neit_jnf

iTrader: (17)

Ok, I emailed Evans requesting their NPG+ MSDS and they emailed it back to me. I attached Sierra's also for comparison and fun purposes. Keep in mind that NPG and NPG-R are different from NPG+. Lets the endless discussion begin!

Summary of ingredients:

Sierra:
Propylene Glycol 94-96 %wt
Water 3 %wt
Proprietary Additives 1-3 %wt

Evans NPG+:
Ethylene Glycol 66–70 %wt
Propylene Glycol %wt not specified
Water %wt not specified but from Evans webpage info it should be <3 %wt
Proprietary Corrosion Inhibitor Package <2 %wt

technonovice

This was asked in the thread that was closed because of sniping:

Quote:
Originally Posted by rx7tt95
For those using ECU's such as the Power FC, at a reading of 100 degrees Celsius, the ECU's "logic" kicks in extra fuel to help "cool" the combustion temps and help to lower coolant temps. The stock ECU does the exact same thing. There's no real way to control it on the PFC, even with the Datalogit. There are several functions the ECU will not relinquish full control of. Idle mixture being the other (just ask anyone with 850cc primaries!)


This is a very interesting point. The coolant temp sensor does not know the difference between Evans or Prestone so when it sees 100+ degrees C it starts dumping fuel. I'd be curious to see datalogs with AFR's from those conditions. How rich is it and how much the injector duty cycle has increased to compensate under load?

If its dumping enough fuel, it could even be reducing power levels. Has anyone logged and dynoed this?

rynberg

The PFC does NOT add fuel at high air intake/water temps, it pulls more out. However, it DOES retard the timing. This is plain to see with the datalogit software, where the fuel and timing adjustments vs air/water temps are clearly shown and are adjustable. It is suspected that the stock ecu acts similarly.

neit_jnf

iTrader: (17)

what's sniping? just saw few guys flaming eachother...

7racer

what's in NPG-R??? Just wondering as I bought into it and put it in the seven

ronbros3

Damn, I been running EVANS since 98 still same fluid add a little when I make a change in the car , I say 7s need two (2) thermostats, one controlled by temp, the 2nd stat. by boost because it needs a faster instant flow at the spark plug area, thats where detonation starts, P/G does not cause the hot spots in that area where it could go dry momentarly, from slower coolant flow. just-a-thinkin!

scotty305

iTrader: (2)

So it would seem that Evans is NOT the same as Sierra. But what's this about a ≥ 69% Ethylene Glycol content? I thought NPG stood for "Nonaqueous Propylene Glycol" ?


Here's another MSDS:
http://ptcl.chem.ox.ac.uk/MSDS/ET/ethylene_glycol.html


Pure Ethylene Glycol: specific heat capacity of 0.71
Evans NPG+ Coolant: specific heat capacity of 0.66

Boiling point of 100% EG is 196 C , which would be 384.8 F.
Boiling point of Evans is 190 C, (their MSDS says 375 F).



I'm going to go out on a limb here and bet that you'd see similar results from a 70% EG / 30% water system, at stock pressure. The boiling point of the coolant mixture should be around 235-240 F at 0 pressure. Add 11 psi pressure and you should be looking at a boiling point above 260 F

Has anyone got the time and means to test my theory?

-s-

Recentlyconverted

wait, but why would it pull fuel, isn't that seriously bad? especially in hot weather??

maxcooper

Hotter = less oxygen for a given volume (note that volume is "assumed" based on measured pressure), so less fuel is needed.

But I think there are also some settings to increase the fuel at high temps. These settings would compete with the basic reduction in delivery described above.

It's been a while since I looked at the settings, but knowing what you can set and a basic understanding of how the FI system works should be enough to understand what's going on.

-Max

maxcooper

I also don't get what conclusion we are supposed to draw from this thread. It seems to beg us to decide something negative about Evans, but I don't see how the posted data supports that judgement. ???

Rice Crispies:
99% Rice
1% Crispie

Cheerios:
69% Cheery
30% Ohs
1% Crispie

SEE!!! SEE!!! I told you about those Cheerios, they can't be trusted!

Um, what?

-Max

technonovice

If it is true that it alters the fuel at all regarding coolant temps then it would seem Evans would require a little more tuning to keep the mixture correct at higher temps in particular. Perhaps it is not enough to be concerned over?

scotty305

iTrader: (2)

Max,
As with most threads, there are a few discussions taking place at once. This one is a bit harder to follow, since it's a continuation of an old thread that was locked. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/npg-110f-air-temperature-428138/

On that thread, someone stated "Evans = Sierra" , and this thread seems to be in reponse to that statement. It appears that Evans is much closer to Ethylene Glycol (traditional 'green' coolants) than Sierra.


My personal take is that the main problem with our stock cooling system is the pressure it runs at, which allows boilovers. Remember that the system was originally designed to run at 1.3 bar, and subsequent problems led to cooling system recalls that included a lower pressure cap: http://fd3s.net/cooling.html#CAP


On the other hand, I've never heard of any failures or problems due to Evans. Damian uses it in his track car, and I know that plenty of other racers have had good experiences as well. It should be very obvious that our cars require a higher boiling point than what we're seeing from EG & water at 13-16psi. Evans is one way to acheive this.

-s-

neit_jnf

iTrader: (17)

I didn't post this thread to get good or bad conclusions about Evans but to provide the MSDS that a lot of people seemed to want in the gazillion other Evans threads. I posted the Sierra's as well because a lot of people seem to think they are the same.

NPG stands for Non-aquous Propylene Glycol which is the base ingredient of the original NPG

NPG+ is a blend, according to the MSDS it contains about 25% PG

I love NPG+ and use it on my FD, I would use it on my other car but I'm not planning to keep it for long.

KevinK2

datalogit manual suggests:

FUEL ENRICHMENT

1) basic richer corrections at AIR temps above 100C, and leaner corrections below. These are standard values, and can be adjusted. Range is -30C to 80C.
(this is not obvious, since they are reducion factors for higher temps, but not reduced as much as theory would dictate for lower air density)

2) "boost and AIR temperature" based fuel enrichment
3) "boost and WATER temperature" based fuel enrichment

These two are more crude, but still are adjustable variables. Not sure of the extrapolation method, but a water temp of 230F at 14 psi may get you about 6% more fuel.

All 3 of the above are in "settings 2"

There is also a basic cold/warm start enrichment table that goes from -30C to 80C.

TIMING RETARD

Standard values are 3 deg at 80C air temp, and 6 deg at 110C water.

KevinK2

good point. if cruising with t-stat near closed, the bypass ports are small, and flow could be somewhat reduced. quick to full boost and flow could be reduced vs a wide open t-stat.

More significantly, pressure can drop near ambient cruising, esp aft decending a hill on highway, even with high temps and open t-stat. Sudden full boost with low pressure leaves BP near 224F with 50% egw, and hot spots more likely if bulk cooant temp is near 220 on a hot day. NPG+ (EG with some PG) has advantange since pressure is not req'd.

maxcooper

Sorry I jumped on you. I had been reading the other thread and I guess I brought some of those feelings in here.

I am running NPG+ also and so far I am pleased with it. I haven't tested it on the track yet, but I expect that I will be able to get it to work better than water and normal coolant worked for me, even if I have to do a little tweaking.

-Max

Matt Hey

I think you're on to something here but I wonder about your conclusion. NPG+ does stand for "Nonaqueous Propylene Glycol" but why would they call it this if it's mostly Ethylene Glycol? Also how could it be safe for animals and why does Evan's tell people to add PG instead of EG in emergencies. I don't think NPG+ contains any EG! Yes, I think the formulation in the first post is WRONG!

Now if you would like to compare 100% PG to 100% Sierra (contains some water) to Evans NPG+ then that would be more interesting to me. I bet NPG+ is almost all PG.

I did drain my NPG+ into a pan and put it in the oven at ~350 F to remove extra water and it barely bubbled. It seems to work as advertised and I like it.

neit_jnf

iTrader: (17)

I took the formulation from the MSDS that I posted, did you even look at it??

And if you read a little more you'll see where the NPG name comes from...

Just is case, MSDS stands for Material Safety Data Sheet and is required by Federal Law for companies to provide it for every chemical they produce

KevinK2

should one believe an MSDS, or a baseless opinion?

oven test at 350F means nothing, as BP's for PG and EG are similar, and each is above 350F.

The EG has about 1/2 the viscosity of the PG, so Evans added a bunch to get away from requiring bigger pumps and rads. Also improved heat transfer. Still good stuff for those that need it. Expect some good 'dater' from Max.

Matt Hey

A MSDS sheet floating around on the internet could very well be fabricated. I don't believe everything I read on the internet. Do you have a Tornado air intake and one of those magnet fuel savers? I bet you could get some real good gas mileage in your RX-7 with BOTH of them . However, I have changed my opinion on this since reading this...

----------------------------------------------------------------------------------------------------------
Discovery of a Practical ADH Enzyme Inhibitor
Prevents Ethylene Glycol Antifreeze Poisonings
de-tox disclosure

Sharon, Connecticut
October 8, 2001

Evans Cooling Systems, Inc. (ECS) of Sharon, CT disclosed its technology to detoxify ethylene glycol (EG), a common antifreeze ingredient, and to prevent poisonings and deaths from oral ingestion of that substance.

Thousands of human EG poisoning cases occur annually in the U.S., as do tens of thousands of pet and wildlife poisonings. Without treatment, EG poisoning progresses through a number of steps including metabolic acidosis, the deposition of calcium oxalate crystals, kidney failure, and death. Most human poisonings, if treatment is started immediately, can be reversed by procedures that are painful and expensive. Most animal poisonings end in death.

Ingested EG is not itself toxic until it becomes metabolized by the alcohol dehydrogenase (ADH) enzyme to glycoaldehyde. Glycoaldehyde becomes metabolized further to three toxic metabolites - glycolic acid, glyoxylic acid, and oxalic acid. These are the substances that cause the damage. ECS's method combines an ADH enzyme inhibitor with the EG to prevent the first step in the process from taking place, namely the metabolism of EG to glycoaldehyde. Without the glycoaldehyde, the toxic metabolites are not produced and the poisoning does not occur.

John W. Evans of Sharon, CT and J. Thomas Light of Lakeville, CT are the inventors of the new technology. Evans and Light discovered that propylene glycol (PG), a common commodity chemical that is considered essentially non-toxic, acts as an ADH enzyme inhibitor and that when PG is mixed with EG, the PG effectively prevents the toxic metabolites from being produced were the EG to become ingested. Of particular significance is the fact that the inventors found that only a small percentage of PG need be in the mix to detoxify the EG. According to Evans, "Our testing was a real eye-opener. You only need about five percent PG in the mixture with EG to prevent the oral toxicity of EG."

In conjunction with an EPA certified testing laboratory, ECS tested the toxicity of its EG and PG mixtures and compared the empirical results to estimated results generated from a common industry formula. "There was no connection whatever, as the experimental results were far better than those predicted by the formula," Light said. "It amazed us that we found mixtures of EG and PG that were actually less toxic than PG itself."

Evans, who is President of ECS, said, "Sometimes there is good news to report on developments that will help make the environment safer. This discovery promises to end the oral toxicity of many EG-based products, including antifreezes and aircraft deicing fluids." It is the intention of ECS to use the technology in its own proprietary waterless coolants and to license it to the producers of EG-based products that are generally used with water.

US and Foreign Patents Pending.

-------------------------------------------------------------------------------------------------------

My conclusion was based on the fact that EG is always poisonous. Many leading anti-freeze manufacturers must have believed this too or they would all have "pet friendly" anti-freeze for many years now at the same price as EG.

The oven test wasn't meant to prove anything about the formula, just to say that the product meets its claims. The Tornado and magnet fuel savers guarentee better fuel mileage or your money back. When only one company makes a product I am skeptical but NPG+ at least works and has advantages.

rx7tt95

The PFC DOES INDEED add fuel. I had a chance to "experiment" a bit last week when unbeknownst to me, the secondary fan stopped operating on high thanks to a faulty wire connection. As such, the car's temp would gradually climb to 98 degrees and settle there for a bit before moving on to 100 celsius. Once I started hitting 100, the car became noticeably richer, evident by the integrated Innovative wideband I have sitting in the passenger's seat at all times. It's similar to the a/f increase one sees with the a/c on at idle.

When you mention it pulls fuel out at higher temps, you're probably basing that off the water temp tables...well there's another level of "logic" in the PFC which does indeed increase the amount of fuel to help lower temps when things start to get out of hand.

rx7tt95

I apologize for not responding sooner...I'm not receiving e-mail notifications as I should when there's a new post.

neit_jnf

iTrader: (17)

Well the MSDS I posted was directly emailed to me by Evans as a response to my email request. Maybe they falsely fabricated it and are violating EPA and OSHA and who know what other Federal Goverment Regulations...

rx7tt95

Kevin brings up an interesting point here...one of the issues with the rotary besides the extreme heat it puts out is how quickly it does so. The stock thermostat can provide enough of a restriction to actually keep the cooling system from doing its job when pushing higher boost levels on worked over motors. This is especially true in very hot climates (like SW Florida!). As such, I do not run a thermostat, just the thermostat housing with the mechanism cut out. When it rains, the car runs very cold, in between 70 and say 78 degrees celsius but runs just around 80 when it's 93 degrees and sunny, even with the a/c on. This of course, is with working fans! I'm sure most with high 300, low 400hp cars have seen their temps rise when on boost. Now you know why!

rynberg

You are right, there are multiple levels of adjustments....

The PFC does reduce fuel as water temps go up, until they hit nominal at 80C.
The PFC does reduce fuel as air temps go up.

HOWEVER, as you pointed out, there is another level of control, which increases the fuel added at high water temps when under boost. Thanks for the correction.

So, you DO need to retune the PFC settings using the datalogit to shift this behaviour higher up the temp scale IF you think that it's safe to run the car at 110C+ temps with the Evans.