Cooling...Is it an issue? Help out the newbie!

[fourwhls]

Hello all. I am a lurker that finally decided to register and participate.

Here' my scenario:

I have a '92 Sunburst with a '00 1.8 installed running a LINK ECU. The head and block have been decked, so I have an estimated 10.25:1 compression ratio. I am looking to up the HP while maintaining reliability.

The car is a dedicated autocross/track car, so basically it's a trailer queen. It is still registered and insured, but doesn't see a lot of street miles. The car is an awesome autocross car and I'm always vying for FTD, especially since the install of the new Hoosier 275s.

The problem is I am always yearning for more power when I go to the track. I can hang with the best in the corners, but I get my a$$ handed to me on the straights, only to wait for them again in the corners. It's getting old.

If the car was a dedicated track car, I wouldn't have a problem choosing my methods of FI. I would install an intercooled turbo setup and call it a day. BUT...I only track the car 25% of the time. I don't want to give up throttle response for the other 75%.

I really like the FFS system and being an ME that plays with solid modeling on a daily basis, the ability to download and rotate Tom's model only entices me more.

I think I will be happy with 200-225 RWHP. I am currently putting down 128 RWHP. The only issue I have is cooling at the track.

One of my students, last weekend at VIR, was driving a 3rd gen RX7. The ambient temps were in the low 90s. It was a great car, but he was fighting heat all weekend. He was so worried about his car, that it was impossible to get him focused on his line. I don't want to deal with this. I want power in a reliable package.

If I were to go the FFS route, I would forgo use of the 5th injector and just richen the fuel through larger injectors and tuning via the LINK.

I would run a dual core aluminum radiator and some sort of external oil cooler.

Is this going to be enough?

I guess I have the option of WI, but I'm a little scared. If I tune the car for a meth/alcohol injection and the pump fails/line clogs/etc, the engine is toast. I'm not a fan.

[socal pat]

NO! it's not enough. The cooling of the intake charge post-blower is critical to engine life. The E-cool is like a water/meth system, but you won't run out of fluid and don't have to worry about an additional pump. I respect the ability of bigger injectors to provide plenty of fuel, but you'll also need some sort of intercooling of the intake flow to keep ping at bay. And with a coldside, injecting something into the intake manifold is about the only way.

[FormerDatsun510Man]

The key to running a FI'd track setup that you want to have maximum reliability with is the following based on what I have found with my car:

1) High performance radiator (recommend the PWR if you run a Hotside setup or Tom recommends the Koyo for the Coldsides)

2) Run a conservative pulley (boost) ratio for the mechanical setup you are running. In other words, look at the variables with your engine/supercharger setup and do some research to figure out the most reliable pulley ratio. For example, on your setup you are running a CR of 10.25:1. As a result it may be wise to run a pulley size about 5mm smaller then what would normally be recommended for your engine. Rule of thumb is you run about 1psi less boost (5mm smaller pulley) per half a point of CR increase. Also, consider the octane fuel you will be running. Tom recommends race fuel as cheap insurance on the Coldsides at the track. I would tend to heed his words :). If you have only 91 octane, you will want to be extra careful with the boost you run. For my Air/Air intercooled Hotside, I run the pump 93 octane with no problems on the track. If I had to run 91 octane, I would probably go with the 126mm pulley rather than the current 130mm pulley I am running.

3) If you run a Hotside setup use the Air/Air IC. From my experience, on the track running a Hotside, the Air/Air IC is the only way to go. I will mention though that I think I run my engine harder than most :). I squeeze every last 100rpm to the rev limiter at every chance I have. Nice thing with the TDR Air/Air IC is that it simply doesn't heat soak and you can beat on the engine to redline lap after lap without any overheating or detonation issues.

4) And this is probably the most important of all! Be sure to take you car to the dyno and tune it for a safe 12:1 a/f ratio across all rpm. This accomplishes two things. First, it ensures that your setup is making the power and performing like it should.... best to catch any problems keeping the power down before you hit the track. And besides, things that are mechanically hindering power can also be things that could lead to engine damage on the track. Secondly, it ensures your engine is running a safe a/f ratio for continual boosting on the track. When I first got my Hotside eons ago, I downloaded what were the same maps that were for another '99-'00 Miata that had the same setup and had been dynoed. So I thought with these maps my setup was safe and didn't go to the dyno for a while. I even took it to the dragstrip like this. Well, long story short, I found out on the dyno it was leaning out big time at 6000+ rpm. Turned out to be my fuel pump. I wouldn't have known this without going to the dyno and would have blown up my engine on a road course in no time. No way I could feel 14:1 a/f ratio as being bad from the SOTP. Even my a/f gauge (narrowband) was reading "rich". But I learned better at the dyno that day.

Bill

[fourwhls]

Thanks guys!

After a lengthy conversation with Tom yesterday, I believe I have determined what I want to do....

I plan to purchase the base cold side kit without Engine Management or Ecool. I will then add bigger injectors to supliment the fueling needs, use my LINK for tuning, and water/alcohol injection for cooling in lieu of the 5th injector.

I need to educate myself further on water/alcohol injection. I will start another thread in the modification section and hopefully some of you guys that have been down this road will help with the education process.

[snakebit]

Thanks guys!

After a lengthy conversation with Tom yesterday, I believe I have determined what I want to do....

I plan to purchase the base cold side kit without Engine Management or Ecool. I will then add bigger injectors to supliment the fueling needs, use my LINK for tuning, and water/alcohol injection for cooling in lieu of the 5th injector.

I need to educate myself further on water/alcohol injection. I will start another thread in the modification section and hopefully some of you guys that have been down this road will help with the education process.WHY do you want WI over eCool? eCool works so well and there's no tank to run dry.:confused:

[Mx5-4me]

WHY do you want WI over eCool? eCool works so well and there's no tank to run dry.:confused:

I'm guessing he wants to use his link. I dont think the link will control a 5th injector.

[fourwhls]

Yes I will be using the link. and Yes I could still use the 5th injector, but I would have to use a PC pro to control it.

So if I were to use the 5th injector I would have to use two different control units to tune the AFR. It's hard enough with just one, I don't care to take on two.

I do like the fact that I wouldn't need a separate pump and storage tank if I were to use the eCool, but it's not the best option for me.

Water/alcohol does a better job of cooling than gasoline.

My set up will come with its downsides, but that's something I will have to deal with. My car is a dedicated track/autocross car, not a daily driver. I don't have a problem adding one more step, topping off the WI system, to my regular maintenance routine before each run.

[BlackStripes]

hey Shawn!!!

This is Hector with the yellow Mustang!!.. how are you man??

Funny see you here... specially since i have an '02 with a MP62 :D ... I told you i love Miatas ;)

[fourwhls]

Hey Hector,
Good to hear from you, its been a while.

Another convert...Were you tired of not being able to catch the little yellow Miata?

I had a blast running from that beast of a Mustang you have.

Hopefully my transition to the SC world will allow me to really piss off the high HP cars.

I'm headed to SP this weekend with Mazda Drivers. Are you going?

[BlackStripes]

Dude, you are gonna be VERY fast in that little BlackStripes ;) . I love the flares!!!

i miiiiiiiight go to VIR mid Nov. but somehow i am in 'winter mode' ... I ran SP Main week and a half ago and the track is FAAAST with the new pavement!

I am sure I'll see you @ the track soon!

BTW. Have you bought the SC yet?

[fourwhls]

Not yet...If I don't ball my car up or blow an engine this weekend, it will be ordered Monday.

I'm really looking forward to some power. I can't wait. :D

[J_Man]

If you're planning on tracking this car, do the coolant reroute ...

[fourwhls]

Coolant re-route will be done as well as the addition of an aluminum radiator. I am also going to install a oil cooler.

[Race Grandpa]

How do you re-route the coolant and how big of difference does it make.

[jwalton]

How do you re-route the coolant and how big of difference does it make.

There are a number of ways to do it, all detailed on m.net. The biggest pain is that you will end up mounting the thermostat (and its' housing of course) at the back of the block near the firewall. It makes thermostat changes a little more interesting but the benefits are big. I had to rebuild my engine pre SC'ing due to overheating the 4th cylinder during track days. Remember that was normally aspirated too. Going FI would only make matters worse.

All that said, if you aren't going to the track and you're only going to be enjoying the car on the street, you probably don't need to worry about it.

[Steve]

How do you re-route the coolant and how big of difference does it make.

Doing it properly is the key... some of the re-routes floating around out on the 'net don't work (I know because I've seen and removed some of them here at my shop.) One of the most common mistakes is placing the coolant temp sensors outside the thermostat. This causes the engine to always run too rich because the ecu sees an incorrect water temp. The 01-and-up cars are especially sensitive to this: I've seen one case where the A/F was too rich by over a full point from this (also another reason not to run a cold t-stat in these cars.) Just by relocating the sensor on this car the WOT A/F went from 11 to 12:1.

To put it simply, you're returning the coolant flow path back to the original way Mazda engineers intended it to be when they first designed this engine (for a transverse, FWD/AWD installation.) In a Miata installation, only a small portion of the cooling water flow goes around the 4th cylinder so it runs hotter that the rest of the engine. In stock form on the street this is not a big concern, but as soon as you hit the track, add power, or both, this becomes a big problem.

I've been testing my about-to-go-public coolant reroute kits for several months now. I can tell you that in testing using sensors mounted at the front and back of the head I often see a 20+ degree F difference between the two sensors. With my system installed the rear temp is within two degrees of the front and overall engine temps are a bit lower.

[Gord96BRG]

Steve,
If you produce a complete, 100% bolt-on kit compatible with a FFS coldside, I'll buy! (Keeping a functional heater would be a requirement, too!)

The problem with ALL the re-routes on m.net and elsewhere is that none of them are complete - there's always a "go to your auto parts store and rummage through their bins to find a new hose to fit the new layout" or "take this to your machinist" or "get this piece cut and welded".

[Steve]

The very first kit will be for 1.6 cars (and anyone else with a stock intake manifold and no EGR pipe to deal with.) After that, the very next kit I release will be just for the FFS Coldside. Tom's manifold design requires a slightly different pipe bend and mounting points, but those are not a problem. I will be sure to let everyone know as soon as I have it ready.

[FormerDatsun510Man]

Steve,

Don't forget us Hotsiders! :stuart: :stuart:

I'm running a lot of power (probably close to 240rwhp) and could definitely use this as I track my setup. I run the heater during track days as an attempt to keep temps evened out. I had a 160 deg F thermostat in there and found that it made the car run too rich (like 11:1 during highway cruising) when the outside temps dropped below 50 deg F. I was thinking of trying the 180 deg F one, but then decided to just go back with the stock 195 deg F one and solve the overheating problem (during the summer with the A/C on) some other way. Car runs much much better with the standard thermostat. Currently I am running more powerful fans and a PWR radiator, with foam sealing the fan shrouds. The radiator could use some ducting though. I was thinking of doing that next, but if the coolant reroute also works in dropping the temps down... that would be golden.

Bill

[snakebit]

Is FM's scooper available for NBs?
Do they sell it independently of their FI kits?
Anyone made their own version? :hammer:

[Wayne-n-Fla]

FM's scooper ? are you talking about the BEGI scooper ??, that one works with innercoolers to direct fresh air into the cooling system so it dosen't have to take "leftover" hot air from innercooler.
A friend built one, but it's first incounter with a speed bump wasn't pretty.

[Steve]

Steve,

Don't forget us Hotsiders! :stuart: :stuart:

I'm running a lot of power (probably close to 240rwhp) and could definitely use this as I track my setup. I run the heater during track days as an attempt to keep temps evened out. I had a 160 deg F thermostat in there and found that it made the car run too rich (like 11:1 during highway cruising) when the outside temps dropped below 50 deg F. I was thinking of trying the 180 deg F one, but then decided to just go back with the stock 195 deg F one and solve the overheating problem (during the summer with the A/C on) some other way. Car runs much much better with the standard thermostat. Currently I am running more powerful fans and a PWR radiator, with foam sealing the fan shrouds. The radiator could use some ducting though. I was thinking of doing that next, but if the coolant reroute also works in dropping the temps down... that would be golden.

Bill

Hi Bill,

In any 1.8 Miata that still has a factory ECU I will use nothing but the stock thermostat.

Proper airflow management through and around the front of a Miata is critical to keeping them cool. The key is to maximize pressure differential through the radiator. This means sealing up the front ductwork so no air bypasses the rad, a good shroud and fans for low-speed cooling, and reduce positive air pressure under the car as much as possible. I see an awful lot of cars with big sloppy holes cut around intercooler pipes, fan shrouds that don't work, undertrays with big gaps between them and the rad, or undertrays completely removed: every one of these cars overheats.
I've built custom ductwork and undertrays for Miatas that work quite well. One of my customers has an FM2-powered NB track car that's also a full luxo-boat: A/C, P/S, ABS, and leather interior. On top of that the car has an auxiliary oil cooler and big brake ducts, all ducted through the mouth of the car. That car has been proven to cool safely even on a 100-degree trackday. I may start selling the undertrays soon, but you would still need to do some fab work to seal up around the intercooler and radiator.

My reroute kits will fit (almost) any car running a stock intake manifold. The tricky part to all this is the myriad of throttle body inlet pipes that everyone uses... it doesn't affect the rear-to-front pipe, but it looks like there will be three or four different front hose arrangements to connect from that pipe to the radiator. So far I've confirmed them on n/a cars, FM/BEGi turbos, and Jackson S/C's, as well as with different radiator brands. I still need to find a local car with a TDR intercooler to verify any issues caused by their radiator relocation. So far, the only case I've found that won't fit without more mods is the AVO turbo inlet pipe that has an aux. injector in it: those will have to have a new pipe or the injector reolcated. The FFS Coldside-specific kit will be the only one with a different water pipe: that was easy to confirm since I own one.

[snakebit]

FM's scooper ? are you talking about the BEGI scooper ??, that one works with innercoolers to direct fresh air into the cooling system so it dosen't have to take "leftover" hot air from innercooler.
A friend built one, but it's first incounter with a speed bump wasn't pretty.Woops, yes, I meant BEGI's scooper. With no intercooler in front of the rad, would it make much difference?

I got a bunch of different sized foam strips from the hardware store and sealed my rad up very tightly. Haven't run on the track yet, but have had no street cooling issues at all in the FL summer heat, even put my silly vampire teeth back in the "mouth".

[Steve]

Woops, yes, I meant BEGI's scooper. With no intercooler in front of the rad, would it make much difference?

I got a bunch of different sized foam strips from the hardware store and sealed my rad up very tightly. Haven't run on the track yet, but have had no street cooling issues at all in the FL summer heat, even put my silly vampire teeth back in the "mouth".

On the scooper, I know two people that ran them on the street: both were destroyed by curb/driveway/road debris impacts. A sharp piece of metal facing forward is not nearly as forgiving as a plastic bumper or spoiler.

Good move with the foam: it definitely makes a difference. All those little gaps add up to a lot of air that would otherwise go around the radiator.

[tann3r]

Quick question, how important is sealing the fan shroud to the radiator?

If I do not have any cooling issues when the car is idling, would there be much to gain by fully sealing the fan shroud? Will it help cooling at speed or only at low speeds/not moving?

Currently when my fans kick on at idle, they turn off in ~20-30 seconds. This is on a 53mm koyo, and no extra shrouding to the stock fans.

[ThomS]

Colin I can not tell you about more Hp or cooling at speed but I can tell you when I was in AZ. last summer and having some work done at Mike's place I also had a Koyo 53mm installed. Before this happened no colling problems at all. But after it was installed and the fans were not sealed,
it was over heating, and after that was fixed o problems even at idle in the heat of AZ.

[jwalton]

Quick question, how important is sealing the fan shroud to the radiator?

If I do not have any cooling issues when the car is idling, would there be much to gain by fully sealing the fan shroud? Will it help cooling at speed or only at low speeds/not moving?

Currently when my fans kick on at idle, they turn off in ~20-30 seconds. This is on a 53mm koyo, and no extra shrouding to the stock fans.

HUGELY important!!! I had the same thing (pre-sc'd) and it started overheating once during stop-n-go traffic on the freeway during a 110+ degree day. Admittedly a pretty crazy set of conditions, but not exactly unheard of. Think of it this way, without sealing the shroud, your fans are really not doing much, just sucking hot air from the engine side of the rad and pumping it around in circles, pulling only a small amount through it. This is not about what happens when your doing 30+ mph, this is about low speeds.

[FormerDatsun510Man]

Without sealing the fan shrouds around the radiator you lose the suction effect of them pulling air throught the radiator. Instead the fan would pull air from the sides behind the radiator, thus losing a large amount of its effectiveness. As the vehicle speed increases more air is being pushed through the radiator from the front, so the fans operation becomes less important. But around town, the fans are very important for cooling.

Bill

[tann3r]

Looks like I've got some sealing to do. Thanks guys!

[bogey]

Use various widths of heater hose. It works better then foam insulation strips. 3/8" and 1/2" can be pressed into the gap and glued with a touch of superblack.