[teamxrsx]

The weakest point on the K20A is the pistons. You have to worry about the pistons crumbling more than anything else at 9000+rpm The stock valve srpings can handle about 9300rpm's before it experiences valve float(on average of course). The stock retainers should be OK for that range too.

It is a fact though...revs kill motors.....if the engine's rev-limit is too high for the set-up.

I would not be concerned with all of this at 8600-8800rpm, if your engine is tuned correctly.


CJ

 

[Glimpse]

anyone? anyone using the 9000rpm toda package and redlining their car every day with a stock bottom end?

I redline daily at 9k, sometimes at 9,250. I have been doing so for roughly 15,000 miles.

I know of others who do the same. The bottom end is safe up to 9,500.

 

[Dr.Honda]

I redline daily at 9k, sometimes at 9,250. I have been doing so for roughly 15,000 miles.

I know of others who do the same. The bottom end is safe up to 9,500.

Ah finally someone who has been doing it for a while! Now i'll feel safe revving to 9k when i get k-pro and cams!

 

[LanceM]

I've been revving to 8600 since hondata #4 came out

Lance

 

[aznboysrfr]

I redline daily at 9k, sometimes at 9,250. I have been doing so for roughly 15,000 miles.

:drool: :drool: :drool:

 

[dolfin]

They aren't "weaker" springs, just a different design. 8600 is not a problem for the stock motor.

And talk of broken rods at 8600 is just silly.

Yeah that.
I'd be more worried about valve float between 8500-9000 than I would breaking a rod within the operating range of the engine.

 

[dolfin]

It's also very important to note that anyone who has seen a dyno of our engines, a stock type-s engine stops making power above about 7900-8100 rpm's. The only way to see power above that is with the ITR intake mani and cams, or other aftermarket stuff. It matters not if you have I/RH/E/kpro.. your engine will not make power up there without cams and intake mani

 

[ADAMS~K20Z]

The weakest point on the K20A is the pistons. You have to worry about the pistons crumbling more than anything else at 9000+rpm The stock valve srpings can handle about 9300rpm's before it experiences valve float(on average of course). The stock retainers should be OK for that range too.

It is a fact though...revs kill motors.....if the engine's rev-limit is too high for the set-up.

I would not be concerned with all of this at 8600-8800rpm, if your engine is tuned correctly.


CJ

I blew up my 2004 K20A2 when I misshifted. RPMS were 9210, Floated 6 valves and droped one entirely in to the number 1 chamber causing gobs of damage.

As for the original post. My 05 shifts at 8400 all day, can't see the rods damaging at 8600, just silly~

~Adam~

 

[Fast.Shark]

8600k daily and im fine.

 

[b9ev]

anyone? anyone using the 9000rpm toda package and redlining their car every day with a stock bottom end?

Third post in on this thread. 9k multiple times daily.

 

[JTSmith]

8600k daily and im fine.

Do you have an electric motor in there or something?

But anyway, I've been pulling 8600rpm from the time my car had 12,000mi up until it had 39,000mi. The last 2,000mi have been with the rev limiter at 8800rpm.

But there is still no way I would trust this bottom end to a daily rev limiter of 9k or over. If the guys in H1 are having problems with these motors coming apart at 8600, then I don't see the need for me to prove them wrong. That's one expensive risk I'm not willing to take just yet.

 

[Bitchhopper]

I've never taken my car past 6500 rpm, but I baby it :dontknow: My RX-7...now that's a car to rev out past 9 g's. It's good to know that the RSX can handle stresses past 8600 rpm

 

[Glimpse]

Right out of the FAQ:

I heard Hondata increases the rev limiter. Is that safe?

Hondata says: "The JDM J20A has a 8600 rpm limiter, whilst the US K20A2 with the same internal parts has a 8100 rpm limiter, so we are comfortable increasing the rev limiter to 8600 or 8800 rpm. One important point is that hitting the rev limit places a lot of stress on the engine, no matter where the limiter is. It is better to rev to 8500 rpm than hit the limiter at 8100 rpm. Also do not hold the engine on the rev limiter if you miss a gear - I've seen more than one engine expire this way. Another factor with the rev limiter is that the early K20A & K20A2 engines had weaker dual intake valve springs. Honda upgraded these some time in 2002 to a single valve spring (supposedly from the S2000). Owners of the earlier engines should consider changing the valve springs if they race the car. You'll lose a little power doing this. Connecting rods are a point of debate at the moment. We know they can fail at 9500 rpm, so setting the rev limit below 9000 rpm seems like a good idea.

K20A and K20A2 rods are exactly the same. This implies that 8,600RPM is definitely not a problem.

We see failures at 9,500. I rev to 9,250 on a normal basis (this will change after tuning). Take that for what you will.

 

[DavidT]

9000RPMs? Not a prob

Man I love that picture of my cluster. I don't drive like I'm on a mission so my car hardly ever revs that high but it's nice to know I can do it and pull away from other cars that bug me

 

[goofy]

Another factor with the rev limiter is that the early K20A & K20A2 engines had weaker dual intake valve springs. Honda upgraded these some time in 2002 to a single valve spring (supposedly from the S2000). Owners of the earlier engines should consider changing the valve springs if they race the car.

:nervous: should i be worried? i have 02.

 

[park83rsx]

:nervous: should i be worried? i have 02.

Nope.


I really dont believe double springs would be any weaker at all, just from my knowledge of spring dynamics.

 

[Glimpse]

Nope.


I really dont believe double springs would be any weaker at all, just from my knowledge of spring dynamics.

Indeed, they certainly aren't weaker. The primary difference that has led to this whole "weak spring" confusion is operational specification. The dual springs behave differently at very high rpm than single springs. Thus, damage from a misshift is more likely with the dual spring design. This however does not imply the springs are "weak" in any way, as they actually work better than a single spring in the normal operating region (i.e. below the 5th harmonic).

 

[aznboysrfr]

Early 02's have double valve springs. Which are stronger than single ones. So revving should not be a problem, because valve float will be less likely to happen, except for at VERY high rpms.

I heard Hondata increases the rev limiter. Is that safe?

Hondata says: "The JDM J20A has a 8600 rpm limiter, whilst the US K20A2 with the same internal parts has a 8100 rpm limiter, so we are comfortable increasing the rev limiter to 8600 or 8800 rpm. One important point is that hitting the rev limit places a lot of stress on the engine, no matter where the limiter is. It is better to rev to 8500 rpm than hit the limiter at 8100 rpm. Also do not hold the engine on the rev limiter if you miss a gear - I've seen more than one engine expire this way. Another factor with the rev limiter is that the early K20A & K20A2 engines had weaker dual intake valve springs. Honda upgraded these some time in 2002 to a single valve spring (supposedly from the S2000). Owners of the earlier engines should consider changing the valve springs if they race the car. You'll lose a little power doing this. Connecting rods are a point of debate at the moment. We know they can fail at 9500 rpm, so setting the rev limit below 9000 rpm seems like a good idea.

hm, it seems that opinions are conflicting

 

[Glimpse]

hm, it seems that opinions are conflicting

I believe park83rsx is talking about performance in the normal operating range... Using the terms "stronger" and "weaker" is a little misleading in any case.

 

[Dr.Honda]

It's cool that you rev to 9k and sometimes 9250 dailydriving but i'm wondering how long it would last if you were racing around a road course or something with a few of the guys?! Of course this is with a baffled oil pan!

I know the k20a/a2/and z1 can take 9k rpm with the stock bottom end but ca it handle extended high rpm like the road course with proper baffled oil pan and whatever?