nickmc07

iTrader: (1)

Hello All,

Trying to run through all the maintenance upgrades on a new to me FD.
It is stock mechanically and has ~35k miles.

short version: does performing only maintenance mods warrant new Water Pump and Thermostat?

long version:
I have replaced all the vacuum lines with silicon & changed over check valves to viton from dale.
replaced coolant hoses with new hoses from mazda. its RHD and having issues sourcing the heater core hoses F10061211B & F10061212A but all others replaced
i am going to replace the two belts.
installing a Koyo radiator and Pettit Ast
Precat was never present in the JDM downpipe
New Engine Oil
New Trans Oil
New Diff Oil
New Fuel Filter

As I am looking at the relatively empty engine bay due to performing all the upgrades above, I contemplate if i should replace the Water pump and Thermostat. I have not run the car in warm weather, but had no issues with 65* outside temperature but likely not ideal scenario for determining the functionality of the thermostat or WP. There does not appear to be any weeping or residue around the water pump housing.

I am not opposed to swapping out the parts if i should, but trying to figure out where to draw the line in the sand.

Thank you for any input.
Nick

TomU

iTrader: (11)

You list looks good IMO. No need for a new water pump unless it's leaking. You may want to look into an aftermarket water temp gauge. The stock gauge is worthless. As for gear oil, i really like NEO. It's a little pricy, but worth it. As for JDM parts, you may need to source from Japan (e.g. RHD Japan)

nickmc07

iTrader: (1)

Thanks Tom.

Water Temp Gauge, yes that is what i have gathered. Considering Oil Pressure and Wideband in front portion of midpipe also.
I've been looking at PLX due to the small footprint of the guage: https://www.plxdevices.com/ProductDe...e=897346002719
a friend ran the system in his car and had only positive feedback.

I believe the Koyo radiator has a port for sensor instal, but need to research pre vs post thermostat installation. I'm leaning towards that possibly being a secondary temp gauge, if used at all, and sourcing pre thermostat for a primary water temp.

I'll make note of the oil recommendation. I believe I used Redline for the trans and Mobil1 for the diff.
I had checked RHD Japan, no luck on those two hoses. An international site has one of the two available but the part number for the other returns hardly any results. given the flip flop of the steering column and heater core those two appear to be quite easy to access and likely not too overly heat cycled vs the LHD placing them right above the downpipe.

Sgtblue

iTrader: (16)

nickmc07

iTrader: (1)

New OE Thermostat, no Water Pump. I'm good with that.
Yes, the line is still there, i will review that post and add.

Plugs, i left if off but plan to replace. need to research which are ideal for stock.
AST, have a Pettit picked up from forum member.
Coolant caps have been tested with a pressure tester.

Fuel system, oversight there, i like the suggestions
Brake flush, fluid looks good but i will check that out.

Oil pressure was more replace the existing junky sensor and gauge and source that factory location. good to know, i am used to aftermarket turbo setups where that is one of the first items to keep an eye on.

Thank you for the input and suggestions.

cr-rex

iTrader: (114)

You're doing an excellent job with what you have going on now. You're taking a very smart approach to the upgrades/mods on your car. As far as your spark plugs, you can use the stock bur7 and bur9 or switch to all bur9. When it comes to fuel, a new fuel pump with sock, replacing the plastic oring fitting on top of the fuel pump with a submersible fuel hose and doing the 12v mod to the fuel pump will all be great additions to your set up. Doing that along with sending your inectors off to be cleaned by injectorsrx will refurbish the whole fuel system. I would also recommend deleting the fuel pulsation damper. It's never happened to me but apparently they're prone to cause fires.

Sgtblue

iTrader: (16)

nickmc07

iTrader: (1)

Plugs, probably left that one a bit shy of information. I came across a post this week mentioning arguing with a Parts Store employee about needing different plugs. All too familiar with this owning Ford Rangers as their 4cyl uses 8 plugs and every parts desk seems to believe they know better when you try to explain why you need 8. It brought to light that i do not have information about whether the FSM calls for varying range plugs or if that was performed due to modifications.

cr-rex post suggest two diff plug types from the factory. i will pull up the manual to inform myself.
I will look into those other suggested modifications.
Trying to keep it as close to stock as possible despite some of the commonly removed items (AST, airpump, emissions) given the multitude of opinions on their need.

thank you again to everyone for the input, i know this isn't a new topic and certainly not trying to recreate the wheel but had some questions that I really didnt find explicit answers to in the other posts I read through.

Sgtblue

iTrader: (16)

TomU

iTrader: (11)

If you are doing plugs, probably should replace the plug wires as well

And replace the brake fluid. It gets contaminated with water over time.

cr-rex

iTrader: (114)

Let me clarify.... the bur7 and bur9 are stock. All bur9 is not. I was saying switch to all bur9. It's a common/popular thing to do

Sgtblue

iTrader: (16)

NGK
(Leading/lower) BUR7EQP
(Trailing/top) BUR9EQP

If your car is stock, running stock boost, that's all you need IMO. And they're available at any chain parts store. Same with plug wires if you choose to replace them. NGK is OEM and there is nothing better... except you may have to go to MAZDA or one of the forum vendors for the wires.
Spark Plugs 93+ RX-7
Plug Wires 93+ RX-7

TomU

iTrader: (11)

FWIW, i tried 9s in the lead holes at stock boost (for the most part) and they fouled

Second on staying stock (NGK) for both plugs and wires

Craig King

Good info here - I'll remember it when I purchase my first FD.

nickmc07

iTrader: (1)

Thank you for the explanation. i knew about the dual plugs but this clears up the picture quite a bit.

is the increased pressure and smaller exposure to the leading plug at this point in combustion cycle the reason for the colder plug?


thanks, this will save me some searching.

+ thermostat and gasket
+ oem plugs and wires
+ checking fuel pump
+ brake fluid

thank you for the input everyone.

Sgtblue

iTrader: (16)

I'm not a big-brain, but suspect it's colder to reduce the chance of pre-ignition. You want to make sure it fires after the leading plug or bad things happen. IIRC the trailing plug is shielded to maintain as much hard-seal contact with housing as possible.

nickmc07

iTrader: (1)

​​​​i wanted to comment:
Wouldn't timing of spark be controlled with the coil/ecu?
But a quick search shows my interpretation of what you meant is incorrect and your answer is quite spot on.
​​​​​​
This result of search From NGK:

When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, keeping the firing tip cooler.

*A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.

My interpretation of this in application to rotary to mean trailing plug is subjected to more heat than the leading plug, warranting the colder plug to prevent pre ignition.