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TR - Euro Cam timing - overheated cats

Discussion in 'Boxers/TR/M' started by vincenzo, Feb 18, 2008.

  1. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,928
    Rifledriver in a post dated 2/24/06 said:
    "...As an example the US TR uses exactly the same cams and if I recall correctly the US ex cam is timed different by 4 degrees, not very much. Too little to see. It was done to reduce hydrocarbons at low RPM because the cats of the era could not take that level of HC output. If you use the European timing spec it WILL overheat the cats. I know, I have tried it..."

    The euro engine picks up 10HP with the cam timing & exhaust sys changes.

    Anybody ever try these settings on a US car with no pre-cats & only cats in place?
    Any speculation on how the euro settings might work with Hyperflow main cats & no pre-cats?

    Thoughts?

    Thanks,
    Vince
     
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  3. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,331
    Alabama (was Mich.)
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    Jeff
    I was considering changing to Euro-spec timing a few years ago, but in the end decided against it do to the reason Rifledriver noted. My car does not have precats or cats, so I could have made the change without worry. But I was concerned about the future, if I was ever to install the original exhaust....I would have to pull the motor and put the cam timing back to the U.S. It would be nice to know if newer cats would handle the change. Then we could all dial up another 10 horsepower on our TRs.
     
  4. Rock

    Rock Formula 3

    Nov 9, 2003
    1,652
    Toronto, Canada
    Full Name:
    Rocco
    early euro tr's have higher compression and different intake cams.
     
  5. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,331
    Alabama (was Mich.)
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    Jeff
    Hello Rock: I believe that the cams for U.S. and Euro cars are the same for both lift and duration, it's just that the Euro cars intake camshafts are advanced by about 4 degrees. The exhaust cams are the exact same for both lift, duration, and timing.

    NOTE: If your using a cheapie reprint shop manual for the Testarossa, be sure it's for the U.S. cars. The one I was using was for the Euro cars and when I was degreeing my cams I discovered that my intake cams were way off, only to find out that I was referencing Euro spec timing information and NOT U.S. information. Upon receiving the U.S. car spec.s I then concluded that my cams were spot on timing-wise. Just a word of warning.
     
  6. Rock

    Rock Formula 3

    Nov 9, 2003
    1,652
    Toronto, Canada
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    Rocco
    Hello Jeff, my info is from the 1984/5 factory parts book. All non cat euro cars have different pistons and intake cams. When they went to KE injection the parts were the same across the board. And thanks the timing tip.

    Rocco
     
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  8. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,928
    Apparently cats are in fact exothermic,. Presumably, it comes down to whether or not the hyper-flow cats could withstand more heat than the F-car original cat design. Of course, our check engine light would need some 'adjustment'.

    This is from Wikipedia:
    "Temperature sensors
    Temperature sensors are used for two purposes. The first is as a warning system, typically on obsolete 2-Way catalytic converters such as are still sometimes used on LPG forklifts. The function of the sensor is to warn of temperature excursions above the safe operating temperature of 750°Celsius of the two-way catalytic converter. Note that modern catalytic converters are not as susceptible to temperature damage with many modern three-way platinum based converters able to handle temperatures of 900°C sustained. Temperature sensors are also used to monitor catalyst functioning - usually two sensors will be fitted, with one before the catalyst and one after to monitor the temperature rise over the catalytic converter core. For every 1% of CO in the exhaust gas stream the exhaust gas temperature will rise by 100°C."

    Is an air pump (O2) required to get that 100 deg C rise with CO? Any Chemical Engineers out there in F-Chat?

    I shot an email to Troy at Hyper-flow & hope that he weighs in on this thread with some info.....

    Hey, its a free 10HP - I'll chase that one!

    Rgds,
    Vince
     
  9. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,331
    Alabama (was Mich.)
    Full Name:
    Jeff
    This is turning out to be a great thread! ROCK: Can you post the specs for the non-cat Euro intake cams?

    Yes...it seems that our K-Jet Fuel Injection system is a real performance killer. From what I've read, Bosch designed it to meet emissions requirements, and not high performance applications. It's actually surprising that Ferrari got as much horsepower as they did using this setup on the Testarossa. Too many bends and flow restrictions for the incoming air, and there doesn't seem to be much we can do about it. Really aggressive cams make problems for the K-Jet system due to back-pulses/reversions in the incoming air stream - or something like that.
     
  10. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,928
    This is exactly why this has my attention:
    http://www.gethoned.com/parts.php?get_price=yourparts&show=automotive

    There is HP locked into those bends.

    Lets see, perhaps:
    Some cam timing... 10hp
    Some exahaust system changes... 15hp
    Some intake flow improvement... 10hp

    from 390 to 425hp & the heads don't even have to come off. I like it

    Rgds,
    Vince
     
  11. johng

    johng Formula 3

    Oct 23, 2004
    2,284
    northern va
    Full Name:
    john g
    i'm pretty sure the US car has 380 hp and the euro is 390 hp. so you would end up with 415 hp with those mods if you have a US car. why not just go to electronic fuel injection? maybe with a motec. that should bring in decent hp..?
     
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  13. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,928
    Thanks for the correction - you are correct. There goes 10HP :-(

    Too far from stock to suite my taste. No doubt some HP would be let loose.

    If HP was a primary goal, I'd get a 500HP crate motor, an old Chevy & a bottle of Nitrous! It would be fun too!

    Rgds,
    Vince
     

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