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Discussion Starter · #1 ·
If you put a bigger then stock turbo and ran it at stock psi would it damage the engine?

The thought kinda washed through my head and I cant for the life of me thing of a reason why it would harm the engine so I must be missing something. Like could you put a larger turbo in limit the boost to like 15psi and drive it without a tune for a short period without trouble? Im not at all trying this or attempting it I just a curiousity thing.
 

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......... you wouldnt be asking unless you were thinking of doing it, and yes, it could still damage your motor, because your stock injectors couldn't handle adding extra fuel. a larger turbo will flow more air volume (CFM) at a given pressure than a smaller turbo.
 

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FUNCTION OVER FORM
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......... you wouldnt be asking unless you were thinking of doing it, and yes, it could still damage your motor, because your stock injectors couldn't handle adding extra fuel. a larger turbo will flow more air volume (CFM) at a given pressure than a smaller turbo.
+1.....
 

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Doesnt Will Bill have access to a flow testing bench for these injectors?

Basically you need to figure out what the system flows at max duty cycle.

Let's assume the stock injectors will indeed flow just enough at 95% duty cycle. But in order to flow that much fuel the injector pulse length increases to the point of almost remaining open, and runs into the problem of not being able to spray enough fuel during the time allowable for the intake cycle.

Basically, you're injector could be spraying constantly and you could still lean out the car and grenade.

You could run a bigger turbo, with similar flow rates no problem, even slightly higher hp numbers. But there is a limit, obviously.
 

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If we had a MAF no problems, depending on how much bigger you are going...
We have have a TD04, and I was running an equivalent upgrade as a TD05, and it ran fine. It wasn't at it's full potential, but it ran fine on a MAF equipped car. MAF saw more CFM's so adjusted fueling accordingly maintaining boost.

I believe we have a MAP = your screwed
 

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Stay out of double digit boost and you'll be fine. I wouldn't go WOT without a tune unless you're just talking about an upgraded stocker. The ecu will handle it just fine during closed loop but your a/f will be out of whack open loop. I drove from Austin to Dallas and back with the BR turbo untuned. Tried to get a custom tune but they ran out of time.
 

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Discussion Starter · #7 ·
Yea I knew I was missing something. It isnt just about Pressure but flow. I was taking CFM into account.

I really wasnt planning on doing it. I was 99.9% sure that the answer was you cant do it. But I was just trying to figure out why exactly.

RubyH's comments kinda interesting tho. So pretty much our cars assume the amount of air flow based on pressure (which is differnt depending on turbo). So the tune would be needed to assert to the ecu what new flow values to assume per pressure. Im still waiting for a good tuning solution before I get a turbo upgrade.
 

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Discussion Starter · #8 ·
Stay out of double digit boost and you'll be fine. I wouldn't go WOT without a tune unless you're just talking about an upgraded stocker. The ecu will handle it just fine during closed loop but your a/f will be out of whack open loop. I drove from Austin to Dallas and back with the BR turbo untuned. Tried to get a custom tune but they ran out of time.
This is kinda why the thought crossed my mind. Moving the car before tune but after install. My other thought was to just make a boost leak on purpose by like through a filter between the intercooler and the intake manifold so that it would run 0 boost so that it can be moved after install.
 

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RudyH's comments kinda interesting tho. So pretty much our cars assume the amount of air flow based on pressure (which is differnt depending on turbo). So the tune would be needed to assert to the ecu what new flow values to assume per pressure. Im still waiting for a good tuning solution before I get a turbo upgrade.
If I understand it correctly, MAF will be very accurate as to air flow as it directly measures it.

MAP will calculate based on other variables what the MAP is going to be. That said, I think MAP should be accurate regardless of altitude, as it measures pressure of the air passing it prior to hitting the turbo. Mind you, not sure how that affects the wastegate - I thought ours wasn't electronic, just adjustable by us (hence why canned tunes work beyond what Dynojet owners may try to convince you have otherwise).

I'm not an expert though to make that fact.
 

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3.5L TT but wrong body
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This is kinda why the thought crossed my mind. Moving the car before tune but after install. My other thought was to just make a boost leak on purpose by like through a filter between the intercooler and the intake manifold so that it would run 0 boost so that it can be moved after install.
That, or just keep the wastegate open with some wire... Wastegate fully open on any turbo should keep it from making more than 1-2psi, if it can make any boost at all. That way all you have to do is undo the wire keeping it open, attach the actuator, and you're good to go.
 

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Discussion Starter · #11 ·
That, or just keep the wastegate open with some wire... Wastegate fully open on any turbo should keep it from making more than 1-2psi, if it can make any boost at all. That way all you have to do is undo the wire keeping it open, attach the actuator, and you're good to go.
I'll keep that in mind. That seems like the quickest easy solution for a short distance untuned journey.
 

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You could probably get by without the wire too... You may make a little boost at first but the exhaust pressure should force the wastegate open without an actuator keeping it shut. A little wire tieing it back would just be some insurance.
 

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Doesnt Will Bill have access to a flow testing bench for these injectors?

Basically you need to figure out what the system flows at max duty cycle.

Let's assume the stock injectors will indeed flow just enough at 95% duty cycle. But in order to flow that much fuel the injector pulse length increases to the point of almost remaining open, and runs into the problem of not being able to spray enough fuel during the time allowable for the intake cycle.

Basically, you're injector could be spraying constantly and you could still lean out the car and grenade.

You could run a bigger turbo, with similar flow rates no problem, even slightly higher hp numbers. But there is a limit, obviously.
Yes i have been flow testing see below

Ok so as some of you know Euroexport recently bought a fuel injector test
bench where we can do all sorts of testing on injectors including coil test,
leak tests, flow test, backflowing, cleaning, rebuilding etc..

So i had a simple goal put to bed how much the stock injectors flow and also
to flow the EVO X injectors that everyone swears by...

Sorry for the less than perfect video, it's done with my Sprint EVO which
doesn't auto focus when doing video.

RESULTS
Hyundai Genesis Coupe 2.0T Fuel Injector info(our fuel pressure is bold/red)


Hyundai Genesis Coupe Video
YouTube - Hyundai Genesis Coupe 2.0T stock fuel injector bench test

360cc/min @43.5psi - 3bar
420cc/min @51.7psi - 3.5bar
426cc/min @55psi - just over 3.5bar
440cc/min @58psi - 4bar
 
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