Conversion to Non-Interference Engine

[prj]

Worse squish = less efficiency, less power.

[quattro84]

Our engines need squish, that's how they are (crappy) designed. It makes the propagating flame front move during combustion at the right rate.
Has to do with efficiency as stated before, but heat dissipation as well.

Anywho, reducing will not make the engine run bad, but you will never reach the last % on your quest to max performance.

[cooperquattro]

ok thanks ,so no good for big hp?

[prj]

It's not that simple.
A 2.2T with a thicker head gasket will almost always make more power if you are running pump fuel. Unless you go to extremes.

So if you lower CR until about 8.0:1, even at the expense of some squish, you will gain power as long as you are running pump fuel.

2.2T is very damn simple.
To get 500hp on pump all you need is a 3076R/0.82, 3" exhaust, fuel supply, thick gasket and then something to control all that.
You can use stock cams, stock head etc.

[UrS4boy]

...2.2T is very damn simple. To get 500hp on pump all you need is a 3076R/0.82, 3" exhaust, fuel supply, thick gasket and then something to control all that. You can use stock cams, stock head etc.

And aftermarket H or I beam rods?

[prj]

And aftermarket H or I beam rods?

Not needed if you don't go nuts on boost.

[UrS4boy]

Not needed if you don't go nuts on boost.

Sorry. I think that is bad advice at 500 hp levels.

[prj]

Sorry. I think that is bad advice at 500 hp levels.

How many 500hp cars have you built and tuned?
If you keep boost and revs to a sane amount, it's just fine.

I got cars running 450 hp on stock rods for over a year now without any problems, using a mix of 95 and 98 RON.
500hp just means they'd hold the boost a little longer.

[Jamo]

Quanity does equal quality however in this case because the 3076 on the 2.2 averages around 600nm torque it can run on stock rods if your running a coilpack car.
On a 3B I wouldn't dare with spark hop being a real danger to the engine

[prj]

600nm torque is if you don't exceed 2 bar.
Which you won't with stock compression ratio, as you'll be knock limited.

However, you can happily do 2.3-2.4 bar peak and taper to 2.0 at redline on lower CR. That'll give more than 600nm, and I would not run that much on pump fuel.

But yeah, people like to blow lots of money on an engine build, and then run a small turbo, which is not very cost efficient.
Just sticking a big turbo on happily gets you to 480-500hp on this engine, so that's what I'd do.

However, if you are re-building your engine anyway, you might as well do the rods, since they cost nothing compared to the work involved in the engine rebuild.

[djh]

so how much power would be lost and how much of an issue is it for running a big turbo on a stock compression engine but with rods done and headwork?

[prj]

I wouldn't even do rods if keeping stock compression ratio, unless you are increasing the octane level of your fuel or running different fuel.

[Rocco]

600nm torque is if you don't exceed 2 bar.
Which you won't with stock compression ratio, as you'll be knock limited.

However, you can happily do 2.3-2.4 bar peak and taper to 2.0 at redline on lower CR. That'll give more than 600nm, and I would not run that much on pump fuel.

But yeah, people like to blow lots of money on an engine build, and then run a small turbo, which is not very cost efficient.
Just sticking a big turbo on happily gets you to 480-500hp on this engine, so that's what I'd do.

However, if you are re-building your engine anyway, you might as well do the rods, since they cost nothing compared to the work involved in the engine rebuild.

WTF do you want to mean? You would not run more than 2bar as peak and 2bar redline?

[djh]

I wouldn't even do rods if keeping stock compression ratio, unless you are increasing the octane level of your fuel or running different fuel.

Its already done. New rods, shells, headwork etc. I just want to know a rough guide how much power i'd be loosing with a big turbo i.e. gt35 or gt40

[prj]

Its already done. New rods, shells, headwork etc. I just want to know a rough guide how much power i'd be loosing with a big turbo i.e. gt35 or gt40

Unless you run some sort of octane boosting, you will hit a brick wall at 2.1-2.0 bar.
And a 3076R/0.82 can run 2.0 bar to redline, so fitting anything bigger is useless. You will pretty much gain almost nothing (maybe 5-10hp) and lose lots of spool.

This is on stock head.