k24 RPM limit

[CRXer]

hahaaahaa,i missed that post yonas.......8300rpm???....."stock" bottom end......

were gonna have to alert air traffic control to divert the planes next time your running out the creek in case one gets shot down by a k24 piston,imagine how fast those little babies are running,honda would be proud

[integral90]

the point is liam,what does the torque curve look like after 7krpm?
ive never seen anybody dyno a k24 past 7krpm,its prob cos the torque curve is headed off into the abyss by then.

That's with stock ECU and cams, all the runs it hit the 7200rpm redline while still climbing hard. With the right breathing mods I think the stock cams could make power to 7500rpm or so.

My point about the shift isn't so much about where you land in the torque, but just how big the gear is. It would be like redlining 2nd then going into 4th and flooring it. You'll fall back into the torque sweet spot but it doesn't matter because the gear is so damn long.

I'm sure you could get away with the longer 2nd of the K24 in a lighter car, but the Euro doesn't build momentum as quick as lighter cars obviously, the gear really kills it. After discussion with people I reckon on the 1/4 mile there's .2 or .3 in the 2nd gear.

[tinkerbell]

Ok for circuit. Then changing from 1st to 2nd wont be a problem.

yep!

if you are 'worried' about pushing too hard, then be conservative with upper limit

it is always better to make it home, than be 0.1 faster...

plus driver ability > than engine power

[Chris_F]

yep!

if you are 'worried' about pushing too hard, then be conservative with upper limit

it is always better to make it home, than be 0.1 faster...

plus driver ability > than engine power

totally agree, thanks for the input..

I'm thinking 7400-7500 should be totally fine for circuit work. 1/4 times mean very little to me so there's no point pushing it too hard

[CRXer]

That's with stock ECU and cams, all the runs it hit the 7200rpm redline while still climbing hard. With the right breathing mods I think the stock cams could make power to 7500rpm or so.

My point about the shift isn't so much about where you land in the torque, but just how big the gear is. It would be like redlining 2nd then going into 4th and flooring it. You'll fall back into the torque sweet spot but it doesn't matter because the gear is so damn long.

I'm sure you could get away with the longer 2nd of the K24 in a lighter car, but the Euro doesn't build momentum as quick as lighter cars obviously, the gear really kills it. After discussion with people I reckon on the 1/4 mile there's .2 or .3 in the 2nd gear.

sorry liam,i wasnt trying to compare my second gear to yours,i was just sending out some sympathy cos i know what its like competing with a tall second gear in my little shitbox 1000kg class.

the point is how much torque at 7500rpm,"stock" k24 cams?
even with as much as 50% torque conversion between 1st & 2nd gear,u might find your car making 50% less torque at 7500rpm.

u cant compare different cams,cos as soon as u change the cam profile uve just lifted the mechanical limit imposed by the stock cams.
it doesnt matter what breathing mods,how much u fiddle your vtc,or what other NA tricks u try to introduce more mix into the motor,u r still stuck with the fact that the stock valves will only open for so far & for so long,with the stock cams & u just cant supply what the motor is demanding at higher rpms.
500rpm is along way relative to running out of cam efficiency.

the only way your gonna get more mix in the motor,short of changing the cams is to pull the head & hack away at the valves & ports or cheat with forced induction or different gas other than atmospheric air.
honda would of already given u a head start on getting the most out of the stock cams from the factory,so your window of improving their efficiency would be even smaller still.

when u use terms liking "climbing hard" it just leads to people assuming your misinterpreting the power band.
if uve got no torque curve present on the graph,just hold your power curve graph at 45deg clockwise & then look at it. It will give u a better understanding of where & how fast the powerband is dropping away.
dont forget power is just torque proportional to rpm.

[integral90]

sorry liam,i wasnt trying to compare my second gear to yours,i was just sending out some sympathy cos i know what its like competing with a tall second gear in my little shitbox 1000kg class.

the point is how much torque at 7500rpm,"stock" k24 cams?
even with as much as 50% torque conversion between 1st & 2nd gear,u might find your car making 50% less torque at 7500rpm.

u cant compare different cams,cos as soon as u change the cam profile uve just lifted the mechanical limit imposed by the stock cams.
it doesnt matter what breathing mods,how much u fiddle your vtc,or what other NA tricks u try to introduce more mix into the motor,u r still stuck with the fact that the stock valves will only open for so far & for so long,with the stock cams & u just cant supply what the motor is demanding at higher rpms.
500rpm is along way relative to running out of cam efficiency.

the only way your gonna get more mix in the motor,short of changing the cams is to pull the head & hack away at the valves & ports or cheat with forced induction or different gas other than atmospheric air.
honda would of already given u a head start on getting the most out of the stock cams from the factory,so your window of improving their efficiency would be even smaller still.

when u use terms liking "climbing hard" it just leads to people assuming your misinterpreting the power band.
if uve got no torque curve present on the graph,just hold your power curve graph at 45deg clockwise & then look at it. It will give u a better understanding of where & how fast the powerband is dropping away.
dont forget power is just torque proportional to rpm.

You're exactly right, and I accidentally posted the dyno graph with the AFR instead of torque

Here's the torque graph: