rx-7s have a coolant cooled throttle body, So my friend said i should disconnect both throttle body hoses and tap them together bypass the throttle ????? idk why but he said it will make a difference in performance???????

idk...........what do you guys think.?

 

you're thinking of the double throttle. It's best to delete it all together, but only if you understand what it does and the possible downsides of boosting before the engine is warmed up.

There are some good writeups on deleting the double throttle, however much like the non-sequential mod, there's an easy way to do it with less gains too.

Easy way is to locate the DT actuator, which is just behind the TB on the UIM. disconnect the vacuum hose and tie it off, then tie open the DT actuator(which is very easy, since I believe the DT is open when the actuator isn't activated).

the long way involves removing the entire UIM to pull out the butterflies and actuator, then welding the holes shut and sanding the inside of the weld to be smoothe with the inside of the UIM. It took me about 20 minutes to remove the actuator and butterflies and to cold weld the holes. My engine builder did the sanding, block offs and solenoid removal.

 

Personally I wouldnt bother unless you were rebuilding and could do it properly, blocking off the nipples where the TB gets is coolant from. The biggest advantage to this mod really is only to eliminate a potential leak and if you just connect the 2 together you arent eliminating that potential leak.

 

The throttle body is WARMED by the coolant running through it. This is to prevent the butterfly from icing up which can happen at near freezing temperatures and high humidity. Ice forms in the throttle body in these conditions because of the venturi effect which drops the temperature and then ice forms.

 

thanks for the info guys. im just gonna leave it alone.....maybe eliminate the double throttle later on....

 

While the difference in intake temp without hot coolant running through the throttle body is not going to make a huge performance difference, re-routing the coolant around the throttle body does make removing the throttle body and the UIM an easier (not to mention less messy) task. So if you're a tinkerer you might want to consider it. Be aware than without the throttle body coolant, your car will think it's still cold with regard to idle speed, since the wax rod and the fast idle cam won't have the coolant to react to. So you'll have to remove or safety wire the fast idle cam to the warm position. This can sometimes lead to stalling just as the car is turned over if it's cold outside, but a light blip on the throttle can stop it if she looks like she's gonna die. Then you're on your way!

 

Here's the walk-thru of what Prophet just talked about:

http://www.rx7.org/Robinette/throttle_body_coolant.htm

 

Do you still have to do this if you are running a Power FC?

 

Whoops. I meant to mention that. Thanks Mahjik.

 

It's not really an ECU controlled function.