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Tuned 348

Discussion in '348/355' started by marc556, Dec 21, 2007.

  1. marc556

    marc556 Formula Junior
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    Jul 15, 2007
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    What is the maximum power we can have on a tuned 348 with a 2.5 ECU version ?
    Originaly, the power of my car is about 300hp.
    How can I increase the power with a stainless steel sport exaust?
    I want to tune the ECU, what are the possibilities?

    thank you

    Marc
     
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  3. No Doubt

    No Doubt Six Time F1 World Champ
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    The OEM fuel injectors can't really support more than 360 hp, and realistically you are going to bump into injector problems (e.g. lifespan) above 340 HP.

    ...and you are only going to get to 340 HP if you really, really bump up the amount of air that goes in to your motor.

    You can tweak the exhaust and air input to exceed 320 HP without any drama, though.
     
  4. vvassallo

    vvassallo F1 Veteran

    Aug 4, 2006
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    I'd support ND on this. It's not really a 2.5 vrs. 2.7 issue as it is how much air and fuel flow the stock parts are capable of. There is all sorts of room to increase air flow, but it's not going to help if you cannot provide the fuel flow to maintain the proper ratios over the entire rpm range. That said, the stock injectors have some upside, but once it's reached, you need higher capacity ones. Our plan is to see how far we can push the stock injectors and see also if we can exceed their capacity and warrant an upgrade to 24 lb. injectors still using the stock intake and configuration (with modifications).
     
  5. marc556

    marc556 Formula Junior
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    So, if I understand well, there one way to upgrade easily the engine, to modify the fuel and air flow. My idea was to do it.....
    I need also to modify the ECU program at the same time???
    What is the maximum power I can have?

    regards

    Marc
     
  6. dkny

    dkny Formula Junior

    Jun 8, 2005
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    ND, what would you say is the best way to get the increased airflow to our engine? Are we talking different air filters, custom intake plenums.
     
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  8. No Doubt

    No Doubt Six Time F1 World Champ
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    The 348 Competizione LM's used 8 individual throttle bodies instead of the OEM 2 tb's on ours. That's far and away the best way to increase airflow (and that's why the 355 went that route).

    But there are other ways. Cone airfilters right next to each of our 2 tb's (moving the MAF's as close to the tb's as possible at the same time) would help eliminate the air pressure drops in the bends in the black tubes and OEM airbox.

    Bored out tb's would help, too.

    Larger MAF housing our stock electronics would help, as well.


    Now, enlarging the intake plenums would benefit the system, but where it gets interesting is if you can enlarge the intake runners that connect the plenum on top to the cylinders below. The OEM sized runners should be giving us faster airspeed for more torque, but at the expense of peak top-end power. Enlarge those runners and you lose some low-end torque but gain top-end HP (sidenote: the 1990's era Toyota MR2 used valves to open additional intake runner space such that the MR2 had max torque at low end as well as max HP at top end).

    Superchargers and turbochargers (and/or super/turbo normalizers and intercoolers) would also help airflow.

    You want the largest air intake scoops in the highest pressure regions available on the car, with the aggregate fewest pressure drops from initial intake to final ingestion.
     
  9. vvassallo

    vvassallo F1 Veteran

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    Funny u should mention this... :p

    Also, do not forget that intake mods/enlargement are part of the equation. Getting the gases out of the engine is just as important and is part of the overall power boost model. What if you had, say, larger header pipes, exhaust pipes, cats, free flowing muffler and a 355-type exhaust bypass valve...?

    Whoops, that formula looks familiar. :)

    As for the ECU, sure u can program more fuel, air and spark into the stock setup with no other mods, but maybe u should let ND handle this for you, eh? Once you start monkeying around with system modifications, then you have to get a new chip set for each step up. Damned 2.7 is not programable on the fly - too bad.
     
  10. dkny

    dkny Formula Junior

    Jun 8, 2005
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    OK, so for a DIY garagae guy, I can handle everything except going to 8tb's.

    Is there any info, pics on doing any or all of these typ of upgrades, what are we talking about for boring out the tb? Does our MAF have a screen that should be removed? Any pics of cone filters mounted to the TB? I have full access to a machine shop and am itching for a project. Could one fessibly make an intake manifold, mount it to the existing runners then relocate the MAF and tb's. I have seen some similar mods but they made the entire intake again.
     
  11. No Doubt

    No Doubt Six Time F1 World Champ
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    Each MAF has 2 screens that should be removed to reduce the pressure drop by some 24%.



    You could make the intake manifold larger, but that's not required to move the MAF's. Some rubber hose and C clamps will permit you to move each MAF right up against each tb.




    The shorter your intake plumbing, the less chance you have for pressure drops!
     
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  13. vvassallo

    vvassallo F1 Veteran

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    Warning about moving the MAF's. My mechanic tells me of dirty MAF screens on the tbs side from blow back? orsomething. I wonder about moving them closer, if they might risk being gummed up. ND, any thoughts?
     
  14. No Doubt

    No Doubt Six Time F1 World Champ
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    Getting more power means different compromises...shorter MAF life may be one of those.
     
  15. Elliott

    Elliott Karting

    Jun 28, 2007
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    I know this is off topic, but I got worried reading vvassallo's post:
    "My mechanic tells me of dirty MAF screens on the tbs side from blow back?"
    Is this a 348 quirk, should they be cleaned??
     
  16. No Doubt

    No Doubt Six Time F1 World Champ
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    Our MAFs are self-cleaning.
     
  17. Davidt

    Davidt Formula Junior

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    OK......I want 340HP to. ;)
     
  18. dkny

    dkny Formula Junior

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    Is it fair to say there are a number of us that would like to "bump up" our hp without totally changing our stock looking engines? Maybe we could start a thread for the easy stuff, and slowly work into the more advanced projects. We should vote on a team leader that would guide us through our endevour. My vote is ND!!!
     
  19. Houston348

    Houston348 Formula 3

    Oct 18, 2006
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    what is the stock HP on a 1995 Spider? i thought it was 320 .. no?
     
  20. Davidt

    Davidt Formula Junior

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    +1 for ND ;)
     
  21. No Doubt

    No Doubt Six Time F1 World Champ
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    I should have cone air filters and MAFs next to the tb's by the end of January. I'll post some dynos of my car stock, then with the MAFs moved adjacent to the tb's, and then I'll post a dyno of my car with the above plus my own chips tuned for my 348's M2.7.

    I may make a change to the cats while I'm doing the above, as well.

    Anyway, that should take care of the "easy" HP gains that are possible with these great cars. I'll make the posts such that anyone who can turn a screwdriver will be able to duplicate my setup.

    I predict that we'll all be able to bump up to 330 HP with fresh spark plugs, hyper-flows or straight pipes, MAFs moved, and my chips installed in our M2.7's. Maybe even higher.

    Might take another year before I get around to doing the same chip for M2.5's, though.


    But, in the meantime, the first thing that you can do with a flatblade screwdriver is to remove the 4 wire screens on the front/back of our 2 MAFs. That will reduce the MAF pressure drop by some 24%, a worthy mod!

    No need to wait for me on that one (and yes, I've already done it to my car...3 years ago and counting without probs!).
     
  22. marc556

    marc556 Formula Junior
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    +1 for ND
     
  23. vvassallo

    vvassallo F1 Veteran

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    Yep, MAFs supposedly self-clean using heated filaments. My mechanic was referring to goop that doesn't clean easily. Good to hear ND has had no probs, so I might just pop those suckers off, but I'll leave them in the stock situation.

    HP ratings are, well, somewhat ellusive. 348's in the US rate at 300 HP; 312 HP for the later SS, Challenge and Spiders; 320 HP for the later Euro cars. What do the engines really make? Heh, get youself to the dyno and find out. Mine seems to have a believable output, but it serves as a baseline for mods, not for verifying the factory power claims.

    And dkny, we are already doing this for you, so stay tuned. My car is being modded completely internally and within the stock configuration, so no one will be able to see evidence of our work, except, hopefully off the line. :)
     
  24. dkny

    dkny Formula Junior

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    sounds great, it really is great to have you guys in the community
     
  25. Ingenere

    Ingenere F1 Veteran
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    By using a Tubi and test pipes, and my company's ECU work, I am around 340hp.

    The real improvements came by putting the car on a bit of a weight loss program to go along with the power increase.
     
  26. WilyB

    WilyB Formula 3
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    Would you happen to have a dyno chart of your engine, and could you either post or PM me details about that ECU please?

    Thanks!
     
  27. gandalfthegray.

    gandalfthegray. Formula Junior

    Jul 18, 2006
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    This can be done while using a stock chip?

    Also, may I ask what purpose do the screens serve?
     
  28. gandalfthegray.

    gandalfthegray. Formula Junior

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    No Doubt???


    What are the screens for?
     

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