OFT Tuning to 8,500 RPM
 

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.

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.

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

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.

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.

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?

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.

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

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

You sure those aren't the dyno operator, what you're pointing out is right at the start of the run. The 'OEM' torque dip is no longer there - my thinking was if there is power limiting intake restriction somewhere between 3500-5000 rpm, you wouldn't be able to fix it like that with headers. Obviously, the degree of skill of the tuner and the header design also makes a difference in how smooth things are, but the good design flatten out the stock motor's torque dip pretty impressively:

https://s3.amazonaws.com/pandlmotors...dyno-graph.jpg

And interpolation of a graph can also remove the minor dips smoothing peaks and valleys. This can be achieved via VVT adjustments to choke down the low RPM cylinder scavenging from the intake for a smoother or non existent dip. But I believe more TQ and low end power can be obtained as well from a better intake design. It is still a bottle neck
You can see the stock TQ peak at about 140 and drop. Imagine starting at 140 and climb