The Turbo Conundrum

[WingsofWar]

Originally Posted by Chocoholic005

You just assume that I'm a turbo only guy... When it comes to the small car game, I and many others, prefer a 4 cylinder turbo to keep weight down and even moreso the subaru motor for its low center of gravity. Honestly I'd prefer a H8 or an H6 with a screw type eaton supercharger on it for the torque factor while still keeping it a lightweight car, but both are a bit of a pipe dream.

You just proved my point. You prefer a turbo. And like many others, would want a turbo because it offers a certain level of power. AKA you are turbo spoiled, if you weren't, you wouldn't have made this thread, and complained about the compression ratio. You would have been more excited to get experience in N/A tuning. Are you saying you saying my assumptions are wrong? that you would love a low output high performance N/A to start with? tell me im wrong!

Keeping the weight down? you do know that turbos and superchargers add weight vs its NA counterparts.

H8? what car currently has flat8? None that i know of.


I am a turbo guy myself, its easy to get addicted to boost, but i know for a fact that id ditch any turbo setup for a properly tuned high performance N/A.

Id like to spend more time on throttle with an N/A and concentrate on rotation, rather get distracted by boost pressure, spend less time on WOT,and spend time feathering the throttle during rotation.

[madfast]

all you turbo guys, how much boost do you honestly think you can run on pump gas?

maybe relevant, maybe not:

http://heffnersperformance.com/heffner_ferrari.htm

fwiw the 458 has the same 12.5 CR and DI.

[Chocoholic005]

On a small sports car, yes i prefer a turbo. On a large car I do not.

N/A tuning is definately a fun thing to play with, but not on a car with so little N/A potential. The car will be realitively maxed out, we can't expect much more than 100hp/L.

Superchargers and turbos do add weight but not nearly as much as a V8 would with the same power output.

And no cars currently use an H8, tho i wish they did, thus why its a pipe dream.

[Chocoholic005]

Originally Posted by madfast

all you turbo guys, how much boost do you honestly think you can run on pump gas?

maybe relevant, maybe not:

http://heffnersperformance.com/heffner_ferrari.htm

fwiw the 458 has the same 12.5 CR and DI.

4 psi. Maybe. But if the pistons aren't forged, which i'm guess they are not based on Subaru's track record, probably less.

[Dragonitti]

I guess the only "good " thing about the expected compression is that you won't need to run a lot of boost to make the 300whp goal. Maybe 5psi will get you there on the right turbo (one that's responsive, dual BB and water cooled).

[Allch Chcar]

Originally Posted by Chocoholic005

4 psi. Maybe. But if the pistons aren't forged, which i'm guess they are not based on Subaru's track record, probably less.

Why did you make a new thread? We already have one for this,Compression ratio 12.5:1. Bye-bye Super charger & Turbo build?.


I still say 12.5:1 is purrfect! >:3

[WingsofWar]

Originally Posted by Chocoholic005

On a small sports car, yes i prefer a turbo. On a large car I do not.

N/A tuning is definately a fun thing to play with, but not on a car with so little N/A potential. The car will be realitively maxed out, we can't expect much more than 100hp/L.

Superchargers and turbos do add weight but not nearly as much as a V8 would with the same power output.

And no cars currently use an H8, tho i wish they did, thus why its a pipe dream.

Im sorry, when i read your posts i have a hard time understanding what your talking about. I feel like i have to translate, as if your English is bad or something.

Let me get this straight...

On a small lightweight sports car...you would prefer a turbo..i get that, many people do. whether you NEED boost depends on the application and use.

On a big heavy sports car..you would prefer a big engine. Right? turbo/supercharger are up in the air as long s the engine is big

and you believe that the FRS is maxed out, even with that airbox, the 3 metal cats that are restricting exhaust flow, economical fuel maps, less aggressive timing maps, with its already 100hp/l just short of s2000 territory and still the 2nd best N/A power output under $100k USD....and your saying its less N/A potential?

I have a feeling you only are interested in sports cars that are close to supercar status. Not entry level sports cars. with a price range of 15k-25k which will have performance standards different than territories such as 370z/GTR/Corvette/911/Mustang/etc..

[MF_DEUCE]

Originally Posted by WingsofWar

You just proved my point. You prefer a turbo. And like many others, would want a turbo because it offers a certain level of power. AKA you are turbo spoiled, if you weren't, you wouldn't have made this thread, and complained about the compression ratio. You would have been more excited to get experience in N/A tuning. Are you saying you saying my assumptions are wrong? that you would love a low output high performance N/A to start with? tell me im wrong!

Keeping the weight down? you do know that turbos and superchargers add weight vs its NA counterparts.

H8? what car currently has flat8? None that i know of.


I am a turbo guy myself, its easy to get addicted to boost, but i know for a fact that id ditch any turbo setup for a properly tuned high performance N/A.

Id like to spend more time on throttle with an N/A and concentrate on rotation, rather get distracted by boost pressure, spend less time on WOT,and spend time feathering the throttle during rotation.

[Kostamojen]

Originally Posted by Chocoholic005

But as far as the subaru engine goes, lowing the compression ratio is a piece of cake compared to most engines. And swapping in 9.0 or 9.5:1 compression pistons could easily allow for a 300-400whp turbo setup with little modification to the rest of the vehicle. This is assuming of course that Subaru continues to use forged rods along with their forged crank and the 6 speed trans is beefy enough to take it.

EJ internals are NOT compatible with the FB/FA motor, they can't be used.

So in order to even do what you are saying, someone is going to have to design and manufacture rods/pistons for the motor.

[Ryephile]

Originally Posted by Chocoholic005

...The amounts of pressure this high compression motor will produce combined with a turbo will likely lead to the motor dieseling. ...

So what you're saying is, you have no idea, and you haven't done any math, let alone simple experiential postulating whatsoever to back it up.

Here's how it's going to happen in reality:
1.) People buy the car
2.) Power Whores will fabricate turbo setups
3.) The smart ones will calculate that with 93 octane and the stock 12.5:1 static CR, they can minimize risk with 6 PSIg, or push the envelope with 9 PSIg. Of course, if the stock powertrain can't physically handle the added power, something will break. If it stays together, and the power level is acceptable, Job Well Done.
3b.) The adventurous ones will keep cranking up the boost until they find the transient fuse...which is hopefully the same as the long-duration fuse.
4.) Stronger components will go in. Perhaps at this point, lower static CR pistons, assuming the CFD was appropriately transferred from the stock pistons so to not ruin the DI fueling swirl.
5.) With stronger powertrain, boost will be cranked up until further breakage or desired power level is achieved. Job Well Done.

[PAImportTuner]

1. 12:5.1 is nothing for a DI car. Add a turbo, the HPFP can handle it. The rods and pistons are the concern, especially on this type of rod design.

2. COBB will not have an AccessPort for the N/A ECU. Nope not going to happen, for the STI BRZ car yes, since this setup should be the same as the new gen WRX/STI it would be a simple as adding ECU serial. I can't even get them to make an AP for the R53 MINI which is supercharged, that's with 15+ owners at least wanting it too.

3. Properly sized DI Turbo > N/A.

[Ryephile]

Originally Posted by PAImportTuner

1. 12:5.1 is nothing for a DI car. Add a turbo, the HPFP can handle it. The rods and pistons are the concern, especially on this type of rod design.

2. COBB will not have an AccessPort for the N/A ECU. Nope not going to happen, for the STI BRZ car yes, since this setup should be the same as the new gen WRX/STI it would be a simple as adding ECU serial. I can't even get them to make an AP for the R53 MINI which is supercharged, that's with 15+ owners at least wanting it too.

3. Properly sized DI Turbo > N/A.

1. 12.5:1 isn't "nothing", it's 12.5:1. Your in-depth knowledge of the engine weak-points are appreciated.

2. Who cares? Cobb isn't the only player. STI BRZ.."yes", then "should"? Your hopes-n-dreams don't count for reality.

3. Your opinion is noted.

[Dragonitti]

I can care less about a COBB AP. I don't want one button control. Give me something that's integrated.

[Matador]

Originally Posted by WingsofWar

Originally Posted by WingsofWar

You current turbo owners are a bit spoiled because of boost. high performance N/As are pretty fucking hardcore, and not many have experienced when and how to use that kind of power when boost junkies hype up turbos like its the best and only thing you need in motorsports.

Agreed. And I'm saying this as my brothers Turbo'd car (10:1 CR no less) Sits not 10 feet from where I am.

Originally Posted by Jordo!

There is no reason to automatically assume that the compression will be too high for boosting -- DI systems are VERY good at quenching knock.

Originally Posted by Allch Chcar

Why did you make a new thread? We already have one for this,Compression ratio 12.5:1. Bye-bye Super charger & Turbo build?.


I still say 12.5:1 is purrfect! >:3

A million times this. :Ban:

Originally Posted by Ryephile

So what you're saying is, you have no idea, and you haven't done any math, let alone simple experiential postulating whatsoever to back it up.

Here's how it's going to happen in reality:
1.) People buy the car
2.) Power Whores will fabricate turbo setups
3.) The smart ones will calculate that with 93 octane and the stock 12.5:1 static CR, they can minimize risk with 6 PSIg, or push the envelope with 9 PSIg. Of course, if the stock powertrain can't physically handle the added power, something will break. If it stays together, and the power level is acceptable, Job Well Done.
3b.) The adventurous ones will keep cranking up the boost until they find the transient fuse...which is hopefully the same as the long-duration fuse.
4.) Stronger components will go in. Perhaps at this point, lower static CR pistons, assuming the CFD was appropriately transferred from the stock pistons so to not ruin the DI fueling swirl.
5.) With stronger powertrain, boost will be cranked up until further breakage or desired power level is achieved. Job Well Done.

Originally Posted by Ryephile

1. 12.5:1 isn't "nothing", it's 12.5:1. Your in-depth knowledge of the engine weak-points are appreciated.

2. Who cares? Cobb isn't the only player. STI BRZ.."yes", then "should"? Your hopes-n-dreams don't count for reality.

3. Your opinion is noted.