UberTeg

I edited my rom so my rev limit is 3000 rpm below 10mph, and my normal 7200 afterwards. Is it bad to bounce off the rev limiter @ 3000-4000rpm?

And does anyone know what the minimum vehicle speed at which vtec will engage?

keebler65

it depends on if the limiter is cutting the spark or the fuel. if it cuts the spark, there is no harm. if it is stopping fuel, then you're creating a lean condition which is what is dangerous.

DIRep972

iTrader: (1)

i dont see the point of setting a 3200rpm rev limiter. please explain why u did this

racerxadam

launch limiter??

Joseph Davis

I have a VSS-based launch revlimiter of 3K, which is fuel cut since it is a Honda ECU revlimit. I have no problems with it, checked my plugs after testing it and everything - no signs of detonation and the engine is fine. I, uh, use it every day.

lazerus

two step rev limiters are very useful for perfecting a launch.

UberTeg

which ecu j.davis, ,and did you make it yourself? I modified a P75, and i used the VSS sensor And of coarse a little code hook ^^

UberTeg

Joseph Davis

I've run both PM6 and PM7 code, as designed by George Ricketts from PGMFI. My assembler sucks, and I'm too busy with other things on a daily basis to care to exert the mental energy required to learn.

I mainly alpha and beta test a number of programs for various different people on PGMFI. Some of the betas on my harddrive are very interesting in nature.

DIRep972

iTrader: (1)

ahhhhhh. haha my bad. shoulda known u were talking about a 2-step

UberTeg

IC, so you're basiclly the bitch? ^^ I got some P75 boost code i'm too afraid to test if you're interested ^^

genop

can someone explain to me why it is dangerous to cut fuel instead of spark? Not saying anyone is wrong, I just dont understand. If there is NO fuel, how can it detonate?

EpDarks

Ever herd of Air/Fuel ratio? Cut the fuel and you'll have only air correct?

Air burns HOT! Burning only air, with no fuel... bad.

That is what I'm GUESSING. Educated guesses phuckin own.

hybridsol

And here I am puttin' gas in my car like a sucker. I could have been running on air the whole time!

UberTeg

Not quite, gas is very picky, and will only burn withing a narrow a/f window. So in theory, a fuel cut should be safe and vey effective. But if pulse is cut during the fuel pulse, enuf fuel maybe left to ignite creating a lean condition. Also if u are runnign super rich, and soem fuel is left in your cylinder, you could create a lean condition. Some people think left over fuel can line the cylidner walls igniting it...

UberTeg

haha, reminds me of what homer said ^^

Joseph Davis

Bitch describes it, yes. I'm worried about P75 code not working on the regular old 1720 motherboards I have laying around, but I know someone with a P75 I can trade (been meaning to) a chipped P06 to. I think I can do it, I just need to build an adapter harness, already have the dizzy. Drop me an email?

UberTeg

<-- is running P75 rom on his good old regular 1720 OBD1 PR4 board Runs great, it actually improved my gas milage, but I get MAD jerking @ light throttle while trying to maintaina constant speed occaionally, usually only when the engine is cold.

edit:
you got


[Modified by UberTeg, 5:15 AM 2/4/2003]

mos

Nobody has mentioned anything about wear on mechanical parts and drivetrain. Your rev limit is usually reached when you are wide open throttle, and it also happens to be at or near peak horsepower on engines like the ones in our cars. Bouncing off of ANY type of rev limiter cannot be good for your rods/crank, drivetrain or transmission. Can anybody comment on what these mecahnical effects may be?

You guys worrying about extra heat from going lean, need to remember that going extremely lean, as in NO fuel at all, does not cause more heat. Outside of a narrow mixture range ( 8:1 to 18:1?? just a guess ) no combustion would take place at all.

UberTeg

you can make the bouncing short and smooth by setting the fuel resume very close to the fuel cut... thus not putting as much stress on the internals.

Civicdrgrcr

5th gear is kill zone for your motor never bounce off rev limiter in 5th.

BLKCRX

one thing iv noticed thow with hondata launch rpm, is when you hold the rpm, at your launch the car run's very very very lean... and without changing the fuel tables drastically there's no real way around it... i think.. unless someone’s got a suggestion for this...

Regards James

Jdm_Rice_Monster

I also have to add on rev limit bouncing. Is it ok if it bounces a little when going through gears. I still havent prefected driving my car getting the most out of each gear then shifting before I hit it sometimes. It all just happens to quick espicially on not so great of tires.

DIRep972

iTrader: (1)

bounce off the rev limiter in 1st gear when racing. it gives ur car a seconed to catch up to the wheels and more momentum when u go into 2nd.

EpDarks

Hmmm...

But bouncing off the limiter creates a quick gas --> no gas --> gas --> no gas, etc. Multiple times in a second.

I'd imagine that it's pretty hard to make it PERFECTLY cut off fuel, then cram more fuel in when the revs go down, then PERFECTLY cut it off again, etc. Right?

But hell, the limiter is there for a reason, that reason is to NOT to damage to the motor. Can't be that bad to bang it on occasion.