355 bhp for the experts! | FerrariChat

355 bhp for the experts!

Discussion in 'Technical Q&A' started by 355f, Jan 21, 2004.

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  1. 355f

    355f Formula Junior

    Nov 1, 2003
    Ok guys!! Ive tried several mods to my car tubi ectect and really found the claims made for them in bhp to be without foundation.

    Anyway, more to the point im having lets say a warmed debate with a guy who has a 96 355 with tubi, no cats, a 'challenge airbox' whatever that means and a modified ecu to allow for these changes ( not sure whos done that) anyway, reckons its good for 50BHP I say no way!!

    Oh by the way, NO internal engine changes

    comments please from people who really KNOW!!

  2. mk e

    mk e F1 World Champ

    Oct 31, 2003
    The twilight zone
    Full Name:
    The Butcher
    I don't remember seeing anyone post before/after dyno numbers with mods similar to what you are describing to a 355. I have seen similar mods to other cars and they tend to gain very little, maybe 2 or 3%. That said, discussions with allan always remind me of the monty python skit that starts with
    "I'd like an arguement please"

    and ends with several minutes of
    "is not"
    "is to".......
  3. Aircon

    Aircon Ten Time F1 World Champ

    Jun 23, 2003
    Melbourne, Australia
    Full Name:
    #3 Aircon, Jan 21, 2004
    Last edited by a moderator: Sep 7, 2017
    I've heard different opinions...but my experience is this....changing exhaust from standard/without bypass/challenge on the same dyno on the same day no measureable difference. Using motec with challenge exhaust, different day, same dyno, no difference. Others have, apparently, had different results, but for the life of me, I can't see how! All these tests were on challenge cars btw.
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  4. rob lay

    rob lay Administrator
    Staff Member Admin Miami 2018 Owner

    Dec 1, 2000
    Southlake, TX
    Full Name:
    Rob Lay
    You do the exhaust for the sound, not the power. K&N probably gives more power than an exhaust.
  5. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    I'm in the no way catagory. 3-7 HP sure I'll give them that 50 no friggen way.

    Now if they opened up the engine, put in cams for 9,000 operation (25/65) instead of 8,250 (16/55), increased compression to 12.0:1 (from 11.0:1), shortened the intake trumpets by 1", shortened the exhaust headers by 3", gutted the CATs (all 4 of them) and added 9" to its effective length so it operated like a collector, and then modified the ECU and fuel system to cope--then--maybe 35 HP

    Open up the bottem end and knife edge the crank, ballance, polish both the crank and connecting rods, add air flow ports between throw webs, reduce oil pressure to 75 PSI from 100 PSI, port all oil flow channels and pipes, slow down the water pump and alternator by 25%, remove the power steering and A/C accessories, in addition to the first paragraph; then we might actually be talking 50 HP.
  6. snj5

    snj5 F1 World Champ

    Feb 22, 2003
    San Antonio
    Full Name:
    Russ Turner
    Having been around dynos recently, I can tell you that 50hp is a lot on an unblown 3.5 engine that is already making at 100 hp/liter delivering pretty damn precise fuel metering and ignition already.
    I'll go as high as 10 - 15 tops with the ecu and exhaust going with no filter.
  7. vincent355

    vincent355 F1 Veteran
    Rossa Subscribed

    Apr 8, 2003
    Wine Country
    Full Name:

    Let's do it and see! Who's donating the car?

  8. pino

    pino Karting

    Nov 1, 2003
    South Central PA
  9. Aircon

    Aircon Ten Time F1 World Champ

    Jun 23, 2003
    Melbourne, Australia
    Full Name:
    oooooooops...thanks for reminding me! I tried with/without air filter..no difference. (at least not measurable on a chassis dyno)
  10. zsnnf

    zsnnf Formula 3

    Sep 11, 2003
    On my F40 I personally saw 25-35 with Tubi and another 10-15 with Cats. Air filters made no difference. Removing back pressure allowed another 3-4 pds of boost. I have been told it is normal to see this on an F40. I doubt if you would see this much on a naturally aspirated motor.
  11. Aircon

    Aircon Ten Time F1 World Champ

    Jun 23, 2003
    Melbourne, Australia
    Full Name:
    Damn...i wish i'd played with the exhaust when i had mine!
  12. ferrarifixer

    ferrarifixer F1 Veteran

    Jul 22, 2003
    Full Name:
    Phil Hughes
    Did you have an F40 then........tell us all about it.

    Manifolds definitely make a difference, much more so than silencers. The road car ones are really quite restricive, just looking at the 4-1 collector glow white/transparent hot on the engine dyno will tell you that.

    Going to larger diameter pipes will raise power but possibly lower torque, or at least make little change. An all new 4-2-1 system like the Michelotto 360 step 3 system makes another 7 BHP....and cost $AUS10,000

    Having no air filters allows the reversion, or airstream pulses, to up set the air flow meters slightly, the filter need to be in to "damp" the air flow.

    Air box temperature makes a big difference. Reducing intake charge temp by 5 deg c will give good gains......2% or more.

    The cheapest gains are in weight saving.....driver first!, then dynamic stuff (flywheel, pistons, gears), reciprocating or rotary parts generally, then chassis un-sprung (wheels, tyres, brakes, springs, shox, uprights), then chassis generally, especially overhang weight (bumpers, silencers, lamps, oil/water tanks)
  13. 355steve

    355steve Rookie

    Jan 22, 2004
    right gentlemen,

    i am the person with the 355, tubi,no cats,chipped,etc.
    now as i explained to mr 355f i am not to up on all the tech stuff and i never CLAMED my car had reach 40/50 bhpn extra from just changing an air box!!

    what i tried to discibe was info that was given to me, and as i said to mr 355f quote" it was something to do with changiing the plemens on the car BUT I AM SURE IT A LOT MORE THAN THAT!!, so i have been back to the guy and he has told me the following. changing the type of injection to open top throttle bodys and then useing a weba or motronic ecu and remapping the car MIGHT see those sort of gain!!!
    no a def but approx.....

    it is always best to hear both sides of a story which someone has really taken to hart!!!

    once again i know there are a lot of experts out there.. I AM NOT ONE OF THEM but next time when a novice askes for a bit of advice and does not post not all the info surpplyed to him cut a bit of slack!!!!
  14. FL 355

    FL 355 Formula 3

    Nov 3, 2002
    Ft Laud
    Full Name:
    Frank Lipinski
    Total Performance runs an ad in the Ferrari News Bulletin. They claim to have a 355 ECU upgrade for +22 HP...cost $595.

    Tubi has been debated several times here. Only thing you gain is the sound...I prefer stock sound anyway. Many here have stated that Tubi will actually decrease performance and I was told the same thing by the service manager at Shelton...the 355 is pretty well engineered as is and the cats are free flow. If you prefer the sound do it, but don't expect a HP gain.

    Gaining 130 HP would be difficult outside of added NOS, Turbo, or any other Mod that would hinder durability and reliabilty.

    355 is a sweet car - just leave it stock.
  15. manu

    manu Formula Junior

    Feb 20, 2002
    London, UK
    Full Name:
    50hp from plug in-mods is near impossible on what is already a very highly strung engine.

    Putting it simply 99% of ECU upgrades simply increase fueling etc - most of which is utterly wasted and delivers zero power.
    This would not *necessarily* be the case if the amount of cold air entering the engine could be increased IN PROPORTION to the additional fueling from the ECU. Larger intakes, better insulated, with freer-flowing filters *may* give the *potential* (an important word) for more air to enter the engine in a stable way in which case, with an appropriate fuel mapping you could expect more power.

    When it comes to exhaust mods, it's a similar story. Unless (like a turbocharged F40) the power output is extremely sensitive to backpressure there is not a great a deal a cat-back exhaust can honestly do other than lower temperatures, reduce weight and give a better noise. Moreover de-catting *on THIS car* is primarily a measure to release a better noise, reduce temperatures and protecting the cats (which despite their free-flowing nature) are prone to failure. However quality race headers which optimise exhaust pulses (starting to get beyond my realm of knowledge here I admit) WILL deliver more power *if they are an improvement over stock.*

    However it is a COMPLETE falsehood that Ferrari extract the most from their cars... err NO WAY. (think stock intake is placed over cats/near silencer!) Their primary concern is maximising profit per unit. They develop, cost effectively, a car with competitive price and comparable peformance to other manufacturers within the realms of emissions regulations- that's it. If you think they optimise or give a **** about every aspect of performance and they original design cannot be improved upon you are WRONG.

    For example, it IS possible to develop ECUs which overide the input from the Lamda sensors and subsitute the optimal value ALL the time, allowing you to de-cat without warning lights etc thereby *marginally* reduce backpressure (yes don't start - modern cat's are all free flow - don't tell me -NOT -cue 355 manifold failure debate) - now if you add some quality headers (essential) and a quality muffler (reduce backpressure a tad more substantially) with a better thermally insulated intake with higher quality filters (will they still do the filtration job?? - another can o worms) THEN - THEN you can expect some more rwhp. (possibily at the risk of a reduced bottom end)

    Next question is HOW MUCH extra bhp??
    Well - that depends on how million other factors:how strong was your engine in the first place?? what's the outside temperature??? how much drivetrain loss does your car show. (why should this vary? hmm!).
    Dyno printouts which show sub 10hp + or - differences are absolutely worthless. Correction factors, fan inputs can be made make a dyno output vary considerably.

    I have one customer that dynoed his early TR post Tubi install and he said he gained 22hp - I FRIGGIN SOLD HIM THE Tubi and even I told him that was impossible... he was adamant.

    I've been as unbiased here as I can. The bottom line is if you love your car then go for it - try it - see what works and what doesn't - on the basis it doesn't hurt the car then you have nothing to lose. But don't be so silly in thinking that Ferrari have got EVERYTHING right. It's not true. They've done a good job but not a perfect one.

    P.S. Mitch - I'd be interested to hear what YOU think of plug-in mods?
  16. 355steve

    355steve Rookie

    Jan 22, 2004
  17. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    If, by plug in mods, you mean changing ECUs etc. I suspect that there might be 3-7 HP lurking by moving the engine away from the emsisions friendly setting controlled by the lamda sensor and richening up the mixture. But the added fuel will more likely increase the operating temperature of the cat and shorten its life.

    But I think you got one parameter wrong in your diatribe: I think Ferrari builds as much HP into the engine as they can manufacture without having to individually tune each ECU to each engine*. You can claim this leads to profit, I will claim this leads away from hassle in manufacturing. We are probably both right.

    *Tuners have the luxury of taking the engine as it is and tuning its operating envelope with only the smalles notion of meating actual emissions (which are much tighter than what can pass in tail pipe sniff tests).
  18. rexrcr

    rexrcr Formula 3

    Nov 27, 2002
    Kalamazoo, MI
    Full Name:
    Rob Schermerhorn
    (I added emphasis)
    Bravo! Precisely what I've been stating for years. Common misconception is "Ferrari designed and installed it, therefore it's the best and cannot be improved." Ughh.

    Don't get me wrong, I love what Ferrari does, but they don't always do it to the ultimate. They must stay in business first.

  19. notoboy

    notoboy F1 Rookie

    Jul 8, 2003
    Full Name:
    Hey, I'll offer my 355 up for the engine mods. Have been contemplating doing something for some time, because it kills me that I spent so much on a car that a sub $30K Mitsubishi can take in excelleration.

    The 355 is a great car with great sounds, but a little slow for todays cars that raised the bar considerably in only 2 years.

  20. BigHead

    BigHead Formula Junior

    Oct 31, 2003
    Outside of Boston
    Full Name:
    Ok, I'll bite, David. I'll make your 355 a whole lot faster. How much are you willing to spend? Seriously.

    Keeping in mind, of course, the path to speed is not limited to increasing horsepower. Give me your 355 and, say, $30k or so, and I'll make your car 10% faster around the track, all without touching the engine.



  21. rketex7

    rketex7 Formula Junior

    Jan 8, 2004
    Full Name:
    Has NOS been brought out in the pass. Some NSX had good success but then the motor goes south eventually. It's just a matter of time...stress...! Just my 2 pennies
  22. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    How many laps would NOS be useful? Last time I was out at TWS I ran 72 minutes in a single session! A whole tank of gas!
  23. mk e

    mk e F1 World Champ

    Oct 31, 2003
    The twilight zone
    Full Name:
    The Butcher
    "Hey, I'll offer my 355 up for the engine mods. Have been contemplating doing something for some time, because it kills me that I spent so much on a car that a sub $30K Mitsubishi can take in excelleration.

    The 355 is a great car with great sounds, but a little slow for todays cars that raised the bar considerably in only 2 years."

    Why screw around with mufflers, air filters and ecu programing for a couple hp?

    Come to the dark side and feel the power of boost, where gain is measured in 100s of hp :)

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