PoMan Ferrari

I will make a bracket for you over the weekend so you can mount it on the cross bar where the original AST bracket was bolted on. I forgot to tell you that all the cars I have done have the AST eliminated. AST is just trouble. It does not really do anything.



I will have the Hiper Damper group buy page up over the weekend as well. Thank you



Chuck Huang [/quote]

Chuck,



I would not dismiss the AST out of hand. Why?



I can explain but it would take more than a few pages of technical description. For the sake of conciseness, lets ask a few questions:



1. Car companies are notoriously cheap; if they can avoid putting a part on a car, they will. Then why does Mazda built a special tank in addition to the overflow tank?



2. Mercedes, BMWs, Audis, Volvo and even some American cars use an AST. Their AST don't look like ours b/c their ASTs are real AST containing about 1.5 to 2 quarts of coolant.



3. O-rings are used for seals where clearance are large (like in rocket boosters). O-rings don't seal well below their operating temperature. Our engines use o-rings to seal the coolant passages. At room temperature, they tend to allow air in (Check with KD rotary on this). Why not use an AST to eliminate air in the system?



Eliminate the AST if you think they're not worth the trouble but at least look at the evidence objectively before dismissing it out of hand.



In my case, I eliminated the factory AST so that I can use a Volvo AST from an S-70. No more coolant buzzer and not knowing my coolant level. I'll post pictures if enough people bug me about it. [/quote]

I don't want to turn this thread into an AST debate but let me just briefly share my experience and thought on it.



1. I have eliminated AST on my car for over 4 years never had a problem.



2. How does AST eliminate air? There is a pressure cap on there which opens up at 0.9 kg/cm2. It normally will not open, otherwise, all your coolant will be going to your over flow tank and that usually means your car is overheating. So that cap will not open until your car is overheating. If there was really air inside the cooling system, it will stay there until the cap opens.



3. When AST is eliminated, a 2nd gen water filler neck replaces the stock one and you bolt the AST 0.9kg/cm2 cap on there. There is a hose which goes from the neck to the over flow tank. So your water pump housing serves as an AST now.



4. So why did Mazda put an extra AST there, I have no idea. I just know the stock one splits easily so the Mazda engineering department isn't that thoughtful in my opinion.



5. If your water seal do not seal well, that means the exhaust gas is going into the coolant passages heating up the coolant and that means overheating and a new motor. An AST is not going to save your motor from a leaking water seal. It does not take too long for 1200F exhaust gas to heat up the coolant and make it boil.



6. I personally think the stock AST is just redundant, especially when it is so small in size. And that's probably why I never saw any advantage of disavantage of using a stock AST or an aftermarket or not because their beneficial factor is too small to measure.



If you have some technical bulletein that you can share with me and educate me on this subject, please direct me to a link or book. If I said any thing wrong above, please correct me as well. Thank you



Chuck Huang [/quote]

Here's my set up:



http://www.rx7club.com/forum/showthread.ph...threadid=186995

apexkw

vmounts are awesome....

amp

chuck....i have a concern on rad drain plug location..

not in the ideal location..above low point ..looks reversed from the pics

rotaryextreme

that has been taken care of. it's on the back side now.



Chuck