It runs!!!!!!!

Started it up this afternoon. Open turbo. It came right to life, with me giving it a little gas (but it did that before for reasons I won't go into). It's obviously running really rich, but otherwise it didn't to appear have any obvious leaks. I ran it for about two minutes to check everything out and cut it off. I probably won't mess with the car again until after exams. I really should be working on term papers anyway and not messing with this thing. I will get it towed to Henry's to get a midpipe made.

Quote :

"Well, rotor housing wear, etc...but if you charge your gas with a little lubricating oil instead of relying solely on the squirt pump, that can help. I'd probably want to use Amsoil 2-cycle 100:1 mix. Anybody know of folks who've used this stuff for this reason?"

Running two stroke versus the factory oil metering system is a hotly debated topic among rotary owners. The key issue here is that 89+ rotary engines (including Rx-8s) have an electronic oil metering pump rather than a mechanical one like my car and all earlier rotaries had. The oil metering pump essentially drips oil into the housings using oil injectors. The electronic ones are way less reliable than the mechanical ones (although they consume less oil), although there is a failure sensor. The oil injectors in rare cases can get clogged. Some people argue that 2 stroke oil is better for lubrication than regular motor oil, so they use that reservoir that was mentioned.

I personally have retained my stock mechanical oil metering pump. I will probably throw a little two-stroke into the gas eventually just for safety. On a side note, 2004 Rx-8's had poor ecu programming which did not inject enough oil and caused some engine failures, especially in automatic transmission cars.

And as far as rotor housing wear affecting the life of the engine... well the more wear a housing has, the lower your compression numbers will be, but there are plenty of housings with 100k+ miles doing fine. My car has used housings and it runs fine. New housings are nice but will add close to $2000 to the price of the motor.

[Edited on November 29, 2007 at 10:34 PM. Reason : .]

11/29/2007 10:32:29 PM

Quote :

"yeah you turn an rx-7 into a camaro."

dumb

11/29/2007 10:46:46 PM

Quote :

"i'd buy it, if i wanted to 3-rotor it."

expensive, and i suspect it adds more weight than the LS1, while trashing the F/R balance.

Quote :

"Duke, gonna have to bust your chops on this one. You do enough stuff to any engine and that's exactly what it becomes. "

At least the LS1 is pretty bulletproof in stock trim...

and yeah, you can make it unreliably hotly-tuned, but there's no reason, at least for me. It makes so damned much power in a relatively mild state that there's no reason to run it on the ragged edge. Start making 400-500 hp with that 13b, and the reliability/durability (which isn't exactly pacesetting to begin with) plummet even more.

11/30/2007 2:50:37 AM

My car came with 182 (flywheel) horsepower from the factory and an LS1 came with over 300. That's part of the swap's appeal. Both were very impressive for their day but now actually seem weaksauce considering how much performance has increased in cars over the last 10 years. Although if you dyno a 2nd gen Rx-7 turbo and an Rx-8, they tend to put down almost the same amount of power with way more torque in the Rx-7 obviously. Stock they made 182 hp @ 6500 and 183 torque @ 3500. It was hardly a torqueless, high revving motor in stock trim even by today's standards.

[Edited on November 30, 2007 at 7:31 AM. Reason : .]

11/30/2007 7:27:52 AM

I don't disagree.

11/30/2007 10:30:08 AM

Update: I got a midpipe fabricated today so now the exhaust is hooked up. I took the car out and it's, well, running like crap. Extremely rich and will not idle at all. My wideband was literally pegged at 7.3:1 AFR and a shitload of black smoke was coming out the back. I think my water temperature sensor is bad (the one that goes to the ECU), as it was reading 45 C when my other gauges were reading about 210 fahrenheit, which is about 100 degrees F off if you do the math. According to my Power FC map the engine is dumping in an extra 30% fuel at that temperature. The car was also starting to heat up, and then I remembered that I never bled the air out of the cooling system. Also, some smoke is coming from the turbo. I don't know if that's an exhaust leak at the V band flange or somehow my brand new Garrett turbo is fucked up. I have an oil restrictor in the oil feed line and the car does not appear to be leaking any fluids.

I will probably order a new sensor and start working on the car again in a week or two.

[Edited on November 30, 2007 at 7:40 PM. Reason : .]

11/30/2007 7:39:02 PM

cant wait to see vid and times

11/30/2007 8:07:09 PM

Update: checked the thermostat and it's opening fine, but my dumb ass never topped off the coolant... it was down half a gallon. fan clutch seems ok. It should be ok for cooling now I hope. I will eventually put the stock undertray on again to improve airflow to the radiator.

I replaced the water temperature sensor and it is now reading accurately, so it won't dump a bunch of extra fuel (it was literally reading 50 C too cold). But it turns out my throttle position sensor is bad... only reads 0-4volts and resistance is out of spec. So I am ordering a new OEM one today. Hopefully replacing both those sensors will make the car idle way better and not dump so much fuel in.

Oh and my oil pan is leaking. Fuck. I am going to have to replace the oil pan (hopefully with some help, as I have never attempted this before, only watched someone else), and I am going to install an oil pan brace while I'm at it. http://www.banzai-racing.com/fc_OPB_instructions.htm

12/14/2007 10:45:54 AM

[money pit]

[Edited on December 14, 2007 at 11:26 AM. Reason : .]

12/14/2007 11:13:41 AM

Well, I finally figured out why the car has been running like shit. I didn't have my pressure sensor hooked up correctly... bad vacuum source. I started the car today and started datalogging, and it turns out the thing would not read vacuum. MAP should have been at about 400 millibars and instead it was reading 1 bar... resulting in 5 times more fuel delivery than it should have. I'll get it hooked up properly this weekend and it should hopefully idle and drive decently then.

12/22/2007 2:36:34 PM

um yeah it's been about 6 weeks since I've updated this thread. basically it wasn't just me having the MAP sensor hooked up wrong... i had what turned out to be six vacuum leaks . I basically redid a bunch of vacuum routing, replaced gaskets, and had to take my upper intake manifold off about 5 times to get everything fixed. Good thing I have a pressure tester. http://www.boostpro.net/prodtester.html

And of course the base map I that the company sent me was way too lean, so I ended up reverting to an FD basemap. Now I am tuning the idle and all that jazz. If nothing big comes up I should have it tuned in a week or so and then I have to get a damn inspection b/c it's months out of date.

2/2/2008 7:38:42 PM

Pardon my ignorance, but what good does an oil pan brace do for an FD?

2/3/2008 6:24:54 AM

Quote :

"m yeah it's been about 6 weeks since I've updated this thread"

i never even noticed this thread before. honestly i thought it was about daryls maxima.

2/3/2008 10:21:12 AM

^^ There are two points to an oil pan brace, or so I am told.

First, Rx-7 oil pans are somewhat leak prone. One of the motor mounts goes through the oil pan which results in uneven torque on it and can eventually lead to leaks after a lot of hard driving, especially on older pans that aren't in perfect shape. The brace is supposed to more evenly spread the torque on the pan and prevent leaks.

The second purpose of the oil pan is to reduce flex and stress on the various iron and metal housings, especially the rear iron endplate. The endplate on the rear of the engine is especially prone to cracking on my 88 engine unfortunately due to inferior casting compared to the later models. This cracking usually occurs under the stress of detonation and means you have to pull the motor to replace the endplate.

Either way, I figured out my oil pan isn't leaking as far as I can see. I was just faked out by all the spilled fluids over the engine bay. There is still a really slow phantom leak that I can't figure out exactly, but I don't think it's the oil pan at just this moment.

[Edited on February 3, 2008 at 3:50 PM. Reason : .]

2/3/2008 3:30:36 PM

Quote :

""i just don't like it when people change the soul of a car an RX""

Dude your not loosing your virginity your building a machine....faggots I swear

2/4/2008 3:14:31 PM

Gettin my tune on.

Here I am going over a 5 minute datalog of me driving around my neighborhood. Clearly the AFR's are fluctuating more than I would like, but it's not as bad as it looks. The car is currently set to run open loop 100% of the time, because the closed-loop control only works properly if you have a cat and smog pump still on the car. There are just a couple cells that the car was ending up in that were way off though. In that screenshot, the yellow cells are cells that the car actually reached while I was driving it. The numbers in the cells represent a % correction of another map ("base map" tab in the program) that gives the injector pulsewidth necessary for the car to achieve lambda at a given loadpoint... hypothetically. From the factory this correction map is way rich in a lot of cells, even for a stock FD. So I am leaning a lot of stuff out.

I've boosted the car about 5 psi now under half throttle and I must say that it sounds way different than it did on stock turbo and my old canister style Greddy exhaust. It's a bit quieter at idle now. If my camera weren't so pitiful (no video capabilities) I would post a video actually. Also, because I converted to speed density with this computer, I removed the stock flapper-style airflow meter and apparently that changed the sound of the blowoff valve significantly. Whereas before it was a high pitched "pssh" , now it is a somewhat lower, fluttering sound, presumably because the flapper door baffled it. When I hit 5psi the external wastegate starts to crack open (I have no boost controller) and it sounds like unadulterated rotary POWAH.

Still haven't gotten it to the carwash yet. I want to get the cruising AFR's tightened up a bit more before I venture more than a mile from my house. Luckily it's not overheating or leaking anything. I redid my oil return line in stainless steel and I had to replace a broken coolant hose clamp that was making the car drip.

[Edited on February 6, 2008 at 5:16 PM. Reason : .]

2/6/2008 5:04:32 PM

I don't know if anybody even reads this thread anymore but...

Today I ironed out most of the driveability issues (except it will idle at 1200 sometimes and I can't figure out why). On the highway and around town it cruises at 15.5:1 AFR. It should be good for low 20's mpg if I stay out of boost. Then I threw some 110 in the tank and datalogged a 1st gear pull then datalogged a 2nd gear pull.

In first it probably hits 6 or 7 psi. This is because I have no boost controller so the HKS wastegate is getting a direct signal right from the compressor housing. 1st gear was of course much more fun on stock turbo. It used feel like a v8--torquey (ok, 250rwtq but it has a 4.10 rear) from about 2500-5000ish and then fell off. Now the torque doesn't build until 4000 or so. I'm sure a boost controller would help this somewhat, but given my manifold and turbo combination there's only so much I can do. Luckily the lack of low end torque means I don't have any wheelspin problems yet.

I got on it once in second, up to about 6000 rpm. It was running a bit lean, around 12:1 or so, but it really started pulling around 4500. Once again a boost controller will be a big help here. I maxed at about 13psi and I'm sure it was doing at least 300 to the wheels, probably closer to 330ish though. Tomorrow I am going to fiddle with the mixture a little more and maybe see if I can find a place for a 3rd gear pull (up to like 95-100mph) that won't get me arrested.

2/7/2008 8:32:13 PM

i read it, but just because i have always loved the turbo 2

if i ever have 7 grand I dont need , I'll buy one

read : never

2/7/2008 8:41:15 PM

Quote :

"HE'S RUNNIN A 2000 WITH OVER A HUNDRED G'S UNDER THE HOOD"

2/8/2008 12:57:02 AM

Quote :

" 100G HONDA 2000 "

2/8/2008 1:41:43 AM

^^^ you can get one in decent shape with a rebuilt motor for $3000-4000. $7k will get you a mint unmolested one with like 100k on the clock and a good compression original motor.

2/8/2008 8:49:37 AM

Give me a ride in yours. I always wondered how much power rotary racer's had.

2/8/2008 10:13:23 AM

I'm still tuning it. It's close to being dialed in without a boost controller at about 13psi. Should be doing at the very least 320 to the wheels (which is what an FD on stock turbos will do with the appropriate supporting mods at that boost), possibly a lot more than that.

2/8/2008 4:55:18 PM

finally got the interior back together. also rewired the fuel pump because I believe I was getting a pressure drop under higher boost levels and a resulting lean condition.

As far as tuning goes, well driveability gets a little better each time. The car was cutting off on me occasionally and I went through my datalogs and found a few lean cells in the fuel map causing the problem. I also finally got my cold starts tuned. At one point it took like 5 seconds of cranking to get my engine to start cold. Now it starts as well as it did stock, after basically doubling the cranking fuel map in the coldest areas.

because of that fuel pressure problem I haven't been able to take it much over 5000 rpm in second gear due to the car leaning out, but I should get a little more tuning done this week and hopefully have it running decently at about 13-14 psi, which should be over 300 to the wheels at least.

2/25/2008 1:43:20 AM

Almost two months later, now here's an update.

First, tuning a standalone for near-stock driveability is a difficult and time consuming process. For example, obtaining a stable and consistent idle under all conditions can be tricky. My cold starts were taking a long time, the car ran really rough on cold starts and would cut off, etc. What ended up working was advancing the timing a crapload at idle compared to the Apex'i basemap. About 10 more degrees of timing advance helped cold starts immensely and made a smoother advance curve under low load starts from traffic lights. I am not running an idle air control motor so my idle is adjusted using a mechanical fast idle cam and some throttle body adjuster screws. Right now it idles at around 1100-1200 cold, then fully warm it's around 800 or so.

Another thing I'm really understanding is how finicky a speed density system really is, especially when it's 100% open loop. I switched my plugs to 10 heat range NGK irridiums (1 step colder than stock) and the car wouldn't even idle cold. I fixed a boost leak and that threw off my maps, etc. Tuning the transitional part of the map from vacuum to low boost is also tricky on an open loop system. In daily driving with little boost you will get near atmospheric pressure and start to spool a little. So for best spool you want a richer mixture (13's or so at that level of engine load) but if you don't carefully tune the cells you will end up dumping fuel in when you aren't even trying to drive the car hard.

Currently the car boosts 19psi and pulls very hard. The only issue I have been dealing with are some hesitations. It sounds like ignition breakup or something, but it doesn't always happen. For example, I can drop the hammer in first, redline it, redline second, and it will pull smooth and break a little traction in first. Then I can give it 1/3 throttle in 3rd gear, it will build boost and then I can hear it missing a little bit around 10psi or so. So yesterday I installed an MSD 6AL box for the leading ignition and as I mentioned I am running irridium B10EIX plugs (which are actually for a bike), currently gapped to .028. I tried gapping them down to .022, (this was when I didn't even have an MSD box) and it seemed to help hesitations slightly but the car really idled like crap and needed a ton of timing to be stable.

I'll take the car out for more tuning today. Once I get the hesitation figured out this car should have 400rwhp in it.

4/17/2008 11:10:30 AM

tuning rx7s ftl good luck mang

4/17/2008 11:13:52 AM

it's fun to me actually, at least when you are marking progress and the car steadily improves. Of course it can get really frustrating, but I've learned so much about how EFI systems work. It also means that if something goes wrong I have the knowledge to be able to fix it.

4/17/2008 11:16:18 AM

^ its not really all that complicated to understand how it works, diagnosing problems is a whole different ballgame though

4/17/2008 11:26:18 AM

Well you can understand how it all works in the sense that you know a series of tables and sensors control fuel and spark delivery, but how those tables and sensors interact and which tables you should modify and in what order is the tricky part.

For example, you may find that the car seems to need a lot of gas to start smoothly/not stall from a dead stop, more than it ever needed on stock ECU. This is a common problem on any car with a standalone system. Well there are a number of things that control that. There are several cells in the base fuel map, and these are also influenced by a correction factor based on engine water temperatures and engine intake temperatures. There is also an accelerator pump correction that injects extra fuel based on the rate at which the throttle is opening. In this particular engine management system that is controlled by 3 separate functions: a maximum additional pulsewidth vs. rpm (with a decay function for that function itself), and then a scaling function of % throttle input vs. % max additional pulsewidth. Externalities such as Fuel pressure (and fuel pump voltage) can also affect all this. It's really interesting stuff, but it's a big time committment and I understand why people pay tuners a couple hundred bucks to take care of this stuff.

[Edited on April 17, 2008 at 11:44 AM. Reason : an automatic tranny car makes it even more complicated with the lockup stuff etc]

4/17/2008 11:43:16 AM

Quote :

"Once I get the hesitation figured out this car should have 400rwhp in it."

Wow. I'd really like to see it one day, after you get the bugs worked out. Maybe you'll even let me butt dyno the car in passenger seat? Keep up the great work!

4/17/2008 12:54:35 PM

cool, it's good to see someone taking the initiative/chance to really learn something worthwhile. i'm sure you can appreciate the cost/benefit of a professional tune now also.

you're dead on about speed density being sensitive to any changes. the upside is once you get everything like you want it, it's a pretty rock solid way to meter and chokes in all the air you want. imo, the ease of tuning maf is better for n/a, but sd has a slight advantage for boosted applications. some people claim it's sensitive to large temperature changes, but i've never heard of anyone around here having problems.

for your misfire/ignition problem, you might want to look at the msd box. i've always had great performance from them, but i know a lot of people think anything less than the digital boxes are junk (including a couple of the "in the know" here). what kind of datalogs are you seeing when it's breaking up?

i'd love to try that 400rwhp estimate on for size when you get it done. if that's anywhere close to right, you should walk past my car pretty easily off the bottle. either way, it would give you a reasonable estimate since i know all of my power, track, etc. numbers. your friend aubrey's car would be a nice run too.

4/17/2008 1:24:39 PM

i know shops u can pay 250 bucks to get a professional tune. im sure most shops in the area will do it for this price too. i guess it's fun to learn the stuff urself. but at the same time are u going to get it running as good as a pro tuner would?

4/17/2008 1:36:50 PM

probably better..

a pro tuner is just like any other consultant... most have a "good enough" level
unless they're truly passionate about your car which then they'll probably charge more..

4/17/2008 1:52:39 PM

^^^ It's funny how you say MSD boxes suck unless you get the digital ones. The only one I ever saw fail was a digital one. I have a friend who bought a DIS-4, the one with 2 step, and it crapped out on him after a few weeks. We pulled it apart and it was obviously remanufactured very poorly and sold as new. There was hot glue and bad solder joints everywhere.

I've been thinking about the Speed Density vs. Mass Airflow debate and I think that having a MAF sensor would make fuel tuning easier, but you really want to tune timing in a boosted application based on manifold pressure. It just seems like you could be flowing X grams/second on a turbo car but if you don't have a way to measure pressure it's just not going to be as precise of a timing curve to reduce the chance of detonation.

As far as taking it somewhere for a tune... I don't trust ANYONE with this car anymore, except a few nationally known shops that are far, far away from here. If somebody is going to fuck this car up, it's going to be me. If I blow the motor (and it'll happen eventually), so be it. I can get it rebuilt for $1500 anyway.

Will I get it to run as good/better than a pro? Well I've thought about this a lot. I've bought an e-book on how to tune this software and I've corresponded online with several professional tuners, so I've learned a lot from them. I think the main thing a professional has over me is experience. They can make the hard judgment call of when to give that extra degree of timing, what are max acceptable EGT's, just lean can I go on a given octane, etc. And that's what saves motors, or makes that few extra hp safely. Since I am only running 100+ octane on this car that has saved my ass a dozen times. I've had the car lean out due to fuel pressure problems and it has never noticeably detonated. I would have never attempted this on pump gas. No way.

On the other hand, there's a lot of info out there on the basic process of tuning the driveability stuff, but it just takes a lot of time. I doubt a pro is going to get every single low load cell in the fuel map tuned for optimum gas mileage for $250. Nor will he have the time to adjust the cold start timing advance and fuel curve half a dozen times to ensure consistent AFR's both at idle and in cold running low load driving around town. On their own cars of course they do, but as sumfoo1 mentioned, they have to know when to say "good enough" if they are going to run a successful business.

4/17/2008 2:30:40 PM

let's have an internet race

http://videos.streetfire.net/video/240sx-KA-T-GT30R_155732.htm



About your hesitation under part throttle: in mine, it was the acceleration/throttle tip-in settings that fixed it. Gotta add more fuel for those milliseconds after you get back on the throttle. Of course, mine's not a rotary so...

4/17/2008 2:54:55 PM

when do i get a ride ray?

4/17/2008 3:57:00 PM

Glad to see someone learning some skills. Keep it up, it will pay off soon.

4/17/2008 9:01:37 PM

^^^that turbo is almost as big as mine.

4/17/2008 9:04:45 PM

ill walk that rx7 with my shit bucket.

[Edited on April 18, 2008 at 12:18 AM. Reason : .]

4/18/2008 12:18:41 AM

tchenku, is that really your car? Which GT30 housing is that? they come in different A/R's.

If we race, we are racing for dome.

[Edited on April 18, 2008 at 12:55 AM. Reason : or did you just find that video on streetfire randomly?]

4/18/2008 12:51:14 AM

pretty sure it's his. he had used to have an ka s13 anyway and was talking about turboing it. iirc he blew the ka and did a rebuild adding the turbo?

4/18/2008 1:44:42 AM

.63 housing

i bought the engine turbo'ed, overheated it, fixed it back to normal, bent all the valves, and fixed back to normal

4/18/2008 9:23:12 AM

lol

4/18/2008 10:12:09 AM

^ yeah I know how that goes.



Here is my leading (rotaries have two spark plugs per rotor, the leading fires first) ignition timing map if anyone is curious. X axis is RPM, Y axis is bar (well technically K/cm^2) of MAP (10000 = atmosphere, 20000 = 1 bar boost, etc).

The area that I have boxed is the high load timing area. Currently I am advancing the timing until about 4000 (to help with spool), then pulling one degree and leveling off as the engine hits the peak torque area which is most prone to detonation. Then I am gradually advancing timing a little bit all the way up to redline, where combustion pressure is a little lower and the risk of detonation decreases somewhat. I know advancing timing at high rpm might be a little risky, but so far my knock counts seem to be ok and I am running race gas. On pump gas I would probably just level off the timing curve and not advance it at all.

[Edited on April 18, 2008 at 10:22 AM. Reason : I'm still playing with this map. I need a dyno to do more with it.]

4/18/2008 10:20:03 AM

im going to wilmington to get my pos dyno'd in less than a month on a random weekend with my buddy. they are cutting me a lil deal on the dyno, nothing worth driving out there but we're doing it for fun.

if you want to bring ur unit out to and get it tuned out there i can let u know when we are going.

4/18/2008 10:27:08 AM

washed the car yesterday so I got some new pics:













[Edited on April 18, 2008 at 12:05 PM. Reason : yes I know the fan shroud is ghetto, it won't be like that forever]

4/18/2008 12:02:14 PM

+1 for a clean looking car... Is it possible to V mount the radiator/intercooler on an Fc?

I know a couple guys who'd love to see your car. I'm not sure if you are on the rotary forums or whatnot. If not, check out http://www.ncrotaries.com/
It's a small, but cool group of mostly educated rotards. They do meet next Sat. at Southern States Mazda. You should bring it by! I'll be there with the v8 944

4/18/2008 12:31:45 PM

nice man. wtf did u do to that k&n filter, lol.

4/18/2008 12:38:27 PM

Hesitations are gone, and have been replaced with wheelspin . It spins at the top of 1st and sometimes at the top of 2nd, but that's with crappy 225 Sumitomo tires. I played around with the boost controller and now I have 19psi at around 6000 rpm (as opposed to hit it hitting 15 and then creeping to 19 like before), and this turbo can barely hold that to redline (8000) as it's starting to drop off slightly, although using an ebay MBC probably doesn't help. That's kinda slow to build boost I know, but the result is a very linear powerband, s2000 or Rx-8 style, except with more torque (relatively speaking). I know horsepower is peaking around 7500 because looking at my map I have to actually decrease injector duty cycle at that point to keep a stable AFR curve. If I had the money I would've bought a GT35R and stainless divided turbo manifold, and then boost probably would have built 1000 rpm sooner at least.

[Edited on April 21, 2008 at 12:48 PM. Reason : .]

4/21/2008 12:47:35 PM

looking pretty sick raymond

5/2/2008 12:48:11 AM