b-kelsey

I'm looking to see if anyone knows how to increase the rev limiter...

jscobey

I don't know if you really want to do that anyways. Honda knew what they were doing when they set it. It would be hard on stock internals to rev higher. Plus if you look at a dyno graph for a stock VTR it starts to drop in torque and HP once you get past about 9500 RPM.

I believe the HRC ECU's have a higher limit but are designed for modified engines. Plus good luck finding and HRC unit. I'm surprised no one has found a way to turn a stocker into the same "map" as the HRC unit

7moore7

HRC ECU gives it +500 rpm or so I think. Mikstr has/had a custom unit I think with no rev limiter that blew up his motor on a dyno (and it didn't go much higher than the HRC unit before it grenaded). These are v-twins with a firing order that doesn't balance out well at high rpms. Why are you asking? The cams,valves, stroke, porting, airflow, etc was all designed around a set of parameters that can only be pushed so far...

ChikinLady1011

to increase the rev limiter, the easiest and most practical way is to buy an inline.

8541Hawk

I believe my HRC ECU has no rev limiter but have never tested it..... though I do know it can turn more than +500 rpm over stock.

Not sure if they are all the same but on the 2 HRC units I have owned I have backed off before the rev limiter ever kicked in.

Tweety

AFAIK the HRC unit has no limiter... I have been as much as 500-1000 rpm over stock limiter without ill effects, but that's on a seriously built engine, a bone stock one would probably grenade before then...

Best way to get the same thing, is get an aftermarket ECU and program it with the HRC parameters... The information is on the forum, just search for it... Just keep in mind, you need to build the engine up to tolerate the abuse, and make use of it as well, otherwise it's fairly pointless and potentially expensive...

RCVTR

No rev limiter on the HRC unit.

Plug one in to a stock engine to test it and the valves will float off the cams, hit the pistons, knock the valve retainers out, get sucked into the cylinder, break off and the valve head will end up impaled sideways into the piston or valve seat, after several cycles of bashing around in the combustion chamber.

Other than that, you should be fine.

RCVTR

I saw the results in a CBR1000RR race engine that Bob Hayashida had partially built for Ken Hill. Bob had a real job during the day and was supporting Ken's bike at night. He got the bottom end built and the HRC ECU installed, but did not have the HRC parts for the top end yet and Ken had a race to do.

He told Ken specifically not to overrev the engine...

Poor Bob had to pull several all-nighters to get another engine built.

mikstr

Yep, been there, done that, have the repair bills to show for it........

msethhunter

This. Without serious mods, you are at a huge risk to scatter the bottom end all over the place.