good post art...
>>and open thermostat(cut out the guts and blocked off the w/p bypass hole.)

can someone explain this to me more, why this helps drop temps? isnt it open already by the time ur up at those temps? or is it only about flow, havin git 'gutted' allows coolant to flow better?

 

heh, yeah....if we're stuck in the 80's with carb'd motors, that may hold an once of truth, however, most properly tuned ECU's (including the oh so conservative stock ECU) will dump lots of fuel and retard ignition like crazy in these temperature ranges, i think it would almost be appropriate to "tune" for evans NPG if you planned on running sustained high temperatures

if your butt dyno is going to be the decision maker in whether or not you should lay off the throttle while your temp gauge is pegged out, you need to reconsider your options

 

Damian...

this is from Mazdaspeeds website...the FAQ portion

http://www.mazdamotorsports.com/weba...ubject=cooling

Water Pump/Thermostat

If you are using a stock (cast-iron) water pump, we recommend "gutting" the stock thermostat, leaving just the thermostat casing. Because some "restriction" is helpful, generally removing the thermostat is not as effective as using a gutted thermostat or restrictor. It is also important to plug the thermostat housing's water bypass. This can be done very easily by tapping the hole (1/2" pipe tap) and installing a plug

 

Damian,

on your track car do you run an underdrive pulley?

 

which is the thermostat housing's water bypass?

 

Sounds like cheap insurance. Should have gone with Evans with the lately departed KDR motor. Live, learn, and get poorer...

 

thanks.... I'll check my track cars setup, maybe this was already done.

 

not the main pulley no, but they both have the greddy water pump pulleys on them

 

Art, I'm looking for the Evans NPG+ to stabilize my engine temps @ WOT for 30 minute open track sessions in 85 F to 90 F summer heat. What I got was a steadily rising water temps driving @ 8 to 9/10ths in 85 F ambients. By the end of the session, the water temps would reach between 115 and 120 C. I'm thinking my luck ran out, and a hot spot formed in the front rotor housing, and pre-ignited the combustion mixture, leading to a chipped front rotor apex seal. With Evans, did your engine temps ever stabilize, at say, 130 C (266 F) for an entire session? IOW, your engine temps never got higher than 130 C regardless of how how hot the ambient temps were, and how hard you were pushing your car? If this were the case, I'd say the Evans NPG+ was doing the job very well!

 

a few random comments on ur last post sleepR1:

>>thinking my luck ran out, and a hot spot formed in the front rotor housing, and pre-ignited the combustion mixture, leading to a chipped front rotor apex seal.

1) that may have been the case, I just want to add somthing, keep in mind I have no idea what im talking about :-) the hot spots may have caused a messed up pre-ignition that lead to a messed up seal, however, in the fore front of my mind it is not why i want to stop hots spots, i want to eliminate hot spots because to my understanding hot spots is what kills the housing seals (not rotor seals, im talking housing water seals), a localized hot spot causes the metal to expand uneavenly, slightly warping the housings, and possibly exposing and/or compromising the water seals to the point of failure.... that = engine rebuild. thus, no localized hotspots that are caused by boiling coolant (as evans seems to eliminate wiht its rediculous high boiling point) means the engine can run hotter safer and even basically 'overheat' without actually damaging the water seals, obvisouly there is a limit here...but in a normal coolant situation, even a moment of boiling coolant in a bad localized hotspot can cause 'engine rebuild' level damage.

>>With Evans, did your engine temps ever stabilize, at say, 130 C (266 F) for an entire session?

2) also, on the temps you guys are talking about... i run high temps that peopl freak out about, and im only in the 110-115 range and dont freak about it.... but dam, 120-130 is kinda out of control, like other changes need to be made, for example ducting enhansements (if a larger radiator already has been done), i definelty do not want to see the other side of 120 C but even with wack ducting i dont think my car has gone over 110-115 C in 90-100 F degree track days, 20 min sessions all out. the funny thing is that theoretically you could run at 130 C and the engine would be fine since you are still far below the boiling point of evans, ... however at that point the high temp may have other negative side affects, like crazy oil temp, or whatever.

I'll try to log data in my next events and post the temp data. I always bring the laptop, just end up having to much fun fartin around and taking passengers around, and i forget to hook it up and log data.

 

damian, Art and I have FMIC/Rad setups. Art's is an Apexi GT, and mine is a GReddy 2-row FMIC. We're trading slightly hotter engine temps for cooler air intake temps (my AIT peak is 50 C on a hot day). Art says his temp was 265 F (129 C) with Evans on hot days. Personally I have not seen hotter than 121 C with conventional coolant and GReddy FMIC/Koyo rad. Your track car is very well prepared, and has a conventional SMIC setup, IIRC, which usually runs cooler, but with slightly higher air intake temps. I look forward to your datalogs. BTW I run Mobil 1 15W50, boiling point of 450 F, so the Evans NPG+ will boil (375 F) before the Mobil 1 15W50 will! I'm stuck with FMIC/Koyo/J-spec seq twins for awhile, so I have to figure out how to make this setup work for open tracking on hot days. I'm hoping Evans is the answer with my new larger ported motor!!??

 

ahh ok, i can see why the higher collant temps are there from the fmic setup.
how is the ducting to the radiator on you car? have you done any 'extra' stuff to close any gaps and/or direct air better?

I'll try to take oil temps logs too, I did some nice ducting on teh oil coolers to the ms gtc nose, so my oil temps stay pretty low.

speaking of noses, do you and art also have stock noses?

 

I had foam packed in the air spaces between the rad core, engine bay wall, and undertray. I have a stock nose and hood.

I ordered 4 gallons of Evans NPG+, thanks for the links!

BTW, I almost went with the NPG-R, but didn't want to make coolant changes every other year. NPG-R's 400 F boiling point, thinner viscosity, and better heat transfer properties weren't worth the hassle and expense compared with the lifetime NPG+.

 

good deal, i hope the evans hepls your cooling situation, im sure my gtc nose is helping me with temps too, the radiator and oil cooler holes are much bigger than the stock nose.

did you ever see my ducting threads (before i got the track car)?

https://www.rx7club.com/forum/showth...hlight=ducting

https://www.rx7club.com/forum/showth...hlight=ducting

https://www.rx7club.com/forum/showth...hlight=ducting

 

Wow, damian, you've gone way beyond any effort I'd embark on for ducting. I used packing foam to seal up the crevices between the rad core, a la Crispy Rx7 I'm $3000 deep into an engine rebuild right now, so $90 for 4 gallons of Evans is a reasonable expense for engine temp stabilization.

 

Damain, would you recommend running evans on a compeltely stock car? Just for it to last longer? And Minimize localized boiling??

 

>>Wow, damian, you've gone way beyond any effort I'd embark on for ducting.

hehehe :-) you should see what im doin with the track car now... LOL a post will be coming soon ;-)

>>Damain, would you recommend running evans on a compeltely stock car? Just for it to last longer? And Minimize localized boiling??

yep, I run evans in my street car and even if I never tracked it before, I would still run evans in it for the other protection it provides and the fact that I can run zero pressure, now all the rad hoses are not under pressure and last longer and are less likely to crack/split/pop and leak. :-)

 

Ok I just checked the site but there are different types. Is there a FAQ or something or what do you recommend for a non- modded Rx7. May receive some bolt on later. BTW can I reuse it?? Lets say in the future I want to replace the radiator. At 22$ a gallon, could I try to empty the system and reuse it again later? Thanks! Damain.

 

Read this whole thread

 

Aww hell no =P. Come on!

 

I did. It's not too bad.

 

yeah, read the whole thread LOL

- yes you can reuse it if you dont contaminate it when you save it

- ngp+ is what i would get but ask some others to see if they chime in reasons for gettign a different kind

 

here is my track car ducting thread i just started:
https://www.rx7club.com/forum/showthread.php?t=332256

 

yeah the highest i have ever let my rx7 go is 115c if it hit 117 i would have pull over but usually it runs 80c-85c: normal driving and 100c in hard driving

 

Bringing this back.

I've been running Evans for the last 14K (3 years) on a Malloy Reman with an auxiliary electric water pump between the outlet on the block and the heater line.

Car has been running great. However, my gauge has been rising toward the upper white line under heavy boost even though my PFC doesn't rise above 105C and ambient air temp of 85F. Off-boost, the gauge drops immediately to the midzone

QUESTION: ********Has anyone running Evans NPG+ seen this: your dash temp gauge rising under boost but immediately dropping off boost yet your PFC doesn't budge from 104-106C?********