Lag on MHD Stage2. Boost leak?

[taranfx]

I just tuned to MHD stage 2 with downpipes and chargepipe.
I feel there is almost 1second lag before I get push even in sport mode. and I feel car isnt making much power (maybe its just me).

Note: Roads were wet when I logged this. Is it traction control cutting power in DTC mode? I did several WOT and this was the max boost I got. Is there a boost leak or something else wrong? Maybe timing corrections?

https://datazap.me/u/taranfx/boost?l...=3-4-13&solo=4 (Screenshot below)



Another one: https://datazap.me/u/taranfx/boost?log=1&data=3-4-13-15 (DTC was engaging heavily at low rpms)

[studio54]

hi

maybe you could post a log with just a 3rd pull with dtc off from 2000 or 2500 rpm to 6500 rpm on a dry road

see you

[BimmerAg]

A couple of things:
First, DTC will definitely cut power if you leave it on. To understand what is actually happening you need to do a pull (safely) with traction control fully off. You also need to keep your foot to the floor the for the whole pull. It looks like you were feathering the throttle between 50-80% on your pulls.

Second, it looks like you're starting your pulls at about 1500 rpm. It's not very good to lug the engine like that. Also at that low of engine speed there will definitely be more lag, there's just not as much air flowing to spool up the turbo. Try starting your pulls at 2500-3000 rpm as instructed by MHD.

[taranfx]

Originally Posted by BimmerAg

A couple of things:
First, DTC will definitely cut power if you leave it on. To understand what is actually happening you need to do a pull (safely) with traction control fully off. You also need to keep your foot to the floor the for the whole pull. It looks like you were feathering the throttle between 50-80% on your pulls.

Second, it looks like you're starting your pulls at about 1500 rpm. It's not very good to lug the engine like that. Also at that low of engine speed there will definitely be more lag, there's just not as much air flowing to spool up the turbo. Try starting your pulls at 2500-3000 rpm as instructed by MHD.

https://datazap.me/u/taranfx/log-152...=0&data=3-4-13



3rd gear pull full throttle. I see actual boost dropping after a while. Is this boost leak? How bad is the leak?

[houtan]

that log is normal. It doesn't look like you have a boost leak to me. The stock turbo runs out of breath in the upper rpms. You could can gain a few more pounds up top by maxing out wgdc, but the ots 91 octane map is not going to do that. You need to run e30 or get a custom map, such as an etune.

[studio54]

i don't know if it's a boost leak or not, but it seems to have a bit of lag, with stock turbos i believe it's supposed to reach 13psi after 500-550 rpm in 3rd gear and then full boost at like 600-650rpm

on your log it looks like your full boost is reach after 1000+ rpm

[taranfx]

Originally Posted by studio54

i don't know if it's a boost leak or not, but it seems to have a bit of lag, with stock turbos i believe it's supposed to reach 13psi after 500-550 rpm in 3rd gear and then full boost at like 600-650rpm

on your log it looks like your full boost is reach after 1000+ rpm

Oh. What do you think causes this lag?

[studio54]

Originally Posted by taranfx

Oh. What do you think causes this lag?

i often read that when it lag or slow spooling it could be bad or worn boost solenoids especially if your car has 60k (or 100.000 km)

but it probably could be a lot of things, did you get this lag after installing the chargepipe/downpipes? did you installed the o ring from the stock chargepipe to the new chargepipe?
(your small drop of psi after peak is weird)

also if you installed downpipes you can check by watching if your both wastegate arm mecanism doesn't touch anything and are totally free to move

how are your vaccuum line too ? (at idle you should read something like -9 to -11+ psi on the mhd PSI gauge)

is this stock airbox ?

you could check all these things and see if something is wrong

edit: just seen you had N55, but you could probably check these things anyway

[taranfx]

Originally Posted by studio54

i often read that when it lag or slow spooling it could be bad or worn boost solenoids especially if your car has 60k (or 100.000 km)

but it probably could be a lot of things, did you get this lag after installing the chargepipe/downpipes? did you installed the o ring from the stock chargepipe to the new chargepipe?
(your small drop of psi after peak is weird)

also if you installed downpipes you can check by watching if your both wastegate arm mecanism doesn't touch anything and are totally free to move

how are your vaccuum line too ? (at idle you should read something like -9 to -11+ psi on the mhd PSI gauge)

is this stock airbox ?

you could check all these things and see if something is wrong

edit: just seen you had N55, but you could probably check these things anyway

My car is 58k miles so yeah it could be that. I'll read if its DIYable.

I feel I had a lag on stock downpipe as well but there is no way I can confirm that. Yes the metal chargepipe has O-ring. I had to remove throttle body to install this chinese chargepipe. It could be that one screw of throttlebody isnt tight enough or there's a leak somwhere on the pipe connections.

I dont see a wastagate arm, I guess its not there in n55. Same for vacuum lines

Yes stock airbox, stock filter. Should I upgrade to k&n dropin filter?

[studio54]

Originally Posted by taranfx

My car is 58k miles so yeah it could be that. I'll read if its DIYable.

I feel I had a lag on stock downpipe as well but there is no way I can confirm that. Yes the metal chargepipe has O-ring. I had to remove throttle body to install this chinese chargepipe. It could be that one screw of throttlebody isnt tight enough or there's a leak somwhere on the pipe connections.

I dont see a wastagate arm, I guess its not there in n55. Same for vacuum lines

Yes stock airbox, stock filter. Should I upgrade to k&n dropin filter?

Possible for your chargepipe, you could check this.

On N54s, replacing both boost solenoids is DIYable, and it cost 80-90$ per item (Pierburg boost solenoid), on N55 there is only one and should be DIYable too.

I didn't know at first you were on N55, so my informations about rpms and lag are maybe false with n55. You can contact MHD and he will tell you if your log is ok or not. It's him who told me that stock n54 turbos made 13 psi in about 500 rpm in 3rd from 2500rpm.

He also told me that stock air box (with drop in or not) is ok with OTS maps (stage 1/1+ and stage 2/2+).