Hello everyone, I did a search and didn't come up with anything. But my question is whats the highest RPM you can take the h22 up too? I remember seeing 8k, and that was pretty high and dangerous . My car gonna be street/track just wanted to know before I start tuning it.

 

You won't make any more power past 7500-7600 rpm
so i wouldn't rev past that

 

the highest is revs is 8000rpm, but there is no point unless your still making power up there

 

It is worth letting it rev up to 8000RPM, so that you can stay in VTEC once you shift. Otherwise, on tight, slow curves you'll be exiting below VTEC.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scott21 &raquo;</TD></TR><TR><TD CLASS="quote">It is worth letting it rev up to 8000RPM, so that you can stay in VTEC once you shift. Otherwise, on tight, slow curves you'll be exiting below VTEC.</TD></TR></TABLE>
NO-----use your vafc and adjust vtec if you have one

 

mines cuts off a little after 8, like 8100 or 8200

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SKDRCR &raquo;</TD></TR><TR><TD CLASS="quote">
NO-----use your vafc and adjust vtec if you have one </TD></TR></TABLE>
That would be a good idea if you think your smarter than the Honda Engineers. What I mean is that I think they have some good reason to having it engage at a certain RPM(oil pressure). I have no idea what the reason could be, but if not than why not just set it at 2k?

Edit: Oh yea, and I've had my tach on my car go up to what I thought was 8200, but it could have been 8k.

 

Vafc? i would be careful about that! adjusting that could cause so much leanage, unless you have fuel mapped it, even that doesn't answer the man's question. my 2000SH has an 8100 fuel cut off!

 

... use the vafc and a dyno to figure out the best engagement point... as for rev limits... build the bottom end with some beefy rods and light pistons... then you dont have to worry about revving as long as you keep it under 11.5k.... my friend had a built h22 that didnt pop untill 12k (why did he rev that high??? hes a moron... [a rich one])...

 

HAHA have you ever felt what happens when you set VTEC at 2-3000rpm? Man it is funny. A pull from first is great until 3000RPM and then it is like you shifted to 5th. When my brother and I were editing fuel maps for a P72 we set VTEC at 3k and it had that great VTEC sound but what an acceleration drop-off! VTEC is only good after about 4800 RPM stock. I think stock is set about 5100 though.

You can see how a stock vtec powercurve is not very smooth on a dynograph. By 4800 RPM the primary cam lobes and the secondary lobes are producing the same power. So why not use the VTEC cam lobes? By 5100 RPM the VTEC cams are producing approx 20-25 more HP. People use a VFAC to set the VTEC so that the secondary cam lobes pick up where the two cam profiles meet so that the power curve is a lot smoother.

I don' t think that there is much to worry about lubrication issues with screwing with Vtec. Remember that all engines are tuned to pass EPA emission regulations, not to produce the most/smoothest power, this is proven by the fact that a stock P13 ECU's air/fuel ratio wavers between 14.25-12.5. It is usually fine until VTEC then it goes rich, where if Honda had tuned it better they would be able to claim even more HP. If lubrication truely worries you then get a prodrive oil pump gear to incearse pressure/effiency. Also, the Honda people also have to cover their asses when they make a car. Their car has to be reliable so that they don't loose money on all of the 100,000 mile warranties that people pay out the nose for.

H22mark, Search around and you'll find some stock h22 dynographs. There is almost no reason to take a stock H22 above 7000 RPM. The stock peak curve is around 6800and by the time it hits the rev limiter you will be down 10 HP from peak and from there it drops off real quick. Unless you upgrade the valvetrain and toss in some Skunk2 or Crower cams there is no need to worry it. Save your bottom end the wear and tear.

Scott21, If you are using a Vtec tranny then if you take it to 7400-7500 you will stay in VTEC. Honda did a pretty good job gearing for the stock VTEC switchover.

hope this helps.

 

u guys have weird H22's because my fuel cuts off @ 7600 rpm.

the stock tach is 400 rpm fast, so 8000 on the stock tach = 7600.

at any rate, yes it's important to shift at around 7600 because you'll upshift right into VTEC. you can change all of these things with electronics and some internals (aka stuff like your rods)

you don't get a VAFC to set VTEC at 1200 RPM. the reason for getting a VAFC is to flatten out the torque curve. usually that means changing vtec x-over to around 4800 rpm, but that depends on the mods, tuner, conditions, any # of variables.

anyway to answer your question, yes to drive as fast as possible, you will need to take it to redline, it's a high revving low displacement NA 4 cylinder. it was made for high revs...

 

So basically if I rebuilt my motors valvetrain and upgrade pistons and rods the h22 should be, tunable to go past the RPM limits you all are talking about.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h22mark &raquo;</TD></TR><TR><TD CLASS="quote">So basically if I rebuilt my motors valvetrain and upgrade pistons and rods the h22 should be, tunable to go past the RPM limits you all are talking about.</TD></TR></TABLE>

yup. i'm no engine builder so i wouldn't know the specifics for that. i'm sure one of NA gurus here will pipe up.

still, that's when the cost/benefit analysis comes into play with the build: how much hp will you get out of simply making redline 9000 as opposed to 7600? the higher redline is probably a correlated side effect of building the engine to make more power, whether it's through higher CR or whatever.

insofar as a stock H22 goes, it's set up so that the shift @ redline puts you right at the start of VTEC, for obvious reasons.

 

here's the deal, people think H22A's can rev up to 8000RPMs because on the stock prelude gauge cluster the RPM needle is acutally off by 400RPMs, meaning that when you are at around ~7600RPMs your stock gauge cluster is reading 8000RPM.

And as stated above, it is important to shift at redline so that when you upshift you not only land in VTEC on your 1-2 shift, you also land in a higher powerband as the next gear follows. But also, going to far past redline for those of you who have chip'd OBD1 ecu's, can also slow you down since you are actually starting to loose power at around ~6800RPMs.

 

i got a question.. if cars have rev limiters/fuel cut offs, how come it dont work when u are at 7500rpms in 3rd and misshift into 2nd? my ***** all messed up and im wondering y it didnt work. do u guys jus think i would have to replace my valvetrains? what are chances of me having crack heads/block and holes in pistons?

 

the fuel limiter doesn't react quickly enough to a misshift to save your valves from getting all fubared.

sometimes you can survive an incident like that, but if your **** is all fucked already, chances are you got yourself some bent valves.

g/l

 

mines built and i sometimes miss gears after shifing more than 8500rpm ... I need a triple tilton.. maybe that will cure it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mattmw88 &raquo;</TD></TR><TR><TD CLASS="quote">
That would be a good idea if you think your smarter than the Honda Engineers. What I mean is that I think they have some good reason to having it engage at a certain RPM(oil pressure). I have no idea what the reason could be, but if not than why not just set it at 2k?

Edit: Oh yea, and I've had my tach on my car go up to what I thought was 8200, but it could have been 8k.</TD></TR></TABLE>

Yes and thats why on a basicallly stock h22a, you can gain damn near 25 whp in the mid range by lowering the vtec point to about 46-4700.

And if you engage it that low, the car will bog like hell, the lobes are too big to make any power at that low of an rpm.

The fuel cut off on a stock ECU is 7700. And yes its best to shift near cutoff so you fall into a meaty part of the powerband on the next gear.

 

the highest i could take mine is 8200 before it cut out

 

With my S2 stage II the vtec changeover is set @ 4600, and it imediatiely jumps 10hp after the switch.

BTW I take my stock h22a4 bottom end to 8500 when racing, and thats not on some inacurate tach. My hondata has the redline set at 8500, and thats where he was taking it on the dyno.

 

My H22A8 Revs happily to 7500 rpm before I change gear (to stay above 5500 rpm VTEC engagement) and the rev limiter is at 8200 rpm. The UK Accord Type R I drove had to be reved to 8000+ rpm before changing to stay above its 6000 rpm VTEC engagement.

So from that I would think that the H22 is capable (depending on version and pistons/rods etc... used) of reving to 8000+ rpm since Honda will have engineered in a factor of saftey, but as many people have suggested it will be pointless reving higher if you are using standard cams etc... as there will be no power gain

 

It depends on your build also. If you use an AN-R header that moves you graph up and peak into the high 7000s, then you might need to shift at 8000RPM.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h22poweredgsr &raquo;</TD></TR><TR><TD CLASS="quote">i got a question.. if cars have rev limiters/fuel cut offs, how come it dont work when u are at 7500rpms in 3rd and misshift into 2nd? my ***** all messed up and im wondering y it didnt work. do u guys jus think i would have to replace my valvetrains? what are chances of me having crack heads/block and holes in pistons?</TD></TR></TABLE>

Fuel cut-off isn't going to stop gearing from spinning the engine.

Allow me to elaborate:
Imagine you're blowing into a fan, and your breath is making it spin. So, if you're blowing too hard someone covers your mouth to keep the fan from spinning too fast. Thats fuel cut-off.

Now, if you spin the fan with your hand you can cover your mouth as much as you'd like and the fan is going to keep spinning. Your hand is the engaged gear.

 

does anybody know which h22 model motor is the overall best motor, i plan on doin a h22 swap into my si coupe due to the torque it produces, i wanted to know which is the most reliable with vtec and the best year it was produced