evo unknown

iTrader: (25)

So i installed a cobb accessport with the stg 2 map along with new vacuum lines cobb sent me, because the new lines are supposed to have a different size secondary restrictor pill.

With that i was only boosting 1.2 bar. So i returned the stock line in with the secondary restrictor pill removed and was reaching 1.5 bar (about 22psi), which is what the map is set at.

However, in 1st gear i get 1.3 bar and it pretty much holds there, 2nd gear same thing, 3rd gear and up i get 1.5 bar peak and drop to 1.3 bar.

So it seems that in the first two gears i am not getting the correct boost amount.

I uninstalled the AP and tried a run and the same thing was happening, so I am wondering if the AP is even controlling the boost or if it it just the secondary restrictor pill that was removed which is causing the boost to increase.

I called cobb tech and they suggested to me to adjust the wastegate actuator. i have not heard of anyone else having to do this.

Any ideas to what is going on or suggestions. (there are no boost leaks lol)

sparky

iTrader: (1)

Could be that in 1st and 2nd gears you are seeing the actual boost setting, and that the slightly higher PSI in the three upper gears is being caused by boost creep.

sparky

iTrader: (1)

You could try Cobb's suggestion of playing with the WGA's spring pressure. I assume that they want you to incease the spring pressure, not reduce it, right?

evo unknown

iTrader: (25)

yes they want me to shorten the spring to increase the springload. however, the nut to adjust that would be almost impossible to adjust b.c of rust buildup on it b.c of it's location right near the exhaust manifold.

i just put the secondary restrictor pill back in and i'll see what it does now. I believe u were right with the boost creep, for some reason that just did not pop into my head. i'll be back on in a little to post anything new.

sparky

iTrader: (1)

If there is a significant rust builup on the end of the actuator rod then you will want to remedy that. It is fairly straightforward to remove the WGA assembly while the turbocharger is still on the car. Just remove the two bolts that fasten the bracket to the compressor housing and pop out the cotter pin that secures the end of the rod onto the flapper valve's pivot arm. Once you have the actuator assembly on your workbench, then just spray or soak the rusty threads with WD-40 and scrub with a wire brush.

If the rust buildup is moderate then you may be able to spray the end of the actuator rod with WD-40 and get at it with a brush while it is still mounted on the car.

evo unknown

iTrader: (25)

hmm, i may try that, but i may be having other issues.

i uninstalled the AP. and the stock vacuum line is back in with the secondary restrictor pill.

1st gear 1.2 bar, 2nd gear 1.3 bar, 3rd and up 1.5 bar. i am still underboosting and then extremely overboosting after returning the car to the way it was. wtf?

evo unknown

iTrader: (25)

returned everything to stock, checked all line and clamps and all...no leaks..i have no idea why i am still overboosting.

please ppl help

evo unknown

iTrader: (25)

bump..read my thread and help

evo unknown

iTrader: (25)

i now have the stock lines in with secondary restrictor pill, and i was still getting unstable boost as i went through the gears.

so i installed the stg 2 map again hoping it would at least control the boost and it is. i am hitting stock levels now which is ok, except the map is supposed to be hitting higher psi.

again any thoughts?

atkins

iTrader: (13)

i think you are pretty much on target with cobb's specs for stage two. i quote

Boost Targets: Peak boost of ~22psi tapering down to ~20psi, +/-
.7psi, by 7600 RPM redline, depending on vehicle and conditions. If
your vehicle is not achieving or exceeding the boost targets, you
may need to mechanically adjust your boost control system, please
refer to this document

you are seeing 22psi and then tapering back down just like cobb says. the reason you dont see 1.5 bars in 1st or 2nd gear is because the car is tuned in 3rd gear and that is were the boost target is set. in lower gears its using the same boost target but the load on the engine is less then what it is in 3rd were it was tuned so you wont achieve that 22psi. if you were seeing 22 psi in first and second gear you would probably see 23-34 psi in 3rd, 4th, and 5th as the load is greater.

jeff

atkins

iTrader: (13)

remove the secondary pill and you should be good to go see above post. the cobb mapping will not hit and hold boost to redline there will be a fluctuation. that is one advantage of using an ebcs and a perrin stage 2 map for the ap...boost is greater and it holds to redline

jeff

evo unknown

iTrader: (25)

well it seems that the oem boost solenoid is not holding boost like it should.

so do u think a manual boost controller set at 22lbs would fix this issue about the different boost pressures in each gear?

atkins

iTrader: (13)

i think it is a combination of the stock bcs and the actual cobb map, if you are going to buy a manual boost controller you will need a tune.

if you are going to tune i would highly recomend using the stock boost control system over a manual boost controller and just upgrading the ebcs and tuning for it. both will cost you about the same around 100 bucks plus the tune and they are both super easy to install. if you are going to tune i would hold off untill you purchase some other mods to take advantage of the cost of tuning so you are not paying for further tunes in the future if you upgrade something, it can get expensive real fast tuning for every mod you get one by one.

as far as seeing different boost in lower gears that will pretty much be constant with what ever you do just because as the car goes threw its gears it gets closer to a 1 to1 gear ratio which increases engine load. a good tuner can make it more consistent though.


jeff

evo unknown

iTrader: (25)

thanks. i do not plan on doing any more mods, and do not have a place very local for me to get tuned and i didnt want to go the email flash tune or anything like that. i felt the cobb stg 2 would be good for a while. cobb suggested a mbc but said it was not needed. the person i purchased this from is also feeling my issue is the oem boost solenoid cannot control the boost increase, and a mbc or ebc would hold it. he said he had 22lbs in all gears. thats why im leaning towards a hallman mbc. thanks for ur input tho and if u have anything else please let me know.

evo unknown

iTrader: (25)

the mbc will allow me to turn up and control the boost better than the oem solenoid can, and the cobb ap map is the tune. the maps are somewhat conservative, but what i wanted right now. uploading the map adjusts the boost a/f ratios and whole bunch of other goodies which is supposed to eliminate the tune.