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Euro exhaust on a 3.2L US car?

Discussion in '308/328' started by James in Denver, Jul 23, 2019.

  1. James in Denver

    James in Denver Formula 3

    May 23, 2006
    1,953
    Centennial Colorado
    Full Name:
    James in Denver
    Is there any way to modify the exhaust system (headers, special pipes, enough room?) of a US car with 1 exhaust inlet on the muffler to a Euro 2 exhaust inlet muffler?

    I have the stock exhaust muffler on my 3.2 (Mondial actually, but more people hang out here) and wondered if there would be enough room to have 1 cat but 2 outs from the cat to the muffler. I imagine the space is small, but any suggestions, even if I have to have something fabricated, would be helpful.

    Anyone done this before?

    James
     
  2. nerofer

    nerofer F1 World Champ

    Mar 26, 2011
    10,331
    FRANCE
    Well, I don't think so, no. Unless you are ready to invest into a tailor-made system made by an exhaust specialist. This taking into account that I'm speaking with the 328 in mind, I'm not familiar with the Mondial.

    The exhaust silencer used on the "3,2 cars with cat" is dimensionally different from the one used on the "non-cat cars": it is shorter in width and higher, this to clear a space for the catalysator and the "Y" pipe which collects the flow of exhaust gases from the front and rear headers and sent it into the cat (forward of the exhaust silencer), which, in turn, feeds the exhaust silencer.
    Furthermore, this exhaust silencer "for cat cars", despite being shorter in width, is nevertheless bolted more rearwards on "328 with cats" than the one on "328 without cats": see the grille around the exhausts on "328 with cats", which is pushed two inches rearwards compared to "328 without cats" (given the appearance that the exhaust pipes themselves are shorter on "328 with cats") this to clear the space for the exhaust. Using the pick-up points on a "328 with cat" for mounting the exhaust box of a non cat-car would have this exhaust box sticking out at the rear (and probably be mounted too high, by the way). And I don't think you would have enough space to mount the catalysator in front of the exhaust box: there is actually no space whatsoever there on a 328 without cat between the rear header return pipe an the exhaust box.
    And you would need to have special pipes manufactured, and special headers too (remember those on catalysed cars are wrapped like doughnuts in an isolating material that does not exist on "non cat" exhaust). And you would need lambda probes, etc...
    Not cost effective. But if you are ready to have a complete exhaust line manufactured to suit (headers, intermediary pipes, catalysator, exhaust silencer...), well...

    Rgds
     
  3. dinonz308

    dinonz308 Formula Junior
    Rossa Subscribed

    Nov 26, 2017
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    Dean
    So you're saying that because of where the rear silencer mounts, getting the complete kit (manifolds/headers, link pipes, rear silencer) from someone like Larini it still won't fit without modifying the mounts for the rear silencer?

    https://www.larinisystems.com/collection/ferrari/328-corse
     
  4. nerofer

    nerofer F1 World Champ

    Mar 26, 2011
    10,331
    FRANCE
    #4 nerofer, Jul 24, 2019
    Last edited: Jul 24, 2019
    Larini does not manufacture one single exhaust line which would fit either a 328 without cat or a 328 with cat. It manufactures a silencer for cars with cats, and one for cars without cat; plus headers and intermediary pipes which can only go onto the silencer for the non-cat cars, due to the routing of the rear manifold discharge tube (to the left, not to the right)

    You will therefore note that the entry tube into the Larini "exhaust silencer for a 328 with cat" is the same than "the entry tube of the factory exhaust silencer": a single point. Which means you would need the same routing of the discharge/exit tube from the rear header, which is reversed on car with cats compared to the one of the cars without cats. On cars with cats, both headers discharge on the passenger side into an "Y" pipe, which itself then route the exhaust gases into the single cat, or a test pipe if you don't want a cat; and then into the exhaust box. Single entry point.
    But I don't see any specific headers from Larini for the cars with catalysed exhaust; you cannot use the ones they display as they only fit the "non cat exhaust" (= routing of the discharge tube of the rear header), so fitting their "silencer exhaust for cars with cats" on a car with cat means keeping the factory headers.

    On cars without cats:
    - the front bank header (no doughnut wrap-around material, "extractor header" for our british friends) discharge into the right (passenger's side) entry tube to the exhaust box via an intermediary pipe.
    - the rear bank header (no doughnut wrap around material either, of course) discharge into the left (driver's side) entry tube to the exhaust box, via a short intermediary pipe.
    Two entry points into the exhaust box, one each side.

    As said above, the headers are therefore different for a car/exhaust with cats or not.

    Question: could the shiny "extractor headers" from Larini, made for a car without cat considering the routing of the rear exhaust, be mounted on a car designed to have a cat, with their intermediary pipe and then non-cat exhaust/silencer?
    My guess is that AT THE VERY LEAST the pick-up point under the trunk would have to be modified (remember also that the trunk of the catalysed cars is shorter/less deep than the one of the non-cat cars also... ). I do know nothing about the internals of the engine, and the consequences of changing the exhaust system.

    But if Larini is manufacturing a specific stainless steel exhaust silencer for cars with cats, instead of offering the same single system for both cars with and without cats, it probably means that the one for car without cats is not substituable.

    Rgds
     
    dinonz308 likes this.
  5. James in Denver

    James in Denver Formula 3

    May 23, 2006
    1,953
    Centennial Colorado
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    James in Denver
    I bought my exhaust muffler 2nd hand, for a cheap price, but I think it's Euro (it's not here yet) so, absense of stripping the car of the cat (which would require (I assume) a different ECU or at least changing it to adjust for the lamba sensors, I don't think I can go to "straight pipes" and, based on what was said above, it's probably cost prohibitive to fabricate a series of things for the exhaust to work.... ---argh--- Luckily, it wasn't too expensive... probably cause the previous owner realized the same thing as above.

    Thanks again for the thorough answer and response!!!!

    James in Denver
     
  6. mike996

    mike996 F1 Veteran

    Jun 14, 2008
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    Mike 996
    To change a 328 ECU (Don't know about Mondial, I assume it's the same) from US to Euro involves changing one wire on the Microplex. So that's no issue at all. You'll gain a bit of low end but won't pass a smog inspection with the Euro setting.

    FWIW, There is only a 10 HP difference between the US/Euro 328 motor. It would be totally unnoticeable even if changing the exhaust alone gained all 10 horses...which it won't. The Euro had the different exhaust, a different ignition curve, and If I remember right, slightly higher compression, 9.8:1 instead of 9.5:1 to get that 10 HP.
     
  7. ferrariowner

    ferrariowner Formula Junior

    Feb 21, 2014
    592
    Mansfield, TX
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    Ron
    Let me add a couple of more items to Mikes post. The cams are also timed differently on US and Euro cars, not just the ignition timing curves. I think one of the biggest items however is the weight differences in the two cars. US cars have heavy doors and bumpers(250 pounds).
    To your original question, I think you can install a set of euro headers and euro muffler and everything will plumb properly. Also, the heat shields on US and Euro cars are different. If you spend the money to convert to all the euro exhaust and ignition modules, it will probably feel more powerful. But you will spend a lot of $$ for little power.
     
  8. mike996

    mike996 F1 Veteran

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    #8 mike996, Jul 25, 2019
    Last edited: Jul 25, 2019
    FWIW, if you read all the road tests of the 328 back in the day, you will find that MOST of US mag tests of the (US) 328 had a quicker 1/4 mile time and quicker 0-60 times than the European tests of the (Euro) 328. Since the US version had 260 HP rather than 270 HP and was heavier (I had no idea it was 250 lbs heavier - -WOW what a porker!), I suspect that was primarily due to the method of testing - US testers were likely more inclined to drag-race type starts (Rev it up/dump the clutch) for acceleration tests from stopped whereas most European testers were probably gentler off the line. That, of course, gives you (relatively) poor acceleration times for test purposes. A better test for engine power is the 1/4 mile trap speed or times to accelerate between different speeds in the same gear - assuming same final drive gear ratio - 60-80 MPH in 5th, for example.

    With the power difference, the the top speed end of the 328, the Euro would have around a 2MPH advantage over the US version - ASSUMING they had identical drag coefficients. I have no idea if they do or not. The weight difference between the two would not affect the top speed.

    Basically,. unless you are adding a noticeable amount of HP - based on my experience with engine building/competition on cars of this weight, I'd say AT LEAST 25 - it's not worth doing if you are expecting any usable performance gain on the street. For racing, well, that's different. If you have 260 HP and the identical car next to you has 265, he will win, all else being equal.
     
  9. nerofer

    nerofer F1 World Champ

    Mar 26, 2011
    10,331
    FRANCE
    Well, having the two exhaust "at hand", so to speak, perhaps the simple thing to do would be looking at the mounting points and if these would allow bolting the euro exhaust on the US car or not.
    It is worth noting that everything is very tight on an "euro" 328 exhaust as far as routing the pipes is concerned; for instance, the long intermediary pipe from the front bank is "S" shaped to go through the suspension and clear the shaft from the gearbox to the wheel; mounting an aftermarket exhaust box is not always easy if it has not been precisely manufactured. Tolerances are very tight, so everything needs to be perfectly adjusted.

    Rgds
     
  10. nerofer

    nerofer F1 World Champ

    Mar 26, 2011
    10,331
    FRANCE
    Mike: the US car is not 250 lbs heavier than the "Euro", if we are talking 328s. It is true for certain models of the 308, especially the GTS QV. As for the 328, for which eveything pertaining to the US model has been much better integrated, the weight difference between US and "Euro" version is only 30lbs (see the annexes of Dirk Michael Konradt's book, in German: "Autos, die Geschichte machten: die Ferrari 308 und 328; MotorBuchVerlag, 1990: the weight of every variant of the 328 and 328, as given by the scale, is listed here)
    The F105 040 version (catalysed engine for US & Australian cars, letter "X" in the fourth position of the VIN) is 260hp, has a slightly lower torque than the "euro" engine, BUT is also geared differently, which tends to supress any difference in acceleration.
    It is worth noting than in Europe, acceleration tests figures were often given for the GTB and for the GTS, and that the GTB achieved slightly better acceleration in most, if not all, tests.

    Rgds
     
  11. nerofer

    nerofer F1 World Champ

    Mar 26, 2011
    10,331
    FRANCE
    The 250 lbs weight difference is true only for the 308, especially the 308 GTS QV. The figure is not valid for the 328, for which integration of the emission control devices, etc...has been much better: equivalent versions (GTS US vs GTS "euro"; GTB US vs GTB "euro") weight differences between US and "euro" cars is only 30 lbs for the 328. See the reference in my above answer to Mike.

    Rgds
     
  12. nerofer

    nerofer F1 World Champ

    Mar 26, 2011
    10,331
    FRANCE
    Values for the three type of 3,2 engines are:
    Euro engine, not catalysed: type F105, fourth digit position of the VIN: letter "W": 270hp; torque is 31 Kgm (or 304Nm) compression ratio 9,8:1
    US/australia engine, catalysed: F105 040, fourth digit posit° of the VIN: letter "X": 260hp; torque is 29,5 Kgm; compression ratio 9,2:1
    Swiss engine, catalysed, KE-3 jet: F105 046, fourth digit posit° of the VIN: letter "C": 255 hp, torque is 28 Kgm, compression ration 9,2:1

    Rgds
     
  13. mike996

    mike996 F1 Veteran

    Jun 14, 2008
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    Mike 996
    Good info, Neo, thanks! I'm very happy to lean that the weight difference between the Euro/US 328 is only 30 pounds! As an adult my own weight has varied that much over the years! ;)
     

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