09Factor

^^^ BTW it is easier to unplug the stepper motor and remove the TB to take the bottom hose off. Use a 10mm socket for the 4 bolts.

To clean up the engine bay I went so as to remove one of the hoses.
The hose that was removed was the one that connects to the rear rotor end place (iron).

Take the front one that connects to the coolant inlet ( follow the hose back to where it connects) and attach it to where the rear was connected.

While doing this you will spill coolant on the block. If you don't want the smell when the car warms up, use some rags. Don't forget to remove them.
I'll have to post pics sometime.

canaryrx8

iTrader: (3)

I got it done no problem, although i had the worst luck with dropping stuff into the engine bay last night while working on it which added about 20 minutes to a 5 minute job

bxb40

Reading this with interest... the post that got me here was from "Old Rotor" and he claims that this simple mod allows him to run 87 in warm/hot weather.
https://www.rx8club.com/rx-8-discussion-3/no-more-detonation-%2Amiac%2A-121249/
This info seems ignored in this thread but it might be used for the final explanation... if there is one.
My car has identical issues with Old Rotor, hence I'll do this DIY asap... and hope for the same happy ending ;o)

canaryrx8

iTrader: (3)

Would there be any way at all this mod could have a possible,remote,other-wordly effect on gas mileage? I noticed after doing this and prior to my engine being swapped that after doing this mod I gained about 60 extra miles out a single gas tank. I was averaging about 200-210, after doing this (and nothing else) I'm now sitting at 210 with over a 1/4 tank left. This is also the case with the new engine but I suspect that may be because it's new I do have an AEM intake installed as well, but it's benn on there a long time and as I mentioned, nothing else had changed when I originally noticed the improvement.

StealthTL

iTrader: (1)

Not too likely.....

The mod might affect the IAT but it is after the air has been measured, and the fuel is already dialed-in - so too late to effect the ratio.

S

canaryrx8

iTrader: (3)

that's what I figured, just trying to figure out why my car has suddenly started to get better mileage, and this is the only thing that has changed....weird.

HCTR154

^^^I read somewhere on this forum, that warmer weather = better mileage and that cooler weather = more power. Maybe that explains it....but probably the explanation lies with your right foot!

TeamRX8

iTrader: (25)

lol, a 1/4 fuel tank indicator could actually mean almost empty from what I've seen so far, it's definitely not linear many times

Stingray

I just did this mod...took about 30 minutes...I only had a coupler, 1/4 and used the original clamps...I also had a 3/8's but i just couldn't get it to fit in all the way...I just pushed the lines under the throttle body and then capped the nipples on the throttle body with some vacuum caps I had laying around

Ktreece777

Does coolant come out when you disconnect the hose?

jeffe19007

Yes, coolant comes out when you disconnect the hose.

And as 09 says, dry it up if you don't want to smell it for a while. For a couple of days I was inspecting for leaks due to the smell.

I did both this change and the MazSport fan control. No leaks yet.

jeffe19007

Further photos for those that may need them.

First shot is upper throttle body with coolant port capped and clamped.

Second shot is where I trimmed back the coolant lines and looped them into each other. They are at the red wire tie binding the rubber hoses together. I only trimmed back the upper hose, which I retained on the off chance I move to cold county.

The third shot shows how I routed the wiring for the relays to the MazSport fan controllers. I routed them across the tower brace and in through the existing entry into the fuse box, as opposed to across the front of the car and into a new hole MazSort suggested.

And don't mind the dirt it has been a little dusty here lately.

09Factor

Jeff, Between the TB mod and the Fan mod any noticeable changes?
Like , Throt response, takeoff from stoplights...

bxb40

Quick update - I did the mod using the screw, and my pinging on 87 gas is gone, just like "Old Rotor" mentioned... The only explanation I can think of is turbulent flow of coolant is not possible anymore, and that would have been the cause for the noise.
Monitoring coolant temps: 95 to 102C, depending of driving style and ambient temps.

DOMINION

I found the link that MM posted great!
http://rotaryinsider.com/rx8-59.html

But can someone tell me where I can find the the bottom TB hose in the first pic so I can trace it to the bottom of the TB?
I'm pointing to the top hose right?



This is the top hose right?



Gos to the top of the TB



But I can't find where to trace the bottom hose so I can use the 5/16" barb and hose clamps

Thanks,
-Gil

expo1

You didn't remove the intake tube. Things become much clearer once you take that off. You also can get by without cutting the hose in case you want to put it back on in the winter. In THIS photo you can see the TB hose next to the oil fill tube.

DOMINION

Thanks bro I'll do that. I'm on my way to homedepot now to buy my parts and will post pic's in a bit

DOMINION

OK I just got back from homedepot and they don't have any 5/16'' barbs so I got a 1/4'' and a 1/8'' brass pipe nipple. Think these are too small?
I should have went to lowes

mysql101

it's hard to find the correct size. You can get one size too big and jam that sucker in deep enough that it can't leak.

DOMINION

Still working on it. Eating dinner now. I'll post pic's when its fin.

DOMINION

Wow it was not that hard at all. E.T.; was about 20min. Looks kinda funny but oh well. I did not cut the hoses so if I need to undo this mod I can still put it back

Don't think you guys need pix but if you do let me know and the 1/8'' brass pipe nipple worked great!

jeffe19007

I found the correct 5/16" barb at Ace hardware. The local Home Despot didn't have that size. Not even a hook for it.

Dave, didn't see your post earlier. This change seemed to help hot weather drivability. I mean better idle, and better throttle response on those really hot days.

For those that live in colder country, can you tell me how cold it needs to get before putting this back in place is a good idea? In case I take my 8 on the road in the winter.

DOMINION

+1^
I parked in the shade cars temp was showing 101 and did not move. Also the fans where not running as hard and no bog down on rpms well parked with the A/C on.
Temps are way down now that I have don this mod and A/C was on for the rest of the day for the drive home. Have not had a day like this for a long time. I norm dont drive with the A/C on but my temps where not going over 118 like befor! Also seams to cool down way faster.
I recomend every one in the hot are of the us do this mod.

Michael's8

Forgive me if this is a stupid question, (and I fear that it is, but don't know any better so I must ask):

If I were to install the Mazdaspeed CAI, is this mod something that can/should still be done? (Probably at the same time I'm doing the CAI, right?)

I bought the MS CAI, but haven't installed it yet. (Just moved and my garage is totally trashed). Just not sure if putting the CAI in changes anything. We have just moved to Mississippi, and it's REALLY hot here. Thinking this would be good for me if it is still viable with the MS CAI.

Thanks to anyone who can offer some advice. Does anyone here have the MS CAI who's done this? Any feedback?

Take care, everyone, and thanks again.

Michael

DOMINION

The MS CAI will just replace your stock air box.

This mod will help keep your TB cooler IMO, and it takes about 5 min to do.
If you know your 8 (and I know mine) you will feel a jump on the gas peddle also keeps your car cooler IMO. My fans don't come on and off and on and off like befor, but run at a nor pace then high when need to. Also when useing AC and comeing to a light or stop, no bog down on RPM's or jumping odd idle that every one states is nor when AC in on.