Stillen Gen3 Intake, Berk Hi-flow cat, and Stillen cat-back exhaust

axio

Hey guys,

I finished the install today. I started a few nights ago, doing a little after i got home late from work each night. Overall, the Stillen intakes are pretty easy. I was pretty scared at first of damaging the front fascia during removal, but it wasn't that bad. Just make sure to unbolt all of the bolts underneath. The Nissan service manual's picture shows 4 bolts, but there's a total of 6 more bolts i had to take off to get this to come off. Just an FYI. The quality of the Stillen intakes appear to be pretty good.

For the Berk high-flow cats, definitely make sure to use some liquid wrench. The one in the DYI section showing you how to do the cat install works great, and was only a few dollars over at Home Depot. With the Stillen intakes in place, i was able to find clearance through the engine bay to get to those top bolts which gives everyone trouble. I stuck with using a breaker-bar and 1/2" drive extensions, u-joints and socket. The 1/2" drive tools were strong enough not to break. I did need extra leverage on one of the bolts so i used the bar from the racing jack and slipped it over the breaker-bar. By doing that, it made things much easier. The quality of the Berk cats look great.

Semtex, we were talking about the O2 sensor bung on the cats. There IS basically a very small opening where the bung connects to the body of the cat, so the steel wool trick in the bung should probably work and there's probably not much to worry about with it falling into the body of the cat. The hole at that junction is fairly small, probably just a LITTLE bit smaller than a hole in 3-ringed binder paper. I decided not to put the steel wool in there since I kinda forgot to pick some up and didn't remember until the install, and since there's plenty of room to get to them from underneath the car, i'll try out this fix in case i ever throw a CEL.

The Stillen exhaust was not hard to install. Removal of the stock exhaust was pretty easy and the Stillen exhaust easily went into place... until it was time to bolt the pieces up. Like everyone else, it seems, the Stillen exhaust would sit on the cross-brace. I followed the instructions, keeping the bolts loose, jacking up the area by the y-pipe and cross bar, then tightening up the bolts, but like everyone else it seems, the piping decided to rest on the cross-brace. I used some hose clamps as was suggested on this forum, and it still didn't have enough space to clear. I might go try to find some smaller hose clamps and give it another try. My other idea was to use those silicone mats you can find at Bed Bath Beyond and stuff, those silicone potholder squares or whatever you call em. I was gonna fold one in half to double-up the thickness and then place that in between the cross-brace and the exhaust. Obviously it'd still be resting on the exhaust but maybe it'll help dampen the rattling/raspy/vibration. The quality of the Stillen exhaust seems so-so to me. Two of my flanges were not straight, and seem to have been bent/warped backwards at the points where the bolts line up. And obviously how it rests on the cross-brace isn't that nice.

Overall, the car sounds great. It's definitely way louder than stock and it's pretty throaty. It sounds like a cross between an exotic and a V8, at least from what i can tell. The problem is i hear a lot of metallic rattles and vibration, sounding very raspy especially upon mid to wide open throttle. I'm assuming that this is cuz of the exhaust pipe resting on the cross-brace. I'll let you guys know tomorrow if the silicone square works in helping with the sound dampening.

As for how it feels? To be honest, I just finished breaking her in before i started putting these parts on, so i can't honestly tell you if there's any difference over stock. But there's a few people here that have been kind enough to dyno their cars with these mods to show unbiased gains. Thanks guys

If you're doing all this work in your own garage, it helps (with the cats at least) if you have something nicer than those little $20 floor jacks that only lift up to 14" high. Just a suggestion so you can get more clearance as you rest the car onto the jackstands. I also used hockey pucks as a cushion to help prevent any damage to the pinch rails.

I have a question though. Assuming the silicone square works as a buffer so the rattling is gone, is there anything wrong with leaving the exhaust resting onto the cross-brace? Will the constant heat transfer from the exhaust pipe damage or warp the cross-brace at all? After parking my car, i can still hear this clicking noise 10 minutes later from where the exhaust pipe rests on the cross-brace, i'm assuming from the expansion/contraction from the heat.

I'd take it to a muffler shop to have them try to fix it like other people in this forum have, but i won't be able to get to one until another two weeks. Plus i think it just really sucks that we pay all this money for an exhaust system just to have to take it back to a muffler shop and now pay to have them fix this when it should have been built with clearance in the first place.