ROSHX7

For some reason my Radiator Cap isn't sealing properly. I get some spurts of coolant around the rad cap area. It usually happens right after I rev the hell out of the car. THere is no coolant leaks anywhere else, just around the rad cap area. So I suspect my RAD CAP is bad...should I replace it with the Mazda original RAD CAP or should I try this more expensive MAZDASPEED 1.3 bar rad cap?

baix2

a higher pressure cap does make the fluid has a higher boiling point..
stock is 13lbs and comparing to 1.3 bar = 18lbs?? i dunno if it's safe or not,
i remember jim from mariah told me it's cool though

ROSHX7

According to the SHOP that sells the cap, a higher pressure rating makes the COOLANT flow around FASTER and thus reduces the engine temperature even more...is this TRUE or just some BS?

hurleyboi514

i dont know how just changing the radiator cap would help u run cooler, but ive heard the same thing alot. its worth the $20 probably. if not, it sure looks good!

fc3s.org

I would just go with the OEM cap. I have never had any problems with it, and I have no cooling problems.

baix2

oh yeah now i remember that my roomate who has a 240 SR20 motor, he just thought have a nismo rad cap was cool, so he bought one,
the pressure was higher, and he was on the freeway, and boom,
busted the radiator and coolant everywhere

it was a stock radiator though,
so i say don't risk it, if u don't have a cooling problem, stick with stock

baix2

i am not sure about that one,
but from what i learned from class, fluid mech or thermal

a higher fluid velocity usually has a lower pressure
just imagining a flow through a nozzle, pressure are gonna built up b4 the outlet nozzle area, and fluid accelerate through the nozzle outlet...and obvious they have lower pressure then..

just obvious when something is more pressurized, that means more force and stress on them... and i dont' think it will flow faster comparing to a lower pressure

BlackSport0187

Get the Greddy performance radiator cap from RX7.com. I've had it on my car for awhile, and have had no problems as of yet.

In fact my temp gauge used to reach the half way mark when my car was at full temp, after I installed the cap it now takes along time for the needle to reach it's maximum temp, and that is now only at the 1/4 mark. If RX7 only companies sell them for RX7s, then I'm sure they've done their homework, and any neccessary modifications (if there were any) related to the cap would be advised upon. Installing it on the stock cooling system is the easiest way to safely lower the temp.

Hope that helped,
Ike

P.S. My friend had the same leak, around the cap, so he got a Greddy too. He now has no leaks whatsoever, and his car also seems to run cooler.

NCsublime

I'd get the higher pressure cap. They definitely can reduce temps because of previously stated reasons. It's also probabaly cheaper. It's up to you though.

-Derek