[RESOLVED] Slow boost response after shift

[blazinglaser_90]

Hey guys I've done the research and so far i can't find an answer to what i am looking for. I am using a megasquirt stand alone EMS system. So i guess this question is more for someone whose done an AEM, or similar EMS. The car has rock solid AFR's during a pull in any gear and what happens after i shift is the problem. First the car takes FOREVER to come back into boost, between 500 and 900 rpms to reach the 20 psi the car is running currently. The air fuels after the shift seem fine and i am only running 15 degrees of timing at boost right now getting my air fuels dialed in. Does this seem like an issue with possibly accel enrichment settings after the shift or maybe is it the lack of timing the car is running causing it to take forever to boost back up. The turbo btw is PTE 6152 with a mitsu bolt on housing

 

[bpestilence]

I am fairly experienced with MS, and I don't think it is your problem. I would look at a more mechanical problem... Compressor surge. A loss of boost between shifts means you are surging the compressor and losing boost because of it. A BOV will prevent this... If it is large enough, sensitive enough and set correctly. You are moving a lot of air at 20 psi, and your BOV may not be up to the task. Your profile doesn't say what BOV you are running, so I dunno.

 

[slowgsr]

during a 4th gear pull when does it reach full pressure? perhaps your just not reving the engine out enough to put you back to where you would have full pressure in the next gear. Try using a wot shifting feature.

 

[blazinglaser_90]

i am running i Tial bov and during a 4th gear pull it will get full boost around 3800 - 4200. Its just weird how it runs amazing then falls on its face i will upload a log screen you can see the bottom of the log is boost and it takes FOREVER to get back on its face haha

 

[lazyazzdaddy]

this might seem like a dumb question but are you recirculating your bov ?

 

[blazinglaser_90]

no i am not, its a standalone EMS running a 4 bar map sensor and air intake temp sensor so no need to recirculate =)

i am just thinking its gotta be something with the accel enrichment just b/c its fine till i shift, let go of the throttle and then make a dramatic change back into the throttle so i am not sure runs great for one gear ough !!! =)

 

[toofast82]

It could be a fine tuning issue. Try shifting faster and keeping your foot on the gas some as well if you can't implement a "no lift to shift" This may help you out some. Could be compressor surge as said

 

[94Jettameowpsst]

could be a tuning issue but if you dont shift like you have a dogbox or have nlts this turbo is pretty laggy, im running it right now. If i were to do a 2/3 shift and take a second between gears it'll fall on its face or if i dont rev it out enough it'll do the same. However, it does sound like a tuning issue as well.

 

[blazinglaser_90]

raised the accel enrichment up ALOT between shifts and its perfect now