Boost issues
#43
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teamNJCT
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Join Date: Mar 2007
Location: Parsippany, NJ
Posts: 16,645
Originally Posted by jsg93085
here's the wierd thing though... im the only one running the 2.1 manifold with this issue...
looking at a log i took using my laptop with the AEM log software, the max percentage my injectors reach is like 75%...
i dont think it could be a vacuum source problem for the wastegate since the source is coming directly from the compressor housing (just like internally wastegated turbos)
the wastegate is a TiAL Sport 38mm with a small yellow spring
there is no dump tube on the wastegate, but todd did make a 6" one that directs the exhaust down, but it doesnt connect to the downpipe.
i believe the fuel pump is in need of replacing since the engine hiccups when i punch the gas to WOT in 3rd and higher when just cruising around at about 3.5-4k
it was also hiccuping when i went out to the track last weekend, and got progressively worse each run. the first run i did had no hiccups at all, but when i went through my 2 through 5th runs, the hiccuping started to get worse in 3rd, 4th, and 5th gears. it was so bad that it threw a P0171 code and the hiccuping was horrendous in my 5th (and subsequently last) run that i let off the throttle before 1/8th mile and cruised in 5th to the end...
i may be just getting the short end of the deal with my setup... UMS tunes really conservative (since theyre located here in phoenix with 110+ summer days), so they may have been running out of fuel by just trying to keep afrs good and anticipating for really hot weather (since i dont have a water/meth kit)...
looking at a log i took using my laptop with the AEM log software, the max percentage my injectors reach is like 75%...
i dont think it could be a vacuum source problem for the wastegate since the source is coming directly from the compressor housing (just like internally wastegated turbos)
the wastegate is a TiAL Sport 38mm with a small yellow spring
there is no dump tube on the wastegate, but todd did make a 6" one that directs the exhaust down, but it doesnt connect to the downpipe.
i believe the fuel pump is in need of replacing since the engine hiccups when i punch the gas to WOT in 3rd and higher when just cruising around at about 3.5-4k
it was also hiccuping when i went out to the track last weekend, and got progressively worse each run. the first run i did had no hiccups at all, but when i went through my 2 through 5th runs, the hiccuping started to get worse in 3rd, 4th, and 5th gears. it was so bad that it threw a P0171 code and the hiccuping was horrendous in my 5th (and subsequently last) run that i let off the throttle before 1/8th mile and cruised in 5th to the end...
i may be just getting the short end of the deal with my setup... UMS tunes really conservative (since theyre located here in phoenix with 110+ summer days), so they may have been running out of fuel by just trying to keep afrs good and anticipating for really hot weather (since i dont have a water/meth kit)...
Honestly, the hiccup sounds like your running too rich, and if you're at 75% on the F/IC running only 6PSI, you ARE running very rich. My peak load on the F/IC, near redline (peak HP) is only 58% and I'm running twice the boost.
I had a similar problem when I was street tuned. When I first had the car dyno'd, it was running so rich, that my AFRs were off the chart (below 10) and PTuning had a hard time getting the car to actually rev over 3000RPM, it kept sputtering when it was put under a load.
#44
yea, i dont know what is going on... todd & UMS claim that the fuel pump is to blame
the problem is that its not 6psi though, the wastegate spring is 3.626 psi and the spike doubles that after like 5k rpms...
UMS has a really close relationship with AEM and have tuned other tCs, but mine is the only one with these issues...
the problem is that its not 6psi though, the wastegate spring is 3.626 psi and the spike doubles that after like 5k rpms...
UMS has a really close relationship with AEM and have tuned other tCs, but mine is the only one with these issues...
#45
Originally Posted by jsg93085
yea, i dont know what is going on... todd & UMS claim that the fuel pump is to blame
the problem is that its not 6psi though, the wastegate spring is 3.626 psi and the spike doubles that after like 5k rpms...
UMS has a really close relationship with AEM and have tuned other tCs, but mine is the only one with these issues...
the problem is that its not 6psi though, the wastegate spring is 3.626 psi and the spike doubles that after like 5k rpms...
UMS has a really close relationship with AEM and have tuned other tCs, but mine is the only one with these issues...
#49
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teamNJCT
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Join Date: Mar 2007
Location: Parsippany, NJ
Posts: 16,645
Originally Posted by jsg93085
oh, i also forgot to mention that the vacuum line for the F/IC is teed off of the nylon line for the boost gauge. in case that has any effect on whats going on with my car
#51
i'm no scientist but it looks like in the tial install manual it shows the boost controller routed to the top port of the WG. seems to make sense that you would want pressure adjusted by the MBC to be applied to the top of the plunger inside the WG. that would counteract the exhaust that is allowing the plunger to open up completely and allowing an unlimited amount of pressure to spike your turbo.
correct me if i'm just an idiot haha
correct me if i'm just an idiot haha
#52
found all this on this site: http://www.boostcruising.com/forums/...hp/t76436.html
In order to run a manual boost controller we need to tee off of the vacuum line which runs from the turbo compressor housing to the compressor reference port. The manual boost controller works using a spring and check ball, by screwing the adjusting screw into the boost controller you put more pressure on the spring which reduces the amount of airflow through the boost controller and into the boost controller port. Less airflow means less pressure will be assisting the spring to keep the wastegate plunger shut. The pressure in the vacuum line going to the compressor reference port will equal the pressure the turbo is producing. A boost controller will allow you to direct some of that pressure to the top of the wastegate diaphragm creating two opposable forces. By adjusting the spring pressure of the boost controller you can vary the amount of boost that the turbo will make before opening the wastegate's plunger. If you want to run a higher boost level than the wastegate spring allows you will need a boost controller.
The manual boost controller is a very simple device that can help you make more power from your turbo setup. Here are three additional things to keep in mind about wastegates:
Without a line running from the compressor housing to the wastegate's compressor reference port boost pressures will keep increasing forever. This will quickly destroy your engine!
Run a wastegate as close to the desired boost pressure as possible this will help the boost controller handle the pressure better.
You can't reduce your desired boost pressure lower than the spring rate.
In order to run a manual boost controller we need to tee off of the vacuum line which runs from the turbo compressor housing to the compressor reference port. The manual boost controller works using a spring and check ball, by screwing the adjusting screw into the boost controller you put more pressure on the spring which reduces the amount of airflow through the boost controller and into the boost controller port. Less airflow means less pressure will be assisting the spring to keep the wastegate plunger shut. The pressure in the vacuum line going to the compressor reference port will equal the pressure the turbo is producing. A boost controller will allow you to direct some of that pressure to the top of the wastegate diaphragm creating two opposable forces. By adjusting the spring pressure of the boost controller you can vary the amount of boost that the turbo will make before opening the wastegate's plunger. If you want to run a higher boost level than the wastegate spring allows you will need a boost controller.
The manual boost controller is a very simple device that can help you make more power from your turbo setup. Here are three additional things to keep in mind about wastegates:
Without a line running from the compressor housing to the wastegate's compressor reference port boost pressures will keep increasing forever. This will quickly destroy your engine!
Run a wastegate as close to the desired boost pressure as possible this will help the boost controller handle the pressure better.
You can't reduce your desired boost pressure lower than the spring rate.
#53
yea, i havent tried your suggestion yet tCrollin08... i dont really want to until i have the new fuel pump and have it on the dyno (where im not tweaking it, lol)
right now the boost controller is just sitting in my toolbox in the hatch area
and i still need to get my exhaust done...
right now the boost controller is just sitting in my toolbox in the hatch area
and i still need to get my exhaust done...
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