Had some fun with Andy-who-is-no-longer and Mac-N-Cheese Saturday, datalogging some key functions of the R56 motor. These datalogs were done on the Helix R56 mule, with no engine modifications, on local streets and highways. Being a guy that fast-forwards to the money shot, I'll get right to it: we saw as high as 15 pounds of boost! Those 15 pounds were ephemeral, however, typically lasting only a second or two. we also saw boost drop off tward redline, with a peak of no more than 11 pounds.

Here is a cluster of boost data points that we collected on about 15 minutes of running on city streets and a couple of highway pulls.



Traffic was such that we had to abort many runs before redline. I'll put the thing on the rollers in the next couple of days to get a better look at high RPM.

And here's a single run looking at boost. Note the quick drop off. We had to abort at about 4300rpm due to traffic.



Andy was trying to convince me to vice-grip the waste gate vacuum line just to see what happened, but I though the better of it until we have a good idea about fuel airs. I gotta get back to work, but I'll post more later...

 

That's what the ECU does to get "overboost". See if bybassing the waste gate gets you higher peak boost with no codes, and sell the vice grips as a $300 "re-tune"

Matt

 

Wow those numbers/curves are way different than what I'm seeing on my R56.

 

Ryephile:

You got the midwest version

What are you seeing?

 

Ah, I just remembered the magic question: Were you measuring this at the compressor outlet or intake manifold? As for my number, they're available here.

 

Looks like an ecu is going to be the key with this new car

 

There are a lot of keys to this car, or more accurately, a lot of locks. To tune the software will be more challenging than ever: The direct injection and high compression ratio are at the top of hard-to-tune list. Because DI is a relatively new technology, there doesn't exist an abundance of 'big' injecotors to allow greater fuel. As expected, there is some head room in these injectors, as you can see here with a boost vs. fuel/air mixture graph from a street datalog:



But more fuel isn't the automatic solution to bigger boost: the compression ratio will also cause tuning headaches. That $300 re-tune could end up being a $6000 motor.

 

Great info Eric. A question for ryephile: I noticed your comments about the intercooler on your Michigan MINI post. What temps were you seeing through the intercooler, and do you think there will be good increases with bigger after market intercoolers?

 

--->VurnB: The ambient was ~40F and I was seeing anywhere from 45F-60F throughout my datalog session. I have not looked at the physical constraints of the intercooler position, but my first impression on this is the intercooler doesn't need to be a first priority for getting the most out of the stock long block & turbo. Helix is headed down the right path by focusing on the ECU coding; that will help greatly.

--->Helix: One thing to note is the "stage 1" JCW does not change the injectors, which means there is still headroom beyond that "stage 1" power level. You're also on the right track taking note of the compression ratio. PM me if you want help on nailing this down.

Cheers,
Ryan

 

Talking about the intercooler, I heard on a white roof podcast over on motoringfile that core it's self is small but its the way that the pipes connect to the core that are the biggest restraints. So a aftermarket intercooler to free up flow as well as increase size could work out.

 

Thanks Ry:

No doubt we'll be talking in the future. One thing that still baffles me what is controlling the overboost and how quickly it resets. When you dyno your car this weekend I think you will find that your first pull is by far the best. In our initial test we got very good torque on the first run and then it settled about 8 ft./lbs. less for the subsequent runs. We tried several different things, including shutting the car down between runs, and even letting is sit for 30 minutes under the fans to cool. Here are the raw results:



The 'base' run was our first, and the 'test' run was the mean run from all of the other runs. To test this, I'm going to drive the car home tonight, off boost as much as possible. I'll shut the car down several times to get through some drive cycles, and then dyno it tomorrow afternoon with datalogging to see if we get one 'hail mary' run followed by several lesser runs.

 

It's controlled by a bunch of MINI fleas and they have to rest after each squeeze!

Is the wastegate diaphram connected straight to the turbo outlet? Does it go through a switch? Any connectors on the back of the wastegate? Is it something as simple as a flow restriction to the waste gate? (I doubt it, but it would be a cheap way to overboost for short times...)

Matt

ps, just squeeze the tube and have at it!

 

I'll be doing OBDII datalogging to see if the car is running overboost or not. I can also coach the operator into whether or not the ECU will be tempted into overboost; I've found it's very simple to get overboost when desired, no matter how frequently per each key-on/off cycle. I'll post along with the dyno plots what parameters they were obtained.

Matt: I haven't torn apart the engine bay [yet!] but I'm not sure if I'm seeing the blow-off valve or the wastegate actuator [scary eh?]. Whatever it is, it's "going to the back of the engine bay" [also scary]. I'd expect Helix or Webb to have a better answer, as I'm sure they've already taken a brief look at it.

Cheers,
Ryan

 

I took removed the Air box on my 07 today. On the piping just before the intake manifold there is a "T" of sorts. The small pipe goes up to the cowl. I know it's not getting any air from there. It has a small canister in line. This might be your answer to how the over boost is "allowed." I did not see any sensors or switches on the piping. Some one with more knowledge should take a look.

 

I looked on Real OEM and the Canister is a sound Generator???