He should ditch his tuner first. LOL. I hope it's not the same tuner that's going to try to tune Osiris, because it is not nearly as intuitive as the Haltech. Sorry if the truth hurts bud, but that's the way it is. UpRev has done a great job considering all the reverse engineering, but when it comes down to it, the driveability of a car with any of the standalone fuel, timing EMS systems (Osiris included) will only be as good as that dictated by the experience level of the tuner and the effort put into it.

Overboost is a real concern and it would preclude me from using Osiris without something to address this. Just because it hasn't happened to you, doesn't mean it won't happen to someone else. On the Haltech, overboost is implemented with a fuel cut. Fueling resumes when boost drops back to a predetermined value. Not sure about the FCON.

You guys realize that all you need is a hose melting, coming off or developing a leak (going to the boost controller or wastegate) to have overboost that WILL destroy the motor?

 

 

haltech, aem, motec >all
piggy back world utec and power fc are the two top dogs...

 

^^ Keep thinking that.

 

This is just nuts. The FCON has no overboost failsafe? Yikes. When I was hooking up my boost solenoid, I was thankful that the Haltech had overboost protection. The knock issue I can understand and usually if you're going to get knock it will be most relevant at peak torque, which is under 5k.

 

Raj, I'm not so sure about this. I just looked at the installation drawing for a Tial WG and for the HKS EVC. If the line coming from the intake side comes off, your boost will drop down to spring pressure. The only way I can see overboost occuring is if there is a problem in the boost controller itself.

I don't recall ever seeing a serious overboost problem being posted in the forum. I have seen boost creep, but that is a different issue altogether. I have seen that on Greddy turbos running high boost without a W/G relocation kit.

Not to say that overboost protection would not be a nice feature, but I don't see it as being absolutely necessary. Other than the Haltech, which EMS's actually provide this specific feature? The F-CON doesn't.

 

Out.

 

What if you accidentally connect your atmosphere port to boost and vice versa? Now that I think about it with external wastegates you may be ok with a hose coming off. With internal wastegates, the situation is reversed. Maybe I'm just paranoid, but preparing for the worst can help prevent disasters, right? What if your stepper motor fails, a wire becomes unplugged from the boost controller, or a fuse blows that was feeding the boost controller? What if your wastegate actuator fails?

While I concur the risks are low, and it might not occur for any given individual, to say that it cannot happen based solely on personal experience, is bit of a stretch. I know westpak has alot of experience, but still.

If it ever does happen, you'll be thankful that you've got protection. I have encountered boost cut, when going from closed loop to open loop on the dyno. My open loop tune was configured during the summer. I ran the same open loop #s in cool weather and I hit 16.5 psi. The Haltech shut it down hard at that point. It all happened so fast, there is no way I would've recognized it quickly enough to shut down. Not that I would've blown the motor going to 17 or 18 (I don't think, as the map is tuned ultra conservative in that area).

While the FCON may not have overboost cut, I believe the EVC VI has an overboost alarm. You may want to set that up.

 

No matter what, a spring should be used. If the boost controller is properly designed, it should not maintain boost pressure beyond the spring rating if any of these things occur. For example, my safety mechanism on my meth/water injection system is to disconnect the ground from my boost controller if the meth/water tank runs dry. As soon as power is disconnected, the boost immediately drops to around 8 psi, which is what the springs are rated for. The same thing will happen if the fuse blows.

Have you heard of the overboost problem actually occuring on somebody's car? Any threads that you can post links to?

 

15$ and make your own overboost protection
with this
http://www.aquastealth.com/pressureswitch.aspx

and a solenoid to vent the wastegate.

or you can wire that switch up to your coil wire and kill your spark like they did here
http://www.nicoclub.com/articles.php?id=158778

 

^^^^

Nice find, Rich.

 

Terry, I have not heard of an issue on my350z. This is the only forum I have time to really keep up with though.

str8dum1, it's nice to have some kind of protection, even if it is a little extra headache. I know most OEM turbo cars have some kind of overboost failsafe - if nothing else a pop off valve...

 

Most OEM turbo cars have a boost sensor that cuts timing or fuel during an event of overboost. Back in the day I can remember having to fool this unit by crimping the vacuum line or a bypass harness when I turned up the boost on my MR-2, RX-7 and Eagle Talon Turboed cars.

 

If one were running just on spring pressure, say 7psi, with no EBC, and the line melted or popped off, you would overboost. You need that boost reference from the compressor to the lower port, to help open the gate. Remember, for example, that 7psi at the intake manifold does not necessarily equal 7psi of exhaust pressure at the wategate.

A "good boost controller", as has been mentioned previously, has no way of cutting fuel/ignition in the case of overboost. Score one for the Haltech

 

I don't know what this means, but watevs (im guessing you disagree with my opinion but that is to be expected, im a dumbass in my own right)



I have never heard (or read online) horror stories of cars over-boosting, worst i've heard of is cars creeping so badly they detonate on the dyno (silly hondas!). but that is about wastegate sizing...
Besides looking at our kits, what kit doesn't have wastegates with low psi springs for our cars? If your bc fails you wont overboost....
so imo overboost protection is a cherry on top feature.

EDIT:
g35tt said almost exactly the same s*** lol

 

^yes. I do disagree with your list. Lol@Just throwing out top brand name. But everyone has diff taste. So forget it.

Op, osiris isn't bad idea, I havent really heard any complain about dyno flash ECU(osiris or technosquare). But its all comes down to what your friend and his tuner feels safe to go with. Defi, I will skip the piggy system for sure.

For the price, osiris will cheaper than standalone. But if there is used haltech ems, I think it won't be much diff.

Standalone or reflash, either way he will be happy with it. Good luck.

Editp, you had rx7? Was FD? Or FC? If was an FD, can I shoot you a pm?

 

Hi Chris. I again looked at the HKS EVC installation diagram. If the lower line popped off, the pressure in both the lower line and upper line would drop significantly (they are usually connected with a "T", so disconnecting the lower line will bleed pressure from the upper line). Thus, pressure applied to the top of the poppet valve should decrease significantly, which should take it almost back down almost to spring pressure. I have heard of people using spring pressure alone without a boost controller, so I would think that this situation would be somewhat synonymous.

 

I am just saying that my e01 can be set up to cut boost if it exceeds a programmed setting, is that a "good boost controller"

 

gotcha.

 

I see what you are saying, but it doesn't work like that. Without that lower line connected, there is no boost signal to overcome the force of the spring, therefore the gate would remain closed until boost built up so much that the exhaust pressure itself started to open the gate, but by that time you've most likely doubled your desired boost pressure.