I have a Haltech now installed into my car and will be doing the following.

Replacing S5 TPS with Haltech TPS.
Doing throttle body mod and removing coolant line and going direct to BAC.
Also porting of throttle body

Question / Concern
The hose the connects from Rear Iron to Throttle body and then the hose that connects the Throttle body to BAC.
So I want to go from rear iron to BAC

What hose do you replace it with?

Do we have a part # or a generic name /size? or best alternative?

I have seen some vague descriptions saying a preformed 90deg hose but what lengths/size/diameter?



Thanks All

 

Also does anybody have pictures of their setup if done like so.

 

well, if it helps, after the bac the line goes up to the back of the waterpump housing.
myself, i just ran straight from the rear iron to the waterpump housing.
if you go that route, its a chrysler water hose (my parts guy just gave me exactly what i needed, cause he knows his domestics too well)
im not sure about keeping the bac, but not the part on the throttle body. might make your search for hoses rather difficult.

 

Go to the local auto parts store and get some hose. I think it's 5/16"? Either that or 3/8". Just going from the water pump housing to the BAC to the rear iron will work.

Strictly speaking the coolant feed to the BAC isn't really needed if you don't drive in the winter.

 

I'm not sure if the BAC valve alone (no thermowax) is capable of providing enough bypass air to have a stable cold start idle (without putting your foot on the gas, which is a pain), if you care about that.

The double throttle system is worthless (and its removal is what gives you the performance benefit), but I do NOT recommend removal of the thermowax/mechanical fast idle system. I know that coolant hose is a bitch, but Mazda put it there for a reason, and both FC and FD throttlebodies have it. If anything, you can get away without the BAC valve (especially if you have no A/C) and keep the thermowax. That is my current setup with a Power FC. I have the OEM coolant hose from the rear iron going to the thermowax, then some heater hose going from the TB to the water pump housing. After adjustment of the TB screws, the car starts and idles reliably at about 1200 rpm and then cuts down to 850. After adjustment of the dashpot it never stalls on deceleration either.

I got so annoyed with the lack of a dashpot and thermowax after a while that I put them back on my car. Like I said, there is no reason to remove them and they do improve driveability.

 

I live in Southern California so the temps do not get too cold.

I am sure the bac can do.

Also haltech should help..