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Discussion Starter #1
Hey guys,

This is my first post and i've tried to done as much searching around as possible but couldn't quite come up with an answer so I have a few questions.

I have an '06 STI that I was looking at adding some power to. My previous car was a superchareged '02 corvette but the wife said the 2-seater had to go :( So long story short, while the STI is quick, speed is relative and i'm used to having something faster.

Anyhow some questions.

1. How much power can the bottom end of the 2.5l handle?

2. I understand 14.5lbs of boost is what the stock STI turbo makes. How much boost does an 18g or 20g TD05 make?

3. With tuning, can either of those turbos run off of pump gas?
 

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Master Baiter
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1) There's no XXX number that will be the difference between a blown motor and not. There are certain power levels that do mean it's a question of when (typically, 400whp is where a motor budget is advised), not if, the motor lets go, but it's not a sure thing.

2) Turbos don't determine PSI, the tune does. 20PSI from a VF39 (stock turbo) is different than 20PSI from an 18/20G.

3) You can run any turbo you want on pump gas. Obviously, higher octane = higher knock protection, but 91/93 octane can be used on either turbo with success.

Is your car stock?
 

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Discussion Starter #3
Hey ej thanks for the response.

Yes my car is stock as far as I can tell.

So what would be the advantages of going to a larger compressor size ie a 20g over a 16g if they can all be tuned to run the same boost?
 

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Nimrod said:
So what would be the advantages of going to a larger compressor size ie a 20g over a 16g if they can all be tuned to run the same boost?
18psi from a 20G > 16G. More airflow = more power.

Before considering a turbo upgrade, go StageII and see if you need more...

Sent from my Droid using Tapatalk
 

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1.Everyone asks this question. There is no magic number. It's scientificly impossble just to say "xxx" number as there are so many variables involved.

2.Depends on fuel,mods,altitude and tune. Just because the stock boost pressure is 14.5 psi doesn't mean thats all it can do either.
Stealth 316 - Turbocharger Compressor Flow Maps

3.All turbos can run off pump gas...........
 

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Discussion Starter #6
Hey guys thanks for the responses. as you can tell I am a turbo newbie

I am now beginning to understand. so basically the larger compressor turbos would be more helpful in the upper rpm range because of the increased flow over a smaller However because I won't be churning out massive rpm I really shouldn't need a different one (yet).

How much boost can you run before the fuel injectors need to be swapped out?
 

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Again... it's not boost. It's how much airflow before injectors need swapped. ANYTHING larger than a VF series, or a 16g you need injectors. You wouldn't be satisfied with either of those turbo choices as it is though.

Where are you located? Altitude has a lot to do with how much power you'll get with what turbo
 

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Just try and keep this in mind... On the stock bottom end (or middle end of a boxer?) you really shouldn't go above 380whp if you're trying to be safe. Keep in mind.. that's WHEEL horsepower. 380whp is equivalent to 482hp at the crank if you consider an ~ 20% parasitic drivetrain loss. That much power out of a 4banger is insane.

We had a conversation a while back regarding turbos, PSI, flow, etc... and I can't find it right now. Ron... you were in on that conversation. Do you remember what the thread was called?
 

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Discussion Starter #9
I'm around sea level for altitude. Yes 380whp is a crazy amount, especially considering I was running almost that much on my vette with an engine twice the size.

Sinister, will the stock injectors work fine if I were to ramp up the PSI on the exisiting turbo charger with a tuner to say 16? More PSI = more fuel needed right?
 

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yes, but there is a limit on the turbo's efficiency. My suggestion? purchase a downpipe, and either a catback, or the catback adapter (this is what I have), an EBCS (grimmspeed is what I got) and get a professional tune.

If you have any future of using multiple fuels (ie E85), an accessport would be a great idea instead of the protune and the ebcs. and then later as you find parts to add... get a protune when you install them.

Be careful... we all started with just an exhaust! (look at my progress thread in my signature)
 

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We had a conversation a while back regarding turbos, PSI, flow, etc... and I can't find it right now. Ron... you were in on that conversation. Do you remember what the thread was called?
I don't remember off hand but the link I posted explains all that pretty much.:)
 

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Discussion Starter #12
Spekaing of exhaust, can anyone tell me what the deal is with the exhaust/headers on ebay being extremely cheap? Is it just chinese crap and I should spend 5x as much money buying something else or is it worth a shot?
 

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Spekaing of exhaust, can anyone tell me what the deal is with the exhaust/headers on ebay being extremely cheap? Is it just chinese crap and I should spend 5x as much money buying something else or is it worth a shot?

Remember the old addage: "You get what you pay for".
 

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Pro Manscaper
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^^^This.

And Rambo is spot on. Sometimes people get lucky with a decent Ebay no name part, but its few and far between. Look for good name brand parts at a cheap price with used stuff. That's what I've always done.
 
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