Setting my MBC.. how much HP over stock should 15 psi make?

(full exhaust + stage 3 ecu coming soon)

but for now, running 15 psi how much power might my 2.0t make? 185 --> ???

You will feel a differnece and a little more power but it's hard to put it to numbers because every car is different but you will def feel a differnece in power...

15 psi if you can hold it which is harder to do than most realize and a open air filter and 3" intake piping will produce prob. 200-210 bhp. It really will just liven up your car low in gears (mostly 3rd). IC would up it a bit and give you the ability to hold boost a little better. good luck!

JT

I found that the MBC gave a lot more action in 1st and 2nd gears, but not too much otherwise. Lots of tire spinnage in 1st :p

The question, as posed, has a lot of variables. Boost is a measure of restriction of airflow. Increasing airflow through the restriction point will lower boost yet make more power.

Additionally, you have to factor in the question of where the boost is made in the rev band. 15PSI at 3000 RPMs and 15PSI at 6000 RPMs are two VERY different things. With an MBC and stock, or mildly altered, base boost you will see 15 PSI low in the revs and by the time you get to 5.5K or 6K you will be down to 11 or 12 max. The truth is that 15PSI at 5500-6000 on a SAAB 2.0 with good supporting HW will make 250+HP. The problem is that the MBC won't let you get there because in order to hold 15PSI to 6K you'd have to peak well over fuel cut. There are ways around this but the best way is a tune.

Sad; but true.

The stock T25 will flow enough air to hold 16PSI to 6K but makes peak power around 5500 with about 18-19 PSI.

If you can hold 11-12 PSI to 6K with a good exhaust and I/C you can make 230+


D-

Thank you everyone, sounds good to me I just need a little more pep in my step!

shorten wastegate arm a tad and you could probably get up to 220 maybe

Ive heard of this shortening wastegate rod to increast boost pressure but was always iffy about doing it.... Anyone have any input on this?shorten wastegate arm a tad and you could probably get up to 220 maybe

yeah it works.
on the stock wga, I don't know how well but on an aftermarket one like Forge,
it does the trick.
that's how I'm getting around 1.1 BAR on my car.

The question, as posed, has a lot of variables. Boost is a measure of restriction of airflow. Increasing airflow through the restriction point will lower boost yet make more power.

Additionally, you have to factor in the question of where the boost is made in the rev band. 15PSI at 3000 RPMs and 15PSI at 6000 RPMs are two VERY different things. With an MBC and stock, or mildly altered, base boost you will see 15 PSI low in the revs and by the time you get to 5.5K or 6K you will be down to 11 or 12 max. The truth is that 15PSI at 5500-6000 on a SAAB 2.0 with good supporting HW will make 250+HP. The problem is that the MBC won't let you get there because in order to hold 15PSI to 6K you'd have to peak well over fuel cut. There are ways around this but the best way is a tune.

Sad; but true.

The stock T25 will flow enough air to hold 16PSI to 6K but makes peak power around 5500 with about 18-19 PSI.

If you can hold 11-12 PSI to 6K with a good exhaust and I/C you can make 230+


D-


how can you eliminate the feul cut off? is it just a matter or replacing the stock ecu with a tuned up one?

how can you eliminate the feul cut off? is it just a matter or replacing the stock ecu with a tuned up one?

Fuel cut can be altered, yes, but its not something one would want to attempt while running an MBC, of course.

The question, as posed, has a lot of variables. Boost is a measure of restriction of airflow. Increasing airflow through the restriction point will lower boost yet make more power.

Additionally, you have to factor in the question of where the boost is made in the rev band. 15PSI at 3000 RPMs and 15PSI at 6000 RPMs are two VERY different things. With an MBC and stock, or mildly altered, base boost you will see 15 PSI low in the revs and by the time you get to 5.5K or 6K you will be down to 11 or 12 max. The truth is that 15PSI at 5500-6000 on a SAAB 2.0 with good supporting HW will make 250+HP. The problem is that the MBC won't let you get there because in order to hold 15PSI to 6K you'd have to peak well over fuel cut. There are ways around this but the best way is a tune.

Sad; but true.

The stock T25 will flow enough air to hold 16PSI to 6K but makes peak power around 5500 with about 18-19 PSI.

If you can hold 11-12 PSI to 6K with a good exhaust and I/C you can make 230+

X2 and very well spoken!


D-

Fuel cut can be altered, yes, but its not something one would want to attempt while running an MBC, of course.

X2 :nono;

I've been thinking of uping base boost by adj. the WG but hopefully will be getting a stg 4 tune from JZW or Nick in the next couple months. Will I still want to do that with a Tune Comtrang? Or is it not needed? Thanks

JT

The tune will do it for you...it will adjust not only fuel cut but will allow for the right amount that is needed for your setup...with a tune an mbc should be taken off

[QUOTE=Ryan33;1772387]The tune will do it for you...it will adjust not only fuel cut but will allow for the right amount that is needed for your setup...with a tune an mbc should be taken off[/QUOTE

Thanks, but was asking if you can still up base boost by adj. the WG. I know the MBC comes off with a tune unless your running a secondary boost switch with a MBC like Eric P. did.

JT

X2 :nono;

I've been thinking of uping base boost by adj. the WG but hopefully will be getting a stg 4 tune from JZW or Nick in the next couple months. Will I still want to do that with a Tune Comtrang? Or is it not needed? Thanks

JT

If you're getting it from a pro, the necessary adjustments are made. In the case of a stage 3 or so, for example (don't know what boost request is for stage 1, 2), boost request may be at 18psi so naturally everything should support that change including the fuel cut.

Fuel cut can be altered, yes, but its not something one would want to attempt while running an MBC, of course.

C'mon Comtrang. You know I can't stand down from debating this categorical statement!

I've been running an MBC equipped car for three years with a $2 diode clamping MAP voltage. You have to know what you are doing, and I don't recommend it for everyone, but it can be done safely and successfully.

Nowadays however, tunes are so cheap and easy there's not much point.

Just want the answers to be correct not dogmatic heresay.

You know I've got nothin' but love for ya' though!

D-