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CHEF |
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{USERNAME} wrote: {USERNAME} wrote: it could be that you just have too much of an effient system to allow it to run low boost. I would try a 10psi spring and have 10psi as your minimum level. My ED has a similar sized T4 with a smaller 38mm tial gate and 10psi spring and Ive never had creep issues ( but, I dont have the same kind of manifold ) so I too am scratching my head on this one... As an example of flow vs restriction...on my BA XR6T, the stock dump pipe looks to be 2.5in with a very small internal wastegate and a ordinary looking cast manifold, not exactly flow city there, but I know guys that have put larger dump pipe and exhaust on only to end up with boost creep ( and thats with standard edit )... same deal as what your getting MAybe your only easiest solution is a decent EBC to hold boost down he isnt getting boost creep, he is having trouble with getting to much boost. creep and over boost are the opisit Ah...ok To quote from Garrett... What is boost creep? Boost creep is a condition of rising boost levels past what the predetermined level has been set at. Boost creep is caused by a fully opened Wastegates not being able to flow enough exhaust to bypass the housing via the Wastegates itself. For example, if your boost is set to 12psi, and you go into full boost, you will see a quick rise to 12 or 13psi, but as the rpm's increase, the boost levels also increase beyond what the boost controller or stock settings were. Boost creep is typically more pronounced at higher rpm's since there is more exhaust flow present for the Wastegates to bypass. Effective methods of avoiding or eliminating boost creep include porting the internal Wastegates opening to allow more airflow out of the turbine, or to use an external Wastegates. |
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fritzz |
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lol sorry. i am mixing my words up, i was thinking wastegate creep. sorrym8
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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fritzz |
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my mate has a turbo ed 4l, he has a stage 3 cam 8.5:1 comp, race seires pistons, ported head, gt35/40(1.06ar rear), 6boost manifold and a tial 44mm wastegate plumed into the side of the turbin housing and he has no trouble wat so ever with boost. he has a 10 psi spring and on the gauge it makes exactly 10psi and getts there extreamly fast!!
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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CHEF |
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I'd try the 10psi spring...
I know Seton500 had the same issues with his on a low psi spring on his ED... higher spring sorted him out ( I think, may have been other issues too ) |
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ebs_4l |
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{USERNAME} wrote: I'd try the 10psi spring...
I know Seton500 had the same issues with his on a low psi spring on his ED... higher spring sorted him out ( I think, may have been other issues too ) ok, it seems a few arent understanding the situation a low psi springs lets the wastegate open with less pressure, a high psi spring takes more pressure to open it. i have a 7psi spring, which means my wastgate is completely wide open over 7psi manifold pressure, that means it is venting as much as it possibly can, even still venting as much as it can, the boost still goes upto 13-14psi... by fitting a heavier spring, this will push the wastegate shut more, therefore, decreasing wastegate flow, and increasing boost pressure.. im yet to remove the wastegate and test it with it straight out the 1.5in outlet setup hopefully that holds the boost down, meaning i just need to upgrade to the 50mm turbosmart gate
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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EBXR8380 |
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Is the wastegate pipeing on one exhaust collectoror the whole lot?
In pic it looks like its on one # 4 ??... Are you 100% sure you have pressure lines connected properly???
_________________ As in ZOOM 126 edition |
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fritzz |
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i just put in my 11.4psi spring, and it went strait to over boost and it cut injectors. i have the overboost set at 15psi. so tomorrow im going to try the 4psi spring and play around with the boost controller.
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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CHEF |
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Hey graham did M"s car have this issue with the new manifold and the old turbo? Kind of a similar set up
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tjb45 |
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Just a question for all the guys that know a lot more then me ... I don’t see how a waste gate spring can be rated at a specific PSI. As each different motor/manifold/turbo will require the turbo to spin at different rates to produce the same PSI, and there for have different pressures in the turbo manifold.
ebs_4L, I think your right, if your still getting 14psi with no waste gate attached you will defiantly need more/bigger waste gate pipes. You would think two 1 1/2 holes in the manifold would be enough to let out enough exhaust gassed. Good luck.. Tim |
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ebs_4l |
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{USERNAME} wrote: Is the wastegate pipeing on one exhaust collectoror the whole lot?
In pic it looks like its on one # 4 ??... Are you 100% sure you have pressure lines connected properly??? the outlets are joined to the collector in the area where there is kinda an open chamber, like, it is above the joins in the pipe, it is vented from the inside edge, and the number 4 pipe you can see. yes, lines are hooked up ok. as i said, with the wastegate removed, i still got 14psi... today i aim to take the gate off once more, this time it will be with the 1.5in outlets, instead of the 1.25in. If that stops it boosting too far, then i just gotta get the bigger gate. if not, then i will be running a low boost setting of 15psi
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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CHEF |
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HAve you considered mounting the gate straight off the exhaust housing? it means butchering the housing, but could be your best bet
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ebs_4l |
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i have consided it, and dont like the position, or the appearance, i will run a 15psi base before id do that.
the wastegate spring psi, means, with that amount of pressure on the pressure signal line, the wastegate will be fully open... meaning, provided your wastegate is big enough, you shouldnt see any more than that amount of boost
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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fritzz |
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today i tested my wastegate on the bench with a gauge and the air compressor to find that the 4psi sping opened at 10psi and my 12psi spring opened at 25psi, so i am gessing that the exhaust gasses help open it a little.
how many psi do u recon the exhaust gasses would make, to help open the gate???
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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EBXR8380 |
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{USERNAME} wrote: Hey graham did M"s car have this issue with the new manifold and the old turbo? Kind of a similar set up
NO but he did have issues with internal gated Gt3540...No matter ho much we machined out wastegate ... Are you guys saying that with w/g off manifold it still makes boost???? If ths is the case, then some thinking is required in how its connected to maifold.. It seems the path to turbine is better than w/g???? If you saw the small gates on my SC 61's you'll be surprised that they hold boost from 8 PSI upward... Keep in mind with decent turbo, holding boost low requires high wastegate flow... YesI would say the w/g spring has to push against exhaust pressure?? Otherwise how is it going to close???
_________________ As in ZOOM 126 edition |
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CHEF |
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Where you guys running your vac line to and from? Comp housing straight to the gates side port is best
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