Jeff20B

iTrader: (13)

It runs! Kinda. Well, it fires up on Aaron cake's map which is super rich and the timing is like 10 degrees which I don't need. It also tends to flood if I do it wrong, but it's easy to clear if I pull the fuel pump relay wire and crank until it "catches" then hook it back up. The flood clear mode in the MS doesn't seem to work correctly (still needs to be set).

I got the full 3" exhaust done finally. It's painted and in. Also test fitted the O2 sensor today. Worked out a nice routing for the wires. Gotta get the gauge in.

How does it sound when it "runs"? No vids, sorry. Maybe later. But I can kinda describe it. It idles with a brap at 2k because of the BAC valve which has to stay open because otherwise it stalls and floods due to richness. Gotta deal with that cold warm up stuff. There's no cooling system yet so no way to run it more than a few seconds each time.

But how does it sound with the new 3" exhaust? Too loud. But then I shoved a restrictor in the tailpipe and it brought the volume down to possibly a reasonable level. I'd prefer quieter though. I still have options. At least when I close the door it's not super loud inside, so I can probably tolerate it.

Not sure how loud it's going to be outside, like at idle and stuff. Not there yet. Gotta get the cooling stuff done next.

But first the wiring needs to be finished. Debating whether to hook up an ignition relay like it shows in the MS instructions, or trust the old car wiring to provide enough voltage. I had to relocate the battery, but I have an alternator I could tap from. The alt has higher voltage anyway... But testing showed that just sitting with the key on - engine not running, it had a .02v drop through the key switch. Not bad.

Also the wideband needs a power source with a 10amp fuse. I might just use the ignition relay for that and add a fuse holder to its output pin 87 or 30 or whatever. The MS' main relay is fed with a 20amp fuse, as per instructions. Then each injector bank only takes 3 amps for a total of 6 with a 5amp fuse on each bank (ss per instructions). Then the MS itself and the BAC valve each have a 2 amp fuse (again per instructions) that haven't blown yet (the BAC valve uses about 1amp at 14 volts, no idea what the MS uses but it's less than 1 amp if memory serves). So I have about 8 amps in use. This leaves me with 12 amps of head room for the wideband. Perfect!

Jeff20B

iTrader: (13)

Well, I had enough of stock twins for three people! I helped get PercentSevenC's FD engine into his FB and hated every minute of it when the twins were what he wanted to use. Then we find out his stock radiator wouldn't fit with the wastegate diaphrams... so out the lump came and the nice simple S5 turbo went back in. Sigh of relief. It fits brillinatly with the block hugger FD intake manifold. Plenty of air gap for cooling. We also hooked up the water lines this time.

So no stock twins for me, although I'm sure it would be nice to experience in my FB, but mine were old and leaked oil into the intake tract. I also disliked how heavy they were. 62 pounds hanging off of six studs - several snapped during removal. That was fun drilling and then easy-outing them. They broke off flush so no way to grab them. Glad it's got a header now, as crappy as it is (I built it to fit the GLC and it was the first welding job I ever did). I could get pics up later but not really thinking about it. Lots of wiring left to do.

ff_drift_lol

nice fab work just no offense would like to see nicer welds. get a mig instead of that fcaw

Jeff20B

iTrader: (13)

Yeah.

Jeff20B

iTrader: (13)

Uhg, now I can't get a radiator to fit right. I should have moved the engine back when I had the chance. Or redo the motor mounts onto the main crossmember.

A bit of good news: I loaded the old fuel and spark tables from 2005 and it almost will idle without the BAC valve open. Has a lot of brap though, which I'd like to smooth out. It needs a cooling system so I can begin tuning.

vipernicus42

iTrader: (4)

Hey Jeff,

Awesome project! Are you using the original rotors, or did you swap in higher compression rotors along with your plans to go N/A? What compression ratio are the original rotors, anyway?

You're giving me bad ideas. Bad ideas that make me want to spend more money, haha.

Jon

Jeff20B

iTrader: (13)

Thanks! Stock rotors, 9.0 compression. They work fine for NA.

I finally got around to the radiator, after a year. Test fitting, with trimmed brackets. I get to weld them tomorrow. Joy!

Rx7_fanofspeed

WOW! Looks great ..

Jeff20B

iTrader: (13)

Thanks! They're all welded up and trimmed where necessary. Paint is drying now.

Jeff20B

iTrader: (13)

And now they're in. Next up is hoses.

TurboGabe

This is EPIC!

Jeff20B

iTrader: (13)

The lower hose is done. The upper hose is done. The heater hose is done. Fans are wired. Oil cooler and lines are installed. The waterpump leaked so I swapped in another. Holds coolant now. Test cranked. Holds oil. Test ran until warm. Some problems. First is it didn't want to run well so I pulled some fuel out of the 55kpa range. Got it to idle at around 1300 somewhat smooth. The air screw on top is all the way open. The oil gets insanely hot. The coolant stayed reasonable at around 197 though. Reason is I drilled six holes through the thermostat valve, so it's like cheating.

Took it for a test drive. Um pretty unpleasant. It has like no tip in so wants to stall or you have to give it a lot of gas then it chugs. Obviously needs tuning there. So I tried 2nd gear instead and it kinda worked. Reminds me of my brother's GSL-SE and all the launch problems it had. Other problems are way too loud inside, so the 3" exhaust has to go. The windows don't roll down so it was sweltering inside. Starting from a stopsign is the worst. I barely got it back on my street then I decided to open it up some. It does ok once it's moving. I easily took it up to 6k I think (unfamiliar with the S3 tach at a quick glance), and it had some power but it didn't really wow me. It acted a lot like seattlespeedemon's S5 big streetport. Not really what I was going for. I know it's a fresh rebuild, gotta keep it below 4k or whatever, plus it's very untuned yadda yadda. I can't let this be my only opinion forming example and so on. But maybe it'll have to be...

Got it back around and parked it. It was so freakin hot when I shut it off. And it stayed hot hours later. I bet it's still warm. I hope it's ok. Oh and it smokes when it runs. Not sure what that's about. Also the fuel pump made an extremely loud noise at the same spot while decelerating on the other street just before turning the corner. I'm like ??? right now. Running low on fuel? Sump cup running empty? No, I don't think so. But maybe.

So there are pros and cons to this setup. More cons than pros I'm affraid. It has lots of problems. It runs way too hot. There is no fan on the oil cooler and no way to fit one. The radiator is too small and no way to fit anything larger without spending 400 to 900 on something custom. The engine needs to move back 2" for a proper radiator but to do it, I'd need to redo basically everything I've done. Therein lies the catch. In my mind I've already completed all that's necessary to have a running setup, as it ran and drove, plus it was a lot of time and work to get it this far. To tear it all out and start over is just asking too much. Especially when there are other possibilities out there.

After hopping in the blue one to move it in order to get the brown one out, it fired up quick and ran perfect, was easy as heck to drive, even while cold, and felt right because I'm used to the chassis by now. It's a lot quieter too, which I've determined is important to me these days. Will this ever happen with the brown one? Well, if it had a similar setup, yes. But with the 20B, I don't think so. Heck the 20B floods every time you start it now. Uhg. I have to pull the fuel pump wire each time, or use flood clear mode.

So what do I do?

Oh two things that come to mind and now make sense are I never drilled and tapped the 20B intake manifold for a brake booster fitting. I just never got around to it; I adapted a tiny vacuum line on a 3/8" hose instead. Also the intake elbow never got a filter on it. Yes I drove the car without a filter! Anyway I was going to cut it and fit a long white spectre filter, but I never got around to it. Why is that? Oh I have the filter sitting here, I just never got it on there due to time constraints and space constraints. Was my subconscious driving this project in such a way that it would force me to come to a conclusion? And was that conclusion to stick it in the baja like I contemplated before?

Update:
The above is from yesterday. Today I test ran it some. It fired up quick and ran smooth... then as it warmed up it got weird again. Still has trouble restarting and floods, but flood clear mode works. This time I stuck a compost bin thermometer down the dipstick hole to monitor oil temps. It got up to 215 degrees F in the pan. This is the hottest oil in the engine before it gets sucked up and sent to the oil cooler, which acts like a free air heatsink as there is no fan on it at this time. Better temps than I thought.

Still way too loud for me, but I'll have access to a full RB exhaust system that can be adapted to 3 rotor use. I may also relocate the oil cooler up to be more in direct air flow from the fans.

My other option is to put this engine in a baja and use a tall 83-85 radiator with two 16" fans. One pusher, one puller. The oil cooler will be in a far more direct air stream.

What about the added weight? I sat on the rear cage and I only lower the car 1/4". I'm 140 pounds. They say the 20B is 80 pounds heavier than a similar 13B. Well, I assume "similar" is an S5 engine or a 13B-RE from the same era. However my 13B is an old school with Y plates and heavy R5 rotors. These parts add up to at least 10 additional pounds. So make the 20B only 70 pounds heavier than my current 13B in the baja. Ok, I can live with that. It makes the math easy. So if 140 pounds lowers the car 1/4" with all my weight as far rearward as it can go, we can assume 70 pounds would only lower the car 1/8". Not bad. Plus the 20B would be low and more forward than where I was sitting, so added bonus there.

There are no space restrictions in the baja. I can run the biggest radiator I need to if necessary, but I somehow think the tall 83-85 with two big cooling fans (or taurus fans if I can ever find any again) would be just fine and way better than the rinky dinky tiny radiator and fanless oil cooler I've got going on now. Only gotcha is the baja can't really handle like a 7 so I might not get to use all the power. Plus people say the back of a bug is really turbulant so the fan(s) run all the time. Oh and I can get as much HP as an NA 20B if I do a turbo 13B.

What do you guys think? Should I keep the 20B in the GSL-SE and redo the exhaust system and cooling setup? Or stick it in the baja and have to redo everything: wiring, exhaust, rear cage, new exhaust, EFI-ready fuel system etc just to prove it has a better cooling system than the GSL-SE?

If you read this far, kudos, friend.

Jeff20B

iTrader: (13)

Looks like I can fit a 16" fan in front of the oil cooler. I'll have to shroud the rest back toward the radiator - should be easy enough to do with sheet metal. Yes it'll be a pusher, so not as effiecient, but, yeah.

If this keeps oil temps resonable, I'll be happy.

As for the exhaust note, it's throaty and kinda too loud. IT keeps upsetting the neighbors. Kinda difficult to even get an idle tune when it's this loud in a quiet residential. What do I do? Why the same thing you do on a 2 rotor FB NA if you've got the RB parts available. You throw in a complete RB "streetport" exhaust system. I'll just have to add a 3rd primary and Y it in at some point before the main muffler. You can see pics of it earlier in this thread.

Will this limit power? Maybe only at high RPM. However 84stock made over 200HP with his RB exhaust and a 7" camden. Then we have Steve84gsTII who made 300hp from his S5 turbo swap feeding an RB powerpulse with a 3" pipe. I can mod mine like that if I want. But I'll start out with the standard 2.375" inlet and see how it does. It's easy to go 3" in the future if I must. The point is his car passes dB limits in CA and 84stock's works for him up in CA. I'm terrible.

jjshaloam

iTrader: (5)

Can you add a baffle/insert/whatever they're called to your exhaust? Though the exhaust diameter isn't as big of a deal on an NA, 2.375" seems to restrictive for a 20B (this is coming from someone running a 4-inch downpipe to a 3 3/4 inch exhaust, though).

Do you have space for a 2nd oil cooler? I'm running dual... I want to say 23-row, but don't quote me... oil coolers with a giant snail heating the engine bay and my oil temps don't go above 190 even when running hard. I don't take it out when it's crazy hot, but it's still been on a track on a Kansas day hotter than what you would normally see in Seattle.

I say leave it in the GSL-SE and add another oil cooler and do what you can with the radiator. If you're considering starting over in a new car, you might as well put that time into just moving the engine back the 2-inches you need to get a larger radiator to fit. I've been looking forward to seeing this finished for a while. Don't give up now. :-)

Jeff20B

iTrader: (13)

Thanks.

Yeah there is already a baffle/restrictor in the tailpipe which helped (still louder than I'd like though). But now I think I'm being held back by the short primary exhaust itself.

It was rotarygod who stated he lost power everywhere when he swapped from the RB "streetport" exhaust to a short collected setup. Everywhere? You'd think a small exhaust on a rotary such as a 2" would not lose low end, but would certainly lose high end due to keeping velocity at low RPM at the expense of hurting flow at high RPM. Likewise a 2.5" should have best midrange and a 3" should have best high end at the cost of some low end.

Makes sense. But I tested a 4 port R5 13B in my rotary baja project with a 2" super short collected system (no room for anything bigger at the time) and it lacked low and high end. Midrange wasn't good either. Then a curious thing happened. I threw in a 6 port 13B and a Nikki on a modified manifold. This engine still lacked low end but it really came alive from 4k to 7k. I didn't understand. How could a 2" have that kind of power?

Then in the GLC I swapped from a short collected 2" exhaust to a short collected 2.5" exhaust and it didn't seem to lose low end, and only gained midrange and high end. Plus it could free rev to 8k which I shoudln't have done so much as it was a fresh rebuild with 3mm apex seals.

Now I'm getting a little distracted. Forgetting what I wanted to say (been too busy lately)... So I'll get back to the 20B exhaust. I feel a 2.375" pipe is too small but it will work for now. How? Because the three primary pipes give up their heat to the outside world, by the time the exhaust reaches the collector, it will have contracted enough that while 2.375" is small for this application, it will still be adequate for low end and midrange. Maybe even some high end. And the other cool thing is I can swap in a 3" inlet pipe on the muffler if I want to later after it's broken in a bit. This will allow high RPM use without hurting low end too much.

Then again the exhaust gasses will be cooler back there than next to the engine, so maybe 3" way back there isn't the right choice? Maybe a 2.75" pipe? I'd have to find a place that sells that size.

Oh and one more thing. The RB thickwall 2.5" pipe has an ID of 2.25" (2 1/4")- same ID as their thinwall 2.375" pipe, so I've got nothing to gain by swapping to RB's thickwall pipe, other than weight. Infact RB doesn't even use thickwall back there. They feel after the presilencers have done their thing, it's ok to switch to 14 gauge. If I went with a 14 gauge 2.5" u-bend to get up over the rearend, that's an ID of 2.375"! Not bad. And we know the muffler itself can flow at least 300HP on a turbo setup which requires free flowing mufflers. I think it'll be ok on this engine as an NA.

I kinda have space for a 2nd oil cooler, but it would totally block the radiator core.

Thanks for the encouragement. Hoping the 16" fan takes care of my temps and the RB exhaust takes care of the noise without hurting power while enhancing low end torque. As far as I know, no one has done a long primary 20B like this before. I wonder how it'll sound.

Jeff20B

iTrader: (13)

Just an update. The air filter is on the intake elbow. The 16" fan is on the oil cooler and supported from above by two brackets. It needs ducts to force whatever doesn't go through the oil cooler into the radiator. Still needs exhaust.

I'm getting closer! I wonder if I'll run out things to do before I run out of month. I gotta switch gears in October to more of a winter vehicle.

spanner

iTrader: (2)

G'day Jeff, I must say you have the most patience I've known of anyone doing a project like this and I commend you. I also have a 20B on the ground in pieces, to build from scratch. I also am torn about whether to install it in 1st Gen or 3rd Gen. I'm somehow tending to go towards the 3rd Gen side , seeing that the chassis/suspension/braking/cooling system is a bit better compared to 1st Gen, that would need to be upgraded.....keep the updates coming dude !!

Jeff20B

iTrader: (13)

Thanks for your positive feedback. I appreciate the kind words.

Ok here's an update. I got exhaust version 2.0 completed. But I gotta change it. Ahem. I went from a short primary 3" to a medium primary collecting at 2.5". It has way more power and provided the WOW factor which version 1.0 lacked. But it sounds bad, all high pitched and ratty/tinny. Must be the RB presilencer I used. Decent overall volume level though. Quieter and better flowing than 1.0, which had way too much bass and was simply too loud. Neighbors were getting upset. It was deafening with the passenger door open, and when you rev it, it would get louder but just didn't seem like it wanted to flow. Strange that a full 3" didn't want to flow. Now version 2.0 can blast a ton of exhaust out the tailpipes. It's really impressive to watch. But I can do better.

Exhaust 3.0 will keep the header and muffler. Only the entire center section will be changed. This time it's getting a true long primary. Each pipe will have its own presilencer. Then collect possibly to 3" then neck down to 2.5" to get up over the rearend. Or just to 2.5". The goal is to outflow version 2.0 and sound a whole lot better. It should stop the ratty tinny obnoxious noises in the process seeing as each primary will receive its own presilencer rather than letting one presilencer do all the work. Does that make sense?

The science behind it suggests that on a 3 rotor, 1.5 rotors are always flowing. However the presilencer I used was never designed for this. It was designed for a 2 rotor FC either turbo or NA (it was the NA version with a sensing tube which I removed to make it like the turbo version lol). A 2 rotor has two rotors phased 180 degrees apart so only one rotor is flowing at any one time. This works ok to collect into 2.5" close to the engine. The expansion chamber inside the presilencer allows the supersonic pulses to dissapate slightly as they enter and it slows them down a little (delays the pulse slightly) before it enters the core. It shapes the note and makes it sound more pleasing by getting rid of the metallic character. This works great when you only have one pulse entering at a time. However on the 20B, this can't occour as 1.5 rotors are flowing at any moment in time. So it has a strange effect inside the exansion chamber, where the one and a half pulses mutually strengthen or enhance each other and produce a louder sound than was anticipated by RB's engineers. The flipside is there is also a much quieter pulse, but it is totally drowned out/overflowed into by the loud pulse. I suspect these 50% stronger pulses are what I'm hearing leaking through the shell, causing the tinny ratty note. The shell is only 14 gauge mild steel. Ok for 2 rotors and they way they run, but terrible for three rotors. Do you follow so far?

So the plan for 3.0 is to grab my nice low mile RB center section for a 1st gen, chop off the rear dual pipe flange and weld on the 3 into 1 collecter from my medium primary center section. Then I'll need to fab up a 3rd presilencer from materials anyone can find online. I just hope I can match the density of the core wrap. I've got some cheap pot scrubbers and I can wrap them with some coarse stainless steel wool. I've tried this before with great success, repacked two dead RB presilencers and built a nice medium/long primary for my REPU. Nice and quiet and has low end torque for the first time since I've owned it. I'd like something similar for the 20B.

Infact I suspect that I can more easily get away with a 2.5" final muffler on my 20B now with version 3.0 than I could with the current medium primary. Reason why is I'll now have three long primary pipes giving up their heat to the outside world, and three 2" presilencers taking out far more pulse energy than a single 2.5" presilencer ever could. That's like over double the amount of total presilencer area. Therefore when the reduced heat and energy reaches the 3 into 1 collector, it will have cooled and contracted enough that perhaps 2.5" is the right size this far away from the engine, and that if I were to use 3" it might hurt low RPM performance and bring back the drone. Remember I'm doing all this exhaust research to give back what porting took away; low end torque! Something the 20B is supposed to be known for! While at the same time retaining high RPM flow potential of a streetport and at the same time again not being ungodly loud, which on a rotary is the rule rather than the exception. Any idiot can build a loud rotary exhaust as the engines are inherantly noisy. Plus I swapped my sleeves over to T2/FD which are that much louder.

If I can "pull this off" I'll be pretty proud of myself.

Jeff20B

iTrader: (13)

I never posted a pic of the complete running setup. Enjoy!

Casual_John

iTrader: (8)

Any photos of Exhaust 3.0?? Is that 20B keeping cool? It looks cool.