More Boost issues for me.... help if you can im lost.
 

Ok been having boost issues of all sorts...fuel cut and all that jazz. i decided to make the car stock as possible and start over.

Currently the car has stock everything except Megan O2, DP, And cat delete.

ok heres the wierd part with a boost controller (Hallman) i can boost 20 psi. no more then that or i hit fuel cut.

took the MBC off and replaced boost line with brand new STOCK hose with the brass pills.

Now the car spikes to 22 - 23 psi. just with the mods above. and no fuel cut.

Whats that about ?

I know 22psi is safe for daily without headstuds... but i really dont want to be up that high yet.... and i have been told that the car just CANT boost that high with the mods i have...

thanks in advance.

Ryan

Fuel cut is due to the amount of air going through the MAF. The computer thinks there is something wrong because there is to much air going into the motor so it cuts off the fuel. An aftermarket Intake/filter can lower or raise where the fuel cut happens. 20 psi may not cut at low RPMs but will up higher or in a diiferent gear/different load. 23 psi may not cut until the correct gear or RPMs. Get a flash be done with the fuel cut.

i keep coming to that same conclusion..... i guess a flash is needed before modding... ? heh. and yeah a cone fliter makes me hit fuel cut at like 17 - 18 psi

Causes:

Engine speed higher than 7500 RPM. This is overrev protection. If your engine rotates faster than the valve springs can pull the valves back up into the head, the pistons could smack into them, causing major damage. Note that simply chopping fuel will not stop the overrev condition if you misshift and the transmission rotates the engine past the revlimit. (The author did this to his friend's M3.)
Engine air flow greater than a certain amount. If the airflow into the becomes too great, the phenomenon by which the MAF counts the air entering the engine starts to break down, missing counts. The factory ECU sets a very conservative limit here. It doesn't need to be as conservative as it is to prevent missing counts. After we removed this limit, we were only able to hit the MAF counting breakdown problem on a first generation DSM with a 20G set to 19 psi on a 3" exhaust.
Engine under high vacuum for more than a couple seconds. This is not a matter of engine safety, but of smog control. Some of the worst smog can occur during engine deceleration. If you are coasting down a steep hill using the engine to help slow you, the ECU will turn off all fuel to the engine to both aid in engine braking and smog production.

You're spiking higher than stock due to the O2/DP/test pipe. This is causing your BCS to have trouble keeping the boost from going high, but it's still tapering like stock.

With the MBC, you don't spike as high, because you're regulating it to 20psi, BUT it doesn't taper like stock. This is the key, because fuel cut is caused by airflow volume as Spaceball mentioned, and we suck in MUCH MORE AIR at higher rpms in higher gears than we do at lower rpm even with the boost spike. You can see this phenomenon clear as day with an SAFC that shows MAF HZ, especially if you set it to peak hold and do 3rd gear pulls to different RPMs. I may see 22psi at 3800rpm, but the MAF HZ numbers are way lower than 16psi at 7000rpm. This is why I think you're hitting fuel cut with the MBC, because it's maintaining higher boost at higher rpms along with the additional airflow from the exhaust.

Yes, get a tune. I've been telling you this for how many months now?

lol but im a broke little school boy =/ thanks for the help again tho.

$199 for the mail-in.

Stop messing around and just get a tune.

199 for the mail with who ? BR ?

dynoflash is the 199 i believe

jestr is 200 also

Dynoflash, of course. All of Buschur's flashes are done by Dynoflash.

Don't get a flash a mail-in flash. If you want to get a flash then get a custom flash by a local tuner. Personally, I do not like flashes. Keep the protection that you have in your stock ECU. It is there for a reason.

Get a used SAFC, go back to stock O2 housing and get the car tuned by a reputable local tuner in your area. In my neck of the woods people are getting great results with an SAFC and a tune. They do not even flash their cars. There are a couple of people on the socalevo forum who had a flash did not like the results and are getting their cars flashed back to stock. Then they get an SAFC and get the car tuned on the dyno by Tuning Tech. They are getting great results.

True but... a safc wont do **** for my Fuel cut or stock boost taper. plus i live in southern ohio..... what the hell is a local tuner ?

NJ, man you are just totally brainwashed by those guys out there. You keep giving the party line over and over and over without actually understanding what's going on. An SAFC won't do half of what a flash can do. Socalevo just hates flashes and gets people jaded towards them. They don't like flashes...fine...but TT cannot do anything to make an SAFC equal to a flash, and that's the bottom line. An SAFC on top of a flash for using race gas or fine-tuning? Sure, fine, but he still needs a flash. Your suggestion is very poor, imo.

Not everyone has a local tuner either, plus paying someone to tune your SAFC is asinine. The point of an SAFC is to tune yourself. It makes no sense to pay for tuning on top of paying for the device itself. Also, a flash does not remove the stock ECU's protection. Where did you get that idea? And why would you tell him to go back to the stock o2 housing? None of this makes any sense...Beefy, keep the o2.