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Allen Brown
05-20-2003, 09:59 AM
I have been running without my water pump bypass plugged off for the last three years in my GSL-SE. I've always had very high water temps and oil temps. I added a second oil cooler to bring the oil temps more in line. Recently, I plugged the water pump bypass. The change in water and oil temps were staggering. I removed my factory fan...I figured for short idle periods I could cool with the heater core/fan on high.

Water temps dropped from 230 to 185, and oil temp dropped from 225 to 195.

So...if you were putting it off this simple mod, or was thinking it can't make that much difference. IT DOES!!! I'm still wondering why I put it off for this long.

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Allen Brown
#36 IT-1
GT-3 in 2004
[email protected]

Eagle7
05-20-2003, 12:40 PM
I'm in the middle of that same procedure on a 2nd gen. I haven't yet found something to plug the bypass. It's about 18 mm. What did you use for a plug?

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Marty Doane
ITS RX7
CenDiv WMR

rx7chris
05-20-2003, 02:33 PM
If you'll check www.mazdamotorsports.com (http://www.mazdamotorsports.com) in the tech section it'll tell you what to do.

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/

Allen Brown
05-20-2003, 02:35 PM
Racing Beat recommends a 3/4 in. NPT plug once the bypass has been tapped.

I couldn't find a 3/4" tap.

So...Once I removed the water pump, I used 3/8" bolt, 2 large flat washers, 2 nuts, loctite, silicone. On the side of the opening closest to the pump side I fished up the bolt and washer up into the opening. Then on the thermostat side, I added the second washer, loctited the nut, jamnut that nut (and loctite), and some grey silicone on the few remaining threads.

The last thing I want is for the bolt to drop down into the waterpump and jamming the impellor. I didn't think 220F would affect the loctite, but if it does, I have the jamnut and silicone to offer a backup.

If you can find a 3/4 tap, go that direction. I just wasn't able to track one down in the short time I had available before I was going to work on the car.

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Allen Brown
#36 IT-1
GT-3 in 2004
[email protected]

Eagle7
05-20-2003, 07:40 PM
Thanks guys. Big help.

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Marty Doane
ITS RX7
CenDiv WMR

PPK
06-02-2003, 12:00 PM
HI GUYS, just wondering if any one is running a thermostat,if so what temp 160,180.When I checked my car it did not have one.At the april school I noticed my temps going up(w-220-240) and it was only in the 50s in LOUDON.Any help or ideas would be appreciated.
p.s. my bypass was plugged off.

Thanks,Peter
ITA#81
NEW ENGLAND DIV.

rx7chris
06-02-2003, 02:27 PM
Peter,
Had the same problem for about a year, then it finnaly bit me at Daytona. One motor later, i put in a stock thermostat, but i gutted it to act as a restrictor. If not i think the water moves way too fast to do any good. Also check your oil cooler, it does about 1/3 of the cooling for the motor, make sure it has good airflow!

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/

Allen Brown
06-02-2003, 06:50 PM
Well, I got to race the car a couple weeks back. Air temp was about 85F. When running by myself, the water temp were about 205, and when my front bumper was only a few feet from the back bumper of another car for a few laps, my water temp rose to about 215F.

This the best it has ever been. Ya, it probably could be better....But this is as good as it ever has been.

I am running just a gutted thermostat, racing beat underdrive double pulley system, a 3/4 height 3 core radiator, 2 oil coolers, (one under rad, and one about 1 1/2" in front of the radiator. Running water wetter, but I think I still have about 30% antifreeze mixed in. This could be reduced, and should help out a bit more.

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Allen Brown
#36 IT-1
GT-3 in 2004
[email protected]

ddewhurst
06-02-2003, 08:01 PM
Allen, water cools 2 1/2 times better than antifreeze.

Have Fun http://Forums.ImprovedTouring.com/it/wink.gif
David

bcarter
06-03-2003, 12:10 AM
Allen,

That was probably my bumper you were right behind...ha ha.

Anyway, get rid of the anti-freeze, it doesn't help things. I run a lot of water-wetter, and although in some cases I got my temps up to about 210, most of that weekend I ran around 200.

Just did a track day, testing, and never got the temp above 180. It was a chilly day.

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G. Brooke Carter
Wheat Buckley Racing
# 10 Challenge Car
2002 Class Champion
Calgary, Alberta

MKB
06-03-2003, 08:36 AM
Back to the thermostat! What is the best way to run.......with a stock one....with a stock one gutted or none at all???

MKB

Allen Brown
06-03-2003, 10:16 AM
From what I have been told, some restriction to slow the water flow is required. I'm not sure if the reason behind the restriction requirement is to keep water from moving too fast, thus allowing enough time to draw out the heat or the flow is too fast, creating voids or areas of water where the flow is almost stagnant with in the water jacket. Simlar to some pools near a water fall.

I prefer the gutted thermostat. Remove the flap only. There is then no possible chance of the thermostat sticking in a closed position.

Thanks David for the info.

[This message has been edited by Allen Brown (edited June 03, 2003).]

bcarter
06-03-2003, 06:20 PM
On my streetport, due to class rules I run a stock water pump, nothing plugged, and a stock thermostat. I don't overheat unless it is a really hot day, and even then it's never been a problem.

wlfpkrcn
06-03-2003, 07:14 PM
Hi guy's

I run the plugged bypass and 190 is as high as the water temp gets. Even on 100+ days.

Eric