Well, we all know you're not holding flat boost to redline like you claim, especially not 23-24psi, because the turbo simply is not capable of it. Maybe with an EBC you can FORCE it to do that, but it's not capable of flowing enough air at that psi and 7000rpm, so it would just be blowing hot air, thus causing detonation and knock.

I don't know why you gained 7mph in the traps, but I certainly don't believe you did it by just raising boost on the same octane unless your original boost was down around 11-13psi. We can gain power with extra boost if we utilize higher octane, but just randomly raising boost will usually cause knock depending on the tune and/or associated mods.

This isn't rocket science, and it's not like I made some crazy bogus claim. Whatever it is you think you're doing with your MBC on a stock Evo is fine, but it's not the norm for Evos in general.

 

I understand what you are saying, but you act like just because YOU haven't seen it that it isn't possible. I'm not going to argue with you...you make valid arguments. I only know what I did to my car. I know I didn't pick up 7 mph because my dick fell off and the car was that much lighter. It HAD to have picked up significant power.

Stock I would see 20 psi and fall to 15-16 by 5500 or sooner. I made a ball and spring MBC and it would hold 22 until about 6200 then start to fall to 16 psi in 1st-3rd gear...but will hold 23psi in 4th and 5th all the way to the limiter. So I stuck a nastier spring in there and had the MBC turned way back when I was setting it...and it held 25 to redline on the short 2nd gear pull that I made. I backed it out all the way and it holds 24 to redline in every gear with no drop whatsoever.

This is all by my gauge so take it for what it is. I'll post my track results when I get back and if I observe it holding 24psi to redline I will try to take some vid of the gauge.

 

I just looped the solenoid back to itself. Not sure if that is the best way. I still have pressure drop in 1st - 3rd gear if I run a soft spring in the MBC, but if I run the heavy spring it holds the pressure perfect. I drive around town daily with the soft spring.

 

Yes, relying on the gauge is foolish when making such claims. Log it with a MAP sensor, and you'll see the boost fall linearly from peak boost to redline. The turbo can't even HOLD 24psi at redline, so not sure why you'd think you're doing it so effectively with only a homemade MBC while still dealing with all the backpressure of the stock exhaust.

It's not the MBC that causes taper - it's the turbo itself not being able to flow enough air at a given psi and a given rpm. It's physics.

 

Why does this thread keep comming back to haunt me.....WHY????

 

hey warrtalon i dont knew if all is right i knew on the dyno i was holding 23psi to red line, but now with stock exusht on and with the heat in the air it seems to drop very hard. some times like 17psi at redline, which also i think the stock exusht and the stock fmic has a facktor. just a question for you, not fighting.

 

i cranked it to 35psi, i flooded the turbo engine and messed everything

 

humm alright

 

Agreed...but you CAN force the turbo to hold more than 24psi.

I missed out on the track due to my silly snorkel...so I'll post how my raising the boost improved my 1/4 times by over a full second later.

 

That is normal with the stock exhaust.

 

its the worst feeling lol, and also runing tune and all on a stock exusht car feels like it wants to go but it holds it back

 

warrtalon, i read the first page and understand, but you need to chillout. Guy just got his evo meaning he's new to the forums. Didn't need to bust his *****.

 

I'm an EE and I sure as hell wouldn't take a $100 sensor as gospel. AFAIK they aren't even professionally calibrated. Do they come with a calibration certificate? If so when was the last time it was checked for calibration? Does the vehicle in question have a grounding issue? Have you ever seen the voltage descrepency between the O2 voltage at the sensor and that logged by the ecu? Its laughable. See what I'm getting at?

I've actually had more than great sucess and acurracy with quality mechanical boost guages. I don't consider an Autometer a quality unit. They are popular and sell well, but they do have some calibration issues it seems.

Anyways I do believe the turbo is more than capable of keeping those boost levels to redline on a mostly stock motor. I don't understand why this is so unbelieveable to you. The stock motor is a decent restriction. With modifications such as cams, exhaust work, intake manifold work, better IC's to densen the charge, and better charge pipes it will more more air easier and be much harder for the stock turbo to keep up.

Furthermore, real life experience. My friends car can spike to 25 and then settle to 23psi to redline. Stock '04 with mbc and a buschur catback.

More real life, I made 300whp on my small 16g on a 1g dsm motor. The PRECISION pressure sensor on the dyno stated that I held 25psi to redline. That turbo can't even be called the little brother of the Evo's 16g its so pathetic. I would run that turbo to 28psi, tapering to 25psi to redline for mid 12 second passes at 111mph.