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Old 12-08-2008, 05:45 PM   #1
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Exclamation How much pressure can i take with my stock engine?!

Hello Guys,
my name is Basti and i am from Germany. I own a 1993 1.6l Miata (import from Canada) which i charged with a T3 turbo.
Can someone tell me, how much pressure i can drive with my stock engine?
Here are my components:
- T3 turbocharger
- Emanage Ultimate + Zeitronix ZT-2
- 360ccm injectors

I think this are the most important facts...
At the moment my car sleeps at a garage, and i am going to change some things...
last season i test with 13psi, but i was very scared that my engine got blown away ^^
So what do you think? Can i drive this 13psi with my stock engine without any dangers?
Sorry for my bad english
Greets from cold Bavaria *g*
Basti
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Old 12-08-2008, 06:14 PM   #2
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please be more vague.
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Old 12-08-2008, 06:25 PM   #3
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seeing as how I'm Bavarian myself I'll lend a hand. It's horsepower, not psi that is the limiting factor. 250-300 and you're getting risky. Under 250hp and you can go a long time. Other parts will break before the engine (if you have a good tune). With the size of those injectors you won't be making anywhere close to the horsepower you'd have to worry about. But if you're running 13psi already I'd imagine your injectors where maxed out many psi earlier. Meaning GET BIGGER INJECTORS.
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Old 12-08-2008, 06:26 PM   #4
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Quote:
Originally Posted by Mazdaspeed_Miata View Post
Hello Guys,
my name is Basti and i am from Germany. I own a 1993 1.6l Miata (import from Canada) which i charged with a T3 turbo.
Can someone tell me, how much pressure i can drive with my stock engine?
Here are my components:
- T3 turbocharger
- Emanage Ultimate + Zeitronix ZT-2
- 360ccm injectors

I think this are the most important facts...
At the moment my car sleeps at a garage, and i am going to change some things...
last season i test with 13psi, but i was very scared that my engine got blown away ^^
So what do you think? Can i drive this 13psi with my stock engine without any dangers?
Sorry for my bad english
Greets from cold Bavaria *g*
Basti
Welcome!
Theres a search function at the top of the page that works wonders, but I'm going to guess the language barrier might interfere.

As far as "without any dangers" I dont think it is possible, because theres always a chance of something going wrong.

What octane do you use?

I would also recomend an intercooler, or water injection (or methanol), or both with anything over 10psi
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Old 12-08-2008, 06:42 PM   #5
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Quote:
Originally Posted by johndoe View Post
seeing as how I'm Bavarian myself I'll lend a hand. It's horsepower, not psi that is the limiting factor. 250-300 and you're getting risky. Under 250hp and you can go a long time. Other parts will break before the engine (if you have a good tune). With the size of those injectors you won't be making anywhere close to the horsepower you'd have to worry about. But if you're running 13psi already I'd imagine your injectors where maxed out many psi earlier. Meaning GET BIGGER INJECTORS.
Sounds good. you also need a intercooler. but for 13psi I'm sure you need larger injectors, or atleast a fmu included with what you have.

Do you have a wideband O2 sensor setup? You can watch your air fuel ratio with that to keep you from getting too lean and blowing things up.


Good Luck!
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Old 12-08-2008, 06:44 PM   #6
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Old 12-08-2008, 06:56 PM   #7
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He's using Zeitronix ZT-2 for a wideband. Does EMB have datalogging capabilities? If so did you notice your AFRs at 13psi? I'm imagining not good.
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Old 12-08-2008, 07:19 PM   #8
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qft

Quote:
Originally Posted by johndoe View Post
It's torque, not psi that breaks things
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Old 12-08-2008, 10:07 PM   #9
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Quote:
Originally Posted by johndoe View Post
He's using Zeitronix ZT-2 for a wideband. Does EMB have datalogging capabilities? If so did you notice your AFRs at 13psi? I'm imagining not good.
EMB has datalogging. You can wire up the WBo2 to the MAP sensor input. I have a friend that does this on his EMB with an LC1.

I know there are instructions out there on the interwebs, but basically you take two wires from the WBo2 and set the scale appropriately in the e-manage software. I'm retarded with wiring anything at this point, so I'm sure someone here can clarify.
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Old 12-09-2008, 12:12 AM   #10
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Originally Posted by Braineack View Post
qft
I misspoke I apologize.
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Old 12-09-2008, 01:55 AM   #11
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I got 12.0AFR at 13psi, I think that should be ok.
I run 98octan fuel minimum, sometimes also 100octane.
I installed also an intercooler, from an Volkswagen Sharan. (exactly this one: http://www.g-performance.de/images/LLK_2.jpg)
I am a bit busy at the moment, sorry.
In ~10hours i will add my Emanage map, ok?
Thanks so far!
Greets,
Basti
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Old 12-09-2008, 06:10 AM   #12
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Hi Basti

Please note that US measures differ from European measures. So the 98 octane gas you use is roughly the same with the US 93 octane gas.

Octane rating - Wikipedia, the free encyclopedia

European dynos often measure estimated engine horsepowers and the US dynos measure horsepowers are at the rear wheels. There is a big difference between these two methods. According to the dyno testing my 1994 has about 18-19% driveline loss. So the limit 250 hp at wheels is somewhere between 300 and 310 horsepowers at the flywheel.

Horsepower - Wikipedia, the free encyclopedia

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Old 12-09-2008, 11:12 AM   #13
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Hey Marko,
thanks for the information about the differences with european and us octane!
The informations about horsepower I still know, but i was not asking "how much horsepowers can i get"
I don't care horsepowers at the moment, i just want to know how much pressure i can drive...
Here you can have a look at my map...I think my duty cycle is ok at 13psi.
SpeedShare - Download beschleunigen.EM2
Some pcis of my car
http://img87.imageshack.us/img87/5821/dsc05386gt9.jpg
http://img370.imageshack.us/img370/9965/dsc05704xg6.jpg
http://img263.imageshack.us/img263/2240/dsc05702vl9.jpg
Maybe some more informations about my parts:
- fidanza flywheel
- act stage 1
- oil intercooler
- 2,4" exaust system

You write my injectors are normally too small for my pressure. how much pressure do you think is the maximum with my 360ccm injectors?
Which parts normally broke down 1st? (not engine)

So far
Greets,
Basti
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Old 12-09-2008, 12:25 PM   #14
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Quote:
Originally Posted by Mazdaspeed_Miata View Post
The informations about horsepower I still know, but i was not asking "how much horsepowers can i get"
I don't care horsepowers at the moment, i just want to know how much pressure i can drive...
So far
Greets,
Basti



It is according to your setup on your t3, on how much boost you can push. That is why everyone is telling you, horsepower ratings for your motor. What are your A/R, and trim? Brainack would know more about that than most of us.
Like my turbo's can run safely at 12psi. A little more dangerous at 13 to 14, 15 is pushing it.

That is basically cause My motor should be around 220-250hp there.

If you have one of those t3's like stephenie, pushin 200hp at 6psi, well.......

But if you have 12.0 afr with those injectors at 13psi, I would not go further, until you have more injectors. After that I wouldn't go more than 14psi. Unless you don't care how long the motor last.

On the 2560 corkey said you will never shorten the life of a miata motor at 12psi. After that. Things don't last as long. 15psi it will last a while, but it will pull a tow on the motor.
Keep in mind, you have a different turbo.

This helped me. Psi is the measurement of backpressure from the turbo exhaust wheel. The bigger the wheel, the more air that flows to reach the same psi as a smaller turbo. Therefore more hp is achieved for the on the larger turbo at 6psi, verses 6psi on a smaller turbo. Just cause more air is available.


That is why people say psi is nothing. It is all about how much air is flowing through the motor to achieve the psi against the exhaust wheel. It is different for every change in a turbo configuration.
That is why a gt2871 has more horsepower at 6psi, than a 2554 at 8psi.

Have a good one!
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Old 12-09-2008, 12:44 PM   #15
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Quote:
Originally Posted by Mazdaspeed_Miata View Post
You write my injectors are normally too small for my pressure. how much pressure do you think is the maximum with my 360ccm injectors?
Which parts normally broke down 1st? (not engine)

So far
Greets,
Basti
It all goes to what afr you can achieve. If you raise the boost, and afr's start to head 12.5, you are risking knock. and BOOOOMB.

Anyway, if you wanted, could you make it richer? If not, and your boost spikes, and You won't be able to supply enough fuel. Or you risk locking a injector and BOOOOMB!

Read brainacks "Diy all in one sticky" under the DIY setion, it is at the top. That will help you.

And also search for the scale of what afr vs what boost you need.

Hey if you find it. Please post it. I need it myself

tranny is solid for 250hp, The rearend can give out in the 1.6L. I haven't had a problem yet, but I also let out inbetween shifts. And I don't dump it hard. But when the clutch is out, she is FLAT ON THE FLOOR!!! Drive it like you stole it, from you older brother and have to give it back! LOL
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Old 12-09-2008, 09:35 PM   #16
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Quote:
Originally Posted by gompers View Post
Welcome!
Theres a search function at the top of the page that works wonders, but I'm going to guess the language barrier might interfere.

As far as "without any dangers" I dont think it is possible, because theres always a chance of something going wrong.

What octane do you use?

I would also recomend an intercooler, or water injection (or methanol), or both with anything over 10psi
Hi Basti; let me give you a short answer: please get an intercooler as soon as possible. If you do so, you'll find that you will be able to run around at 12 psi of boost if you have a good tune. The last issue to be aware of is: fuel octane; try to always buy the highest rated octane gasoline. That will provide extra security.

BTW, many members are used to running around at 12 psi for many, many miles without issues but please: buy and install an intercooler!
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Old 12-11-2008, 12:48 PM   #17
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Hey man,
thanks for your answer!
I got an intercooler since my installation of my turbo!
See my pictures which i have posted.
Greets,
Basti
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