Mazda 20 B engine in SL-C

[Fran Hall RCR]

You have to mount the body with the car at the correct ride height...that's the first step, A pretty close suspension alignment is also needed.

Call the shop and we can walk you through it if necessary

 

[John Milmont]

That engine looks great in there. Cant wait to see this complete.

 

[Cam]

Whoa, that will be a sick slc. Shedding 10 to 20% total weight. On an already light car. i bet power band would feel like a 2 stroke dirt bike for the road that can hit 200mph. Plus lotsa room for twin turbos?

 

[Garry 20 B]

I am going to get the body on the car after setting the suspension, I have to get all this heavy work done this weekend, knee surgery Monday, so I wont be able to do anything but sit in a chair and sand, read about my ECU.

I was suppose to get a Micro tech LT 16, but instead they send me the latest not yet release LT 15, so I want to get that all hooked up. It says the map sensor is built into the unit, which is only around 3/4 x 4 x 5", pretty small.

I can do wiring and sand on the body for the next month or so while I hobble around the shop doing my other work.

My Idec PLC is suppose to be here next week so I can program that, along with the touch screen.

Does anybody know any advantage or disadvantage of a water cooled inter cooler?

 

[Dave]

My Idec PLC is suppose to be here next week so I can program that, along with the touch screen.

What is that? A cheaper alternative to the ISIS system?

Does anybody know any advantage or disadvantage of a water cooled inter cooler?

There are pros and cons to each setup plus front and rear engine applications have their own nuances as well. Since we are dealing with a rear engined car, the SL-C in particular, that is what I will base the pros and cons on, as I see them.

W2A Pros:
Can keep short IC tubing to minimize charge time.
Can locate IC anywhere that can accommodate its size and shape.
Great for rear/mid engine cars where airflow to the rear is not optimal.
Can get intake temps way below ambient for short periods with ice etc.
Can locate heat exchanger anywhere you want with adequate airflow (also a con in our case). The best place in theory is in front of the radiator, but in our case, with the limited size of the radiator and the 20b's extra cooling demands, this is not ideal.

W2A Cons
More weight due to water, pump, additional heat exchanger and plumbing, and perhaps a reservoir.
More things to go wrong due to a more complex system.
Can easily heat soak the IC with an inadequately designed system, particularly if you track the car.
Higher cost.
The need to locate an adequately sized heat exchanger presents a challenge, especially for you with the race tail. I know, I started with the race tail and bought the street tail later.

A2A Pros
Simple setup with few parts means greater reliability.
Lightweight.
Lower cost.
Reliable.

A2A Cons
Finding somewhere to locate a massive IC besides the front of the car.
Intake temps never get below ambient, at best.
Would need longer IC tubing.

I really wanted to run an A2A IC but just couldn't find the space to do it. I was able to find custom cores that would have allowed me to run two IC's in series if i wanted to run one on each side of the car behind the side vents, but alas, I chose to run oil coolers in those spots. You cannot fit an IC large enough behind one side vent.

Another option is to run the oil cooler(s) next to the radiator behind the front brake ducts in the nose and run two heat exchangers for the IC in parallel behind the side scoops in the engine bay, or vice versa. This option makes for a ton of plumbing though.

I finally ended up with a custom A2W system that will do the job with minimal plumbing length and connections. My IC sits in front of and slightly above the engine and the heat exchanger sits horizontally above the transaxle. The vents and additional clearance afforded by the street tail allow this option and I have glassed in an additional scoop in the center between the two standard scoops. Fitting any heat exchanger or IC in that location was not possible with the street tail.

 

[Dave]

My IC sits in front of and slightly above the engine and the heat exchanger sits horizontally above the transaxle. The vents and additional clearance afforded by the street tail allow this option and I have glassed in an additional scoop in the center between the two standard scoops. Fitting any heat exchanger or IC in that location was not possible with the street tail.

Looking at the pics of your transaxle installed in the car and seeing how much lower it is than mine and most others, you may be able to fit a heat exchanger, or even and A2A IC horizontally, between the transaxle and the steel bracing above it. Your only problem then would be airflow through it. You could glass in a scoop or something to remedy that.

 

[Garry 20 B]

I have plenty of room on the passenger side for the inter cooler, its all open in there, just someone stopped by and asked about putting one in and I don't know anything about it.

I found a inter cooler that has both in and out on one side, this would fit in front of the rear tires vent, and on the other side the oil cooler.

I talked to ISIS, and its not the money, its the flexibility, I can program the Idec for the way I want things to work, brake flashing, blinker rates, and use a touch screen for operating the car. ISIS you have to call every time you want to change something, to me the software should be available if you want to customize it yourself for the money it costs. I will have less wires with the Idec, and might make all my gauges in the touch screen, using bars up and down changing lights for different degrees of measure, etc. My ECU will talk to the Idec also with analog and digital inputs, your security system can be made with a finger print scanner, code, etc. I just like Idecs, I have used them in several cars, flash lights at a car show every 5 minutes then shut off, for 10, people don't know what to think, stuff like that I like to do.

 

[Dave]

Who/where did you source the IC from and what are the dimensions? I found plenty of IC's that would fit in there but none were up to the job of 800+ hp. Unless you are talking about cutting a hole in the side of the car and running the IC lengthwise with the car (similiar to the Ultimas), I can't see something fitting in there of adequate size.

 

[Garry 20 B]

I'm ready for 4 months of pain. This was done on Monday the 16th. My other knee was done May 22 this year, it still hurts. Have most of the heavy work done on the car tho now, so now just starting to button up things for a spring finish hopefully.

 

[Fran Hall RCR]

No snow shoveling for you for a while...

Hope your recovery is swift..

 

[Jim]

I'm ready for 4 months of pain. This was done on Monday the 16th. My other knee was done May 22 this year, it still hurts. Have most of the heavy work done on the car tho now, so now just starting to button up things for a spring finish hopefully.

I'd offer you your physical therapy for some time in your car but the commute to Cali might be prohibitive. Total knees are doing great these days, you'll be back at it in no time. Thanks for sharing your build. :thumbsup:

 

[Dave]

Get well soon Gary, we are all looking forward to the updates.

 

[Garry 20 B]

Thanks everyone for the support, leaves me lots of time to look at all the pictures on here

 

[Jack]

Feel for 'ya Garry. Been putting off knee surgery for 46 years!

 

[Lindsey]

When you said "knee surgery", I was thinking arthroscopic.. :stunned: that's a serious bit of cuttin' n shuttin'

 

[Garry 20 B]

I had the right knee done MAY 22 this year, been 6 months and I still feel it and never got back my full range and doc says it won't come back, I can almost sit on my KTM and kick start it, thank god for electric start.

This one is better, or I was at leasted aware of what to expect, so it is what it is.

im going to run some of my fuel lines, oil lines, body mounting for tilting the backend this week. My exhaust is done, I just have go pick it up, its hard to sit in a car for a half hour, even a trip to Summit I didnt do Saturday cause of the pain.

O WELL, Ill post more pics next week.

 

[Garry 20 B]

Since I have some time, I am researching water to air intercoolers. It seems to be they can be smaller then air to air.

Do you use the radiator water for cooling that or a seperate one for it?

I have some room, plumbing is not a problem using engine radiator for cooling it?

What temps do I need to look for for circulating water, motor temps?

 

[Dave]

Since I have some time, I am researching water to air intercoolers. It seems to be they can be smaller then air to air.

Do you use the radiator water for cooling that or a seperate one for it?

I have some room, plumbing is not a problem using engine radiator for cooling it?

What temps do I need to look for for circulating water, motor temps?

An Air-to-Water (A2W) IC needs it's own heat exchanger, pump and coolant lines. You will not be able to use one radiator for both the engine and turbo cooling systems.

There are two main factors when designing an A2W system, flow capacity of charged air through the IC, and capacity of the heat exchanger (second radiator) to remove the heat.

Engine temps should be as with any other engine, 180-220 or so.

Coolant temps for an A2W system can vary widely. These systems have the capacity to have coolant WAY below ambient temps due to their ability to run ice in reservoirs, if so equipped. These types of setups typically are only used for drag racing as the ice does not last long. For typical street or track duty systems, you want the coolant as close to ambient as possible without any short term aids (such as ice), and have the system be able to sustain stable temps under load for long periods without heat soaking the system. This is where the size of the heat exchanger comes into play and trying to find room to fit one somewhere, along with the engines oil and coolant cooling systems, all without compromising anything on a high hp turbo 3-rotor. Fun times.

Mentioned by you previously:

I have plenty of room on the passenger side for the inter cooler, its all open in there....
I found a inter cooler that has both in and out on one side, this would fit in front of the rear tires vent, and on the other side the oil cooler.

Who/where did you source the IC from and what are the dimensions?

 

[Will Campbell]

I would add that any intercooler can improve efficiency for the short term by spraying a liquid like water or alcohol on the air-cooled portion.

I've even seen some intercoolers that are plumbed through the AC circuit so that the intercooler core actually sees cooling temps far below ambient, making it possible to send chilled water to the A2W potion of the cooler that is as much as 40 degrees below ambient.

I've heard that for every 10 degree reduction in charge temp, there is a corresponding increase in power of about 1%. I'm sure that is a rule of thumb, but it does illustrate how lower charge temps increase power.

 

[Kyle D]

^^^
I am an intern in the HVAC industry right now, and I am also currently taking mechanical engineering classes in college, and while I see the "lower EAT temperature=higher power" logic, I cant help but think that more power would be taken from the engine by the A/C Compressor/pulley than would be produced by having lower engine EAT's...
So even though you would definitely have lower entering air temperatures, I would bet that you'll have less power available throughout the entire power-band because of your engine needing to run the AC compressor. I think that if it really was that simple to lower EAT's, then every every turbocharged car produced today would have their inter-coolers running in tandem with their AC evaporators, which they don't...
But Please, those who know better than me, correct me if I'm wrong. I'm not trying to be a troll, I'm just wondering if the laws of thermodynamics check out in this particular example.