850 Exhaust Comparison

Let’s talk about 850 exhausts.  There are a lot of forum threads out there debating the merits of different exhausts, mostly coming down to the inexpensive OBX stainless exhaust (typically $350-450) vs. the more expensive IPD stainless exhaust. During IPD’s annual sales, you can get that exhaust for 15% off, or about $846, but normal retail is $995.  Why compare these two?  Because they are extremely similar looking… at least, on the surface.

Other exhaust contenders include the stock exhaust (OEM) which really isn’t that bad if your goal is something quiet that can pass emissions, and the stainless cat-back setup from Eurosport Tuning (EST) ($599, matches up to the factory downpipe).  If you want the whole stainless experience from Eurosport, you need to also get the stainless downpipe from them for another $749, bringing the total to $1348.  However, they do occasionally go on sale for $479 and $599, respectively, bringing the total to $1078.

Here are some quick stats:

Price Junkyard $450 $995 $1,348**
Sale Price Free $350 $846 $1,078**
Material Steel “T304” Stainless* (actually T409) T409 Stainless T409 Stainless
Tip material Steel “T304” Stainless* (actually T409) T304 Stainless T304 Stainless
Downpipe diameter  ~2″ 3″ 3″ 3″
Cat-back diameter ~2″ 2.5″ 2.5″ 2.5″
Cat included Yes No Yes Yes
No-Cat pipe included No Yes No Some**
Front O2 bung Yes Yes Yes Yes (2)
Rear O2 bung Yes Yes Yes Yes
Rear O2 bung is angled Yes Yes Yes No
Clamp type 1 wide V-band 3 narrow V-band 3 narrow V-band, 1 flat band for the tip 2 triangle gasket, 1 wide V-band, 4 U-bolt
Bend type Mandrel & Crush Mandrel Mandrel Mandrel
Included downpipes 1 2 1 1
Fits conical flange turbo Yes No No No
Fits straight flange turbo Yes Yes Yes Yes
Fits angle flange turbo Yes Yes Yes  Yes
Fits FWD P80 cars Yes Yes Yes  Yes
Fits AWD P80 cars & ’98+ cars Yes No Yes  Yes
Downpipe flex section Yes Yes Yes Some***
Provision for SAS cars Yes  No Yes  No
Tip shape Oval Oval Round Both (choice)

*A highly dubious claim given the high cost of T304 vs T409.  Given that the OBX exhaust “browned out” in about a year of use, it is most likely T409 (or similar).
**Only EST’s downpipe for 1996-98 FWD models (presumably straight flange ones) includes a swappable cat/straight section for removing the cat.  Their other downpipes (the ones for AWD models, presumably angle flange) do not include this section (although they are $50 cheaper ($1,298 normally / $1,038 on sale).
***Only EST’s downpipes for FWD models include a flex section.

As you can see, there are some substantial differences in the systems, most of all the price, but also in the construction quality and fitment.

Since I have three of the four exhausts available I took some close up comparison pictures.  This will mostly focus on the OBX vs. IPD systems, but where applicable I will reference the stock (OEM) system and the EST system.  The OEM exhaust in these pictures has at least 200,000 miles on it, whereas the OBX system has about 10,000 miles and the IPD system is brand new.  The Eurosport exhaust pictures are from their website.

Going through this, you will note the similarities between the IPD and OBX systems, and the OEM and EST systems.


The Downpipe



Here is the OEM downpipe.  Note the somewhat restrictive swan neck at the top, and semi-crushed area in the center where two bungs have been fitted.

Now let’s compare the IPD and the OBX systems:


Here you can see that the downpipes have a much more leisurely curve, without the 180-degree swan neck.  This should improve the flow considerably.  Note also that the IPD exhaust (bottom) has a fitting on it for SAS, which must be plugged if your car lacks this system for recirculating exhaust gases.  Note that you will have to provide your own plug and the threads are not the same as an O2 sensor, so you’ll have to go to the hardware store.  It is unfortunate that IPD doesn’t supply a downpipe for cars without SAS so that this extra fitting isn’t creating a visual and air-flow interruption, but on the other hand, if you have SAS and want to keep it (or need to keep it to pass inspections) then this is the downpipe for you.


Above we see EST’s header pipe for FWD cars, which more-or-less copies the stock design with a larger diameter pipe.  Looking more closely at the turbo connection, the header pipe itself has multiple welds where several 90-degree bends are fitted together to accomplish this, whereas the IPD and OBX systems are a mandrel bend.

_DSF2937 _DSF2940

Here is a closeup detail of the IPD turbo connection (left), compared with the OBX connection (right).  Note that the OBX has 3-inch pipe crushed to fit around the flange’s bolt holes, where as the IPD pipe has a reducer.  Note also the lower quality of the welds on the OBX pipe (although they are not awful).


Comparing the flanges, we can see that they are quite similar (and the same thickness), but IPD’s (left) provides a larger mating surface for the turbo.


Looking at the flex sections, we can again see that the IPD unit (left) has better welds, and overall, a smaller, but higher-quality flex unit.


The flanges at the flex end show a critical difference between the systems – the IPD system (left) has a raised lip for a better seal, and a wider flange.  Note that the OBX system has been leaking, but this may have been because the V-band clamps were not tight enough (none of them were very tight), so take that with a grain of salt.

For EST’s downpipe, we again refer to their picture:


The lower clamp is a gasketed triangle with three bolts – generally more difficult to deal with than a V-band, but with a good graphite crush gasket (available at most autoparts stores for $10-20) these type of unions perform well. Note also the provision for two different O2 locations in the header pipe – one at the top, one at the bottom – and another provision at the straight pipe.


The second section (straight pipe)


Now we come to the straight pipe in the middle, 3″ in diameter.  The IPD unit (bottom) has a cat that is made in the USA.  Unfortunately, it is very small, so I really question how effective it will be compared to the OEM cat, which is about 4 times larger:


However, perhaps the technology has advanced a lot in 15 years and a smaller cat is as effective as the OEM unit.




Above, looking at the front and rear flanges (IPD is the silver one, OBX is the bronzed one) again we can see the higher-quality flanges, and slightly superior welds of the IPD unit.  Further, you’ll notice that the OBX unit uses a one-size-fits-all approach to flanges, whereas the IPD unit uses the appropriate size for each coupling (the OBX flange is too large in many places in the exhaust)


Contrary to popular belief, the OBX rear O2 sensor location is in exactly the same place as the IPD location.


Examining the straight pipe in the EST unit, we can see that they have made a few different choices.  The cat is swappable with a piece of straight pipe for better flow (and smellier exhaust), and the clamp at the back is the wide V-band that the OEM exhaust uses.  There is a provision for an O2 sensor in the straight pipe, as well as the other two in the downpipe.  Like the IPD kit, however, the cat is tiny and probably won’t do much over the long term compared to the much larger stock cat.


The third section (stock muffler location)


Here we have the middle pipe that mounts where the stock muffler would go.  Both IPD (bottom) and OBX (top) provide a resonator, although they are of slightly different design.  This is also the pipe where a 3″ exhaust becomes a 2.5″ exhaust (note the reducer at the right side of the image above.)


Looking at the flanges at the reducer end of this pipe, again, the IPD unit (left) has a better flange, especially where the pipe is welded to the flange for a smooth transition.  The OBX (right) has the untrimmed edge of the pipe remaining.


Examining the mounting brackets near the resonator, we see that the OBX unit (left) has a thinner piece of steel (below) for the support, whereas the IPD (right) uses two pieces the same size, and bends the upper piece to attach parallel to the pipe, creating a longer, stronger weld.

The mid section of the stock exhaust is rather dull.  Just a large sandwich muffler with lots of baffles inside to keep the noise down:


Note that the stock exhaust uses a wide V-band, and there is only one in the whole system:


The EST exhaust below looks quite a bit different.  EST puts a small muffler, instead of a resonator, in the stock location:


The pipe begins with an OEM-style wide V-band, has a U-bolt connection at the first muffler, then another U-bolt, then a pipe, U-Bolt, and a black painted (anti-rust coated?) rear muffler of similar size and dimensions to the one that is used in the OBX and IPD exhausts.  According to EST’s website both mufflers are baffle-less straight-through designs.  You can view more pictures of an installed EST exhaust over at Swedespeed and get a look at the U-bolt clamps they provide.


The rear muffler



At the beginning of this pipe, above, again we see that the OBX unit (right) uses a flange much too large for the pipe, adn attaches it at an angle with a lower quality weld, instead of perpendicular like the IPD pipe (left).


The mufflers are nearly identical in size and shape, although they are clearly different units.  note that the IPD unit (right) has a angled exit, whereas the OBX unit has a bent edit, and that the IPD unit has two perpendicular mounting tabs, versus the angled ones on the OBX.

Speaking of clamps, you may have noticed that every single V-band clamp on the OBX system had been leaking.  I suspect the main reason is that they were not very tight.  Why were they not very tight?  Well, because they are low-quality, small, simple clamps with no locking or tensioning mechanism.


Above: IPD V-band clamps (top) versus OBX V-band clamps (bottom).  The clamp on the top right is for the IPD exhaust tip and is about 1.5″ wide.

As noted above, the EST exhaust includes a rear muffler of similar size and dimensions to the one that is used in the OBX and IPD exhausts.  The black muffler is attached to the pipes with U-bolt exhaust clamps, arguably not the best choice and more prone to leaking.  According to EST’s website both mufflers are baffle-less straight-through designs.  You can view more pictures of an installed EST exhaust over at Swedespeed and get a look at the U-bolt clamps they provide.



Exhaust tips


Finally, the exhaust tips.  The OBX unit (left) is welded on and has a metal plate that reads “Leistung Int”.  Oddly enough, Leistung is a company that makes aftermarket performance parts for Porche and VW, although I find it highly dubious that this is a genuine Leistung product, as Leistung doesn’t make any exhaust components that even remotely resemble this tip.  Not to mention that their exhausts are very expensive, and it is unlikely that OBX purchases exhaust tips from them to resell.

The IPD tip, on the right, clamps on with a large band clamp.  As pictured below, it is round instead of oval and has a much better fitment in the 850 bumper cut out because it is not as wide.


The EST exhaust also includes the option to order either an oval or a round exhaust tip, both of which feature their logo carved in the top:


The EST tip looks pretty nice.

But what about the OEM stock exhaust tip?


Uh… never mind.



Pros Inexpensive, quiet, large cat and muffler, fewest clamps Inexpensive, comes with 2 downpipes, loud and shiny Well-made, fitments for a wide array of cars, has a cat, good V-bands, consistent design front to back, nice tone at idle and low RPMs but quiet on the freeway OEM-style fitment, has a cat, likely the quietest due to the extra muffler
Cons Low flowing, 180-degree swan neck downpipe, rusty & ugly after 15 years on the road. Cheaply made, no cat, leaky cheap V-bands, no option for AWD models, difficult tip fitment due to width, significant noise and drone at cruising speeds Higher price, small cat, should come with a plug bolt for the SAS system (M16, TP=1.5) Highest price, liberal use of U-clamps, 7 clamping junctions using 4 types of clamps, small cat
Overall It does the job and lasts a surprisingly long time in good climates A cheap copy of the IPD exhaust – you get what you pay for. Best quality / cost ratio Overpriced for what you get, but still a good product