to begin with. Good to know. Now only if spring would come soon. Been driving the winter beater around these days

[akyp]

@GrimmSpeed,
Would sealing the box (should be easy to DIY) yield even better performance, or is the box designed to be 'leaky' to relieve excessive pressure?

[Mike Brz]

U should dent the box or cut a hole

[Mike Brz]

Grimmspeed, what size is the intake pipe? And what kind of gains do u get?

[GrimmSpeed]

Originally Posted by akyp

@GrimmSpeed,
Would sealing the box (should be easy to DIY) yield even better performance, or is the box designed to be 'leaky' to relieve excessive pressure?

I wouldn't have expected so many questions to get asked in the DIY thread, sorry guys! As was answered, there is NO problem with the "hungry mouth," and it's been on all of our airboxes. We made a conscious decision not to seal the gap because the box itself is not sealed, and doesn't need to be sealed. This helps promote airflow by not having stagnant sections of air, and also allows for a release of water should that ever get in. You'll notice that the stock airbox is not sealed either. However as far as performance goes, I don't think sealing it makes a difference at all, as the amount of cold air coming in form the snorkel is so substantially greater than the amount of air that would be slipping through the cracks, and since air will follow the path of least resistance this will always hold true.

So you can seal it up if you'd like, but I think any potential for gains aren't really there, especially because it is already making very healthy gains as it is.

Originally Posted by Mike Brz

Grimmspeed, what size is the intake pipe? And what kind of gains do u get?

Hey Mike, the pipe is 3in, and you'll find ALL kinds of info about it and gains right here: http://www.ft86club.com/forums/showthread.php?t=78902

Chase
Engineering

[Mike Brz]

Thanks grimmspeed!

[SubaruLifer]

Got my intake on Thursday and installed it Saturday! Big thanks to GrimmSpeed and others in this thread for their helpful tips!



While it's certainly possible to do this install alone, I found it extremely helpful having another person there while attaching the lid to the box. I pressed the sides of the box to get the holes to line up with the lid while my wife put in the screws. I can only imagine what a PITA it would have been to tackle alone.

Quick question for others that have this: no matter how hard I tried, I couldn't get the included cap onto the noise hole in the passenger footwell (I have the 120V plug cap in there now); is there a trick to getting this in?

[b rawr z]

i lost a bolt when i was trying to install the lid. went in the engine bay and i couldnt find it. good thing it came with an extra bolt (like they knew it was bound to happen lol). as for the included cap. its pretty easy. try putting half of it in first then just kinda squeeze the rubber in.

hardest part for me was the rubber hose and fitting the box in the snorkel. anybody got some tips?

Originally Posted by SubaruLifer

Got my intake on Thursday and installed it Saturday! Big thanks to GrimmSpeed and others in this thread for their helpful tips!

While it's certainly possible to do this install alone, I found it extremely helpful having another person there while attaching the lid to the box. I pressed the sides of the box to get the holes to line up with the lid while my wife put in the screws. I can only imagine what a PITA it would have been to tackle alone.

Quick question for others that have this: no matter how hard I tried, I couldn't get the included cap onto the noise hole in the passenger footwell (I have the 120V plug cap in there now); is there a trick to getting this in?

[SubaruLifer]

Originally Posted by b rawr z

i lost a bolt when i was trying to install the lid. went in the engine bay and i couldnt find it. good thing it came with an extra bolt (like they knew it was bound to happen lol). as for the included cap. its pretty easy. try putting half of it in first then just kinda squeeze the rubber in.

hardest part for me was the rubber hose and fitting the box in the snorkel. anybody got some tips?

You mean the rubber gasket? Make sure you start from the middle of one of the longer sides, and after you pass each corner, push everything that you've done back in. The piece is exactly long enough to make it around the opening, so you really need to make sure it's tucked into the corners. Also, if you look closely at the part you'll be slipping onto the box, you'll see that it doesn't look like this || but instead, one side has an extra bit on it. That side goes to the outside of the box.

When attaching to the stock snorkel, I got it into position, put my fingers inside the snorkel (so hands inside the box), and pulled it on that way. It looked really nice until I went to attach the two bolts that hold the box to the car. At that point, it came off most of the way on the driver's side edge. I don't have any extra noise from that though, so I must still have a good enough seal.