I recently tested my turbo waistgates on vacuum and pressure because I believed they were not working. When tested, I got no pressure or vacuum, so I believe the diaphragm inside of both waistgates are broken. This leads me to two questions:

1. Am I testing the waistgates properly? I heard you have to block one of the ports when testing the waistgates and test around 5-8 psi range. Is this the correct way to test? If not, please elaborate.

2. if I am correct about the testing and both my waistgates are broken, where can I buy aftermarket replacements for the FD Rx7? I saw another thread about the Turbosmart IWG75 but from what I understand that is a universal waistgate and will require some tinkering. Does any company make waistgates where I can simply remove the current waistgates from the c clamp and swap them out? Or does anybody rebuild FD waistgates? Or if there are not aftermarket alternatives, is the best option to buy a used OEM waistgate?

I am in a rush with this so I would appreciate quick replies. I’m grateful for all and any insight - thanks!

 

I haven't heard of people replacing those actuators with anything other than stock ones, although I agree it's just an actuator so there may be other solutions that would work well if they had the proper force and distance and operating pressure.

There are testing instructions on page F-86 and F-90 of the factory service manual, it looks like you should apply different pressure to each of the actuators. Someone recently posted a searchable copy of the service manual, it's great to be able to use CTRL+F and see all the instances of 'wastegate' or 'turbo control'.

 

To test, you do need to block off one port and use something like a Mityvac that can pump up and provide air pressure.

So, with one port blocked, use the Mityvac to add air pressure to the second port. Around 7psi the arm should start extending. Once extended it should stay extended.

If it doesn't move at all or if it creeps back the wastegate diaphragm is bad.

This really isn't super common all things considered. Yes you can use an aftermarket one but that will be a significant engineering effort; you need to make a bracket, fab the linkage, get it dialed in JUST right so it doesn't bind - there's a LOT to get it to work right.

By far the best way to go if they are bad is to buy used replacements. They should be fairly cheap and just bolt on and go. They really don't fail that often so I imagine it shouldn't be too bad to find a good set.

Dale

 

thank you, I’ll try to retest it again today and look for replacements, I really appreciate the help!

 

so I didn’t test them quite right - I’ll try again today. Thank you for providing this