Redline increase?

[cOoTeR]

The first I heard of bumping the redline up was when I had my ZX10R Derestricted. I think most people were bumping the redline up 500-1000rpms. My bike was a 2012, so people had been doing this without issues for a year before I was having my bike flashed. I was sceptical and decided to bump my redline up 1k rpms and never had any issues.

I've seen guys on the H2 forum bump their H2s redline up 1k rpms and I haven't been able to find anyone having problems with it. The H2 SX SE has a redline of 12k rpms and looks like the power is still building all the way to redline once it's derestricted. So in theory revving a little longer will build more boost and more power. But how do you know how far you can push it?

The H2 SX (SE) has the same valves as the H2 but different springs and cam. The bore and stroke are also the same but the compression is different.

[kman0066]

They should be able to handle another 500-1000rpm to handle the occasional over-rev, but raising the Rev limiter removes that cushion, but who knows how much is safe.

You can watch on a Dyno for a power loss from valve float or wait for the bang of a spun bearing...or the sheering of the crank itself in some bikes. It's a risky business. I'm a little nervous there with all that power to cast pistons, let alone at faster RPMs. The gains from the tune alone make me happy and I'll probably do a filter and exhaust, then leave her alone. I think past that, you'd be gambling too much on the non-forged rotating assembly.

Although, given enough engineer in knowledge and measurements, you could probably calculate a safe rpm. I'd personally not touch it until a shop did extensive testing.

[ghostwriter78]

the issue wont be the engine rpm but supercharger... at 12000 engine rpm the supercharger is running at about 100 000 RPM. also consider the increased pressure in cylinder.

[cOoTeR]

the issue wont be the engine rpm but supercharger... at 12000 engine rpm the supercharger is running at about 100 000 RPM. also consider the increased pressure in cylinder.

That is part of the point of bumping the redline. Guys with the H2 have been bumping up the redline to get more boost. They've even changed the supercharger gears to get more supercharger revolutions resulting in higher boost.

Where are you getting the information from that the break in is more important because tage bike had a supercharger? It's a new engine and the supercharger has very little to do with the breaking in of the engine.

[Vmatti]

DIY "changing the supercharger gears"

[Vmatti]

DIY "changing the supercharger gears"

https://www.youtube.com/watch?v=hyeqvU06q9Q

[ghostwriter78]

Didn’t they say that H2 sx SE gears will be sealed so you can’t get in?

[cOoTeR]

Didn’t they say that H2 sx SE gears will be sealed so you can’t get in?

I never saw that anywhere. Just undo the two bolts circled in the picture and you'll get to the top gear. Should be able to get to the bottom gear by removing the side case cover.

[kman0066]

The S/C unit itself is labeled as non-serviceable, the gears going to it could be changed just like the H2. That's not to say you couldn't get into the S/C unit, but they won't be recommending you do or be offering internal parts.

[vcyclenut]

I'm always conservative when raising redline and usually stick to 250 rpm over stock and then only if the bike is holding on to its power well at the stock redline or still building

most bikes are falling off by the stock redline and should be shifted prior to redline anyway and the extra revs are just over rev so you can hang on to a gear longer if wanted.

be interesting to see how this bikes responds to more revs and how far people will push it.