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  1. #52
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    I didnt read what people have to say.. but why mod a LX or DX?

  2. #53
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    MORE POWER!!!

  3. #54
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    but wouldnt u be better of getting a si or sir insted of a dx or lx..

  4. #55
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    no. the vtec actually screws up the timing of the valves in the engine. trust me i know. my family owns an accord lx with vtec. so far the valve timing has been screwed up due to vtec. thats why the 4 cylinder engines are no long produced with vtec, only the sixes

  5. #56
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    Actually, Accord in-line 4 has I-VTEC. Variable valve timing and lift control are suppose to optimize torque and horsepower across the engine's rpm range. I do not see how VTEC can scrrew up the timing of the valves.

    Originally posted by shiriblue
    no. the vtec actually screws up the timing of the valves in the engine. trust me i know. my family owns an accord lx with vtec. so far the valve timing has been screwed up due to vtec. thats why the 4 cylinder engines are no long produced with vtec, only the sixes

  6. #57
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    Originally posted by shiriblue
    no. the vtec actually screws up the timing of the valves in the engine. trust me i know. my family owns an accord lx with vtec. so far the valve timing has been screwed up due to vtec. thats why the 4 cylinder engines are no long produced with vtec, only the sixes
    4 cylinders no longer produced with vtec? how does vtec screw up the timing of the valves. anyone tell Honda yet about the civics? And Toyota is using simlar concept with their engings. there is a nearly a decade of 4 cylinder vtecs running around the world.

  7. #58
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    They no longer produce B series engines, but they produce K series I-VTEC engines.. RSX, civic sir, tsx, etc.. they all have i-vtec, which is a updated version of vtec..

  8. #59
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    A quick crash course for anyone unfamiliar with VTEC:

    VTEC stands for Variable Valve Timing and Electronic Lift Control. The premise is that at low RPMs and at idle, a less aggressive cam grind is necessary to prevent "loping." Ever hear a pro drag car staging up at the gates? Sounds like it's about to stall. It's because he's running aggressive camshafts, and since the cam is spinning more slowly at idle, the intake valve is still open after combustion has completed. That's what causes loping. At higher RPMs, a more aggressive grind is desirable. The idea is that you want to cram as much air and fuel mixture (A/F) into that combustion chamber as possible, so that when it's ignited you get as grandiose an explosion as possible. So what is good at low RPMs is bad for high RPMs. So what do you do?

    If you're Honda, you invent VTEC. What VTEC does is simply to employ different cam grinds at different RPMs. A less aggressive grind at low RPMs for a smooth idle and low to mid range power, and a more aggressive grind up high to produce that high end pop. At a strategically placed "VTEC crossover point," the camshaft switches grind from the less aggressive to the more aggressive.

    What determines this point? Hours and hours dyno testing and tuning. If it is set too low, the more aggressive grind will kick in early, bogging down the engine (think "loping" at 3500 RPM). Too high, and the engine is missing out on valuable time it could be spending with the VTEC engaged. So all those fools who spent on a VTEC timer running stock camshafts just so they could get their VTEC to kick in earlier- they're idiots. They just cost themselves a ton of midrange power. The stock crossover point is optimized for stock camshafts.

    quoted from zoeth on kineda.

    so either way my guess is my car's vtec is set too low and its starting to do the whole "loping" thing. thats why the service guy had to adjust our valves a little bit higher. either way, vtec still kinda messed up the car for a bit. and no my mom does not drag race with it ok?
    Last edited by shiriblue; 11-26-2003 at 12:22 PM.

  9. #60
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    er ok i can't delete this post. so oh well
    Last edited by shiriblue; 11-26-2003 at 12:23 PM.

  10. #61
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    Originally posted by shiriblue
    so either way my guess is my car's vtec is set too low and its starting to do the whole "loping" thing. thats why the service guy had to adjust our valves a little bit higher. either way, vtec still kinda messed up the car for a bit. and no my mom does not drag race with it ok?
    I have an SiR with the B16A motor with dual cams. I left the VTEC set point stock because of that problem of excessive wear, although I did consider doing it at one time. So don't touch it... Did you buy the car used. that the former owner lowered the VTEC kickin? Yeah, that would produce heavy duty wear....

    so mommy doesn't drag race with it... but does sonny?
    Last edited by badrad; 11-26-2003 at 01:17 PM.

  11. #62
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    lol sonny doesn't race the accord. sonny races his camry i4 against a camry v6 on the freeway and wins

    oh there was another part about the whole vtec thing i didnt add. it was about whole engine hp tourqe ration stuff. if you want to read it. just PM me

  12. #63
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    Default alfa to honda to bmw

    An engine’s intake and exhaust valves let the fuel and air in, and the exhaust out. They are opened and closed by the movement of camshafts — shafts that rotate and have little lobes (i.e. cams) on them that contact the top of the valve (either directly or via a rocker arm) and force the valve open. Springs force the valve closed in accordance with the profile of the cam.

    Different cam profiles can have a dramatic effect on the behavior of an engine, such as how much power it makes, and how much fuel is uses. As US automobile emissions laws became more stringent in the 1970s, manufacturers found that they were compromising performance more and more to minimize pollution — although most engines could burn fairly cleanly at higher speeds, the only way to meet pollution standards was to use camshaft designs that compromised performance while at low speeds.

    In 1980, Italian carmaker Alfa Romeo overcame this obstacle when they introduced the first variable valve timing system — a relatively simple mechanism in the pulley that turns the camshaft. It turned the shaft slightly in relation to its pulley when the engine exceeded a certain speed.

    Consequently, the valves would open and close a little sooner and regain some of the performance that was lost by tuning the engine to burn cleanly at low speeds. Yet the profile of the cam lobe remained unchanged, so the amount of time the valve would stay open at a given speed, and how far it would open (referred to as valve lift), also stayed the same.

    In 1989, Japanese carmaker Honda introduced a system that allowed the engine to use a completely different cam lobe at higher engine speeds, so the engine could be tuned for low-speed torque and high-speed power, which had until then been mutually exclusive on many engines. The approaches taken by Alfa Romeo and Honda, copied by many manufacturers since, were limited in that they had just two modes — a high-speed mode and a low-speed mode. It wasn’t long before continuously-variable systems employing the Alfa Romeo technique were developed, but valve lift remained limited to a finite number of modes — until now.

    In 2001, BMW introduced a new valve-timing technology that eliminates the need for a conventional throttle. This new technology, dubbed Valvetronic, became available in North America this year on the company’s 745i sedan. While it’s mechanically complex, Valvetronic is conceptually very simple and yields a 10 percent increase in fuel economy, as well as reduced emissions, smoother idling, and increased performance. The 4,300lb 745i can reach sixty miles per hour in less than seven seconds, and gets 26 miles per gallon from its 4.4 liter V8 engine!

    The BMW Valvetronic system can continuously vary the opening of the valve from barely open to full lift. The significance of this new system is that it allows for the elimination of the throttle butterfly! That’s right — instead of the accelerator pedal controlling a throttle butterfly, it controls the eccentric shaft that sets how far the valves open.

    Theodor Melcher, BMW’s Project Manager for four-cylinder engines made a human analogy to explain the benefits of the Valvetronic approach: “Whenever we are required to make a great effort, human beings breathe in a deep and long process of ventilation. Whenever we need less air, we do not throttle the supply of air by, say, closing our nose or our mouth, but simply breathe in a shorter, flatter process of ventilation.”

    For idle, rather than closing the throttle as in a traditional engine, Valvetronic just reduces valve lift to the minimum required to keep the engine running. When the accelerator is floored, instead of opening a throttle all the way, it opens the valves to maximum lift. And every in-between accelerator position corresponds to an in-between amount of valve-opening — the driver can’t tell the difference between Valvetronic and a conventional throttle — until they notice how much money they’ve saved on gasoline!

  13. #64
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    exactly.. i would take a DOHC vtec over a SOHC anyday.

  14. #65
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    Originally posted by shiriblue
    no. the vtec actually screws up the timing of the valves in the engine. trust me i know. my family owns an accord lx with vtec. so far the valve timing has been screwed up due to vtec. thats why the 4 cylinder engines are no long produced with vtec, only the sixes
    If your modding a car, you shouldnt worry about how long your engine lasts. when your putting performance parts on it, arent u shortening the life of the engine already? cause there is going to be more heat produced, more rpms.. the engine is going to be spinning faster resulting to more wear.
    i am not familiar with the prices or whatever.. but why not spend that 1 grand or whatever to get the sir or si.. thats like 30 or 40 more horses, its better than spending more than a grand for a full exhaust system (headers, muffler) which will probably give u 15-20hp..

  15. #66
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    Originally posted by Chia
    exactly.. i would take a DOHC vtec over a SOHC anyday.
    Please excuse my ignorance, but what's the diff between DOHC VTEC and SOHC VTEC? I don't suppose it's merely the difference between a DOHC and SOHC design?

    -Rick

  16. #67
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    Originally posted by Traum
    Please excuse my ignorance, but what's the diff between DOHC VTEC and SOHC VTEC? I don't suppose it's merely the difference between a DOHC and SOHC design?

    -Rick
    DOHC = dual over head cam (mostly have 4 valves per cylinder, more effective IMO cause it allows more air and gas for combustion)
    SOHC = single over head cam (2 valves per cylinder)

    i believe most vtec applications are DOHC.
    Last edited by Chia; 11-26-2003 at 06:02 PM.

  17. #68
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    Originally posted by Chia
    DOHC = dual over head cam (mostly have 4 valves per cylinder, more effective IMO cause it allows more air and gas for combustion)
    SOHC = single over head cam (2 valves per cylinder)

    i believe most vtec applications are DOHC.
    the older si's and early vtecs were all sohc - likely the cause of shiriblue's mom's accord premature wear and tear. the sir's with b16a engines were dohc. the sir vtec kicks in the second cam for extra breathing.

    as for mods, yeah, i agree to spend the few extra bucks at the beginning getting the higher performance motor options. i've seen a lot of guys buy low end machines, stuff a turbo on, then a few months later rebuild the entire engine since the original stock ones weren't anywhere close to able to handle the address heat/pressure and abuse.

    but at the same time, it really rocks when you build a nice little sleeper - kicking butt of a GTI or Beemer in your momman's little four door rust bucket.... sweeeet.

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