RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   3rd Generation Specific (1993-2002) (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/)
-   -   Why shouldn’t everyone use Evan’s NPG+ coolant? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/why-shouldn%92t-everyone-use-evan%92s-npg-coolant-99933/)

Fritz Flynn 10-17-05 12:27 PM

Mazdacomp front bumper
Mazdacomp radiator
CW oil coolers
all the above very well ducted. I used to have a big ass splitter on it which probably helped even more but I took it off.
the real secret is running a t78 at 11lbs of boost hehe :)

I think in some of my track videos I have up you can see the temp gauge. This car typically runs about 160 or so but the hottest I've yet to see is 190. I love taking out passengers who own 3rd gens and tapping on the gauge when it's like 85 out and the water temp is 170 hehe :) I'll look to see if I recorded anything from the BMW event at VIR when it was so hot. It was probably more like 98 or 100F out that day but who's counting LOL :)

Again what are your oil temps and please loose the attitude :bigthumb:




Originally Posted by Jack
You are saying you maintain 190f on a 95f ambient day on a race track????? well inless you have a purpose built race car (GT3) or have made a pack with the devil you are the ONLY Rx7 track guy I know who has accomplished that feat....Will you share your engineering secrets with the rest of us???


Fritz Flynn 10-17-05 12:52 PM

Jack,
Look at the temps at Summit last NOV in the video titled "Summit NASA 11-04 Decent Lap 1.24". Link to the video is http://fritz.sysadmin-racing.com/ The temp outside that day was probably 55 or 60F The car's running in the 140s. This is the only video I could find that has the temp gauge visible.

Thanks,
Fritz

Jack 10-17-05 01:13 PM


Originally Posted by Fritz Flynn
Mazdacomp front bumper
Mazdacomp radiator
CW oil coolers
all the above very well ducted. I used to have a big ass splitter on it which probably helped even more but I took it off.
the real secret is running a t78 at 11lbs of boost hehe :)

I think in some of my track videos I have up you can see the temp gauge. This car typically runs about 160 or so but the hottest I've yet to see is 190. I love taking out passengers who own 3rd gens and tapping on the gauge when it's like 85 out and the water temp is 170 hehe :) I'll look to see if I recorded anything from the BMW event at VIR when it was so hot. It was probably more like 98 or 100F out that day but who's counting LOL :)

Again what are your oil temps and please loose the attitude :bigthumb:

Is your car Jim O'brian's or Brad Barber's old car? If it's Jim's I drove it at Watkins Glen about 6 years ago. I beleive he was running a T78, he's was delighted on how low he could keep his water temps. btw I have no attitude, Evans has had a number of engineering reviews from various magazines and racers. The product will operate hotter than water under the same load however is far superior to water when a coolant system is pushed. Also I don't have a oil temp guage so I could not give you that info. I challenge people when they make blanket statements to qualify if it's based on opinion or enginnering so should you...

Fritz Flynn 10-17-05 01:28 PM

I understand perfectly the concept behind Evans but I'd rather fix the problem than relieve the symptom.

With the water temps you're running I would invest in an oil temp gauge because with your temps at 268 it's likely the oil could be equally as high and that of course will prematurely wear your engine.

I bought Brad's old car :D I saw Brad's car for the first time 4 years ago and tried to duplicate his design but I'm a cheap bastard so I just took a bit of short cut.

Jack 10-17-05 01:29 PM


Originally Posted by Fritz Flynn
Jack,
Look at the temps at Summit last NOV in the video titled "Summit NASA 11-04 Decent Lap 1.24". Link to the video is http://fritz.sysadmin-racing.com/ The temp outside that day was probably 55 or 60F The car's running in the 140s. This is the only video I could find that has the temp gauge visible.

Thanks,
Fritz


Do you run a thermostat?? you should not run a car flat out with temps in the 140's, 180-190 are optimal coolant temps for a motor.

Fritz Flynn 10-17-05 01:42 PM

I agree the oil pressure is killing me. It's been very difficult to keep the pan sealed :o:

I've since been blocking the coolers off some but thanks for the tip.

Please get that oil temp gauge and revitalize this thread next year with the results :)

It has a drilled thermostat.

In your experience why is it dangerous to run a car flat out with oil temps in the 140s? I'm not trying to be a smart ass I just want to hear from a knowledgable member.



Originally Posted by Jack
Do you run a thermostat?? you should not run a car flat out with temps in the 140's, 180-190 are optimal coolant temps for a motor.


CantGoStraight 10-17-05 02:29 PM


Originally Posted by potatochobit
evans is not practical for street use.

if u ever needed to fill the radiator you would not be able to due only being able to add evans.

This is an interesting statement.....not practical for street use ? ? ? ? If for what ever reason you would need to fill the radiator, I can only think of major failure of one component or another, or a wreck, neither of which you will be driving home from. If a major component needs to be replaced then you simply fill it with "normal fluids after the repair and then redue the Evans treatment after all is fixed. I'm thinking two + years on this stuff in Fla heat and I'm not worried about blowing up a hose, water pump bearing failure or corrosion, so what other than a wreck would cause me to have to add coolant ? ? ? ? Even a belt failure would be caught before damage with this coolant. I guess I'd deffinately have to dissagree with your statement.

KevinK2 10-17-05 03:39 PM


Originally Posted by Fritz Flynn
Mazdacomp front bumper
Mazdacomp radiator
CW oil coolers
all the above very well ducted......:

When you have the flow openings of a mazdaspeed front bumper, you could run Maalox in a stock radiator and stay cool. example:

http://memimage.cardomain.net/member...74_57_full.jpg

Jack 10-17-05 04:06 PM

I thought you were referring to your water temps, however 140f is on the low side of optimal for oil. There is some very good SAE research done on the subject.

Regarding oil temp gauge, yeah I should....regarding high water temps, went to a single turbo last year, helped things conciderably.





Originally Posted by Fritz Flynn
I agree the oil pressure is killing me. It's been very difficult to keep the pan sealed :o:

I've since been blocking the coolers off some but thanks for the tip.

Please get that oil temp gauge and revitalize this thread next year with the results :)

It has a drilled thermostat.

In your experience why is it dangerous to run a car flat out with oil temps in the 140s? I'm not trying to be a smart ass I just want to hear from a knowledgable member.


Jack 10-17-05 04:22 PM


Originally Posted by Fritz Flynn
I agree the oil pressure is killing me. It's been very difficult to keep the pan sealed :o:

I've since been blocking the coolers off some but thanks for the tip.

Please get that oil temp gauge and revitalize this thread next year with the results :)

It has a drilled thermostat.

In your experience why is it dangerous to run a car flat out with oil temps in the 140s? I'm not trying to be a smart ass I just want to hear from a knowledgable member.

http://racingarticles.com/article_racing-44.html

Fritz Flynn 10-17-05 05:09 PM

Yep the front bumper is probably THE best cooling mod you can do for this car.


Originally Posted by KevinK2
When you have the flow openings of a mazdaspeed front bumper, you could run Maalox in a stock radiator and stay cool. example:

http://memimage.cardomain.net/member...74_57_full.jpg


Fritz Flynn 10-17-05 05:21 PM

Jack,
My oil and water run hand and hand.

Basically I don't see a huge problem with low temps other than pressure or pumping stuff but I do see a big problem with using Evans coolant and having high oil temps.

Anyway to each his own I've tried it and didn't like it. If your getting lots of track days out of your car with no problems then keep up the good work :)

If your driving these cars on the street fuck evans and everything else. Stock is all you need. JK......... :bigthumb:

Happy Evans motoring everyone I've said my piece,
Fritz

GooRoo 10-17-05 05:39 PM

I agree, but I would add one other thing to the list:

1) Like you said, large front opening bumper (I also have GTC like that pic of Damian's car)
2) Most importantly: seal the front bumper (really seal, no openings at all if possible) to the radiator with a duct.

I also took a couple additional steps, that I don't think are required for everybody for various reasons:

1) All aluminum radiator so it won't spring a leak (I lost two stock rads with plastic end tanks before upgrading)
2) Evans coolant
3) Since boiling point of Evans is so high, I switched to a no pressure cooling system
4) Since I won't get air in the coolant, I eliminated the AST
5) Since I live in a cooler climate and it's a street/track car, I removed the A/C
6) Metal screen covering all openings to prevent debris from bending fins (Even protected it from a rabbit hit at 65 mph)

http://www.93fd.com/gallery/main.php...serialNumber=2

Results:

10psi boost (35R Single,) 5 sessions per day at Road America, 65-70 degrees ambient, coolant never was over 87 C on the PFC, and that was after following someone closely for a lap

10psi boost (35R Single,) 20-30 minute sessions every 10-20 minutes for 9 hours (minus one hour lunch break) at MAM, 80-85 degrees ambient, coolant never was over 90 C

As an added bonus, I also added a second oil cooler to my stock single cooler system so that the oil temps will be low too. I don't have a oil temp gauge yet so I can't report on those temps yet.


Originally Posted by KevinK2
When you have the flow openings of a mazdaspeed front bumper, you could run Maalox in a stock radiator and stay cool. example:

http://memimage.cardomain.net/member...74_57_full.jpg


ericgrau 06-25-06 05:26 PM

I think I should clear something up on overheating: 200-300F IS NOT HOT ENOUGH TO HURT YOUR ENGINE AT ALL. Overheating occurs when metal actually melts and welds back together. According to my materials class, aluminum melts at 650C (1200F), but can only be used up to 190C (370F) before softening. This is impossible unless the coolant boils, whether through boiling at localized hot spots or if all the coolant is at boiling temp.

Evan's claims to eliminate localized boiling & hot spots because it never/rarely boils, even on a local level. If it really does this as claimed, it should be a great help to your engine even if you run it at 300F all the time. Evan's even recommends installing a higher temp thermostat for better engine efficiency (small increase in HP & mpg). Localized hot spots occur when coolant boils in small areas. Vapor doesn't conduct heat very well, so the hot spot stays that way. The reason it is normally bad to have a high average coolant temp is because there are more local temps above the boiling point. The question is, does Evan's perform as claimed?

What I'd really like to know is how well & how long people's cars have run with Evan's in them, before I pour money into it.

CantGoStraight 06-25-06 06:02 PM


Originally Posted by ericgrau
I think I should clear something up on overheating: 200-300F IS NOT HOT ENOUGH TO HURT YOUR ENGINE AT ALL. Overheating occurs when metal actually melts and welds back together. According to my materials class, aluminum melts at 650C (1200F), but can only be used up to 190C (370F) before softening. This is impossible unless the coolant boils, whether through boiling at localized hot spots or if all the coolant is at boiling temp.

Evan's claims to eliminate localized boiling & hot spots because it never/rarely boils, even on a local level. If it really does this as claimed, it should be a great help to your engine even if you run it at 300F all the time. Evan's even recommends installing a higher temp thermostat for better engine efficiency (small increase in HP & mpg). Localized hot spots occur when coolant boils in small areas. Vapor doesn't conduct heat very well, so the hot spot stays that way. The reason it is normally bad to have a high average coolant temp is because there are more local temps above the boiling point. The question is, does Evan's perform as claimed?

What I'd really like to know is how well & how long people's cars have run with Evan's in them, before I pour money into it.

Not sure what you want to hear, I've been running the Evans NPG+ for over three years now on the street as well as occassional track days (auto-x = longwait in lines between runs) with significant heat soak. I siphon out the coolant whenever I need to work on parts in the cooling system (turbo's, thermostat housing, ect.) and reuse the same coolant. i love the fact there's no water use so there doesn't seem to be any deterioration in any of the cooling system components (no corrossion) It's still a preferense theing as i believe you could have the same results from regular coolant system flushing and change. Localized boiling was only one of my concerns in going with this product. The reason you don't want to run without a thermostat is that 1) you can actually run too cool. 2) you will have too much flow through the cooling system, and less time for the coolant to remain in contact with the engine parts to remove the heat efectively. I may be way off here but it's my understanding of it.

turbojeff 06-25-06 06:11 PM


Originally Posted by ericgrau
I think I should clear something up on overheating: 200-300F IS NOT HOT ENOUGH TO HURT YOUR ENGINE AT ALL.

Overheating occurs when metal actually melts and welds back together.

According to my materials class, aluminum melts at 650C (1200F), but can only be used up to 190C (370F) before softening. This is impossible unless the coolant boils, whether through boiling at localized hot spots or if all the coolant is at boiling temp.

From your post overheating actually occurs BEFORE the metal melts and welds itself back together right?

Consider other materials in the engine. Rubber coolant o-rings will cook long before the aluminum gets up to 370F (your number). Engine oil shouldn't be run over 230-240F. There is a lot more going on in an engine than just the allowable metal temps. The hot parts will expand, maybe beyond the allowable limits of the part, etc.

radkins 06-25-06 10:17 PM


Originally Posted by ericgrau
I think I should clear something up on overheating: 200-300F IS NOT HOT ENOUGH TO HURT YOUR ENGINE AT ALL. .

Tell that to my coolant seals.

scrubolio 06-26-06 09:27 AM

So from the 6 pages on this thread and several other pages on the other threads i get down to this conclusion (correct me if i'm wrong i'm bored at work):

1. Evans NPG eliminates hotspots thus an obvious increase in coolant temps, due to soaking more heat up from the hot spots.

2. Water, water + water wetter, water + coolant has lower temps, but has hot spots.

So the ultimate test would to run Evans, take an infrared photo, and then run your choice of water mix and take another infrared photo and compare the two? Maybe the Evans photo will show a more uniform heat dispersion, while the water mix would show hot spots?

I feel that several people are just going for lower coolant temps regardless of how many hotspots they have, or if there are even hot spots, if the gauge reads lower then its better, while true in most cases, might not always be true, but what do i know

CantGoStraight 06-28-06 12:19 PM


Originally Posted by scrubolio
So from the 6 pages on this thread and several other pages on the other threads i get down to this conclusion (correct me if i'm wrong i'm bored at work):

1. Evans NPG eliminates hotspots thus an obvious increase in coolant temps, due to soaking more heat up from the hot spots.

2. Water, water + water wetter, water + coolant has lower temps, but has hot spots.

So the ultimate test would to run Evans, take an infrared photo, and then run your choice of water mix and take another infrared photo and compare the two? Maybe the Evans photo will show a more uniform heat dispersion, while the water mix would show hot spots?

I feel that several people are just going for lower coolant temps regardless of how many hotspots they have, or if there are even hot spots, if the gauge reads lower then its better, while true in most cases, might not always be true, but what do i know

One thing that Evans does do is eliminate water from the equasion and this means nothing to help in the electrolis's, and corrosion of the engine parts. 3 years on the same coolant. no ill effects as of yet.

Herblenny 06-28-06 01:30 PM

Another endless debate over NPG+ vs. regular coolant..

I'll put my 2 cents..

NPG+ might be a good choice for someone who's going to drive there car on the track and go all out BALLS.. Which means, you are pushing your car so hard that it will create hot spots and worried about blowing your coolant lines during the race or what not.... and going to rebuild your engine regularily because you want your car running tip top condition ALL the time!!

But street driven car that you care more about duration and such, I say stick with water and good ole normal coolant.. Why, because your engine life will shorten when you run your car HOT all the time.. which will be the case of using NPG+.. Sure it doesn't boil and you could run 0 pressure caps.. But it will run hotter.. its proven before and whoever says it runs cooler than water is BSing... If NPG+ is such a great magical solution for longer lasting engines, it would come standard in general production cars.. Have you seen it in new cars in the dealership?? I haven't..

ronbros3 06-28-06 01:51 PM

2 more cents worth , what did I do wrong EVANS has been in my FC since 1998, same coolant, when I have to open the system that requires draining, I just run it thru a paint filter and top it off with new stuff ,420whp works for me !! now check this out its been in mt BBC Camaro since 1989, the early stuff was really thick tho, had to warm the engine slowly on a cold morning,, EVANS is the best coolant you can buy, by the way it was developed for BLACK HAWK helicoptors, it would be kind of silly putting water in a machine like that ! OOPS I guess thats 4 cents worth!

ronbros3 06-28-06 02:03 PM

2 more cents worth , what did I do wrong EVANS has been in my FC since 1998, same coolant, when I have to open the system that requires draining, I just run it thru a paint filter and top it off with new stuff ,420whp works for me !! now check this out its been in mt BBC Camaro since 1989, the early stuff was really thick tho, had to warm the engine slowly on a cold morning,, EVANS is the best coolant you can buy, by the way it was developed for BLACK HAWK helicoptors, it would be kind of silly putting water in a machine like that ! OOPS I guess thats 4 cents worth!

scrubolio 06-28-06 02:13 PM

IMO it seems like with water mix you are ignoring the problem at hand (hot spots). It seems to make senese to assume that your engine will always have hot spots regardless of on the track or street, and with Evans you are giving the engine a uniform heat dispersion. Just becaues your water temp says its cooler doesn't mean your engine is cooler? (i could just be talking out of my ass, but since boiling point is lower on water it can't take in as much heat as Evans, thus since it is at a lower temp than evans when coming out of the engine it gets cooled more when going through the radiator, which is why it "appears" cooler? maybe? anyone?)

Kento 06-28-06 05:53 PM


Originally Posted by scrubolio
It seems to make senese to assume that your engine will always have hot spots regardless of on the track or street...

Why would it make sense to assume that? What makes you think that an engine driven on the street will have localized boiling?

Originally Posted by scrubolio
...i could just be talking out of my ass, but since boiling point is lower on water it can't take in as much heat as Evans...

No offense, but you are. You need to reread some of the original posts on this thread. Water has superior thermal conductivity (meaning it can transfer heat better) to Evans. Evans advantages over water/coolant mix are mainly a higher boiling point (discouraging "localized hot spot boiling") and no electrolysis over time.

Originally Posted by scrubolio
...thus since it is at a lower temp than evans when coming out of the engine it gets cooled more when going through the radiator, which is why it "appears" cooler? maybe?

The coolant temp sensor is positioned before the radiator...

scrubolio 06-28-06 06:05 PM


Originally Posted by Kento
Why would it make sense to assume that? What makes you think that an engine driven on the street will have localized boiling?

Probably wrong on this, unless driven hard...


Originally Posted by Kento
No offense, but you are. You need to reread some of the original posts on this thread. Water has superior thermal conductivity (meaning it can transfer heat better) to Evans. Evans advantages over water/coolant mix are mainly a higher boiling point (discouraging "localized hot spot boiling") and no electrolysis over time.

I've read that, but how do you expect water to take away MORE heat when its ALREADY boiling...it doesn't matter how much thermal conductivity it has, when its at its limit it can't take anymore



Originally Posted by Kento
The coolant temp sensor is positioned before the radiator...

So, since water can't take anymore heat after it boils it will definately be COOLER than Evans coming out, due to Evans soaking up more heat b/c oh the higher boiling point


All times are GMT -5. The time now is 09:50 AM.


© 2024 MH Sub I, LLC dba Internet Brands