murd

If the stock ECU proves to be a problem then why don't we just replace it with a new Bosch Motorsports ECU such as the MS 4 Sport Turbo. It can be purchased to be run with our direct injection engines. Alternately could we find some other manufacturer such as Haltech assuming that their ECU's will be much cheaper. I left an email with Haltech to see if they have a solution.

What other aftermarket ECU's would be up to the task?

I'm assuming that GM may eventually solve the problem for us but not without our money. Assuming they ever get the funding for a Stage 2 and Stage 3 Kit. They also will most likely sell you a new turbo etc with it. Most likely they won't have a kit for atleast 2 years or more.

My brother in law runs the edmonton office for Alamo Industries (turbos) and I have already located the part number for the turbo wheel upgrade that is being sold by Bald Turbo Freak.

If an ECU were available for our car then we could move onto the next stage (upgraded turbo wheel and larger turbos etc)

tom.g

iTrader: (4)

^ I'm pretty sure if you want to run a larger turbo your going to have to get a Custom Aftermarket Tune such as Trifecta, HP, BYT, PPC.....

RYRO14

iTrader: (1)

What is wrong with the stock ECU? It can be tuned for lager turbos.

JPizzle

murd

From what I've read in all other forums regarding tunes none of them are capable of handling the 25 - 30psi and higher airflows that a larger turbo could provide. It appears that the stock ECU safety controls cannot be completely undone without kicking the car into limp mode. Example Dejon Dave (16g turbo) gets 28 psi for 3 seconds before his car goes into limp mode. Same for all other tunes.

Can anyone verify that they hold 25-30 psi without going into limp mode. I mean full runs in 3rd and 4th gears on the street / track.

Bosch MS 4 Sport Turbo sells for 3500 approx. Expensive but works.

Small price though compared to the hastle of future problems encountered from tunes and other setups. I could be wrong though.

We'll see how much other replacement ECU's cost for the car.

wantedSS/TC

iTrader: (1)

I do, 28psi. No limp mode. you need to turn off the over boost controls

Sweetsandman

iTrader: (-1)

Whatever other forums you've been reading on...don't go there anymore. Hope this helps.

umrdyldo

iTrader: (1)

The stock ECU with a tune has been shown to handle cars with over 500whp. I doubt you will be getting there so I'm pretty sure you are fine. HP Tuners and Trifecta will allow you to run as much boost as your car can handle.

If you want much higher pressure I.E. over 23 psi you either have to turn off overboost protection or get the Stage 1 sensors and tune on top of that. Much easier than any $3,500 Bosch ECU

murd

Thanks a million guys. Here is a copy of my correspondence with Borg Warner and the bigger compressor wheel as used by Bald Turbo Freak. I'm going to have my brother in law, Tom at Alamo Industries in Edmonton do the machining for me on my housing.

There is another big CW available that can be fitted into the stock K04 Ecotec turbo which the site you forwarded appears to use (best I can tell from the picture). The CW p/n is 5306 123 2014 and has an inducer of ~46mm. I have attached a comp map for a turbo that uses this CW for reference.

Thanks,

Kurt Henderson
Technical Sales Representative
BorgWarner Turbo & Emissions Systems
Fax: (800) 424-6464
Desk: (828) 684-4095
khenderson@borgwarner.com


Oh and is it worth it to get the sensors from crate engine depot?

I'll probably get the Hptuners setup. Any recommendations?

umrdyldo

iTrader: (1)

Even though the stage kit is a bit pricey. Your long term potential is much greater for the car.

fshizl

iTrader: (1)

does hp tuners support the new sensors?

White_Out

WTF have you been reading?

BYT*SS*TURBO

iTrader: (6)

^That is true if the tuner doesn't know what they are doing :P

HPTuners can support the new sensors with a tune on top of a GMS1 file (which I have).

copson20

Vince at trifecta can tune the stock sensors for GMS1 with out having them.

umrdyldo

iTrader: (1)

right but the stock sensors force the car into limp mode if the PSI is over 22-23 for an extended period of time. Hence why the new sensors are needed.

BYT*SS*TURBO

iTrader: (6)

^That is not true at all.

All the new sensors do is allow you to read up to ~30psi accurately on the RPD.

You can run over 22-23psi on the stock sensors without breaking them OR going into whatever limp mode you are talking about.

wantedSS/TC

iTrader: (1)

^^ what's this limp mode?

umrdyldo

iTrader: (1)

So if the sensors aren't designed to read over 22 or 23 whatever it is, you think they are reading it correctly to the ECU as well?

I didn't say you couldn't run more boost on stock sensors. I thought the computer had a **** fit if you ran higher boost for an extended period of time. Or is that just how the Overboost function works? Sorry if i was misinformed.

copson20

vince allows the stock sensors to read 30lb all day long, all the GMS1 is, is a retune from gm and new sensors that allows the car to read the higher boost. buying the sensors is a complete waste of money.

BYT*SS*TURBO

iTrader: (6)

The ECU doesnt look at the amount of KPA to tune anything. It goes by Air Load % in most cases.

He scales the stock ones to sorta read what you really are. This isn't 100% accurate but you are right, it is better then just blanking out the stock sensors with more then 22psi. Still does nothing in a performance aspect..

copson20

The stage kit upgrades the MAP and boost pressure sensors from 2.78bar to 3.3bar. At sea level (100 kPa atmospheric pressure), this increases the maximum amount of boost the sensors can read from 25.82psi to 33.36psi.

The GM stage kit tune was written to use these upgraded sensors. You cannot run the stage tune (unmodified) without the sensors or you will get a BARO sensor code immediately upon startup and the car will be in limp mode.

The “official” statement by some guy on the forums that claims to be a GM engineer is that the EPA requires 10% of a sensor’s range to be reserved for diagnostic purposes in order to certify the tune. If you believe this statement, that means the highest usable range of the stock sensors is 278 kPa – 27.8 kPa = 250.2 kPa, or 21.78psi, which apparently is lower than commanded boost levels of the stage tune. However, the stock tune has a boost cap of 240kPa, or 20.31psi of boost.

Furthermore, if trifecta modify's either the stock tune (with stock sensors) to command boost levels equivalent to the stage tune, or if trifecta modify's the stage tune to accept the stock sensors, no check engine light, diagnostic codes, or limp mode is experienced. If that last 10% of sensor range was reserved for diagnostics, wouldn’t we get a failed diagnostic code? I would expect so, but we don’t. So, I don’t buy that story.

What is more likely is that GM learned the hard way with the Cobalt SS/SC stage kit that unless they did something with the tune that required different parts, all it would take is one person to buy the official stage tune, and then flash everybody else’s car with it. Who makes the money on this? Not GM. GM’s putting their financial well-being on the line by backing that tune with their warranty yet they are not monetizing it.

There are also some who believe the stage sensors provide some level of performance benefit. This is completely untrue. With Trifectas tune, the people can reach the same boost levels as the stage tune (and even beyond the stage tune), with either the stock or upgraded sensors.

umrdyldo

iTrader: (1)

^^^ very good post