Last Thurs night I made 5 runs down our local 1/8 mile track. The first two were all motor, the last 3 runs I spayed a TNT 100 shot.
The first spray run I engaged at about half track.
Second run I engaged just past the 60' mark.
And the last run I engaged at the line but used a 5200 rpm pill that allowed me to get close to the 60' mark when it engaged.

The first 4 runs were a little hotter than the car has run in the past, around 200 degrees. But I didn't think a whole lot about it since the weather was pretty hot at about 87 degrees. I have a 160 degree thermostat and have my fans coming on pretty low. The car has been running around 195 to 200 lately on the street and it before I changed out my heads a few weeks ago it would run closer to 180 degrees all the time.

After the last run (my best BTW at 7.26 ET @97 mph) my check gages light came on the thermostat was reading almost all the way to the right close to 280 degrees. I quickly shut her down and waited for it to cool, checked the coolant and it was down added about a quart and a half water to it.

No problems with the hour drive home, temps stayed around the 180 it use to do. I was thinking that we must not have gotten enough coolant in it when we changed the heads. But now I think my 160 degree thermostat is bad or the nitrous has something to do with it. The next day we drained the coolant and refilled it with the correct coolant. Made really, really sure it had enough coolant. Then tonight while riding around we hit the bottle a couple of times, the temp was still good, then we did one more spray and there went the temp again, all the way to 280!! Shut her down to cool her off, and eased her home didn't have far to go, good thing because it still wanted to heat up too much. Checked the coolant and it was still full. Pretty sure it isn't the head gaskets, no smoking at all, and no water leaking out any where.

I am new to nitrous and wanted to see if anyone has had this happen with spraying? Or do does it sound more like the thermostat not opening up right. Sorry this is so long just wanted to give you enough info to help figure out what is happening.

Thanks for any help.

 

Air in the cooling system causing hot pockets=overheating...............

 

Yes, that's true. And it does seem that there might be air in the system, but we have gone through all the steps to fill it up. Filled up hot, cold, with cap off, with cap on, while engine running, when it is off, ect......is there something we are missing? If the therm. isn't opening up all the way, could that keep us from getting all the air out as well? We filled up while running the engine and let it heat up so the therm would open. It would bubble some......but the level wouldn't go down much..

 

You might be lifting the head. Are you still running your n/a tune with the spray? I know you and you might neet to pull alittle timing on the bottle. I only run *30 all the time. Did you notice if the overfill had any coolant in it when it was overheating?

 

What's your timing Becky? Did you change it after you ran the nitrous? You might want to bring it down 1 to 2 degrees. Have you been watching the temp on your computer or just the gauge? Reason I ask is because it could be gradually climbing and you wouldn't know it until it's too high then the (dummy) gauge will spike up real quick. Might want to check that.

-Sly

P.S. When did you change your heads???? What kind?

 

lol, I am running more fuel and less timing 29 with the nitrous. But your right, I didn't want too. lol

Car isn't smoking at all...and when it overheated last night it wasn't low on coolant. NL changed out the thermostat with a 180 and made a few nitrous runs today and it seemed to be ok. Didn't try to over heat, will put in another 160 this week I am hoping that will be the fix.....

 

Sly, you where there. lol We put NL's stock heads on my car after I had broke a valve spring. Remember? You are way to busy!!

I was just looking at my scanned runs at the track. And the first two times on all motor it was running hotter than it should. 1st. run was 201, 2nd run got up to 208. No knock and the O2s where in the 920s to 930s.

 

hey becky when did you get some spray how much of a shot? 920 930 litle rich huh . i had that problem when i changed out to a 160 therm i went through my steps and got all the air out of the system it has been fine ever since. give me a hollar when your planning to head to the track next time . im guessing that is at shady side correct

 

lol oh yeah now I remember, I am too busy nowadays

-Sly

 

Hey, I am spraying a TNT 100 shot.
Stock 02s aren't very accurate, it will vary from car to car. On my car when my stock 02s are reading 920-930 the AFR is about 12.5:1 I believe the nitrous might be leaning it out a little more than that. I want to keep it a little on the rich side until I get it on the dyno to see exactly where it is at to be safe.
I was running at Greer last Thrusday with good weather I will be in the 6s.

 

lol I understand that for sure!!!! lol

 

any belt dust around the engine bay?

 

I don't think so, why do you ask?

 

Belt slippin on the water pump on spray and makin it overheat.

 

Oh...........thanks. I have the better H/D belt and it was leaking on all motor as welll. So guess that isn't it. That would have been better than the heads leaking.

 

Thats not good.

 

me i would run a little less timing with the TNT, i think you also have air in the system