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Topic: vtec controller

  1. #11
    Join Date
    Aug 2004
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    Knoxville, Tn
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    Sorry JDM but I have to completely disagree with you because I myself have seen the dynosheet belonging to Chris(the administrator of Accordinglydone.com) and just by moving his vtec engagement up to 3100rpms instead of the factory set 2500 and a lil uberdata tuning he made around 15 more ftlbs of torque from 2000- 4000rpm. I'll agree that a vtec controller alone has no advantage without tuning to coincide with it but the thing to remember is BECAUSE sohc vtec was set up for gas milage
    from the factory it wasnt tuned for maximum power output. This doesnt mean it CANT be tuned to make more power. Just upping the engagement doesnt do much because even though you've delayed vtec...the fuel/ignition maps are still acting as if it has already engaged will will probably just cause a rich condition until it does kick in but, if you alter your fuel and ignition maps to coincide with the later engagement you'll make more power. This is epecially true if you have made many modifications to the engine itself such as porting the head or installing a bigger cam or even bumped up the compression. I beleive moderate power gains could be had with a VAFC because it would allow you to alter fuel settings along with vtec rpm but you'll still have to worry about your timing.
    Me:" check it out bro, I just got my nitrous hooked up!!"
    My brother:"Cool! Now you can blow your engine at the push of a button!!"

  2. #12
    Join Date
    Oct 2005
    Location
    Atlanta Ga
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    65

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    Wow man u just took me 2 skool thanx 4 da knowledge

  3. #13
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    Aug 2004
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    Knoxville, Tn
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    no prob bro, I help the best I can with the few brain cells I still have left,lol.
    Me:" check it out bro, I just got my nitrous hooked up!!"
    My brother:"Cool! Now you can blow your engine at the push of a button!!"

  4. #14
    Join Date
    Jan 2005
    Location
    Fort Collins CO
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    also lets remeber on our vtec cords they activate at 2500 rpm, hardly close to peak anything, so all you get its a loud bog noise if you have a short ram... otherwise you wont notice it, now on a prelude H22 it activates at around 5500rpm right in the middle of the peak torque and hp, thats when you will feal it... if you up your vtec activation to 4000 rpm you will get much more of a boost feeling because you are only 400rpm short of your peak torque, so thats when you will feel it. (i agree with u liltroy)
    Summer Car:
    2002 Honda CG6 Accord EX :: 4 speed :: F23a4 ::


    Winter Car:
    1989 Audi 100 Quattro :: 5 speed :: 5 cylinder 2.3 :: Engine is toast
    (in search of 200 turbo)

  5. #15
    Join Date
    Aug 2004
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    Knoxville, Tn
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    Quote Originally Posted by Accord4me
    also lets remeber on our vtec cords they activate at 2500 rpm, hardly close to peak anything, so all you get its a loud bog noise if you have a short ram... otherwise you wont notice it, now on a prelude H22 it activates at around 5500rpm right in the middle of the peak torque and hp, thats when you will feal it... if you up your vtec activation to 4000 rpm you will get much more of a boost feeling because you are only 400rpm short of your peak torque, so thats when you will feel it. (i agree with u liltroy)
    Thats true to a point but the thing to realize is that the reason your peak torque accures at that perticular is that at that exact moment the high intake lobs and your exhaust lobes are working in perfect unisine (you've got pretty much the same amount of air going in as exhaust going out and you're getting "peak" power). The problem with moving your vtec engagement that high is that your low(non-vtec) cam lobs arent very effecient above 3200rpm so your power wil have tapered off signifigintly for those few rpms before engagement. When you think of vtec, its important to realize that in effect you have 2 seperate cams even though its on the same camshaft its still two seperate and destinctive profiles. What happens when you try to rev you engine(stock f22) to 7500rpms? Well, if you didnt have a rev limiter you would see that it was pointless because you're not making much power there because your cam profile(along with other engine components) werent designed to make power there. The same is true with low cam lob profile of a vtec engine.....at a certain rpm they become ineffective at opening the valves far enough and thus won't make any power there. Damn-mit Reed!!! You know I love ya bro but all this thinking is making my head hurt! I'ma go get some beer before I start having HHP flashbacks,lol. one last thing I'll add first though is that lately I've been speaking with alot of different tuners trying to find a reliable one for my upcoming turbo upgrade and they all say the same thing..that vtec engagement shouldnt and wont be felt much at all if your tuning and vtec engagement are perfect......it should be an almost seamless transistion and the fact that you fell the kick harder in an h22 shows that honda waited a lil too long to engage it and drug out the shorter cam profile too far. Most tuners when working with the h22 will actually lower the rpm slightly that vtec enages at. Just something to think about. ;)
    Last edited by Liltroy; 10-30-2005 at 09:04 PM.
    Me:" check it out bro, I just got my nitrous hooked up!!"
    My brother:"Cool! Now you can blow your engine at the push of a button!!"

  6. #16
    Join Date
    Dec 2004
    Location
    Wisconsin
    Posts
    358

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    i just have to say that liltroy is correct, when they tuned my car they lowered vtec to 4600 rpms instead of 5500 on my jdm h22a, and all i have to say is that before vtec was lowered, frankly i had to wait too long, and afterwords i look forward to it... the only downside to vtec is that i live in a cold wisconsin and i'm always waiting for the engine to warm up/ oil pressure to build up before vtec will even engage... for example 2 days ago i didn't race a blue civic si because my car was still cold and i know i'm only gonna make around 150 hp without vtec. i need my vtec to race an si.
    H22a is the best thing to ever happen to Accords... to my Accord.

  7. #17
    Join Date
    Jan 2005
    Location
    Fort Collins CO
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    hahah yea i know, you woul dhave to do some major mods to make a 5000 or 5500 vtec activation worth wile...yea i know... i was just sayin....
    Summer Car:
    2002 Honda CG6 Accord EX :: 4 speed :: F23a4 ::


    Winter Car:
    1989 Audi 100 Quattro :: 5 speed :: 5 cylinder 2.3 :: Engine is toast
    (in search of 200 turbo)

  8. #18

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    bisimoto <3s SOHCs
    Xx_RAGE_xX

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