09CobaltSS1

Not.. sure.. if .. serious..

user 72239

iTrader: (4)

Interesting. So I wonder if that is a limitation of our pcm boost control... I wonder if you run a manual boost controller if it would be easier to ramp compared to pcm control

09CobaltSS1

I've never tried any EFR with a mbc, so I can't really say for sure how it would react. I quite honestly can't see it being much better really. If anything I would have to think that a mbc would actually make things worse considering there is no way to electronically control wg position to attempt any sort of boost ramp. Setting the mbc at say 28psi would basically force the turbo to produce 28psi as fast as possible, therefor allowing a low rpm/high boost situation to occur VERY easy.... which can be bad news. These smaller EFR's spool up quite fast, so combined with a high boost canister, I'd personally be VERY hesitant to even try a mbc. Plus the use of one takes any sort of boost control away from whoever is doing your tuning. Are you really having that many issues getting your turbo to spool?

user 72239

iTrader: (4)

no not anymore, but I was just thinking outloud cause Full Race and Borg warner have a whole walkthrough on how to make the EFR boost higher and they say if you want over 18 PSI to run the higher wastegate canister. I guess it wears the medium one out faster if you have too much preload.

Herreric

So I know this is an old thread but my ZFR is hitting 30psi and no matter then tune it does. I got my ZFR used, think it has the high boost canister on it?

63 Nova SS

iTrader: (3)

Did you read the replies in your other thread?

08VRSS

There is a way to have a MBC and EBC run in parallel via a hybrid setup i've done it before on my WRX back in the day. Tuning it is easy, no part throttle full boost issue bc thats taken care of via the EBC, then at whatever set point i tune it at, the MBC will take over for full boost. Very popular with the suby crowd. Its called a hybrid setup.

I sold my spare hallman pro evo rx with cockpit cable or I'd have set it up, no time anymore unfortunately. Maybe someday I'll try it again.

If you want to learn, here's the thread, my old results are in there too.

new hybrid mbc/ebc method of boost control - Page 35 - NASIOC

I've had it on internal WG and external WG setups, works beautifully.

And if something goes wrong in the tune and the ECU wants to pull boost, it can with this setup, i've tried it commanding mechanical boost pressure and closing the MBC all the way telling it max boost, it was boosting 7psi, worked like a charm for failsafes. So its all the benefits of a MBC with none of the downfalls.



From the forum:

"a) cockpit adjustability of max boost via a knob.
this is one aspect that i can't stress enough. it is by far the best way to account for atmospheric changes in boost levels as well as driving style changes (highway vs. city, wife driving, valet, etc). two seconds in the morning and it's set for the rest of the day.

b) throttle dependant boost levels.
obviously, this is key to avoiding stoichiometric boost, and also allows a ramping up of manifold pressure so that boost is controlled at partial throttle, instead of coming on when it wants to (ie pure mbc). this improves drivability and prevents engine damage due to PTFB scenarios.

c) rpm dependant boost levels.
haven't tuned this in yet, but the capability is certainly there. i have a strong hunch that tuning in a bit of boost taper at the top end of the rpm range while using the oem turbo is a "good thing," since it will cause the wastegate to open, reducing EGBP without decreasing manifold pressure, since that's pretty much capped by the compressor anyway. less EGBP for no hit in MAP is without a doubt desirable from an efficiency standpoint.

d) rock solid boost response.
when i say rock solid, i mean ROCK SOLID. those who have never used a GOOD MBC will not really know what i'm talking about. what i am talking about is a boost level which will NEVER be exceeded, even for the briefest of spikes. there are simply no spikes whatsoever to speak of.

e) very quick boost increase.
when the throttle is floored, the UTEC's boost map is set to 500, essentially max boost. the GM solenoid closes, which prevents any pressure signal from going through it to reach the wastegate acutator. the ball and spring mbc is a very good MBC in that it provides a very tight seal, and essentially no air gets through that until the spring tension is exceeded by the pressure signal. bottom line: boost response just as fast as a good ball/spring MBC, which is as fast as it gets.

i'm going on day two with the setup and i could not be happier... pretty much every thing i could ask for is addressed. since the picture was taken (during the testing phase) i have shortened all boost/vac lines as much as possible, and secured the junctions with zip-ties. having short, non-obstructed lines is also critical to having rock-solid boost control."