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educate me on disa valve operation
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05-04-2021, 08:18 PM | #1 |
Colonel
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educate me on disa valve operation
I just replaced both disa valves on my 3 stage intake, the car hit 100 000 miles and my mechanic said it was better to replace them , he put a doctors stethoscope on one of the disa and he heard a bit of a rattle. I went ahead an order a replacement kit with the seals from ecs tuning 530$ and he charge me 200$ to have them replaced
So far so good , he actually showed me that the small disa valve was loose so it needed to be replaced, the big disa valve was fine. I went for a test drive and right away I can feel the low end torque is different, the car below 3500 rpm just goes , I m sure the novelty will wear off in a few days but what a difference, as a matter of fact this was the reason I took the car there in the first place because i felt that the low end torque was weak Having said that, with the old disa valves I could feel a bit of a change in torque at around6000- 6500 rpm like the car had a little more power briefly , however with this new disa valves I do not feel that change in torque as much , but the car pulls nice, it makes good noises, no engine light or hesitation , I took it for a 30 minute run on backroads and highway , I got all the way up to red line and the car feels strong , I mean the car drives perfect right now. Im not sure if this is normal ?... maybe my broken valve was half working and now its fully working and it feels a little different? I tried searching the operation of the disa valves, I remember reading what each disa valve did and at what rpm they were supposed to work to give you that extra power, but of course I can not find that information anymore, I find everything but what I need . Can anyone chime in? |
05-04-2021, 11:12 PM | #2 |
Captain
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There shouldn't be a lack of power from having new working valves compared to the old ones at high rpm. I believe the large one opens up at 3500 and small one at 4300 so something at over 6k is odd. Maybe the valve was going bad and weak and it was closing a bit more at high rpm helped by the revs? No idea
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05-05-2021, 09:50 AM | #4 |
Colonel
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oh ok that would make sense. Its not making less power, its the complete opposite, the car has more power around 3000-4500 rpm , keep in mind this 3 stage intake I had was bought used and the small disa valve was found broken . For whatever reason I used to feel a surge in power at around 6000 rpm before, it was more noticeable . I also have headers so I m not sure if what I was feeling was a weak disa valve and headers picking up more power in the higher rpms , if that makes sense.
Lets say the car now has a flatter curve in power in the rpm band , with noticeable more power around the mid range |
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05-06-2021, 09:22 AM | #5 |
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Who knows maybe that's some weird behavior the engine has when the valves aren't working but now is definitely how it should be with a flat torque curve all the way through and great power all along
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05-06-2021, 12:39 PM | #6 |
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