Similar ambient temps to previous track days?

wow, if that's with similar ambients, i'm pretty excited...! I'm going to be trying to finish up my install this weekend. Leaving the fan shroud intact as much as possible and moving from my RB to the AEM intake for a little more room... the hurdle for me is going to be the battery tray.

Did you end up putting that air duct for the battery tray back in? with the added thickness of the radiator and where the inlet / outlet is, i imagine that would be a tight fit, if it fit at all (not to mention the effectiveness of it with the tray cut off there). Any thoughts / concerns on the battery not getting pre-radiator air?

Great feedback Dan, thanks for sharing and glad to hear your results were so positive! So your results with the same car, on the same track with very similar weather conditions show a 40-50 degree reduction in temps over the stock OE radiator! :ylsuper: Fantastic! This is a HUGE improvement in reducing engine operating temps.

Yes, similar temps. Maybe a bit cooler last weekend in the early session, but not enough to be materially different from prior days in the afternoon sessions.



Sorry, I’m not sure what air duct you are referring to. I did reinstall all the battery tray parts thought, albeit somewhat hacked…

I didn’t have any concerns, should I?

Mine has a small duct that takes pre-radiator air and funnels it into the opening on the bottom of the battery tray (should be stock, at least on the S2, since i have a stock engine bay minus the RB intake).

I don't know that it makes a huge difference given that there is no outlet for the air - but if you never even had it, I guess I really shouldn't have to worry other than the heat killing the battery a little prematurely, if anything...

I could be wrong, but I think the previous results were at Laguna Seca. My own data shows that I run about 10-15 degrees cooler at Sonoma than LS so you might be exaggerating these results a little.

On the other hand, this is still undoubtedly an excellent result. 235+ basically means previously the cooling system was overwhelmed, so it could have gone even higher if not limited by the ECU and the driver backing off. 180-190 with the new setup implies there may well be some cooling capacity to spare, since that is around where the thermostat opens (so may even be lower if the thermostat was not working to keep temps up).

I was at the same track with very similar conditions the following day, and my own ECT temps flattened out at 210F (with 70F air temps). That's with a koyo s2 radiator. Still not an apples to apples comparison, since we don't have quite the same setup or laptimes (expect my car is generating a little more heat) but it is a very positive result for Dan's car to be 10-20F cooler than mine.

So after working on it on and off for the last 2-3 weeks, we finally got the radiator in with the stock fan on (some of the ac lines are a little stressed / flexed due to the additional thickness). I don't know how escapedan got it done in one or two days, that amazes me, lol. I haven't even gotten to fitting the hoses, the battery tray or the intake yet.

The stock fan shroud has to be cut on both sides to accommodate the a/c lines, otherwise you won't be able to get the a/c condenser to fit, and I don't know if it's different on the S1 vs the S2, but my a/c condenser bolts in the stock radiator were M6x1.25 (i think) whereas the ones that go in the radiator ar M8x1.25 (essentially the stock bolts were too small / narrow for the hole in the dual pass). The hose routing seems simple enough, but the area that is being worked with is tight (at least for someone like me who is a mechanical noob).

Once everything is in, it's really really tight and snugged down with the way the brackets and everything is set up. There is zero play / give in the radiator from underneath when I try to move it a bit.

Looking forward to getting everything else put back together after cutting the battery tray and putting the AEM intake in over thanksgiving weekend. With any luck, I'll be able to get the car started and start prepping for the next track day in 2 weeks!!

all done (I think)!!

Battery tray cut, but still fits the stock battery (I didn't have to cut the shroud). AEM intake is perfect since it gets the airbox out of the way. I plugged up some of the air gaps using rubber weatherstripping - i hope it holds...

as for the hoses, you'll need a hose with a 90* bend where one side is longer than the other for the return (sorry - didn't measure it... 18" or so on the long end...?? not sure). For the radiator inlet hose, I just cut the lower radiator hose that was removed to attach to where the stock hose went. It's like a 5-6" piece with a 135* bend in it.

One thing regarding the a/c condenser mounting points - the stock ones were smaller than the M8x1.25 on both the bottom and the top. I bought replacement bolts for the bottom and didn't think i had to get some for the top. Two trips to the hardware store like a noob. Also - the holes in the condenser bracket were too small up top, so you'll have to dremel away some of the material to make the hole larger.

Car started back up no problem, I didn't leave any leaks that i'm aware of (yet), fans are back up and running, will drive the car around for a bit next week before the track - will report back with results...

I should say - the install wasn't overly difficult per se, but it was definitely more involving than I expected (though to be honest, this was my first time REALLY in the engine bay).

The piece looks good, and i'm hoping it performs just as well as escapedan's!

Any photos on how fan shroud fits and overall fit.

no - i should have taken more pictures before i put everything back together... the pegs on the bottom are pretty tight of a fit - everything else bolts up fine. Ill take some pics and try to post them.

The fan shroud itself (on an S2) needs a cut on the drivers side to accommodate the a/c condenser hoses and on the passenger side to accommodate the inlet / outet pipes (make sure you cut and allow enough space for the hose too - i ran into a tight fit there for the upper hose).

If the shroud is cut then the air will escape from the sides. So the sides will have to be sealed for it to be effective.

yeah, I put some weatherstripping in there, but did it after the radiator was installed. Probably not the best application, but I was able to close up most of the openings. If i ever go through the hassle of taking everything apart again, I MIGHT try to do it better... only if absolutely needed though, hahaha

There were some gaps on the top and sides on mine, plenty of space for the fans to pull air around the radiator instead of through it. Ari suggested black foam. Since there is currently no engine, we have plenty of room to work. I will take photos when the engine is back in and the shroud fixed. Ideally, I would use the fan shroud Scott has designed for this radiator, but he has gone radio silent as of late.

Scott, where's the fan? My RX8 was a good little boy this year! Bring him a present!

Lol, we're here and working on it Chris! Only so many hours in the day but we are getting close, should be ready for the holiday shopping season!

Quick update - was at Laguna Seca yesterday (27 Dec) and it was cold outside. Air temp was 50 degrees. Car stayed planted at 185 degrees all day. I'm convinced this radiator is rock solid. I would continue to highly recommend it to anyone with overheating issues.

sorry - i had a similar update from Laguna on 12/12-12/13... couldn't get the temps to budge past 190...

I'll be doing some track days with a little more heat over the summer - it's a bit to wait, but that'll end up being a better comparison on the track in 95* temps...

2 days at chuckwalla this past weekend. got the t-stat all the way open, though temps didn't really get past 208. Was reading between 200 & 208 every time I looked at it. This was during 30 minute sessions on saturday and 20 min sessions on sunday, with a 1hr session at the end of sunday. Ambeints between 65* and 75* depending on whether the sun was out or not.

1st time at that track though, so no accurate comparison data.

Results
 

This past weekend the SCCA was at road Atlanta. I spoke with a customer who competed over the three day event and was quite pleased with the before and after results. Tim reported the car consistently ran 185-195f during all of the sessions with the new dual pass radiator. This was 20 and 25 minute qualifying as well as the 25 and 40 minute races!

By comparison, when previously running the Koyo unit the temp's would be in the 230-240f range and in traffic, even higher. Congratulations on the pole position and the win Tim!

A bit more info from another customer (supercharged track car) regarding capacity.
RX8Performance 3.87l
Ron Davis 2.7l
Koyo 2.3l
Oem 1.95l

Thank you Rolf for noting the differences during your testing.

Impressive!

What was the ambient temp at the track?

Tim was quite pleased with the results. Previously he had to start short shifting to cool it down and when drafting other cars the temps rose rather quickly.

Impressive !

I spoke to him Saturday night after the event and I believe he said in the mid seventies IIRC.

Hey guys, fan shroud assembly is up!