I put it so it was the same orienation as the factory t-stat if i remember correctly...

so we will test the cap and tstat sometime this week it look like

Yep. I'll add more foam on the sides as well just incase. But we did put in the thermostat the same way as OEM James.

I thought we did...

Something else that comes to mind that if it is indeed the radiator cap.. why isn't a new one provided with the radiator? If people buy this whole package and know that the pressure and all will apparently be increasing.. why isn't a radiator cap apart of the deal? Just my thought.. and if we had instructions this could also be mentioned there, as a service manual wouldn't mention something like that.

Maybe I'll offer a cap and hoses in time.

Paul.

Maybe not include one in the sale, rather mention that in order to see optimal results the Rad cap should be upgraded.

Wouldn't it be "working results" in this case? I over nighted a Cusco 1.3bar cap btw incase anyone is wondering.

Wait I don't get it, why is there a need for an upgraded cap?

And if you need a cheap cap that has increases in capacity, you can get a Mazda Millenia cap from your local parts department for a few bucks.

There isn't necessarilly a need for an upgrade cap as demonstrated by the number of people who are running these products without issue with temps well below Zelse's even in higher ambient. I guess he's thinking "If I'm going to try a new cap I might as well go BIG".

Paul.

Not nessicarily. I was talking to another car guy and someone from a company I like to buy many of my parts from and they both actually said the same thing when I told them I changed the water pump..that I should've gotten a radiator cap to handle the higher pressure. I inspected the cap and it looks fine to me and feels like it seals fine, but again..I'm no expert. And if it's all about pressure, I may as well get a cap that holds a higher pressure...

Hi Zelse

I have done some cooling mods (radiator + change silicon hoses) and also the radiator cap to 1.3bar previously.
However my 4 mths old reservoir tank of cracked soon after changing high pressure radiator cap + see high temp sustained on track (112c ~ 234F). I cannot conclude that changing the 1.3 bar cap damage my coolant tank
but after changing to a new coolant tank (this tanks cost an arm :mad: ) and swapping back to stock radiator cap for about 5 mths and 3 trackdays in between, my current tank is still surviving.

First of all, that line of thinking is completely incorrect. Think about it, the cap is to hold more ambient pressure in the tank from the coolant and air in the system expanding due to heat. However, changing a water pump does not change the system air pressure in any way, shape, or form. The pump simply circulates the coolant more efficiently, it does not change the degree to which the coolant and air expand in the system and therefore the pressure in the system is the same whether you use the stock water pump or the RE-medy pump. Radiator caps are often misunderstood; they don't help keep your system cooler, they merely change the temperature at which your system tends up boiling over. However, even with a 0.9 bar cap that boilover temperature is so high for the normal coolant mixture that if you are even close to boilover, your coolant temperatures are so high your motor is already toast anyway. Many ill-informed tuners subscribe to the "bigger/higher/larger/etc. is better" theory and I think both of the people here have fallen victim to that.

This thread talks specifically about radiator caps: https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/higher-pressure-radiator-cap-ok-use-179454/

So in otherwords I just bought a new radiator cap for no reason..? I mean seriously the only other option is switch to OEM thermostat because no matter what I'm doing, I'm seeing stupidly high temperatures and I feel like I'm getting shots in the dark on how to approach this and not actual, technical approaches on what the problem could be. I'm not trying to throw anyone under the bus here..but it's like, no one has ever experienced problems like this before?

So should I change thermostat back to OEM for a test? Should I cancel the order of this radiator cap, or keep it and use it? And if I do the thermostat, do I need to flush the coolant again?

Again I apologize if I sound upset directly at anyone because I'm not, I'm upset in general. I stated my temps when I first got it.. I stated my concern..and no one until now finally said "oh hey.. your temps are high" and I don't feel comfortable when "throwing more money" at the problem is a solution is all.

LionZoo, still in Boston? If so, maybe we can hook up this week and you can give your thoughts in person?

I'd say cancel the cap. You can try switching back to the stock thermostat as a first cut and see if that cures it. If it doesn't, it might actually be your radiator, or something in your system that's causing clogs. Another issue; are you sure your temperature measurement is accurate?

I'm still in Boston, but this Thursday to Sunday I'm going back to LA (YAY!). I'll return next Monday. If you want to catch me before I leave, tomorrow evening is your best bet. Sorry about the no reply last week, I ended up not checking this thread as I basically spent the entire weekend in LSAT land. If you want to reach me, best way is through PMs as that gets delivered to my e-mail, which I'm always hooked up to.

hard to not get upset--but try to think how much you are learning here with this experience.
It is a fixable problem--it will take a little work.
If you think it is the thermostat--put the old one back in and try--do the hot water in the pan test on your new one etc.
make sure your fans activate when they should--you know the stuff etc.
Maybe you have a bad coolant sensor?
Who knows at this point.
Do the work and if you cant find anything--PM me --after you have checked everything out and its ok.
olddragger

The initial figures given to me sounded very normal (170-208 and returning to 180s). What I've seen since you've provided details here is that you run higher than normal for your ambient. You mentioned in an earlier post that you were on the highway running in the upper 180s and when you got off the temps moved to in excess of 210 (212,214) idling. I would strongly suggest again that you make sure your fans are working properly. It doesn't matter how well you move the coolant through the system if the air to the radiator is impaired, hence the reason people are speaking about making sure things are sealed well including having an undertray on the car. When you get with Lion Zoo I suspect that much progress will be made. Everyone (And especially myself) wants to help get to the bottom of your situation. I feel confident that you will have success soon and will be happy to do anything that I can to help.

Check fan function again. It has been a problem on some 8s where a fan motor can fail or even get jammed from foreign objects (Engine cover grommets e.g.)

Your humble servant.

Paul.

Well thanks guys, both Oldragger and Paul. Like I said, not directly upset at anyone, just hoping we get to the bottom of this. I actually have Greenblurr and Lionzoo coming over tonight to get to the bottom of this mystery, so I hope we solve this.

If I had a Sherlock Holmes hat I'd rock it tonight. I'll let everyone know.

Hi Zelse
All the best in trying to resolve your prob.

Cheers

So, we inspected the COBB Stage 1 tune and noticed that the low temp fan is set to turn on at... *drum roll please*

207. Yes folks... 207.

We set the low temp to 195 and the high fan temp to 205.

We noticed a SERIOUS drop in temperutures when cruising both on the street and the highway.

70 degrees out, sunny and nice, not really humid. Cruising at 30 mph in 4th gear it stayed around 190 - 192.

Highways cruising 190 and slowly dropping..didn't stay on long enough to see it really drop.

What we DID notice though, is accelerating very quickly on the highway...the temps SPIKED. From 190- to 214 in a minute.

Not sure everyone's thoughts on that, but we're planning on setting the low fan 194, and the high fan to 200. We're going to see how that goes later tonight and go from there. The cap seems fine on the reservoir... so not sure.

Just updating everyone...

(big ups to Ray from BHR on helping us on how to set the temps. :) )

Holy crap 207? That's about when both fans kick on for the stock unit. If you're reprogramming, you can try all kinds of fan on temperatures and figure it out from there. I'd use the Racing Beat temperatures of 188 and 194 for a baseline.

k so we tried the racing beat setting..LionZoo came on over...

87 C for low..
90 C for high.

Idle temp of 183 - 185
Cruising on the Highway and streets of 185 - 187
Beating on it on the highway REALLY hard.. I mean beating the bag out of it.. a gradual increase up to 201 and stayed there before slowly dropping.

So I'm guessing these are the temps we want to see. I'm glad, feels good, not worried. Only thing I'm a bit surprised about is...and James made a good point when he said this too is simply..

Are there anyone out there running stock PCM with this setup as well? If so, what temps are they seeing? It's just kind of surprising I'm the only person to say this and have to adjust the fan settings that much, you know? Thats just me though. Anyways..thoughts anyone?

Big ups to James and Lionzoo again.

My thanks as well to these guys who demonstrate a real spirit of brotherhood in the community of Rotary enthusiasts. I'm going to suggest that all the people who have commented here so far are probably using altered fan settings which is one of the reasons I've stated in the past that our products are a good addition to the RB flash or the Cobb AP (Especially with MM tunes). Your temps weren't terrible but, out of line with the figures we were seeing from other users.

Your case has been educational to me thus far.

Paul.

Gotcha, and a big educational experience to me as well. Thanks to everyone for the help, big ups to Ray for helping James on how to tune the cobb, big ups to James and Lionzoo on testing and going on test drives with me :) And big thanks to Paul for the help here as well and anyone else who gave advice.

As I mentioned, I wasn't trying to really point fingers, I just wanted to narrow down quickly what the problem was and was worrying as deadline got closer and closer. Thanks again everyone and thanks for the awesome product Paul. ;) Looking forward to seeing the hoses in the future.

glad it got worked out man---airflow does help!
OD

Sure does. Thanks for the advice also olddragger :) At some point, most likely Friday, I'm going to finish up the sides of the radiator with some extra foam to ensure it's sealed, just for the hell of it. May as well before nationals.