Results 1 to 9 of 9

Thread: How much Hp would I gain if I increase compression ratio?

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    May 2007
    Location
    Memphis,TN
    Posts
    58

    How much Hp would I gain if I increase compression ratio?

    Look I was wondering is there a computer program out there that would give you expected gain numbers if you where to upgrade your vehicle.

  2. #2
    Join Date
    Jul 2009
    Posts
    546
    Are you planning to rebuild your engine or what??????? That would be expensive. By computer program, there are several ways to go--- (chips, plug and play systems, and piggy back systems) buying a new chip set for your ECU, get a computer program that reprograms your current ECU such as Osiris that uses a plug and play system that does not reprogram your ECU but is able to temporarily adjust settings in the ECU, on the fly, such as Diablo and Cobb tuning systems, or finally, getting your engine retuned at a tuning shop after installing bolt-on parts and then storing the new information on a piggy back system such as technosquare systems, which can also connected to your computer.

    It really depends on your car and what you want to do. Each has its pros and cons and each has its limits.

    Simply increasing your BTDC on your car by advancing it 2 - 3 degrees, can have the same effect as increasing the compression ratio of your car. Your mechanic and technician can do this for you easily and cheaply. However, you wil have to use the highest grade of gas all the time, in order to avoid detonation or the possibility of it. The other way to go about this is to change the intake and exhaust cams in your car to a more aggressive set of intake and exhaust cams, if your car uses overhead cams, and then retune the car. Of course, this would definitely make your car fail emissions and it may also compromise reliability. There are ways to confuse the ECU about your emissions such as using a spark plug anti-fouler.

    Another little secret i found is that, if your car has a seperate EGR system that is connected with hoses to the engine, you can disconnect the EGR without problems and get some small gains. Of course, you will fail the NOx emissions testing and your gas mileage may drop slightly. The EGR is a valve, and when it ages, it robs a car of compeling amounts of power.

    Personally, I have stayed away from reprograms, except for piggy back systems, because all they really do is move the reference table on your ECU to routinely recognize a more aggressive table and state in your ECU, which can compromise reliability in the long run. Its like keeping your heart rate at 150 beats per minute all the time when what you really need sometimes is just 90 beats per minute.

    And if i were to go for a reprogram system, as i have said suggested, my personal preference is to go with a piggyback system becasue it takes its data directly from the tuning variables of your car and stored specifically for your car. It is more costly for such a tune----about $400 plus another $1,000 for the piggyback system, and it is much safer and more reliable. You can switch it on or off depending on how you drive. The plug and play systems are less expensive----some costs about $700 - $800 and you don't need to re-tune your car. The most gains can be gotten from the piggy back systems, after tuning the car. Chips can be cheaper than the plug and play and piggy back systems, but you never know what it is really doing to the car.

    Just my thought. There could be better ideas out there. I don't know.
    Last edited by G35COUPE; 08-23-2009 at 05:59 PM.

  3. #3
    Join Date
    Jan 2004
    Location
    Kyushu
    Posts
    6,039
    Quote Originally Posted by Kalifrajasexi View Post
    Look I was wondering is there a computer program out there that would give you expected gain numbers if you where to upgrade your vehicle.
    the best way to go is to check out manufacturer specific forums that have members that have tuned their cars. from their experiences you can determine what can be done, how difficult it will be, how expensive, and what the expected gains are. what car are you looking to mod?
    Honor. Courage. Commitment. Etcetera.

  4. #4
    Join Date
    Sep 2004
    Location
    Adelaide, Australia
    Posts
    2,496
    If your going to increase your comp ratio, you need to increase the breathing of the motor also with better cams, valves porting etc. Also it depends what fuel you run, a higher octane fuel will be needed also
    SA IPRA cars 15, 25, 51 & 77
    Sharperto Racing IP Corollas
    http://www.sharperto.com.au/

  5. #5
    Join Date
    Mar 2004
    Location
    Eindhoven, The Netherlands
    Posts
    7,833
    Buy Matlab / Simulink.
    Buy a good book.
    Study.
    Study more.
    Study even more.
    Ask for help.
    Programme for 8 weeks.
    Ask for more help.
    Programme some more.
    Pray it works.
    Test.
    Celebrate with a beer.

    I got a simulation that gives you rough figures. But it's only for certain engine types. And I am not able to share as it's part of a production vehicle design documents and secret. But you wouldn't understand anyway as there are so many factors and functions you need to know of the engine.
    Last edited by drakkie; 08-24-2009 at 03:07 PM.

  6. #6
    Join Date
    Feb 2004
    Posts
    9,465
    Drakkie also knows the cure for cancer. But its a secret. And no doctors would understand it anyway.

  7. #7
    Join Date
    Apr 2003
    Location
    Rozenburg
    Posts
    10,012
    Quote Originally Posted by Spastik_Roach View Post
    Drakkie also knows the cure for cancer. But its a secret. And no doctors would understand it anyway.
    They did understand but lost the insight during the celebratory drinking of beer.
    If you should see a man walking down a crowded street talking aloud to himself, don't run in the opposite direction, but run towards him, because he's a poet. You have nothing to fear from the poet - but the truth.

    (Ted Joans)

  8. #8
    Join Date
    Feb 2004
    Posts
    9,465
    Quote Originally Posted by Wouter Melissen View Post
    They did understand but lost the insight during the celebratory drinking of beer.
    it was worth it!

  9. #9
    Join Date
    May 2007
    Location
    Memphis,TN
    Posts
    58
    Thanks guyes, and next time I will put my technical question in that large technical thread. I appretiate you responses and I will take them into thought.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Volkswagen Touran 2003-
    By dracu777 in forum Matt's Hi-Res Hide-Out
    Replies: 23
    Last Post: 04-13-2010, 08:09 AM
  2. Actual Horsepower Of '60s/'70s Muscle Cars
    By Fleet 500 in forum General Automotive
    Replies: 1575
    Last Post: 12-12-2007, 04:00 AM
  3. 2008 Le Mans 24 Hours preselections
    By togos452 in forum Racing forums
    Replies: 32
    Last Post: 11-22-2007, 07:41 PM
  4. Toyota Avensis (T250) 2003-2009
    By dracu777 in forum Matt's Hi-Res Hide-Out
    Replies: 27
    Last Post: 05-30-2006, 01:08 AM
  5. variable compression ratio
    By KnifeEdge_2K1 in forum Technical forums
    Replies: 19
    Last Post: 09-01-2004, 11:02 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •