Why did I over boost? 23 psi!!!
 

BOOM!!! said my motor on Friday night.

This is really disheartning actually. Do all the mods correctly, always make sure that there is enough fuel for the given boost. Yet out of the blue on a cold night I overboost by 13 psi!

Friday night I was taking my friend out to his house. On the on ramp to the freeway I WOT in third (I always do that there). Boost controller set to 10 psi. After the boost kicked and mid way through 3rd my car fell flat on it's face. I knew the car was blown. I cycled to see what my peak boost was and my profecB recorded 22.6 psi! my power FC hit a peak of 17 psi!!! WTF on stock turbos???

I don't get it. :confused:

my mods are
Mild Streetport
CAI
PFS SMIC
DP
MP
RB catback
Greedy boost controller
Power FC
STOCK TURBOS
low boost 10 psi
high boost 12 psi.


I always thought i'd be safe as long as I stay near stock levels with stock turbos. Guess not.

Seriously contemplating LS1 after this one. I've been an owner for almost 9 years and it's my second engine under my belt, and fire that totalled my first FD.

yikes
 

Wastegate failure, vaccum hose issue from your EBC install?

Where you doing any work to the car recently to either of those systems that could have caused it?

I think it's safe to safe something in your EBC system failed.

Two things that can save you next time:

1) Run a aftermarket ECU and program it for a "fuel dump" 2 pounds over your high boost. That way if you do overboost you will bog the engine to a rich choke.

2) Install a pop-off valve and set it to 1-2 pounds over your high boost setting. If you overboost, instant vent to atmosphere that cannot fail.

I'm installing my EBC in a few weeks, and this is the exact thing I'm afraid of! :(

Also, you might want to do a compression check before you consider it blown. 23+ psi is going to blow off any loose vac hoses to the manifold, and if they are off the car is going to run like crap and act blown.

Good luck!

-R4tw

Ouch, makes ya wonder. sorry 2 hear.

sorry to hear.


now join us.

Wow, sorry to hear.
Hope Rotary4tw is right and your engine isn't blown.

Good luck.

Was your wastegate ported? Sorry to hear you lost the engine

Is your wastegate ported?

i wouldnt switch sides over this. you need some fuel upgrades running higher boost. you didnt list upgraded injectors so im assuming your running the stock setup. build a new motor and put some money into everything in that engine bay!

i spent 10 grand over the last winter period with a new motor, all new seals internal and external. went over everthing. its a bit of work having the rotary engine but its pretty cool when you pop your hood absolutely no one knows what they are looking at cause they are used to piston engines.

i guess its easier to have a piston engine but i have much more pride knowing the car is all built right and its got rotors. sorry to hear about your loss. hopefully you figure out what your next move is. good luck

Do it! :icon_tup:

Definitely sounds like one of the wastegate lines got loose and disabled it.

That's really unfortunate. :(

Dave

That sucks. Im about to get a rebuilt streeport, on stock turbos run non. seq. hope that doesnt happen. sorry to hear it

Sad to hear that, Montego. It's been really cold lately around SD, so I've been wary about driving my car out even though I finally got it together and running after a year. My mods are not so disimilar to yours minus the street port and MP, but I was following the same train of thought that as long as I kept it to around 10 psi, I won't have to worry too much.

Stories like yours are so dispiriting when you hear them.

Which onramp were you on when this happened?

sorry to hear that but dont ls1 it my oppion it kills the purpose of having a RX-7 if its not rotary thats what sets it aside form everything else

come back with spinning doritos my friend :) it must be real disheartening to blow a motor like that though. im gonna make sure my ebc is hooked up right to my full non seq turbos.

Damn. that sucks. I was just out beating on my car today. Turbos are loving this cool weather.

FWIW, the LS1 route isn't fool proof either. People have been having issues with the welds on the subframes and other parts.

23psi on stock twins just seems unbelievable. Maybe your boost controller completely malfunctioned.

like someone said above, check ALL of your connectors. chances are the pressure popped off a hose or coupler before it got to your engine.

Worth a shot before you write it off as a loss.

What's wrong with cold weather? The dry and cold weather is the best time to drive this car.

Colder air is denser, typically the car will make more boost in cooler weather. I've seen swings from as high as 16 psi on a cool morning in one part of NJ to 12 psi on a hot track in anothe part of NJ on the same day. This was with my BNRs w/ported wg and leaving my profeb b on the same setting.

Montego, sucks to hear that that happened to you. Sounds like a wastegate line came loose, if I had to guess. If you want to take the motor out and ship it to NJ, I can rebuild it for you for a pretty good price.

daym...sorry to hear Elliot...Stick to the rotor man..dont give up...

Sorry to hear this man!!! FCKN sucks.

Damn....now I'm worried about driving my car to work tomorrow in 19 degree weather.....

Damn, time for a good rebuild :)

OR

Join the LS1 dark side :)

Although colder air is denser, we must remember that this is in San Diego, where frigid temps rarely drop below 50 degrees :D.

Montego, I hope your engine is OK :)

Dont make your RX7 into a MX7!

Some places in SD County were seeing temps in the 20's this weekend! The weather has been nuts here, lately.:lol:

Sorry to hear about that, but I have a suggestion for the future:

- Set the PFC target boost for what you are running. This would have fuel-cut before you hit boost that high.

Good luck with your rebuild!

I agree. WG line either popped off or melted. Sucks to have this happen.

re: the V8 swap , I got to ride in an LS1-FD the other day, and it felt very well balanced, not front-heavy at all. The power was very predictable. If you've got a careful right foot, the car will give you full power the instant you hit full throttle; there's never a power surge when a second turbo kicks in. The owner mentioned that sometimes he missed that surge of power when the turbo(s) fully spool, but if you're looking for reliability and HP per dollar, the LS1 is pretty hard to beat.

-s-

Thanks for the replies guys. I really appreciate your input. This is just a car and I had worst things happen during the last 6 months to really put things in perspective :)

First of all I realize that this is not a ROTARY SPECIFIC failure. Any car would have blown up if over boosted by twice the amount that it was originally tuned for. That is also a reason why N/A power is sounding really appealing right about now.

The car was a body shop I had just taken the car out that night. I seriously doubt these guys touched anything, they are pros.

The fuel dump and pop off valves are a great idea.

yeah I'm gonna go ahead and do a compression test anyway. Though I seriously doubt that it is not blown because the motor sounds completely different. So I am going to go ahead and assume the engine is blown until proven otherwise.


not but my turbos were. I would only creep at the top of third and fourth to 11.6 psi.

See the scary thing is that my motor would only survive if I had enough fuel for 23 psi. That's nutty in itself.

:(

thanks, shit happens. It happened at the palomar 5 north on ramp in Chula Vista

yeah it is :( So you ended up going nonseq also. How did you like it? Me personally I like not having anymore boost issues but the lag bites. Not as much as having no compresion though ha ha


Yeah I heard about the Hinson weld issues. Last I heard he got that taken cared of. But still ya never know.

Yeah on cold night the most I ever saw was 12 psi when I was set to 10. I am tuned safely for 12 so It was ok.


Thanks Rich I really appreciate the offer. This issue is not about being able to afford the rebuild which I can just fine. This issue is more about what if it happens again... I think I would be very afraid everytime I boost even at a low boost setting. And that's no fun :(

I plan to keep this car forever so being somewhat practical HAS to be in my future.

Thanks Kai. What can I say.

I do love my car and it's engine. I love how the turbos kick in, how fire shoots out the tail pipe, how the exhaust tone sound. The handling. All that is pure sex to me.

But this has just blowned my mind.

yeah it been rather cold here lately. Yeah It be really nice if it wasn't blown :)



I'll get around to doing a compression test. I'll keep you guys posted on what's what.

hindsight is 20/20. That would had come in real handy :doh:

Now this actually sheds light unto things. True and realistic preventive measures that gives me hope. :)

BTW my motor had already 52K miles and it ran strong!

props to RnR rotary in upland for that.

Hell's freezing over. Get ready for the end times...
;)

Tell that to 80% of the FD owners who already converted to LS1. lol

Sorry about this. Did you check the wastegate line? I can't think of anything (other than boost controller malfunction) that would cause such a massive overboost. I boosted to 17psi once because I installed an MBC in reverse in my wastegate line - which effectively prevented the wastegate from opening. It would have gone higher if I hadn't removed my foot from the accelerator.

From what I've read on the forums, porting the wastegate is a pretty important safety mod. I'm having mine done to prevent anything like this from happening. If you do decide to go with another 13B, you should probably make sure you get that done...

^you should do more research, because a ported WG wouldn't have saved this engine...or prevented this failure

Where did I say it would have saved his engine? And a ported wastegate does assist in preventing overboost. So whats the problem? I probably should have put "help" in between "done to" and "prevent anything", but I figured you'd able to get the point. I'll make sure I don't forget next time to assist your reading.

Wastegate porting is irrelevant here. Wastegate porting prevents the possible ~3-4psi of boost creep that can result from the addition of a midpipe. And this creep is consistent - it does not just appear out of the blue. Something else entirely is going on for the car to hit 23psi.

Listen Fish, I was posting to help you; not the thread starter...and lose the attitude. I don't need assistance in my reading.

Already covered that...

I thought it would be good advice to tell someone to get their W/G ported...

Really wasn't an attitude, just think it's annoying on how I'm just suggesting on your next engine a W/G port is a valuable reliability mod, and I get bashed on saying it would have saved his engine... So calling me a "Fish" is uncalled for...

DONT GO LS1..stick with your rotors..just be more careful and if you rebuild or some other person..make sure they do every little thing right..good luck

I agree that porting my wastegate is a good idea as far as being able to control boost. In my case, the creep is "below" my high boost. I only crept about 1.5 lbs which really is nothing at all. My 12 psi setting was rock solid.

My engine probably blew at 17 psi (stock MAP sensor) that's 6 lbs below the peak boost that I hit!

I've been talking to my mechanic about this. About a month and half ago I was fidiling with installing my Pre-auto headlights and I removed the M2 intake because I was cutting stuff. It's possible that I knocked loose the wastegate hose without noticing and it finally came off the other night. When I get home I'm gonna take a look.

If that's the case: I'm sticking with the rotary for sure. I'll keep you guys posted

Monty: Any updates on your compression?... Hope It's just something minor. Dwayne

Not sure why you would be disheartened. There's no way you can plan on total failure of any component in the fuel/boost system. Unless you tune for 25 psi on pump gas with the stock fuel system how can you expect it to stay together under anything but what it's tuned for.

that's exactly why. Because out of the blue a total and unexpected catastrophic failure occured. I don't know about you but that certainly takes the air out of my tires.

You are correct in porting the wastegate is important in controlling boostconditions. It however in no way can correct for failure of the control system for dumping excess boost. When systems fail things happen.

Well then sell the M2 intake to moconnor so he can finally quit bumping his wtb thread, and it'll raise some money for the rebuild. :)

I'm sorry it happened to you and can understand it's not something you want to happen, all I can say is what will you do if a connector comes off a fuel injector or one clogs at the wrong moment, any number of things can happen with these cars there age and next to impossible to plan on other than staying on top of maintenance routinely inspecting things as well as possible and hopping nothing ever fails while in a boost condition. Cold weather just amplifies this possibility as boost is so easy to make.

sorry to hear it man

good read! good tips. i am gunna have to be extra careful when i get my car when i drive it to work in the mornings from cold tempatures.

sry to hear man.