I have one of these on my car(came with it) and I have read here that it looks like it's not a good idea to have one due to pressure levels being raised. I also read some past threads about stock OEM ones not fitting properly. So where can I get one that fits that is safe / works properly and will fit my series 3 JDM TT :D

tis a good question... my new koyo has a nismo cap on it and i wasnt sure wether to keep the old girl on or not...

ive run with a Nismo rad cap for ages - both on a stock rad and currently on the Koyo, without problems. Ive had loads of running temp problems in the past, which i thought could be linked to the cap, but these were down to the thermostat, and the airflow being blocked by the number plate! now it runs as cool as Michael Knight in a leather jacket with the sleeves rolled up :cool: :cool:

no probs with mine mate.sound as a pound.

I've had no probs with mine tbh but have read a few thread past and present about rad pressure raised and wondering if I should be concerned

There is no advantages to increasing the stock pressure, it does not reduce coolant temps it only increases the temperature of the fluid at which point it boils. If the Coolant temp is boiling with the stock cap then you have problems elsewhere and adding a higher pressure cap will only make things worse.

 

There are downsides in regards to the extra pressure placed on the radiator, pipes and waterpump - an increased risk of leaks.

 

Thats not to say you will encounter problems. If you have one and its been fine then fair enough, up to you if you want to revert back to stock , but there is no reason for somebody to replace a stock cap with a higher pressure cap.

Edited September 5, 200916 yr by Yowser

are all the stock caps the same? ie all models: na, tt, series 1/2/3/4 ?