AST bypass replacement???
 

M2performance offers a ast bypass, is this a good idea or what? It's cheaper than bying a billet ast so someone let me know if this is a good idea or not? Thanks

Jeff

hey jeff,

for me... i would rather have the ast. i have heard that it causes no problems to rmove it, but i think mazda put it there for a reason. i don't know for sure if it would cause any problems down the line if you took it off. maybe you would have a hard time keeping air bubble out of your coolant sys.

best way to know for sure is to hope that someone who has had their ast removed answer this thread. if you do remove the ast let us know how it goes.

ian

boy this has been debated back and forth.

FWIW you can buy the 2nd gen cap to do the bypass for much cheaper...

it's the 86-88 cap mazdatrix part number 15-1740-N326

http://www.mazdatrix.com/b8.htm

The RX-8 doesn't have one....but my mechanic believes in it. Who knows?

well just looking for feedback, I'm a believer in "if it's there then it's probably got a purpose". Since there probably won't be any convincing arguement I think I"ll just get the billet ast.

I'd bet close to 50% of us don't use an AST. I didn't want another point of failure in the crappy cooling system, and it took some clutter out of the engine bay.

the cooling system plays a MAJOR role to prolong engine life, if the ast was put in there by mazda, it has a purpose, imo i wouldnt want to f*ck with that so i just bought a pettit ast and got rid of the stocker..

The twin turbos were put in by mazda and we all have plenty of reasons to go single. Get rid of it. It will not hurt your engine.

Unlike when your ast craps out on you and drools your coolant all over the ground.
I just hate the argument that the mazda engineers knew all when they designed these cars. ...They f..ed up in ALOT of places. The cooling system is only 1 of them.

If the system is burped properly, then there's no issue. I'm running in the 400rw range, and misbehave daily. I've never seen a temp above 85c on the PFC. I've never heard any funny coolant noises. Ditch the damn thing. If Ray at Malloy advises it, it's good enough for me.

-BN

I dont have AST since 97, and its running fine, never have problem with it.

what all is needed to bypass/remove it?


details about using the 2nd gen cap?

RX-8 has it ... the AST and overflow tank are combined into a pressurized expansion tank, high in the engine bay. most mfgs do this now. It has an added advantage of keeping system pressure up more consistently to avoid excessive local boiling.