I swear I did a search but couldn't find anything...

Should I replace or remove the AST? i.e., what are the advantages/disadvantages of both?

 

I'd replace it. I'd think it's better to have as much coolant in the system as possible.

 

i'd replace it too. my thinking is it's there for a reason, so just replace it w/ an aluminum one. nick

 

Replace it. It's there for a reason.

 

I removed mine, picked up the part used from an 86 RX-7 and had it all completed in about 10 minutes (after the car cooled down that is).

Opens up the engine bay some and the car doesn't run any different or any hotter that I've noticed.

Cost for me $5.00

 

I replaced at first but after upgrading intercoolers there is no place to mount it, that I could find, so I removed it. I have not driven it yet to tell you the truth but I don't see why it should be a problem

 

If you remove it, you will not notice any difference. For those who claim that the extra coolant volume makes a difference, measure the actual volume in the stock AST. If your cooling system is so marginal that you need the few extra ounces in the AST to maintain normal operating temperature, you have other problems. The aftermarket ASTs work fine, but still take up space in an already crowded engine compartment.

 

The AST is there due to the stock steep angle the radiator sits at which causes air bubbles to get trapped. If you have a FMIC which sits the rad back farther and more upwright, you won't need it since there is minimal chance for this......no harm with or without.

 

A very good RX tech told me that, without it extra air WILL be in the system, and though the car may not indicate any hotter at the temp sender areas, "hot spots" can be formed elsewhere in the system by trapped air, and may contribute to coolant seal failure, etc.

Find a place to mount it, its there for a reason.

 

Its there for a reason!!! Its there for a reason!!!
So is the pre-cat, the 80 vacuum lines, the fpd, the crap plastic end radiator, the airpump, the cat, etc....
President Bush is there for a reason too!!!

Remove it, there is no need for the extra cost, space, weight, etc...
My car runs cooler then it needs to. I have no problems without my AST, and I haven't heard from any others who have had problems. It is just hearsay. You need to have your apex seals replaced ever 20,000 miles. Synthetic oil is bad.
Remember your stock AST is there for a reason too.

 

If you want less air pockets when filling the coolant system, try to fill up the coolant system while having the nose of the car lifted, in that manner the coolant will fill from the rear of the motor to the front at an angle, less chance of air pockets that way.

 

replace it

 

depends on your mods. If you have a front mount intercooler a lot of times you wont be able to put the AST. But, without any upgrades, i say just leave it.

Nathan

 

One of the many virtues of this forum is its entertainment value. After hearing some of the opinions pro and con re: the AST, I have reconsidered and will RE-install my stock AST, complete with its cracked top, on the leading edge of my sunroof, so it is up high to allow the air to settle out. It will be connected to the radiator with 3/4 inch diameter plastic garden hose to increase the volume of coolant in it, and equipped with a whirly-bird sprinkler attachment to bleed off the air pockets. Another length of garden hose, fastened with duct tape, will go from the roof-mounted AST to a stainless steel beer keg mounted between the Bose acoustic wave speakers in the rear storage area for additional coolant capacity. A Greddy POV will vent the beer keg into the right half of the RB cat back, just in front of the exhaust tips.

Do you think this will affect the aerodynamics or handling of the FD?

BTW- just... kidding...

 

lol!

 

Don't forget how much slower you will be in the 1/4 with all that coolant weight...

 

 

Thanks alot. I am now totally confused

Has anyone ever heard of an actual failure caused by lack of AST, or are people just paranoid?

 

Heh. It's worth $150 to me to replace it with a billet aluminum one and never, ever have to worry about it again, and not have to worry about anything else which may or may not harm your car as a result of moving it.

150 bucks. The end. It adds a little polished pretty look to the engine bay, too.

 

had my ast removed 6 months ago...it survived through this hot summer..so i think you will be alright with whatever choice you make. to ast or not to ast that is the question

 

LaRacer: yes, people have had it crack on them while driving. Not only do you risk overheating when this happens but you now have a slippery substance possibly spraying out on the road....

I normally agree with you Glass_man but your argument doesn't hold up with removing the AST. You state that the pre-cat, vacuum lines, cat, air pump, plastic end tanks, 80 vacuum lines were there for a reason too. Well, guess what, for the car to meet emissions, control the TT setup, and to reduce weight ALL of those things HAVE to be there. To me, you just argued that the AST SHOULD be replaced.

FWIW, I often hear air escaping from the AST after a hard drive. No one is going to convince me that it's not doing anything....

The facts are simple. There is absolutely no negatives to using an AST (other than the $150). Many people have run w/o an AST for quite a while with no DETECTABLE problems but since many of these people have lost an engine anyway, it's hard to tell if there really are no bad side effects. Why take the chance?

 

Here's a little science project for tonight. Go outside and drain every ounce of coolant out of the car you can get. Know how much that is? Less than 2 gallons. The AST holds a small amount yes, but a useful amount nonetheless when compared to the entire system's capacity. And for argument's sake the Pettit AST holds more than the stocker while also being bullet proof.

 

I think I'll play it safe and go with replacing. Maybe no one has had their engine blow up right after removing the ast, but I'm thinking about any long-term effects. Since my goal is a bulletproof FD I can't take any chances.

 

Not necessarily a bad thing. you could use it like oil slick and make te people you race fly straight off the road. Sounds like a bulletproof plan to me.

 

i would even replace the oem with another oem one since all the alum ones look different and i want an exact duplicate