Anyone feeling amped up?

[blur]

2012 Civic sucks. 6700 rpm redline? for a 4 banger? compare that to their only rwd car, the s2000, with a redline of 8000! If you have ever sat in a car with a redline like that, youd understand why its so important.

I wonder if it can be flashed to get a higher redline though. Imagine a 2.5l 4 cyl with a redline of 9000? lol

[82mm 4g63]

Originally Posted by blur

2012 Civic sucks. 6700 rpm redline? for a 4 banger? compare that to their only rwd car, the s2000, with a redline of 8000! If you have ever sat in a car with a redline like that, youd understand why its so important.

I wonder if it can be flashed to get a higher redline though. Imagine a 2.5l 4 cyl with a redline of 9000? lol

I'll pass on the 9k redline. Having to tach up to 5500rpm to see the torque curve start to climb is not my idea of a fun driving experience. 7500rpm for an NA motor is more than plenty. Hopefully it starts to feel sexy around 4k.

[chulooz]

The AP1 2.0 s2k does have a 9K redline.

[blur]

Originally Posted by 82mm 4g63

I'll pass on the 9k redline. Having to tach up to 5500rpm to see the torque curve start to climb is not my idea of a fun driving experience. 7500rpm for an NA motor is more than plenty. Hopefully it starts to feel sexy around 4k.

Why would a lower redline mean that theres more torque int the low end in this case?

Notice I put reflashed to a higher rpm... AFAIK, in a reflash for higher rpm, you dont do anything to the low end.

[82mm 4g63]

Originally Posted by blur

Why would a lower redline mean that theres more torque int the low end in this case?

Notice I put reflashed to a higher rpm... AFAIK, in a reflash for higher rpm, you dont do anything to the low end.

I noticed. I'm wondering why you would reflash to raise the rev-limiter/fuel cut-off? Do you think increasing the redline automatically gives you more power? It does not, but you are giving yourself less reliability. The manufacturers aren't just throwing low redlines at you to piss you off. There is usually a reason for the fuel cut-off or rev-limiter to be placed where it is.

Look at the EJ25, the engine is good till 7k, they limit it to 6400 to be cautious. The primary limiting factor and reason for being cautious is the crankshaft's inability to oil the internals at higher RPMs. So unless you're going to increase the bore on the lubrication holes, as well as lighten the rotating assembly and rework the valve train, you're not going to notice any performance increase.



Dyno of a 2.5RS. Thinner line is the baseline with factory internals. Darker line is a reflashed 2.5 with Delta wild cams, OBX headers, Magnaflow cat, 2.25" mandrel midpipe, prodrive axel-back, Cobb intake, and LW crank pulley (~$2200).

The factory power band starts to fall on its face well before the redline, just increasing it wouldn't give you any more usable power. It wasn't until after over 2grand in parts that he squeezed a noticeable bit of power out of it.

Granted this isn't the motor going in the FR-S, but I highly doubt the FR-S motor will be a game changer.

[Dave-ROR]

Originally Posted by 82mm 4g63

I noticed. I'm wondering why you would reflash to raise the rev-limiter/fuel cut-off? Do you think increasing the redline automatically gives you more power? It does not, but you are giving yourself less reliability. The manufacturers aren't just throwing low redlines at you to piss you off. There is usually a reason for the fuel cut-off or rev-limiter to be placed where it is.

Look at the EJ25, the engine is good till 7k, they limit it to 6400 to be cautious. The primary limiting factor and reason for being cautious is the crankshaft's inability to oil the internals at higher RPMs. So unless you're going to increase the bore on the lubrication holes, as well as lighten the rotating assembly and rework the valve train, you're not going to notice any performance increase.

There are reasons to raise rev limiter, although the only ones I can think of for a stock cam/valvetrain setup would be to keep the motor in the powerband between shifts and to allow a couple hundred more revs before braking for a corner on track. There are tons of times that I'm bouncing the limiter in a given gear because it doesn't make sense to shift up, just to downshift a second later... extra revs will give you another couple MPH in those areas.

Now once the cams, etc are modified and you can make power above the stock redline, well the reasons are pretty obvious then.

The boxer that goes in this car needs to be capable of at least 7.5-8k IMO with no internal changes.

[SUB-FT86]

B

Originally Posted by blur

2012 Civic sucks. 6700 rpm redline? for a 4 banger? compare that to their only rwd car, the s2000, with a redline of 8000! If you have ever sat in a car with a redline like that, youd understand why its so important.

I wonder if it can be flashed to get a higher redline though. Imagine a 2.5l 4 cyl with a redline of 9000? lol

I understand your love of high revving but the new civic engine (2.4)would be more fun for me because it will give me more readily power and torque for my daily driving habits rather than stressing the engine (2.0) just to make the same power with less torque. I wish honda had installed d/i to the 2.4 so it could be more competitive. I could see the hp/tq rise to 225hp/190tq.

[82mm 4g63]

Originally Posted by Dave-ROR

There are reasons to raise rev limiter, although the only ones I can think of for a stock cam/valvetrain setup would be to keep the motor in the powerband between shifts and to allow a couple hundred more revs before braking for a corner on track. There are tons of times that I'm bouncing the limiter in a given gear because it doesn't make sense to shift up, just to downshift a second later... extra revs will give you another couple MPH in those areas.

I'm not risking my engine for a MPH or two going around a corner by adding 1000-1500rpm's to my stock hardware. If it's that important to earn those few MPHs, do it right and do the supporting mods.

Bouncing off the limiter depends on the vehicle. Cars like Vettes and GT3s can bounce off the limiter and maintain power. You're not going to lose anything coming around a corner by not being able to tach it out a little longer in cars like that. On the other hand, if it's more like a 370Z that falls on its face when it hits the limit as if VDC was activated, then a few more rev's will help.

Now once the cams, etc are modified and you can make power above the stock redline, well the reasons are pretty obvious then.

I'm not arguing adjusting redline once you get into adding aftermarket parts to support it, it's the idea of just reflashing for more RPMs that I disagree with.

The boxer that goes in this car needs to be capable of at least 7.5-8k IMO with no internal changes.

Agreed, that's why I said "7500rpm for an NA motor is more than plenty."

[Dave-ROR]

Originally Posted by 82mm 4g63

I'm not risking my engine for a MPH or two going around a corner by adding 1000-1500rpm's to my stock hardware. If it's that important to earn those few MPHs, do it right and do the supporting mods.

I never meant that 1000-1500 was fine, without supporting changes I wouldn't go past another 400-500. At least with Hondas the OEM valvetrain will handle that all day long, same with other cars I've owned. 1500.. yeah wouldn't attempt that.

Bouncing off the limiter depends on the vehicle. Cars like Vettes and GT3s can bounce off the limiter and maintain power. You're not going to lose anything coming around a corner by not being able to tach it out a little longer in cars like that. On the other hand, if it's more like a 370Z that falls on its face when it hits the limit as if VDC was activated, then a few more rev's will help.

I've never been in a car that slowed down from the fuel cut being engaged, maybe it would at the top of 5th/6th or something but I've never been that fast on a track before. :shrug: Not what I was saying anyways..

Agreed, that's why I said "7500rpm for an NA motor is more than plenty."

I wouldn't say more than plenty, I would say the bottom edge of acceptable but all of my recent cars didn't fuel cut until 8200+.. so.. :shrug: currently one fuel cuts (stock) at 8200, one at 8500, and one will be 9000 soon (with stock valvetrain that would normally cut at 8500).