nubira ecu question

mocpac · Post by **mocpac** » Fri Dec 23, 2005 12:02 am

Simply, 4 years ago my first time in the ? mile I made 17.3 seconds (nubi mk1 99), A chick from the old PR club made 17.0 with a aut nubi (mk2 2000), "Puerto Rico NUbira" made 17.4 with a nubi aut (mk1 1998), la baby racing made 18.6 with his nubi (mk2 wagoon 2001), with 4 subs 12" and 17" rims the 4 had the cars stock.

"Beto" make 18.6 and 17.6 with, intake and strip exaust pipe with a 3" enter and 4" exit pipe. I forgot he also have the TORNADO

. He have a nubi mk2 2003 the last nubi before the nubira 3 (forenza, optra). What his problem can be?

my teory:

*have an adhelpi eci instead of a Acdelco ecu (dont know)
*the car is loosing compresion (because is the strip exhaus)
*the tornado

cant say the driver because is an aut car...

any help?

Audacity Racing · Post by **Audacity Racing** » Fri Dec 23, 2005 12:05 am

perhaps his exhaust is TOO big and he has very little torque compared to teh rest of you. that would make perfect sense.

mocpac · Post by **mocpac** » Fri Dec 23, 2005 12:10 am

we tought that, if that is the reason what he can do about it?

Audacity Racing · Post by **Audacity Racing** » Fri Dec 23, 2005 12:11 am

see if he can get a silencer made for his muffler, they increase backpressure dramatically

Audacity Racing · Post by **Audacity Racing** » Fri Dec 23, 2005 12:13 am

mocpac · Post by **mocpac** » Fri Dec 23, 2005 12:16 am

he have one already. On of the time I thing the higgest was without the silencer.

But even with that the time dont make sence... My nubi and the other 3 were stock he was supposed to be 17.0 or 16. hight.

Audacity Racing · Post by **Audacity Racing** » Fri Dec 23, 2005 12:19 am

bad tires?

mocpac · Post by **mocpac** » Fri Dec 23, 2005 12:24 am

dont think so... we all race with regurar street tires...

I want to know if there are any diference betweens wars.... Well yes... is one nubi 98 have 5 more hp than my 99, and mine have more that 2000-02 the 2003 just have 117hp

well we foun that... but dont know the reason. I think is the ecu.

Dont know if an apex can help here.

mocpac · Post by **mocpac** » Fri Dec 23, 2005 11:13 am

I get a second opinion and you are totally right... AUT car with out a engin mod cant have a complete pipe exuaust or bigguer than 2" 2?".

:twisted:

Post by **PrecisionBoost** » Fri Dec 23, 2005 10:22 pm

Three inch exhaust????

I went with 2.5" mandrel bend and I'm planning on a turbo.

I say he should move back to 2"

I honestly belive that a 3" exhaust will create more restriction than a 2"

99% of the people out there think "the bigger the better"

The larger pipe is probably causing major reversion and there would be very low port velocity.

I'm going to have to explain this exhaust theory some time..... I did it once allready but I should do a really solid technical article.

Also..... get rid of the tornado..... it's useless..... and causes a restriction on the intake.

The intake and cylinder head are designed using a standard flow pattern..... if you add a tornado it makes the airflow chaotic.... the result is that there may be added restriction and poor atomization of the air/fuel mixture.

If the tornado made power..... the auto manufacturers would be useing it.

Those who do have intake systems that provide the swirling action design the cylinder head to work with this flow pattern.

Turbulant air causes more restriction..... the ideal situation is to have smooth flowing air all the way up to the injector....or even inside the cylinder head...... and then at the last moment.... turbulant air flow to mix up the air/fuel and create an evenly distributed burn pattern.

It's all really technical.... I wish I could draw it out in a .GIF and show people visually what happens instead of trying to explain it via text.

Audacity Racing · Post by **Audacity Racing** » Fri Dec 23, 2005 10:28 pm

haha... put the tornado in the exhaust... that might show imrovement in his car!

mocpac · Post by **mocpac** » Fri Dec 23, 2005 10:59 pm