RPM's? - CEG Archives

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What is the highest RPM that a Duratec can be run at safely with all stock internals? Because i know getting a new chip can raise the limiter but how benificial is this and is it safe, i've read about duratec being able to hit as high as 7500RPM.

~Alex

I have ridden with SVT owners that shifted at redline...all the time.

Originally posted by LoCoZsc:
I have ridden with SVT owners that shifted at redline...all the time.

Your suposed to shift anywhere else?

The SVT makes full power up to and SURPASSING 6750 (soft cut) and 6950 hard cut... it will continue to make power to 7200 or so.

This will also drop a near second off your 0-60 times as a shift from 2nd to 3rd is no longer required at 58/59mph.

Check out DemonSVT's website for more info..
Main Site
RPM page

Read the whole site for TONS of knowledge.

Ray

I've past 8000rpm on a daily basis over a long duration.

I would not consider that "safe" though.

The link {of mine} posted above by Ray is a good starting point.

past 8,000 rpms?

since i am going forged rods and pistons and am going to have a full t4 with enough breath to 8,000, what would you think is safe rpm to run with our transmission? Would my cams run out of breath with the escape intake and mazda 6 axaust cams? Demon i assume you might have an idea since you recommended this set-up....By the way on the mazda six exaust cam you have to cut off the water pump extension since it is on the exaust side on a mazda six. That was the only fitment problems...

You go to 8K rpm with a turbo and you may need to look at your transmission. Also, you won't be building boost until 6K rpm with a turbo that breaths out to 8K rpm! Is this a drag only car? If so then that's ok, but if you are daily driving this thing then you're going to be less than happy with anything but a full throttle run.

The problem with our cars is traction and we are not talking about a huge turbo and a small motor here. I was mainly asking if the tranny could hold that consistantly...

Somehow I don't think the synchros will like 8000rpm shifts for a very long time! And 8000romon a FI setup is going to be pushing the ragged edge for piston speed/rod stretch. I wouldn't go there!

Are you asking about the 8,000 RPM "revability" just so you can build a FI car that gives you that bragging right? I'm asking honestly, because there's got to be more useful parts of the Duratec powerband than way up there at Honda speeds.

I can't imagine having all the useable power way up there on the band if this is a car you're going to be driving every day. I'm not so sure raising the powerband will eliminate the traction issues either.

But I'm not very tech-savvy, so if you have a plan forming, then work with it.

-SAV

Originally posted by SAV:
Are you asking about the 8,000 RPM "revability" just so you can build a FI car that gives you that bragging right? I'm asking honestly, because there's got to be more useful parts of the Duratec powerband than way up there at Honda speeds.

I can't imagine having all the useable power way up there on the band if this is a car you're going to be driving every day. I'm not so sure raising the powerband will eliminate the traction issues either.

But I'm not very tech-savvy, so if you have a plan forming, then work with it.

-SAV

raising the powerband will definitely not help traction issues...ask any turbo Honda guy he'll tell you he has plenty of traction issues. I have driven two turbo Honda's that have major traction issues all the way into 3rd!

Originally posted by Stazi:
Somehow I don't think the synchros will like 8000rpm shifts for a very long time! And 8000romon a FI setup is going to be pushing the ragged edge for piston speed/rod stretch. I wouldn't go there!

Even with My pauter rods and diamond pistons?

Originally posted by Stazi:
Somehow I don't think the synchros will like 8000rpm shifts for a very long time! And 8000romon a FI setup is going to be pushing the ragged edge for piston speed/rod stretch. I wouldn't go there!

Ditto!!!!

My thoughts exactly.

Even if the forged rods and pistons are good, you still have to wonder about the stock valve springs, lifters and retainers. I'm not saying they need to be changed but then when you are running rpms 25% to 30% higher than the factory designed redline, you may need to consider them.

Ok i under stand...I just was not sure. I will probly use a 7300 rpm shift point.

the problem is that stresses on components like valves and pistons are related to the rpm squared. The accelerated wear on bearings is linear, or close to it if you don't have oil issues. This is why engines have trouble getting into the higher rpms. 10k is about the limit for steel parts. In a lower-powered, super light engine like a crotch rocket, you can bump that up a little, but in a car like ours you would need to upgrade every reciprocating part to be about as good as you can get (light and strong - low weight minimizes the force as well) with steel before running 8k or more.

I think you will get valve float somewhere over 8k? The valve lashes on our cars can only take so much rpm before they go useless. But I know there are not many guys on here who are hitting that kinda rpm.

I hope the Duratec can handle the redline being set at ~7200 because that's where I am putting it when I get a dyno tune.