sorry... yet another boost Q!

[ttothec]

my actuator has been fiddled with... while i was trying to sort out a prob when i first got my car... but im pretty sure its back in the right position now

might try winding it in a bit just to check anyway

 

[Revo Kev]

Bear in mind the ECU is load based, your unlikely to see as much load in the lower gear so less boost. The sample rates of the logs posted don't help assessing them either, if the sample rates can't be increased then try looking at doing a 4th or 5th gear pull from low rpm to redline... you'll need a lot of non-public road to do this!
Block 114 would tell us whether the requested load values are being met as well.

 

[ttothec]

i could try logging in 4th or 5th to the redline... but its in those gears that the boost seems ok... its only in 1st 2nd and 3rd gear the boost seems a little low... but judging by what revo kev said... i dont think that is totally unexpected...

maybe some one who thinks they are seeing 18-19psi in 1st 2nd and 3rd... mabe do a jog of requested vs actual boost through those gears like i did (i know the sample rates will be low... but we should be able to see how the car is boosting in the lower gears

just a thought

 

[acidstrato]

i just checked a previous 2rd gear log of mine it hit 2390 peak actual

which i make 20psi

a recent log of 4th peaked at 22psi

not a massive difference really

 

[ttothec]

i just checked a previous 2rd gear log of mine it hit 2390 peak actual

which i make 20psi

a recent log of 4th peaked at 22psi

not a massive difference really

do u mind posting the logs, so i can see how quickly it reaches the max and how closely it follows the requested boost on the way up??

 

[gavthelad]

i only hit 10psi last night in first gear!!!......couldnt even get wheelspin???

my car is gradually getting slower. who knows, it might not even move next week?

im seeing 14psi in 2nd, 18psi in 3rd, 19psi in 4th and 20psi in 5th???

im gonna have to do some logs very soon!! which are the exact blocks i need to measure.....115,118 and 020?

 

[__B3NNY__]

i just checked a previous 2rd gear log of mine it hit 2390 peak actual

which i make 20psi

a recent log of 4th peaked at 22psi

not a massive difference really

Is that a 2nd or 3rd gear log lol? If 3rd im sure after changing from 2nd im seeing around 19/20psi, If so look like i could be imagining my problem and could just all be normal.

David.

 

[acidstrato]

'115			
RPM	Load	Absolute Pres.	Absolute Pres.
			
 /min	%	 mbar	 mbar
1640	78.9	1670	1070
1880	94.7	1770	1290
2160	112	1910	1500
2480	131.6	2060	1740
2960	165.4	2210	2100
3880	186.5	2330	2390
3680	60.2	990	2050
3680	11.3	990	1100
3600	9.8	990	1040
3560	70.7	1940	980
3960	173.7	2340	2220
4400	175.2	2190	2190
4800	169.2	2050	2070
5120	161.7	1920	1970
5400	150.4	1610	1890

this is 2nd gear,
i didnt post it before cos its abit messy cos at one point i backed off (see where both drop off and then pick back up)

 

[ttothec]

thanks for doing that... dont suppose i could pester u and again and get the rpm there aswell please??? just os i can see it mor clearly over the rpm...

do u think if my actuator is ver slightly loose... it might be enough for it reach and maintain boost in the higher gears, where it has longer to reach the requested boost, rather than the lower boost where it races through the revs so quick, the slighty "loose" actuator doesnt allow the boost to be held??

i know the actuator isnt loose... but if its tightened slightly it may responed to the requested boost slightly faster?!? just a thought... or does the ECU control it outright??

hope this makes sense... thanks again for the help

 

[acidstrato]

im not great with cranking the actuator tbh

the ecu has the over all control with opening the wg but if you adjust the preload on the actuator then you can keep it closed longer which is what your getting at i think? but this can affect the signals that eventually end up at the ecu and if it doesnt like it it'll pull back and chuck up a code.

it is worth counting the threads after the nut on the actuator rod and as its been messed with maybe winding it out abit if it needs to be

should be around 12 threads

 

[ttothec]

il have a look at how many threads like u said... but i know my actuator has been fiddled witht as it was one of many things i checked when i first got my car as i had a problem i couldnt slove.

so my actuator might not be in the right position

do u mean 12threads on the side down toward the actuator..or the other side to the end of the rod??

id rather not move it from its current position as i dont get any codes as it is... so that will onky be a last resort

 

[gavthelad]

boost is back for me.......harder and stronger than ever?????

strange!!!!!!

 

[__B3NNY__]

So your boosting to 20/21psi in every gear? and after every gear change? Have you tryed holding the revs say at 4k rpm and then planting it to see if your getting full boost? Because i think thats where my trouble lies as i can get 19/20psi if i were to plant it in 2nd from around 2k rpm.

David.

 

[acidstrato]

il have a look at how many threads like u said... but i know my actuator has been fiddled witht as it was one of many things i checked when i first got my car as i had a problem i couldnt slove.

so my actuator might not be in the right position

do u mean 12threads on the side down toward the actuator..or the other side to the end of the rod??

id rather not move it from its current position as i dont get any codes as it is... so that will onky be a last resort

12 threads from the nut to the end of the rod, ok say 11-13 is alright but i can just about make out 12

you wont get any fault codes moving it a thread or to, especially if its wrong at the moment

 

[acidstrato]

So your boosting to 20/21psi in every gear? and after every gear change? Have you tryed holding the revs say at 4k rpm and then planting it to see if your getting full boost? Because i think thats where my trouble lies as i can get 19/20psi if i were to plant it in 2nd from around 2k rpm.

David.

is that to me?

to clarify I DONT hit 20/21psi in every gear every time.

1st gear there is no way i hit 20psi, never logged or properly looked at my boost gauge but its around 15psi peak i think, change up then it'll go hit 20ish in every other gear. although this differs with the point you change up, cos if you change up at say 7k then in the next gear you wont be at the right revs to hit full boost.

if i held at 4krpm with barely any boost, then planted it, i'll hit about 18psi maybe slightly less cos if you look at my logs my peak is at about 4k.

this will be the same/similar for you lol

 

[gavthelad]

i tested mine again this morning on the way in to work.....

if holding at 3.5k im seeing about 19psi if i boot it, its pulling like a train again!!wey hey!!!

 

[ttothec]

just went for a spin in my car... and floored it in 2nd from about 2krpm and my boost gauge showed what looked like 17-18psi... so not that far off

just a thought... if the boost requested by the ECU is based on the load... as mentioned by revo kev... could this infact point to people who are running higher boost are actually more likely to be experiencing problems as the ECU needs more boost to get the required torque??

or is that total crap??

also... could wheel size cause the requsted boost to vary (bigger wheels = more load on engine = more boost required??)

sorry if what ive said is total crap... but not entirely sure how the ECU and everything works... just bits and bobs of what ive read

 

[__B3NNY__]

is that to me?

to clarify I DONT hit 20/21psi in every gear every time.

1st gear there is no way i hit 20psi, never logged or properly looked at my boost gauge but its around 15psi peak i think, change up then it'll go hit 20ish in every other gear. although this differs with the point you change up, cos if you change up at say 7k then in the next gear you wont be at the right revs to hit full boost.

if i held at 4krpm with barely any boost, then planted it, i'll hit about 18psi maybe slightly less cos if you look at my logs my peak is at about 4k.

this will be the same/similar for you lol

It was to Gav mate,

Looking at some of the posts looks like what we are describing sounds fairly normal, To be honest i cant say that i took alot of notice at my gauge before my clutch started slipped (which is fixed now) so i thought the problem started there, Im hoping to do some logs this week, If not ill have to wait till the RR day at the end of the month that should tell me if the car is playing up or not.

David.