OFT Tuning to 8,500 RPM

[bfrank1972]

Originally Posted by celek

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:

[celek]

Originally Posted by bfrank1972

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:

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

[bfrank1972]

Originally Posted by celek

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

Cool - I wonder if anyone has tried extrude honing the stock intake?

Edit: just realized extrude honing isn't really meant for plastic intakes like ours

[celek]

Originally Posted by bfrank1972

Cool - I wonder if anyone has tried extrude honing the stock intake?

Edit: just realized extrude honing isn't really meant for plastic intakes like ours

Its not the smoothness of the manifold its the volume-metric efficiency and design. All Subarus have had this issue. Head flow great. Delivery is something to be desired.

[CSG Mike]

Originally Posted by 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.

Is this a claim, or something already proven?

[Spartarus]

Originally Posted by CSG Mike

Is this a claim, or something already proven?

Unproven. I've been following the Reimax pump inquiry very closely. Probably because I'm the guy who started the inquiry on this forum. (borrowed my initial data from Nigelr32 on the UK forum) No published running data / datalogs at all yet. I purchased one a few months ago, validated the math only and sent it to Element Tuning for testing.

Related: so much misinformation in this thread.

Stock rods are plenty strong. It's the stock pistons that are weak, in the wrist pin area. That's going to be your problem.

The stock intake manifold is the single biggest bottleneck for NA power. Not the valves, not the cams, and certainly not the intake ports.

[Luckrider]

Originally Posted by CSG Mike

Is this a claim, or something already proven?

The valve springs going in a GCS and have a rated performance of 8,200rpm and are tested to 9,000rpm. The oil pump info came from the other thread and I am not sure the full status of its validity.

Valve Springs: http://www.power-division.com/produc...cat=414&page=1

[Tim Radley]

Originally Posted by Spartarus

Stock rods are plenty strong. It's the stock pistons that are weak, in the wrist pin area. That's going to be your problem.

Does anyone have any solid fact to support this? I ask because i'm prepared to rev mine more and log oil pressure but i'm running stock pistons and rods on a fully blueprinted and balanced bottom end. So I can set rev limit to anything in the ecu but it would be nice if someone had a fact saying "we had a failure of ------ at xxxx rpm. It's very simple for me to log pressure and post the data but i don't want to trash my block in the process. My ecu has oil pressure safety cutoff coded in so that's not a worry but throwing a leg out of bed is.

[Tim Radley]

Originally Posted by Luckrider

The valve springs going in a GCS and have a rated performance of 8,200rpm and are tested to 9,000rpm. The oil pump info came from the other thread and I am not sure the full status of its validity.

Valve Springs: http://www.power-division.com/produc...cat=414&page=1

That's 8200rpm with 20lbs of boost. Seat pressure is more than adequate there. Unboosted you could run much higher as long as its good wire.

[Spartarus]

Originally Posted by Tim Radley

it would be nice if someone had a fact saying "we had a failure of ------ at xxxx rpm. It's very simple for me to log pressure and post the data but i don't want to trash my block in the process. My ecu has oil pressure safety cutoff coded in so that's not a worry but throwing a leg out of bed is.

oil pressure drops precipitously on the stock pump at 8200 rpm. If you're on a stock oil pump, anything above that is a time bomb.

That's it.. Other than that, you're on your own. Have experiential data on rods and pistons, but not a whole lot of engineering data.

[Tim Radley]

Originally Posted by Spartarus

oil pressure drops precipitously on the stock pump at 8200 rpm. If you're on a stock oil pump, anything above that is a time bomb.

That's it.. Other than that, you're on your own. Have experiential data on rods and pistons, but not a whole lot of engineering data.

Ok well I might test a bit more rpm but i'm going to fit a dry sump in 4 weeks time. The oil pressure dropping i'm not worried about its whether the rod and piston can take the rpm. My ecu will cut power if the pressure falls so i'm merely trying to provide some conclusive oil pressure data for the rest of you which i'm more than happy to do and publish my findings in the form of real data.