thesaintusa

From Banzai racing eBay store.

https://www.ebay.com/itm/223196873929

Just for fun, this is the 'rat's nest' of lines that RX-7 often end up addressing.


My lines appeared good untl they got up to operating temp when they would not hold vacuum. I went single turbo and got rid of most of the lines (for sequential turbo) and life got better.

Chevota

Thanks for the link That check valve is not what I expected at all. The one in our cars car puts the flapper valve just millimeters from the the vacuum pump so there's minimal dead air space between it and the rotor vane. It's also high speed, up to 100 open/close cycles per second so it sees use more like a reed valve, which is why they break. Not saying that one in the link won't work, I just can't imagine it could possibly work as well as the oem unit. Do you have one these on your 63?

Here's an example of the ad I fell for; https://ebay.com/itm/185676306303 showing the good orange (silicone?) flapper disc, but you get a black one that is flat, thicker and stiff so it's neither high speed, nor capable of sealing on the convex surface it mates against. It does work to a point, just not well enough. No check valve at all also works, to a point, so the cheap chinese one is in the middle somewhere and I'd imagine only gets worse as rpms increase.

That is a rats nest for sure. I can't imagine why that many are needed, sheeze. Are those silicone lines? Were they actually leaking or just collapsing when it got hot?

kevm14

I ordered this all the way from Ukraine.

https://www.ebay.com/itm/115045707705

It was orange. The one in my car was orange and seemingly in good shape. Car has 99k so not sure if it is original. This car was owned and operated in the northeast so it is possible issues like this are much more severe in hot climate cars. Or my vacuum pump has been replaced but I found nothing in the service records on it.

thesaintusa

Chevota,

i think leaking. There were 2 that were clearly cracked with careful inspection.

They are silicone lines, a bit thicker wall than OEM, but the lumen / inner diameter equal to OEM. Definitely not at risk of collapsing which can occur with different brands. I cannot recall which ones I got, but it was a 'kit' from one of the RX7 stores from over 15 years ago. There were definite reports/examples of some silicone hoses being kinked with some of the tighter radius bends (near the center top of the picture I linked).

I am still running the OEM check valve in my RX7, so only posted about a check valve that I have used. I do not know the frequency of open/close cycles that the valve I posted say in my application.

kevm14

This thread made me order a set of 3 lines/hoses as PM.

Siegmann

P/Ns:

Line from vacuum pump check valve to solenoid: 2780981989
Line from solenoid to bank 1 turbo: 2780980889
Line from solenoid to bank 2 turbo: 2780980789

kevm14

Driver's side solenoid to turbo: 278-098-07-89
Passenger side solenoid to turbo: 278-140-01-12
From vacuum pump to solenoid: A2780981989

I just did this and these P/Ns matched what was on my 2014, with 2013 date codes on the lines. So perhaps they updated the bank 1 turbo line for the facelift cars.

I tested the integrity of the lines and wastegate actuators before removing the lines and it seemed to hold vacuum. No lines had cracks either. But I did find this on the connection to one of the turbos after removing. Everything else looked good. 2014, 99k, original lines. Testing off the car it DID leak here so not sure if it sort of fell apart as I removed the line. It means the rubber was degrading for sure.



Pre-repair manifold pressure on a ~0-100 run. Converts to about 12 psi.


After replacing. Calculates to about 13.5 psi.