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Yah, the one Advance Auto Parts rents out is a blow-molded plastic case with a hand pump/gauge and a bunch of different adapters. Find the right adapter, connect it to the reservoir, pump it up to 13 psi and watch the gauge.
You basically buy it for $250-$300 and it gets refunded when you return it.
I installed this radiator yesterday in my s2. The condenser mounting bosses were off just enough on one side that one bolt would not fit. Since I was too lazy to pull the radiator/fan assembly back down to give me room to notch the condensor bracket, I opted for the weight reduction/3-bolt mod. Those installing this might want to compare the condenser mount locations with the stock unit to see if anything needs to be done before getting the radiator in.
After I poured my 25% coolant mix +water wetter in I noticed the paper that came with it says not to use any cooling additives. We'll see how it does, I don't recall ever seeing reports of water wetter causing corrosion so I'm not too worried.
Oh, and it turns out super glue will not hold AC unit foam to metal, but loctite extreme works well.
I was talking to the guys at Koyo when I was buying their N-Flow radiator for my R32 and they told me to not to run water-wetter or any other additives. If I recall correctly, they said it would void the warranty.
^ Yup that was written on a sheet of paper that came with the radiator. I noticed it after install and fill.
BTW after some reading I drained out the system while still hot (not recommended) since the gunk is supposedly soluble when heated. Left a nice tar-like substance in a ring on the sides of the bucket that took degreaser and scrubbing to remove. Thanks again for the warning. Not sure how I've never come across that info after years of using the stuff.
no problem, I ordered an OEM replacement S2 manual trans radiator from Rock Auto today instead today. It was quite a bit less than my discounted S1 radiator from Mazda.
Since I'm not planning to use the OE fan/shroud I'm thinking (hoping/praying?) it won't have a fitment problem in my S1 ...
Originally Posted by TeamRX8
S2 OE replacement vs OE S1 radiator below. I only see three differences
1. S1 radiator is 27mm thick, S2 is 36mm thick
2. Lower mount posts have an extra extension length on them. Not sure if this on the factory radiator or not, but they would protrude below the car on my S1 so I'll just trim them off. Doesn't affect anything. EDIT: no issue at all, use as-is without modification.
3. The RH upper bolt-on point for the fan shroud housing was moved out from near the radiator inlet neck to the outer corner just like on the LH side. Not sure why the S1 had this shroud mounting point located away from the corner. Makes more sense where it is on the S2. I think you could make a metal bracket to extend over and use the S1 fan housing if putting this radiator in an S1 chassis.
I won't be using the OE fan/shroud assembly so no impact on me. Still can't get over how light this radiator is for the size ...
S2 on the LH side, S1 on the RH side
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Originally Posted by ASH8
Just in case you forgot your spectacle's..........
BTW: Thanks for side profile pic.
Originally Posted by TeamRX8
Forgot to follow up. S2 radiator fits the S1 fine. Extended bottom mount pins do not require cutting. Could probably even re-use the S1 fan/shroud assembly, just that only one of the two top shroud mounting bolts will line up, should not be an issue IMO.
just skimmed through the post quickly. so the only major issues of using S2 rad in S1 chassis is the mounting the S1 fan shroud? everything else fits fine like rad mount to chassis and hose location?
i have koyo s1 36mm rad now but considering getting the koyo s2 48mm rad. google search shows that koyo does make a racing version with 53mm core but doesnt say if it's for S1 or S2 and also noted that the lower rad hose was relocated.
Water Wetter is probably worth it if you're running straight distilled water (some race tracks or race organizations require glycol-free coolant).
But, yah, otherwise don't bother.
dedicated "race" car can only run water, or wont pass tech inspection. so water wetter is added to prevent corrosion and helps lubricate the water pump. in the North region, when temp gets below freezing, we're allowed to run 10% antifreeze.
I will never use water wetter again, especially in a rotary engine
what are the rules about anti-corrosion and water pump lubricity additives instead?
but yeah, it’s just one of the top fan shroud bolts if you still use that. No big deal imo, you can rig it some other way to secure the shroud on that side if you think it matters though.
can’t recall ever seeing them offer the 53mm core for this application, but the OE S2 core is sufficient for me. So I haven’t been looking specifically ar RX8 radiators in a while.
Looks like this is it in the diagram below; can’t find it on the Koyorad site, but a number of aftermarket merchandisers have it listed. As a vertical 3-pass it has to go down the inlet side, up the center, and then down the far other side with vertical baffles in between the sections. So that’s likely why the outlet is over on the far side
compared to the 48mm single-pass version
and not sure why they call it a dual pass here unless the center pass is so narrow that the high velocity negates any dwell time there, but this is the flow path I described
I will never use water wetter again, especially in a rotary engine
what are the rules about anti-corrosion and water pump lubricity additives instead?
but yeah, it’s just one of the top fan shroud bolts if you still use that. No big deal imo, you can rig it some other way to secure the shroud on that side if you think it matters though.
can’t recall ever seeing them offer the 53mm core for this application, but the OE S2 core is sufficient for me. So I haven’t been looking specifically ar RX8 radiators in a while.
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any particular reasons why not use water wetter, personal experience or from research? i've always used it all my track cars. never really looked into any side effects, or experienced any personally. it's basically just a thing people at the track do and everyone does it. lol
rules doesnt state anything about using anti-corrosion or lubricant additive, i guess as long as it doesnt make the water as slick as antifreeze.
did a quick search and found this. so definitely less corrosion. but probably not good for water seals on rotary?
Imo it just creates a tacky gum residue on the internal surfaces and there’s no way to guarantee how evenly it coats them. Also, based on my own heat transfer experience (design work for a vessel/tank manufacturing company) I think it acts more like an insulator. So while the “coolant” may run cooler, it’s because the insulating effect is inhibiting heat transfer from engine. You think the engine is running cooler because of the coolant temp gauge, but the engine itself is actually running hotter. Maybe I’m wrong, but I know for a fact that anything of density on the surface will inhibit heat transfer. Some of the tanks we build have a scraped surface agitator just for that purpose. In theory that should make the oil run hotter, but most people maybe aren’t looking for that or made other mods to offset it.
I also feel strongly that water without corrosion inhibitor is not good on the rotary iron plates. They’re very susceptible to rusting easily.
Did some digging and can’t find a press release on the 53mm core for the RX8. However, they state elsewhere that their 36mm Hyper-V core is equal to the 53mm core, but lighter. That’s the core used on Koyo S1 radiator. So the answer may not be as clear cut as you think.
that's interesting, maybe the water wetter react to antifreeze and create the sludge. although i didnt take notice when i used it on my Evo with antifreeze. it doesn't create the sludge when using with just distilled water. i was more concern that it might eat up the water seals or something.
when the shop put the rebuilt engine in a couple months ago, they didnt have any water wetter, so they just used water. i got the car back a week later and drain the water and there was already some rust in the water. there's also a ring of Vaseline in my expansion tank, lol. will try to use hot water to flush it out next time i flush the coolant.
maybe i'll try this purple ice stuff. their commercial seems convincing enough, lol. and no more water wetter "slime"
Did some digging and can’t find a press release on the 53mm core for the RX8. However, they state elsewhere that their 36mm Hyper-V core is equal to the 53mm core, but lighter. That’s the core used on Koyo S1 radiator. So the answer may not be as clear cut as you think.
yeah, racer mentality. we just assume anything that's bigger or more, is automatically going to be better. :D
IIRC, the thicker S2 radiator does not outperform the S1 radiator. My experience notated in this thread shows the S2 radiator barely outperforms the OEM S2 radiator.
My experience with Water Wetter mirrors Team's. I use water plus Mocool in my track cars instead.
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Last edited by Steve Dallas; 07-22-2020 at 07:59 AM.
+1 on staying away from 'Water Wetter" for above mentioned reasons. I would actually extend that mentality to all Redline products imo; been that way since late 90's early 00's to my knowledge.
+1 'MoCool' is much better alternative, used on track many times. I personally like Motul very much.
And fun fact about the 36mm Hyper-V core. Def to the one to get Imo.
I’ve always scratched my head on why they didn’t just make one 36mm Hyper-V core that could fit both the S1 and S2. It could easily have both bolt patterns for the fan shroud difference and they otherwise are interchangeable
that would require them to have both cars on hand for fitment testing? since the OE ones have different dimensions? why did mazda even made those slight mounting changes.
They already had the S1 radiator, all it needed was the other fan shroud bolt hole added, but maybe there was something I’m missing for a bone stock car with all that factory junk in the front.
04-18-2018, 07:52 AM
