Snook

iTrader: (12)

I have a intake, full exhaust with midpipe, streetport, fuel pump, and pettit unlimited ecu, non sequential.

Tonight it was 45 F outside which is really rare for Florida especially this time of year. I have a manual boost controller hooked up to the wastegate control like the non sequential diagram shows. I had a leak in my boost gauge hose so I took it off for about a week or so and today I put a new one back on. I was getting almost 15psi at the middle of 4th gear, 13.5 in 3d, 12 in 2nd, 10 in first. I know this is boost creep but isn't there anything else I can do? I took off the valve and just ran the wastegate hose back into itself with no pills installed but that didn't seem to do much. I know my boost goes up at least 2 psi more when it is cold like this so normally I'm okay but I'd like to run as low boost as possible all the time.

What else is there to do except for porting the wastegate or getting an electronic boost controller?

THANKS
-Snook

ttb

stay off the throttle :P:

poss

iTrader: (5)

even an electronic boost controller won't eliminate boost creep....I know, i've been there
you can run a restrictor plate or port your wastegate, those are the only options that i can think of. of course the latter is prefered.

jimlab

I've got a solution for boost creep, turbo lag, 3k hesitation, vacuum line problems, poor fuel economy, and soot on the back bumper all rolled into one...

poss

iTrader: (5)

and how much might that solution cost?
or at least how much have you spent chasing that dream?

jimlab

That depends on what your firing order preference is.

Well, my dream included a reliable 500+ RWHP also. Of course I sort of got sidetracked and chose to have almost custom made, but that's irrelevant.

scratchjunkie

i got a solution for ya, but it may not be what you want to hear. take your midpipe off and run your cat.

Snook

iTrader: (12)

okay guys thanks
it looks like I'm on top of my game as far as knowing my rx-7 ****.

Like I said I only got worried last night because it was cold. Today it's back in the 70s and my max boost is barely pushing 13 in the higher gears. I'd like to get it lower but that's fine with me.

One thing I did notice is that with nothing in the wastegate line it really struggles to build up boost at all. It stays at 8.5 in the first 2 gears and then at the end of 2nd and in 3d and 4th it builds up more because of the creep. With the bleed valve in the wastegate hose it immediately builds 10 psi but then also has the same max boost. So I'll put the bleeder valve back in there for sure even though it's wide open for the lowest boost and I'll never adjust it for higher.


scratchjunkie: Nothing remaining on my car that has to do with the airpump.

ttb: stay off of it the entire time? come on now

ISUposs: thanks, I think ill just chill in the cold weather haha. taking the turbos off doesn't sound like a **** load of fun.

jimlab: all I have is boost creep and thats not an issue 99% of the time in normal weather. I hardly have turbo lag, 3k hesitation is gone, have about 10 vacuum lines so that's not a problem, I did get 18mpg last time on the highway so I consider that good mpg hahaha, and I have a fix for the soot on the back bumper maybe I'll take some pics. It's kind of like a silencer for the n1 but it doesn't quiet anything down we just made it for the soot and it looks cool. Maybe it gives me an inch more of down low power but I doubt it.


thanks again

Snook

artguy

lol...i bet you do.

it should be ready about the same time that the moon colony is ready for inhabitation.



j

Snook

iTrader: (12)

OH ****!!

OWN3D

Jim honestly do you think the rotary is that bad? I haven't owned mine for long enough to gain the proper experience but I assume that if you know what you're doing it has to be pretty reliable even at high horsepower and a new motor can last years and years right?. There is a lot of **** to worry about though.
With the v8 you just get in and drive and do whatever the hell you want. Maybe check the oil level every month. It's kinda like hey mayn I got 500 hoooorse poweehheerr maaayann. Anyone can own one. I'd think that since you know so much about cars you would be a hardcore rotorhead. If anyone can take care of the rotary and make it last at high horsepower it's you. I feel like we lost one of our big dogs and you went over to the other team.

The rotary is awesome, don't you love looking at your vacuum and idle to see if you still have a motor after every time you boost hard? hahaha

jimlab

I hadn't heard that they were going to start colonizing the moon this summer...

I'm throwing pure cubic dollars at the project and doing everything else I can to get it finished this summer. You should stop by my thread some time and check out the progress updates (and the vast amount of work that has gone into this project).

13brv3

How about installing a pop-off valve?
http://www.rx7.com/cgi-local/3catalog.cgi?cat=9&part=4

This isn't the perfect solution, but it will save your engine, and I can't believe more people don't use them. The biggest problem of course is finding some place to mount it. Maybe it could be T-ed into the BOV hose.

I bought one of these for the plane engine, and it's a pretty nice looking unit. I'm thinking of ordering another one for the FD.

Cheers,

jimlab

The fact that anyone has to preface a comment about the rotary's reliability with the words "can be" says something. The fact that there is a list of "reliability mods" for the FD says even more, if you ask me. I can't think of another car that has such a laundry list of things that can (and often do) go wrong.

That said, no I don't think the rotary is that "bad". However, I do believe that there are better things to be doing with your time than worrying about whether your engine will hold up to "normal" (for a sports car, at any rate) abuse.

I also believe in spreading my powerband over the useable rpm range, not just stacking it up at the top end, and that rules out the rotary and other smaller engines, even if you can get a lot of horsepower out of them with forced induction.

True, but there's something to be said for being able to beat on your car day after day and not having to worry about much more than changing oil.

Nope, I was never really on the team in the first place.

No... two engines in 13,000 miles of driving sort of ruined that "pleasure" for me.

To be fair, I was one of the "early adopters" of rotary technology, and got burned by a couple things that I won't go into that are no longer a problem today after 5 more years of R&D. You pay to play, and especially so on the ragged edge of rotary technology. As I and Gordon Monsen mentioned in another thread, it's an entirely different ballgame today, thanks to those of us who tried the technology of the time and learned the hard way what worked and what didn't.

psi4psi

get a hi-flo cat welded in your MP, you dont need to hook up the airpump. That should reduce the flow to where the non ported wastegate can controll it

BTW how does the pettit ECU handle the streetport and the fuel pump? did not know it could...

Snook

iTrader: (12)

13brv3: very good suggestion. I also noticed many people don't know about that. I had seen it earlier and am probably going to get one eventually. Seems like everyone should have one.


psi4psi: that would be the same as having a high flow cat. Some cats last without an airpump and some don't. I don't want a cat any way I love the midpipe. If the boost was out of control in normal weather I would have to get one though. thanks.

jim I understand what you mean. I'm going to be really careful with my motor and if it blows then I'll be pretty frustrated. If it happens again after that I'll be paying you for instructions on how to install the v8. Maybe you can make some of your money back that way!

jimlab

Well, I understand perfectly why some people don't want anyone saying bad things about rotary engines...

1. The "sweep it under the rug and it'll go away" mentality...

No one wants anyone else to think they got "taken" by buying something less than perfect, so they must maintain the illusion at all costs. Witness the Supra crowd... anyone who even breathes a hint that 2JZ-GTEs actually can blow up is quickly pounded into silence.

2. You simply can't relate to what you haven't yet experienced...

They haven't yet experienced the "joy" of rotary engine failure, and therefore (at least for them) they still believe they'll last forever. Anyone who had engine failures were simply too stupid to maintain or tune them properly. Yeah, that's it.

3. Questioning the supremacy of the rotary engine cannot be done without upsetting the egos of those who worship them...

They equate the specialness of the rotary engine with their own specialness in owning one. In other words, if the rotary engine is this cool, how cool must they be in order to be one of the exclusive rotary club members "in the know" about this "totally superior technology"? The secret hand shake and phrases like "just take 'em in the twisties" are covered at the first meeting...

4. I'm out of ideas. We'll keep a V8 warm for you.

13brv3

You can just dust mine off ocasionally, because I won't be needing it

Every time I read a thread about how unreliable the rotary is, I just laugh. Stock rotary engines are bulletproof when operated within reasonable limits, and custom built engines are just as reliable at higher outputs. Unfortunately, WE tend to take stock engines, and run them at higher power than Mazda ever intended. Of course I say "we" because my FD engine is a Mazda reman (installed before I bought the car), and I now have all the proper bolt-ons. Will it last 100K miles? Uhhh, no

On the other hand, I expect my airplane engine to last about 3000 hours, at mostly full throttle. The 13B engine is probably the most popular non-aircraft engine that is used in experimental aircraft. For the most part, guys keep them to about 160 to 180 HP, but they run full throttle for literally HOURS on end. When choosing an aircraft engine, the top three criteria are 1- reliability, 2- reliability, and 3-... well, you get the picture

Since my Nomex suit won't be here until tomorrow (not kidding, it's for the test flights), please hold your flames until then

Cheers,

jimlab

I'm sure they do, since it isn't even really taxing the engine. Now turbocharge (if you haven't already) and push the same 13B to 400+ horsepower. Is that something you'd trust your butt to in an airplane for hours on end?

Just curious.

vosko

iTrader: (4)

i don't know there have been no *mysteries* about my car.... i think it shows pretty well how a rotary can last with the right ingredients.... it won't have as much power as your car jim but i like it

so when are you gonna get me that cobra diff subframe

13brv3

That depends on where I'm flying. Will I be allowed to circle a big abandoned military airfield in perfect day VFR weather

Seriously, if I wanted 400 HP, AND reliability, I'd start with 3 rotors. Since I eventually want close to 400HP in the FD, without the hassle of installing a 3 rotor, I'll just accept the reduced lifespan of a 13B.

Fortunately, my plane isn't supposed to have more than 160HP, so I won't be tempted to go for big numbers. FWIW, the motor was a brand new engine (not reman) that was reworked by Bruce Turrentine, with 9.7 rotors, and will be turbo-normalized with a max of about 34" MAP (about 2 psi). Normally aspirated, the engine should produce about 200 HP at 6500 rpm, and 230 HP at 7500. The turbo should allow these numbers to be maintained all the way to my legal ceiling of 18,000 feet, where the ground speed will be in excess of 250 mph, until my O2 runs out, or I freeze my *** off

My last plane had a new Lycoming 180 HP engine, that sold for the low low price of $22,000, had a life span of 2000 hours, and only cost about $8000 to rebuild. Contrary to popular belief, they break just like any other engine.

I now must humbly apologize to Snook, for assisting in degrading his thread.

Cheers,

Eggie

What's that? Not drive your car for 5 years?

mazemaster

Thats what I have done. I have my own version of a (POV) popoff valve set at 9 psi mounted by my BOV.

jimlab

I'll be picking it up for final test fitting tomorrow.

Jim Swantko

Stop the blasphemy.... the 2JZ own3s joooo!

I remember my first meeting Jim... I still remember the handshake too... or is that the middle finger shake ....directed towards the 13b?