Jeff20B

iTrader: (13)

Mazda GLC with a 20B in it.

Following the advice of Muy, Aaron, renns and some others, I sought to get it to at least idle and then took it for a spin around the block.

I set the BAC to turn off at 100° and adjusted the throttle stop until it would hold an idle, and let it warm up. I also played with the air valve on top of the throttle body. It could idle around 500-700, but not smoothly. I brought it up to around 1000 and kept it there. With more time I suspect I could smooth it further and bring it down a couple hundred.

Response is certainly different from a carb. It has a part throttle cruise and then a noticeable transition into acceleration mode. I don't know whether this is normal as this is my first EFI engine and my first experience tuning an ECU.

It certainly has some noticeable torque. Even going slow in 3rd, it'll take off as if in 2nd. The stockish clutch disc and pressure plate have got to go.

The exhaust got quite a bit louder. It consists of three Rotary Engineering glass packs. I think I may have blown one of them out already.

It runs hot. The front of the car is very small and I had to locate the oil cooler in front of the radiator. The radiator is the short 3 row core 1st gen type with a 16" electric fan (shrouded 2" top and bottom to fit over 12" core).

It's a little too much engine for this little car. I could make it work, but I have something else in mind for the 20B...

Success: got engine to run, learned how to tune a bit
Failures: exhaust, cooling system

Jeff20B

iTrader: (13)

I started with 3 squirts per cycle, engine size of 244cid (654 x 3 = 1962 (20B) x 2 = 3924cc or 244 cid), the req_fuel was 5.5 in the lower box. It ran pretty badly.

I played around with the settings and it seemed to run best with 2 squirts per cycle, engine size of 300cid and a Req_fuel of 10.0 in the lower box. Heh, 300cid and req_fuel at 10.0. Go figure.

muythaibxr

well, if it's a 20b you should be setting it up like a 4 liter engine.... so what you say makes sense.

Jeff20B

iTrader: (13)

Not quite. 4000 cc comes out to 244 cid in the MegaTune calculator. Only when I upped it to 4920 cc or 300 cid did it run semi decent. That's practically a 5.0 liter. I don't understand what's going on other then it ran best here with a req_fuel of 10.0 (in the lower box).

muythaibxr

well, what I'm saying is that setting it up like a 4 liter, and then scaling the whole VE table would have the same effect, and give better tunability...

SCCA RX7 RACER

It runs hot. The front of the car is very small and I had to locate the oil cooler in front of the radiator. The radiator is the short 3 row core 1st gen type with a 16" electric fan (shrouded 2" top and bottom to fit over 12" core).

I run a street port RX-7 GEN 2 in Mission, Seattle, Spokane, and Portland raceways. 3300 to 8600 RPM WOT with air temperatures of 78 to 80F. My water runs from 185 to 200 and the oil coming from the oil pan to the oil/water heat exchanger 240 to 255F. If I get behind some traffic, it will go to 210 on the water and 270 on the oil. Once I pass the guys, it drops back down. I have run this car in that range for two years and take my engine apart at the end of each season. So far no heat or bearing problems. I run .0025” clearance on rotors and the same on the mains. I have proven to myself and others at the track that what I have works.
1. Get a three core rad. Copper or aluminum same heat loss. Cross flow.
2. Get an oil to water heat exchanger 60,000 BTU min oil in and out dash 10 same with water (1” min) in and out. In stall the heat exchanger at the opposite end of the rad away from the incoming hot water. In this way, the rad cools the water before going to the exchanger.
3. Run one Gen2 oil cooler after the heat exchanger (Dash 10 lines) also remove the internal bypass valve and put in a 3/8 bolt and washers with a stover nut to force the oil through the cooler.
4. Set the oil cooler in front of the rad but (Very Important) duct the airflow from behind the oil cooler under the rad that is in behind. Also, set it as far ahead as possible.
5. On the gen, two ran intake area I have 60% going to the oil cooler and the remainder going to the rad.
6. Seal all the incoming air, air tight with aluminum or coral plastic and duct tape.

With this set up ($750.00 to $900.00 USD.) you will not have any problems on the street or track. It works I FU%$#$%$# with a lot of thing over time and a lot of money to get to this point. So I pass it on to you at no charge. Any thing less and you may as well buy a gun with the money you save and shoot your self in the foot.

DO IT.

Jeff20B

iTrader: (13)

I'm a noob to tuning. What's involved in scaling the whole VE table? For that matter, what should a VE table look like? I posted a pic of mine here. Does my spark table look decent?

Perhaps something for an S5 13B with 550 cc injectors would be close enough for me to use.

SCCA RX7 RACER, where could I get a heat exchanger like that?

muythaibxr

scaling the VE is as simple as going to the menu in your ve table editor, and looking for the menu option in tools to scale the table... it's under VE specific.

t-von

iTrader: (8)

Bingo! This is probably the main thing that made the most difference in cooling your oil temps but yet know one ever does this. The ducting allows for the air to pass through only one thick core and not two therefore making the oil cooler more efficient. This is exactly what I was gonna do to my 20b.

Jeff20B

iTrader: (13)

Thanks Muy. I remember that feature now. I messed with it while bench testing. Of course it's good to have a VE table that's close to begin with. Did mine look ok?

t-von, in a common GSL-SE oil cooler setup, do you think the oil cooler would need to be moved further forward in order to route the heated air under the rad? Could a 45° baffle be installed between them?

muythaibxr

I don't know if it looked ok... I mean it looked pretty normal for a VE table... but there's no way to tell without hooking it up to a wideband and seeing what the AFRs are. Then you can tell if it's reasonable.

You know if it's "right" along with ignition if you can dyno-tune it and get good power.

SCCA RX7 RACER

http://www.fluidyne.com/pl_catalog.html
Here is the company which we bought two units. Note be sure to rubber mount it. Also use min dash 10 oil line. Plus make sure the oil lines are a flexible material you can not stress the oil cooler. We found that they are light weight and acceptable to vibration.

SCCA RX7 RACER

By putting the baffle directly behind the oil cooler, the airflow will tend to stall after it passes the oil cooler. All so, the low portion of the radiator will suffer from restricted airflow by creating a dam in front of it. I just finish prepping my car for this weekend of racing. If my memories serves me correctly from the base of the oil cooler to the front of the base of the rad and it was about 17 inches

Jeff20B

iTrader: (13)

I don't even have a narrowband, lol. I picked up a couple stock FC ones the other day. I'll put one in the header where the three Y into one. I'll get a wideband later. All I was interested in was to get it to idle and drive around the block. Having had succes with that, I can now rebuild it or drop it in something else and hopefully avoid many of the first start headaches you read about so often here.

Check out this datalog and msq to see what's up with my setup. Maybe you guys can give me a few pointers. By the way, the msq was from right before I test drove it as I was using a PC in the car and had to unplug the extension cord before getting underway.

patman

iTrader: (3)

hey jeff, how come you have the ignition set up with a second trigger, and whats up with the funny values for coils e and f?

i actually ditched the late leading mod until i get mine running decently, then i'd like to add it back in... but my ignition decoder setup seems a lot different than yours...any pointers?

(right now I have just a 24-2 wheel, with it set as a 6 cylinder. i did have the 24-4 setup and 12 cyl, but it was running pretty badly.... also 60* after tdc is bdc, which was making me kinda worried...

thanks,
pat

Jeff20B

iTrader: (13)

Second trigger? Coils e and f? You're gonna have to slow down. I don't know what you're talking about.

My car came with a VR conditioner in the form of a transistor ignition module a lot like a J-109 ignitor except it can handle very high tooth counts. I lucked out in that regard. I've never messed with what jsmcortina recommends.

The wheel decoder is simply the version in the firmware I'm using. I'm not sure what they changed about it, but it's been over a year so I'd guess they changed some things.

I've never tried 24-2 (12-1) on the engine, but I did bench test it. 24-4 (12-2/dual 6-1) gave similar results in the injection events when set to 12 cylinder, so I went for the gusto and tried it on the engine. At 60°, it would stop triggering the ignition when at 0° on the map, so I changed it to 50° and that fixed it.

Yeah, 50°. I discovered this while bench testing. I don't know what's going on or why, but 50° worked for my setup. Now on the car, it idles anywhere from -5° (like a stock GSL-SE or FC) to 0°; easily adjustable by moving the CAS a little. When I hit the throttle, it advances like I would expect.

Sorry if I still sound like a noob. I came from the world of carbs and distributors, and I end up treating the MS like a carbed setup without even trying. lol

Carefully try 50° and see what it does for you in 12 cylinder 24-4 mode.

patman

iTrader: (3)

i figured it out (my car, not your settings) running exactly the same settings as a stock fc, except different tooth counts as triggers. so im using 60*. it started and ran fine, although my fuel is way off....im waiting to burn off all my assembly lube before i install my wideband.


all the stuff i was talking about is what it showed when i viewed you msq file. although i read it with my 029q2 configuration, so that may have caused some of it.

Jeff20B

iTrader: (13)

Yeah, 029q2 is probably different enough to have caused discrepancies as the version I'm using is like a year and a half old now.

Is yours boosted?

patman

iTrader: (3)

yep