So I've got two MK10s that I just revived from the bin at the shop and serviced.
One had an old red seat, the other had a -II gray seat. Even though everything was in good shape, because these were basically bags of parts, I did not have the opportunity to test them before service, so I don't know what the IP would have been.
After service, IP on both was low (120-ish) when I used new -II seats but lockup was solid and the dip in IP when a breathed on a reg seemed normal. It would have been very satisfactory but for the fact that the IP was low.
Since these were already pretty much shimmed up, I switched to the -I seats on both to bump up the IP. IP is now on the money (135). So far so good.
Here's the question: Now when I breath on the regs I get a much larger swing in IP. The first stages do not feel "wide open" until IP dips to about 100psi. They crack open just fine and deliver plenty of air, but as I breath deeper, the dip in IP increases (i..e, IP drops) until it hits about 100 and then things seem wide open and no amount of extra breathing demand gets the IP to drop further. IP rebounds immediately to 135 with no creep or drift as soon as I stop inhaling.
Is this normal behavior?
One had an old red seat, the other had a -II gray seat. Even though everything was in good shape, because these were basically bags of parts, I did not have the opportunity to test them before service, so I don't know what the IP would have been.
After service, IP on both was low (120-ish) when I used new -II seats but lockup was solid and the dip in IP when a breathed on a reg seemed normal. It would have been very satisfactory but for the fact that the IP was low.
Since these were already pretty much shimmed up, I switched to the -I seats on both to bump up the IP. IP is now on the money (135). So far so good.
Here's the question: Now when I breath on the regs I get a much larger swing in IP. The first stages do not feel "wide open" until IP dips to about 100psi. They crack open just fine and deliver plenty of air, but as I breath deeper, the dip in IP increases (i..e, IP drops) until it hits about 100 and then things seem wide open and no amount of extra breathing demand gets the IP to drop further. IP rebounds immediately to 135 with no creep or drift as soon as I stop inhaling.
Is this normal behavior?