Testing The Waters

[Jason@DSG]

Why These Engine Internals Are Crucial For FI Or N/A On This Platform According To Jason


***The below is based on theoretical numbers. There are so many factors such as supporting mods, lbs/min flow of any given turbo, altitude, blah blah blah. So basically what I'm trying to do is just point out the advantage for these internals to people who may not know***


Here's a rough calculation based on my knowledge (depends on altitude but this is an average corrected based on 14.7 sea level):

A stock FA20 has a high compression 12.5:1 -- So when you add an AVO Turbo kit at 8psi, your actual compression is approx. 19.3 at boost (8psi). This is a potentially high compression amount and a little sketchy IMO

Seeing that this is a high compression, you have to run 93 octane to keep engine knock away. Although, any turbo car typically needs premium gas for that reason so no change there and it only makes sense as boost increases to run a "safer" fuel.

AVO Kit on 93 octane tuned by Drift-Office with full supporting mods made about 300whp on a stock engine with the OEM base compression of 12.5:1


Let's change that base compression now!


Take the same stats but with a different base compression. Let's say JE or CP pistons at 9.0:1 compression.

At 8psi you're only running 13.9 compression ratio at full boost!! That's almost stock lol

So that means with aftermarket internals at 8psi, you're running potentially 300whp at much lower compression/much safer for the engine



So that gives us two options:


1) Run the same boost from available turbo/supercharger kits at extremely safe compression ratios making it much more reliable

2) Running 19-20 compression at full boost which seems to be OK...


What PSI can you theoretically run with a full boost compression of 19-20 starting with a base compression of 9.0:1 ???


18 PSI


That is 10 more PSI than you can run on the stock engine, more than DOUBLE. While there may be a bit of lag (common with any turbo car), the maximum power will be significantly higher. 8psi versus 18psi is an enormous difference depending on the turbo

Now, the flow of a turbo and maximum potential are all factors but just for numbers sake, you could virtually run more than double the boost.

That brings us to our final items that are out for internals, Darton Block Sleeves and ARP Head Studs. The head studs are going to be out soon, ETA TBD. No one has really tested the stock block yet so it's hard to say what the maximum would be. However, I've run those same Darton Sleeves on the 4B11T platform on T4 6466 twin scroll turbos making 700whp so there's no question they are the way to go for very high boost. ARP Head Studs are that extra protection to keep everything fastened and not lift the head in high boost. Any piston blow-by won't lift the head, or it will take quite a bit.

So bottom line, these internals by lower the compression and being forged, can let you run current available boost from kits much safer, run much higher boost for biggg powwwaaaa or handle race abuse if you want to keep stock compression.



What If I'm Staying N/A?

These pistons are all customizable so even if you're sticking N/A, you can add these to your setup at stock compression (or even 11.0:1) to give yourself that forged internal safety for racing applications. They can handle much more abuse than stock internals making it a really great choice.



I hope this helps, as I said, it's all theoretical and there are many factors but this is a rough idea as to the advantage for those who may not know.


Cheers,
Jason

[diss7]

Some okay information there, but left out some key points.
In the example comparing the avo kit at 8pai at different static compressions, the one at stock compression will be much more responsive and nicer to drive. Both on and off boost.

Another argument is that, why not just run ethanol? If it's not available in your area, but it in buy the barrel and keep it in your garage. Have a pump map, and a ethanol map.

You're not using more than 300whp on the street anyway. If you think you are, you probably have TRC on and don't realise that you're not actually using all the power.

I'm not knocking the kit either. Just making some comments.

I think its good these kits are being developed, it puts more options out there so we can all achieve what we're trying to.

[Jason@DSG]

Originally Posted by diss7

Some okay information there, but left out some key points.
In the example comparing the avo kit at 8pai at different static compressions, the one at stock compression will be much more responsive and nicer to drive. Both on and off boost.

Another argument is that, why not just run ethanol? If it's not available in your area, but it in buy the barrel and keep it in your garage. Have a pump map, and a ethanol map.

You're not using more than 300whp on the street anyway. If you think you are, you probably have TRC on and don't realise that you're not actually using all the power.

I'd have to disagree on both those points unfortunately.

Not many people want to be rolling barrels of fuel in and out of their garage and refueling like that. I don't have ethanol available, and quite a few places don't (sadly).

As for static compression, I disagree. High compression and running boost is just asking for trouble ESPECIALLY running e85 where the blends change. You have no idea how many engines I've seen go because tuning on e85 with the blends changing throughout the seasons causing knock and detonation. Running a static 12.5:1 engine with an 8psi turbo running 19-20 compression ratio at full boost is a dangerous game IMO

On top of that, most of the available turbos are so small that they spool EXTREMELY quickly. You wouldn't notice any lag or difference whatsoever. Now, if we're talking some HUGH turbo then yes, but you would have to have lower compression pistons to do that anyways.

Also, using fuel power on the street, I always use full power lol What's the point of having it if you're not using it? haha

Ultimately, these internals are customizable as well and one does not have to go as low as 9.0:1 either. I just used some basic ideas to convey their use. They're even useful in N/A applications. I was just trying to make a point.

IMO, this car needs a turbo. I've driven many and the FI are totally a different beast. It just seems right. Now, on a stock engine that is 12.5:1 non-FI from the factory, that's pretty sketchy so enter aftermarket internals. You can keep boost lower for quick spool and good response with a smaller turbo like the AVO for example, but keep the full boost compression in a much safer zone also allowing you to potentially use non-93 octane (but always ideal for FI).

[RehabJeff86]

@Jason great write up!! Can you elaborate more for peeps who wants to stay NA for the track and wants to rev up to 9-9.5k rpm, how to build the internal towards this?


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[Jason@DSG]

Originally Posted by RehabJeff86

@Jason great write up!! Can you elaborate more for peeps who wants to stay NA for the track and wants to rev up to 9-9.5k rpm, how to build the internal towards this?


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Hey Jeff!

Sure thing. Basically for anyone really tracking their car, most engines in stock form are okay over time with proper maintenance. However, adding an intake (or panel filter), full exhaust, tuning, alternate fuel, ignition, etc. are all factors in increasing heat and wear.

The OEM internals have specific metallurgy specs requested by engineers when designing the engine. Considering this car is geared for tracking and having a good time, I'm sure they're pretty good. Then again, a high compression ratio OEM tuned to max potentially can wear on things over time.

In the EvoX world (albeit a factory turbo car), we saw tons of failures on cars with simple bolt-ons because the rods were CRAP! Many bent rods causing catastrophic failures.

I even read of a guy on here that bent a rod on his FA20. For me, even in N/A form, you can go nuts and race while having that extra protection knowing you aren't going to bend a rod or blow up a piston (it's still possible, but definitely far less chance than with OEM).

Also, by adjusting the compression even on a N/A engine, you can play with the timing and move the power band around. So for specific track applications, this could be a major advantage especially if you know your gearing and where you're in the power in and out of turns.

Then sometime down the road, I'm sure we'll eventually see cams and valvetrain goodies allowing the RPM to be raised -- all this will work hand-in-hand.

[CajunFRS]

Originally Posted by RehabJeff86

@Jason great write up!! Can you elaborate more for peeps who wants to stay NA for the track and wants to rev up to 9-9.5k rpm, how to build the internal towards this?


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Make power at 9k or just rev to 9k? Can our stock cams be tuned to make any power that high? I would think a different intake manifold/valve train. Plenty of write ups on how to make high reving engines. It isn't lower compression, although forged internals don't hurt. New head bolts would help.

Most Dyno's show power declining in the 7k+ area. Now I'm curious if anyone has built a high revving FA20!

[RehabJeff86]

Originally Posted by CajunFRS

Make power at 9k or just rev to 9k? Can our stock cams be tuned to make any power that high? I would think a different intake manifold/valve train. Plenty of write ups on how to make high reving engines. It isn't lower compression, although forged internals don't hurt. New head bolts would help.



Most Dyno's show power declining in the 7k+ area. Now I'm curious if anyone has built a high revving FA20!

Ya, it would be so sweet to rev to 9k rpm with power all the way on the track!!


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[CajunFRS]

Originally Posted by RehabJeff86

Ya, it would be so sweet to rev to 9k rpm with power all the way on the track!!


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I'd guess the reason we haven't seen tons of NA improvements is because all this easy powaa from boost. DAMotorsports has talked of Cam's. No dynos or any type of real info though.

FA20 is still new. More NA stuff will come I would hope.

[Jason@DSG]

Cams might not do that much on an N/A aside from moving the power band higher UNTIL we get some valvetrain items going to allow high RPM. That will require other mods like oil coolers, catch cans, etc. but N/A will be a bit costly to make over 200whp IMO. Adding a turbo with some lower compression internals will yield much better results, and much safer. 12.5:1 is damn high, especially if you start revving that up. The heat would be quite a bit at 9-9.5k rpm.

[CajunFRS]

Originally Posted by Jason@DSG

Cams might not do that much on an N/A aside from moving the power band higher UNTIL we get some valvetrain items going to allow high RPM. That will require other mods like oil coolers, catch cans, etc. but N/A will be a bit costly to make over 200whp IMO. Adding a turbo with some lower compression internals will yield much better results, and much safer. 12.5:1 is damn high, especially if you start revving that up. The heat would be quite a bit at 9-9.5k rpm.

Well that would explain why they dyno'd the car a few weeks ago and never showed anything.

Could just be they're under a NDA. I would hope no one wants to run a boosted application up that high.

[Jason@DSG]

I'm running 30 psi @ 9000 rpm

[uspspro]

Based on factory turbo DI engines, I would think 10.0:1 would be ideal. Maybe 9.5:1 in CA with crappy 91.

[Jason@DSG]

Originally Posted by uspspro

Based on factory turbo DI engines, I would think 10.0:1 would be ideal. Maybe 9.5:1 in CA with crappy 91.

Most factory 4-cyl turbo engines are actually 8.0-9.5:1 (4B11T, EJ207, EA888, etc.)

[wparsons]

Originally Posted by Jason@DSG

A stock FA20 has a high compression 12.5:1 -- So when you add an AVO Turbo kit at 8psi, your actual compression is approx. 19.3 at boost (8psi). This is a potentially high compression amount and a little sketchy IMO

Seeing that this is a high compression, you have to run 93 octane to keep engine knock away. Although, any turbo car typically needs premium gas for that reason so no change there and it only makes sense as boost increases to run a "safer" fuel.

AVO Kit on 93 octane tuned by Drift-Office with full supporting mods made about 300whp on a stock engine with the OEM base compression of 12.5:1


Let's change that base compression now!


Take the same stats but with a different base compression. Let's say JE or CP pistons at 9.0:1 compression.

At 8psi you're only running 13.9 compression ratio at full boost!! That's almost stock lol

So that means with aftermarket internals at 8psi, you're running potentially 300whp at much lower compression/much safer for the engine

Except that if the engine makes 300whp on 8psi with 12.5:1 compression it's going to make a substantial amount less on 8psi with 9.0:1 compression.

More boost means you're heating up the incoming air more, higher IAT's can also cause detonation.

Ultimately you have to tune for the setup, but there's no reason you can't run higher c/r's with boost.

You can't compare how a built engine takes power compared to one with stock internals, I would bet that peak power output on a built engine with 12.5:1 pistons would be very similar to one with 10.0:1 pistons, but with less lag and a broader power band.