I want to raise my boost to a modest 10-12 psi without spending $500.
On all my previous turbo cars I have bean able to simply add a manual boost controller(MBC) to increase boost.
But on my 1995 850t there is no boost pressure sensor.It's my understanding that the ecm calculates boost from the MAF,TPS and rpm signals.
Can I simply unplug the electronic boost contoller(leave it electrically connected)and replace it with a MBC ?
Will that set codes?
I'm sure this info is here somewhere but could not find it

thanks in advance

 

Who said you can't add a MBC to your 850? A lot of people have MBCs on their 850's. If you get a mbc, get a boost gauge as well so you know what your boosting.

 

How and where do you splice it in?
Do you put it in line wth the hose going to the wastegate as usual?
Then run the 3rd hose from the MBC back to the airbox?
I will run boost and air/fuel gauges

 

MBC Install

Keep in mind that fuel cut is 15 PSI. Don't set it for more than 13.5 PSI to allow for boost spikes. Above 15 PSI on the 15G is out of efficiency anyways.

 

+1 I am running a MBC on both of my cars set to 14 PSI. On really cold days might hit fuel cutoff once when car is cold.

 

thanks for the link
I thought that simply bypassing the factory EBC would cause trouble codes but you say it won't.
Too easy

thank you

 

No problem.

 

So... how about my LPT engine? what's a safe amount to raise boost without severe risk to the engine, and what's the efficiency level of the 13G? I've been debating playing around with it for a while... just a little, nothing radical. If I wanted radical I'd find a T-5 and play with that

 

Um, if you want, probably around 8 PSI I'm guessing. I'm not a hundred percent sure, but I remember reading somewhere that the 13G is efficient up to about 10 PSI. I don't know what fuel cut is or anything on an LPT.

 

Also interested in this topic

 

give oliver a shout at speedtuning.com, software upgrades around $350

 

LPT good for 8-10 PSI. I am running 15PSI on a 13g (1999 S70 AWD) currently and yes it does pull but it is a little out of its efficiency range. I did have a 12PSI tune and it pulled harder with that then the 15PSI tune.

Also to the OP you don't have to spend $500 for a tune. Inmotion, SpeedTuning USA and Upsolute all have tunes for under $500. Like $425, $325 and $200ish. Now yes these tunes aren't the best on the market and they aren't the most researched and developed, but they do work.

I realize you have used MBC's before and a lot of people use them on their Volvo's without problem. However an ECU upgrade is the better choice for raising boost pressures. Safer and easier to do.

 

Still a lot more than a MBC

Right, they have tunes for less than 500, but I have heard stories about using those tunes. Mostly with the tunes not allowing the car to start, running extremely rich or lean, and poor customer service when it came to getting the tune remapped or delivered. Personally, when I'm going to buy a tune, I'll spend the 700 dollars on an IPD tune that I know is well researched and awesome customer service.

 

I am running an IPD ECU and a MBC. I have upped it to 15psi and no longer have the fuel cut off thanks to the IPD mapping. I am ready for a larger turbo, I can feel the limit. I put my MBC in place of the OEM boost controller but left it plugged in. Works great. Such a fun car.

 

im planning to put in a mbc on my 98' s70 glt, should i not bother to put in a hd tcv, because it seems the mbc somewhat cuts off alot of the function of that.

 

I am running a IPD ECU and also use a MBC set to 15. I dont have a fuel cut off anymore(which is wonderful). I put the MBC in place of the factory controller.