I just wanted to thank you for this thread. Due to CA emissions, I have to reverse one of these that was done out of state, and now I know how. When I replace the air solenoid valve, I will do this as well. After reseting the check engine light, hopefully I can run it for a while and get my car CA smogged.

 

After reading through this thread I only saw a couple mentions of capping the coolant feed/return off completely eliminating the hose. Are there any issues to be concerned with if I did it this way using a suitable caps/clamps?

 

I think that's a bad plan. Keep the coolant flow as close to stock as possible. If you want to simplify and eliminate the route through the TB, you can pull the UIM and run a coolant hose from the front to the back.

 

Is the coolant that runs through the throttle body used for anything else? If I recall correctly (haven't looked in my bay for a few days), it's drawn from the thermostat housing and returns to the back of the motor. Is something else relying on that coolant. I have my entire intake manifold removed to do SSV cleaning and replace the OMP lines so I'm hoping to eliminate anything that isn't really necessary, but I definitely don't want to cause an issue by doing it.

 

The coolant line going through the TB serves a couple of purposes.
1) It keeps the TB assembly hot to prevent ice buildup on the throttle plate which could be bad. People might think that it would only be possible if water hit the throttle plate and it had enough time to sit and freeze on there, but there's a lot more science involved which disproves that however I will not get into right now. Even at above freezing temps, water can do some interesting things
2) The line aids in purging air bubbles from the motor. I promise an air pocket is something you never want to have in your motor unless you are purposely seeking out forking up thousands of dollars on a rebuild.
3) Its not even 8am and I just got to work so my brain isn't 100% functional yet, just search around the forums and you will find more reasons not to cap off this line and fubar an important aspect of our cooling system. Additionally, air passes through the TB so quickly that nothing really is gained by doing the bypass. How about the big extremely hot hunk of metal called the lower intake manifold that gets nice and toasty from the exhaust header manifold? How would you plan on keeping that cool? Even if you blocked the heat from the exhaust header manifold going up into the LIM, its bolted directly to an iron and aluminum flaming Dorito spinner, so the LIM will get hot either way and heat up intake air probably more significantly than the measly throttle body ever could.

 

I'm doing this off memory, but the coolant feed for the throttle body comes off of the thermostat housing so it's not part of the air separator tank's system. Or are you saying that it also helps to remove air from the system? My intention wasn't to try and improve performance by eliminating the coolant lines to the throttle body, but to make things more simple in the bay.

 

I decided to just bypass the the throttle body but leave the hose. I read some posts on RX7club about issues with caps melting when the hoses are removed and ports blocked off.

 

If you ever decide to go turbo those two lines are a nice way to route coolant to your turbo CHRA too.

 

And to piggy-back on this, if you go with the Pettit Supercharger setup, you do this exact bypass mod (bypassing the throttle-body in the coolant loop by simply splicing the two hoses together and tucking them away) as part of the installation anyway. I just ordered the 3/8"x3/8" barbed hose connector and screw-down-type hose clamps for my install today.