Installing full NHP system - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Hey all, I got the full NHP system from 2K3_Boxster_S ( good seller ! ) a week or so ago and am about to attempt this install myself. I've never done anything more 'involved' under my car than changing oil, but hopefully with your help and this Pelican guide ) Pelican Technical Article: Installing a Performance Boxster Exhaust System - 986 / 987 ) I wont run into any issue. A few questions though: 1. Can I reuse the existing flange for the engine -> header connection? It looks to be in good condition with some sealant marks ( pics below ), but I'm not an expert. If I reuse this, should I put more sealant on ? If so which sealant is recommended ? 2. How come there's two flanges provided for the header to midpipe connection ? One looks more used than the other. Two set of connection bolts here too .. 3. From my research, the 'worse' thing that could happen ( beside CEL ) is gas leaks resulting in reduced performance ? Is there other things I should worry about too ? 4. How can I tell if I have a gas leak ? Should I add some high-temperature silicone sealant during the install to avoid leaks ? 5. How bad is it if I start the car without any exhaust system on ( in case I need to drive it to my local mechanic to finish my botched up install ) ? Not sure what else I should be looking out for .. any tips would be appreciated.

vijen6, I did the install a couple of years ago. My memory isn't too good but here is what I recall: 1) I remember reading that I could reuse the existing (OE) metal gaskets, and that some weren't fans of the included new gaskets that came with the new exhaust. Probably overkill but I opted to buy new metal OE gaskets from Porsche. No sealant used/needed and I never had any leakage issues. Also overkill, maybe, but I bought new OE Porsche header bolts and torqued them properly and never experienced any problems. 2) I remember receiving a bunch of bolts and gaskets (more than needed) with the new exhaust and assume that is what you are seeing from your seller. I purchased new metal OE Porsche gaskets (one gasket for each side) for the header outlet to mid-pipe connection and probably used the new bolts provided by Maxspeed. No other sealant material used/needed and no leaks. I believe these parts arrived new with gaskets on both parts and your seller just sent them to you the way he received them. When using metal OE gaskets you only need the one gasket per side. 3-4) Since I have no experience with the gaskets that came with the exhaust from Maxspeed I can't really say with any certainty about their effectiveness. But I did have second hand feedback that they weren't the best, which is why I bought new Porsche gaskets which worked perfectly. Maybe your seller had issues with the Maxspeed gaskets and had to use some type of sealant that you are seeing on the headers. It is my understanding and experience that nothing is needed except the gasket (metal) if you go the OE route. I personally wouldn't want to redo any of this work and wouldn't risk using the gasket material that came with Maxspeed system. You will probably be able to hear if you have leaks. 5) I'm not sure how bad (if at all) it would be for your engine to run it this way. Obviously without any exhaust you couldn't have any O2 sensors working correctly which would trigger CEL codes and may cause the engine to run very poorly. My advice would be to get new metal gaskets from Porsche. Take your time. Do it once and be done with it. I hope this helps. Best of luck, ddb http://986forum.com/forums/general-discussions/21654-boxster-has-been-down-month.html

Thanks DDB, just contacted Pelican to order new OEM gasket and bolts tonight. This will delay my install by a few days but if I'm going to do it, I want to do it right the first time.

Whoops .. just realized I posted in the guide section .. can a mod help relocate to the correct section of the board ? Thanks!

Progress update .. For anyone doing this in the future, the parts needed are: Gaskets for the header to engine: 996-111-107-55-M17 ( $5 each from pelican * 2 per car = $10 ) 13MM bolts to connect the header to the engine: 900-378-131-00-OEM ( $3.25 each from pelican * 12 per car = $39 ) Gasket that connects the mid pipe to the header: 996-113-113-00-M30 ( $5 each from pelican * 2 per car = $10 ) While I wait for those to get here I wanted to get all the stock stuff unbolted first. Started on the headers and got 11 out of the 12 bolts off. Stuck on the farthest bplt toward the front on the passenger side header. Can't seem to get sockets in there without removing some other pipes, and cant seem to get enough torque to undo it with just wrenches. Any tips for that ?

Do you have a universal socket that will let you get the ratchet at a bit of an angle where you have plenty of air to swing around in? Or is the hose really that close that you can't even get a regular size socket onto the bolt?

The hose is really close. I can get the socket on without the ratchet, but once the ratchet comes into play, it no longer fit. So even the flex ratchets ( or mine at least ) wont fit. I sprayed it down with some "Bolt Off" so hopefully that will loosen it up enough for the wrench to work. Does anyone know what hose that is ?

Today's update: Finally got both header off. I wasted a lot of time trying to get the O2 sensors out with the header still on the car. Its a dirty job trying to spray 'Bolt Off' from beneath and having it drip on you. Even if you manage to loosen the dang bolt, you're going to have a tough time getting enough slack in the O2 sensor line to twist it out. Better just disconnect the sensors from the car but leave it attached to the header. In hindsight, I would recommend getting an O2 sensor specific socket. I didn't have a 22mm wrench and attempting this with an adjustable was NOT ideal. Ended up with rounded off some corner which I regret considering these sensors are $170 EACH for my 2001S. OUCH!! Maxspeed claims their header weighs 19.2 lbs. On my scale it weighed in @ 18.6 lbs. Stock header weighed in @ 22.8 lbs. Saving roughly 4.2 lbs or ~18% of weight.

Finally got everything installed .. no CEL yet ( knock on wood ) so I take that as a sign that nothing major was screwed up .. in my 5 minute test drive the car definitely feels faster. I'm definitely happy with the performance increase. Three things though I'm not entirely happy with ... and some questions ( in bold ) . 1. Mounting points As is the NHP system mount doesn't connect to the exhaust mount on the bottom of the transmission that the OEM system uses. It also doesn't connect the midpipe flanges to the muffler flanges. The second step is said to be optional by creating DIY mounts because the system is sturdy enough. I feel that its not since I can get the system to vibrate by shaking the cans by hand ( I think this is the reason for complaint #2 - vibrations ) . I'll have to create some mounts, but feel that for the retail price of the exhaust, this should have been an included optional part. Or at least something that can be purchased as an 'accessory'. 2. Vibration / Exhaust note @ low end range I wont elaborate much here until I get a video up of the exhaust note .. but there is definitely something funky at the lower RPM ( 1200-1600 )range. Strange that it sounds just fine ( perfect actually ) at slightly higher RPM ( 3000-3500 ). Is it possible something I messed up in the install process that screwed up the exhaust note and introduce a vibration at the lower RPM and not higher RPM ? A bit annoying since one of the reason I went NHP instead of 'ebay generic' is to avoid exhaust vibrations / drooning. 3. Burning odor Car now emit a very strong burning odor. My GF actually poked her head in the garage to check if everything was okay once I turned on the car because she smelled something burning. To be fair I'm running catless midpipe so I do expect more smell .. but IMHO, this is a bit excessive. Strange because I didn't use any sealant / grease / oil during the install that could need to be 'burned off'. This burning smell really worries me most since I've heard of issues with the passenger side header causing the power steering line to catch fire. I don't know where the power steering line is .. but I triple checked for hose in the vicinity of the passenger side header and didn't see anything too close. Can someone help point me to where this line is so I can stop driving around town with a fire extinguisher riding shotgun ? Thanks!

vijen6, Let me start by saying my install was on a 2000 2.7 with the 5-speed manual. I'm not sure what year, engine and transmission you have so there may be some differences. Does your NHP muffler look exactly like mine in the attached thread pics? I know there was an earlier version of the muffler, and then a subsequent version with added bracing above and below the muffler tip area. You can see the short horizontal braces in my pics. I honestly don't remember much about installing the muffler but I don't think I had any issues or concerns about the mounting location and didn't experience any issues thereafter. I also didn't remember much about the mid-pipe installation but have since looked at some of my old pics and see what you are referring to regarding the mid-pipe flange mounting points (or lack of them). I didn't add any additional supports and didn't have any issues. I didn't experience the lower RPM vibration you describe, but also didn't have any vibrations by shaking the system by hand like you describe. So you may be correct in your diagnosis and the ability to shake the system by hand and cause vibrations is the cause of your lower RPM vibration. So I didn't experience any annoying vibrations or droning (at least none detectable by my untrained ear) in my car after the NHP install. For some context, when I installed my NHP system I removed a Stebro Sport muffler that droned like crazy. So this was a huge improvement for me. If you are coming off of an OE set-up your perspective is probably different. I also had been running without the snorkel for years. I did add a BMC drop-in air filter when I installed the NHP system. I don't remember any burning smells either. Could it be from penetrants you used on bolts when removing the old system? I was concerned about the new headers contacting lines but my research made me think it was a non-issue on my model, year, engine and transmission, and that was the case. I didn't have to move or tie anything up during my install and never had any issues. Depending on your car specifics that may not be the case. Obviously you are right to be concerned and cautious until you get this figured out. I hope others with more to add will chime in as I feel like I haven't had anything helpful to contribute. Keep us up-to-date as you progress. ddb

I don't know that it will have any particular odor, but new exhausts always have some kind of residue on and in them that burns off not long after the first running, and it causes an initial very smokey start-up. But if your system is not brand new and was bought used then this wouldn't be the case. What does it smell like? Burning oil? Burning plastic? Burning coolant?