OFT Tuning to 8,500 RPM

[Luckrider]

After some oil related troubles (or some other unfortunate, but unknown issue), my engine is being rebuilt at Moto-East. In addition to a basic rebuilt, the engine is getting upgraded with new valve springs and a Reimax oil pump which will allow the engine to safely rev up to 8,200 RPM or higher.

With that, I am curious if there is any tuning required to let the engine do this safely beyond just setting the fuel cutoff thresholds to higher values. Do I need to tune various parameters that control timing and fueling, or are the tables already in the basic tune good enough? The car will be run on e85 and 93 octane if it makes a difference.

[swarb]

Look at dyno sheets. Power drops off quite a bit after 7k. No real reason to rev that high unless you have cams that might power up there or need that extra couple mph to avoid shifting in a turn etc.

[steve99]

you might want to talk to @celek @Tim Radley and @Element Tuning

the volumetric efficiency seems to fall away after 7000 on NA motors, so your likely going to need head work cams valves ect to produce more power past 7000 rpm as oposed to just reving past 7000

[Tim Radley]

You need to change the intake manifold to make it rev higher. Cams will help a little but increasing peak power rpm point requires a shorter intake runner length.
Tuning of course. Stock knock settings are conservative.
What valve springs are you using and what are the seat and nose pressures on them?

[Luckrider]

I had a whole large post written up that accidently got deleted when I was almost finished typing it because I refreshed the page. It included a part about knowing power dies off hard NA. That's not my concern at all for doing this. I'm simply curious as to what is required to further increase the rev limit safely beyond what the basic OFT tunes do already

[zkv476]

Originally Posted by Luckrider

I had a whole large post written up that accidently got deleted when I was almost finished typing it because I refreshed the page. It included a part about knowing power dies off hard NA. That's not my concern at all for doing this. I'm simply curious as to what is required to further increase the rev limit safely beyond what the basic OFT tunes do already

As far as the tune, nothing more than define the tables for it really. So essentially scale the table axes to cover your desired rev range (and a little over) and tune for the values for timing and fuel. You can't safely just use whatever's in there, when you exceed the table values it doesn't interpolate the next value or anything, it just uses that cell.

Also I don't think anyone mentioned the oil pump, I don't believe any real testing data exists on it out so there's no guarantees it'll solve oiling issues at higher RPMs.

[Tim Radley]

Originally Posted by zkv476

As far as the tune, nothing more than define the tables for it really. So essentially scale the table axes to cover your desired rev range (and a little over) and tune for the values for timing and fuel. You can't safely just use whatever's in there, when you exceed the table values it doesn't interpolate the next value or anything, it just uses that cell.

Also I don't think anyone mentioned the oil pump, I don't believe any real testing data exists on it out so there's no guarantees it'll solve oiling issues at higher RPMs.

Stock pump fine to 8000rpm on 10W/40 oil. I posted the data on the other thread. Anything above that i don't know as I didn't want to push the stock connecting rods beyond that rpm.

[Luckrider]

Originally Posted by zkv476

As far as the tune, nothing more than define the tables for it really. So essentially scale the table axes to cover your desired rev range (and a little over) and tune for the values for timing and fuel. You can't safely just use whatever's in there, when you exceed the table values it doesn't interpolate the next value or anything, it just uses that cell.

Also I don't think anyone mentioned the oil pump, I don't believe any real testing data exists on it out so there's no guarantees it'll solve oiling issues at higher RPMs.

Beyond what Tim has said, someone showed that the new Reimax pump is good for an extra 5L of oil flow.

That's what I figured it would be as far as tuning. This will be something I slowly build on over time then. I wan't overhead in the tune and then just drive below that for obvious power reasons.

[celek]

Originally Posted by steve99

you might want to talk to @celek @Tim Radley and @Element Tuning

the volumetric efficiency seems to fall away after 7000 on NA motors, so your likely going to need head work cams valves ect to produce more power past 7000 rpm as oposed to just reving past 7000

Originally Posted by Tim Radley

You need to change the intake manifold to make it rev higher. Cams will help a little but increasing peak power rpm point requires a shorter intake runner length.
Tuning of course. Stock knock settings are conservative.
What valve springs are you using and what are the seat and nose pressures on them?

Agree with both statements above.
I think our TQ dip is partially because the head outflows the stock manifold, completely emptying the plenum until it starts to catch back up.

The heads if you think about it, the port design is simular if not the same as the FB25... 2.5ltr Turbo, or the FA20DIT WRX.
They flow enough power to make 750+ HP with minimal or no modification.

That being said on a NA 2.0ltr they outflow the stock manifold. But even with attempts to make an afermarket manifold out there no one is increasing the plenum size enough and the same result occurs.

The head does not need ported its factory flow is fine. The actual bottleneck is the intake itself. @Tim Radley told me he actually gained some power positioning putty in the intake ports to choke it down and gain more velocity. Making it more efficient to the manifold on top.

[bfrank1972]

Originally Posted by celek

Agree with both statements above.
I think our TQ dip is partially because the head outflows the stock manifold, completely emptying the plenum until it starts to catch back up.

The heads if you think about it, the port design is simular if not the same as the FB25... 2.5ltr Turbo, or the FA20DIT WRX.
They flow enough power to make 750+ HP with minimal or no modification.

That being said on a NA 2.0ltr they outflow the stock manifold. But even with attempts to make an afermarket manifold out there no one is increasing the plenum size enough and the same result occurs.

The head does not need ported its factory flow is fine. The actual bottleneck is the intake itself. @Tim Radley told me he actually gained some power positioning putty in the intake ports to choke it down and gain more velocity. Making it more efficient to the manifold on top.

Interesting - I'm genuinely curious to this theory, if the intake is a big limiting factor during the torque dip, how is it possible that improving exhaust flow with a header has such a dramatic impact?

[celek]

Originally Posted by bfrank1972

Interesting - I'm genuinely curious to this theory, if the intake is a big limiting factor during the torque dip, how is it possible that improving exhaust flow with a header has such a dramatic impact?

Its also part of the scavenging of the engine.
The dip is still present after a header "partially" fixes the dip
And most pictured dyno graphs are 3500-4000 RPM and up. The dip is shifted below that.

[fika84]

Hopefully @NotEric6 can get us an NA manifold one of these days......................

[bfrank1972]

Originally Posted by celek

Its also part of the scavenging of the engine.
The dip is still present after a header "partially" fixes the dip
And most pictured dyno graphs are 3500-4000 RPM and up. The dip is shifted below that.

Right, better header design increases flow and can be tuned so that the exhaust pulses improve scavenging on the exhaust side, but if the intake is a restriction in the system, wouldn't we still see that dip?

In general the reason you buy headers isn't for massive gains in the upper RPM range (although there are gains), it's to flatten out the torque dip. My intuition would tell me that the intake isn't part of the torque dip, but I know that the many factors affecting VE over a given RPM range are often not intuitive I was just looking for a more technical explanation.

[celek]

Originally Posted by bfrank1972

Right, better header design increases flow and can be tuned so that the exhaust pulses improve scavenging on the exhaust side, but if the intake is a restriction in the system, wouldn't we still see that dip?

In general the reason you buy headers isn't for massive gains in the upper RPM range (although there are gains), it's to flatten out the torque dip. My intuition would tell me that the intake isn't part of the torque dip, but I know that the many factors affecting VE over a given RPM range are often not intuitive I was just looking for a more technical explanation.

You mean these?
Besides the fact they are out of the power band they do not mean much unless you are cruising along double clutching granny shifting.
But they are still present