[sflgator]

Originally Posted by shiv@vishnu

Quick update:

Spent about 40 hours this week playing around with boost control. Things we've have done/learned so far:

1) The factory boost control solenoids aren't standard PWM solenoids. They are continuously variable valves. Our first attempted to drive them directly with our computer's closed loop boost control logic was an utter failure. All the pre-spool logic that is employed by the factory ECU is there for a reason and trying duplicate it with an external boost control using factory hardware is hopeless.

Next we added our own boost control solenoids (two of them) and relieved the factory boost control solenoids of all duty. Using revised closed loop boost control logic, we actually got amazing results. Instantaneous boost resonse with no spiking, oscillation, creep or any other undesired boost boost artifacts. Next, we tried control boost with just one solenoid. Under steady state conditions it worked just fine. But under normal/dynamic driving conditions, we saw boost spikes, slow spool and all other sorts of wackiness. Turns out that there are two boost control solenoids in the stock car for a reason: To adjust the vacuum pressure in the wastegate actuator lines quickly. If the pressure in the lines doesn't change quickly enough, the wastegates dont respond quickly enough (hence, boost spikes and/or slow spool depending on what the vacuum condition was at that specific time).

Ok... back to having to use two solenoids it is. But wait... isn't it kind of silly to use 2 add on solenoids when there is a perfectly function pair already there? Ok.. so back to hooking up the factory solenoids and figuring out a way to design a system that allows the turbos to generate anywhere from 5 to 20psi of boost (our goal) depending on electronics (mapping). And more importantly, it has to be able to do this without the factory ECU driving the solenoids with any more or less duty cycle than it would in a completely stock car, running stock boost. We wouldn't want there to be any wierd logged data in the ECU, now would we?

I'm happy to announce that it looks like we figured out how to do it. And it doesn't involve adding on any solenoids. And it still retains the factory ECU's low boost-till-the-engine is warm feature. And it can still run anywhere from 5psi to 20psi. And it still doesn't over or under-work the factory solenoids while doing so. So far, we've tested in sea level conditions. This weekend, I'll go up to 4000' and test it again. But so far so good.

"So what about all the current kits of the road? How is this different/better?" you ask

The approach we've employed with the early adopter beta folks works just fine. But the range of available boost is only beteen stock (7-8psi) and 11psi. And boost doesn't seem to be as rock solid as with our new approach. Of course, early adopters will easily be able to retrofit this changes once we put the setup through its paces.

It's been a productive week and I just wanted to share it with you!

Cheers,
shiv

Interesting. I wonder if after all this "extra" tweaking and experimenting that you end up going back to your original Xede setup. A majority of the time, the saying..."if it isn't broken, why fix it?" definitely holds true. So far, so good here in S. FL...mine has been running very well after several hundred miles logged on with the Xede.

[OpenFlash]

Originally Posted by sflgator

Interesting. I wonder if after all this "extra" tweaking and experimenting that you end up going back to your original Xede setup. A majority of the time, the saying..."if it isn't broken, why fix it?" definitely holds true. So far, so good here in S. FL...mine has been running very well after several hundred miles logged on with the Xede.

It's a bit different than the method we used in the beta cars (yours included). Your setup works just fine but in a narrower range of boost performance. Your setup is limited to 10-11psi of boost. And boost pressure in the 2000-3000rpm range tends to oscilliate a few times until it stablizes. Much like the stock car. But with the extra boost, it becomes a little bit more discernible. This new approach offers better-than-stock boost stability and just-as-good boost response at higher-than-stock boost levels. That's a pretty tough performance target to achieve since usually its a zero-sum game in many respects. Usually, you end up sacrificing stability for response or visa versa. So i'm geeked up over here. See... this is me -->

-shiv

[sflgator]

Originally Posted by shiv@vishnu

It's a bit different than the method we used in the beta cars (yours included). Your setup works just fine but in a narrower range of boost performance. Your setup is limited to 10-11psi of boost. And boost pressure in the 2000-3000rpm range tends to oscilliate a few times until it stablizes. Much like the stock car. But with the extra boost, it becomes a little bit more discernible. This new approach offers better-than-stock boost stability and just-as-good boost response at higher-than-stock boost levels. That's a pretty tough performance target to achieve since usually its a zero-sum game in many respects. Usually, you end up sacrificing stability for response or visa versa. So i'm geeked up over here. See... this is me -->

-shiv

Ok...Good luck! But doesn't "up to 20psi" boost seem kind of high (and possibly damaging) to the 335i's turbos? I know I've read horror stories of modded turbo Audi's b/c the turbo boost was increased much higher than stock.

Well, I know you'll let all of us know how you make out, so even us beta testers can decide which Xede "version" we want to ultimately have.

[Jonn335]

I like the sound of this....
looking forward to some impressive dyno results...
and thanks once again for sharing your hard earned info with us all...

[Vinobien]

Sounds like the new setup provides more stable boost. Looking at the previous dyno graphs, you could see oscillations in power. It appears this has been corrected. I would think the beta testers would want any improvement that Shiv is offering - why not?

Shiv, are you considering running a slightly higher boost? Not to rush you, but what timeframe are you looking at delivery of the first wave, even on an order of magnitude?

[musc]

20psi looks like a huge improvement. I wonder what the dyno improvement 9 extra psi more than current beta Xede users will yield

As sflgator mentioned, I'd be a little concerned about the longevity of parts at 20psi. Maybe this will be adjustable? Fuel map dependent? Will be interesting to see.

[Vinobien]

I wouldn't think he would be adding much more boost considering the compression ratio of the 335i. I would have big concerns.

[OpenFlash]

The ability to run 20psi isn't that outlandish. On race gas, it should be perfectly conceivable to run 15-16psi of boost in the low end/midrange. Top end with still be limited to 10-11psi due to turbo limitations. And for those who live at 5000' above sea level where atmospheric pressure is 3-4psi lower than it is at sea level, the'd need to run 18-20psi of boost to acheive the same engine load. The high boost capability is just there when we need it. Of course, it would be taken advantage of by most customers in most situations. But we wanted to make sure that our control over the turbos is good enough to make them do whatever we want (within reason and contraints).

-shiv

[Vinobien]

Got it - I ran 1.4 bar ( 20.6 psi) on my 944 turbo S with no issues - lower comp ratio. What additional horsepower / performance gains are you expecting with the increased boost? This is really good stuff Shiv.

[musc]

Originally Posted by shiv@vishnu

The ability to run 20psi isn't that outlandish. On race gas, it should be perfectly conceivable to run 15-16psi of boost in the low end/midrange. Top end with still be limited to 10-11psi due to turbo limitations. And for those who live at 5000' above sea level where atmospheric pressure is 3-4psi lower than it is at sea level, the'd need to run 18-20psi of boost to acheive the same engine load. The high boost capability is just there when we need it. Of course, it would be taken advantage of by most customers in most situations. But we wanted to make sure that our control over the turbos is good enough to make them do whatever we want (within reason and contraints).

-shiv

What kind of boost range will you have with the new set up running the 93 octane map? Looks like there should be even more power on tap

[OpenFlash]

Originally Posted by catm3

What kind of boost range will you have with the new set up running the 93 octane map? Looks like there should be even more power on tap

I don't think boost pressure will change at all for 93oct applications. Boost will still be limited to 10-12psi due to octane limitations. The benefits of the new boost control system is improved boost stability and higher boost capacity (when conditions allow).

Shiv

[elmaki]

Originally Posted by shiv@vishnu

Quick update:

Spent about 40 hours this week playing around with boost control. Things we've have done/learned so far:

1) The factory boost control solenoids aren't standard PWM solenoids. They are continuously variable valves. Our first attempted to drive them directly with our computer's closed loop boost control logic was an utter failure. All the pre-spool logic that is employed by the factory ECU is there for a reason and trying duplicate it with an external boost control using factory hardware is hopeless.

Next we added our own boost control solenoids (two of them) and relieved the factory boost control solenoids of all duty. Using revised closed loop boost control logic, we actually got amazing results. Instantaneous boost resonse with no spiking, oscillation, creep or any other undesired boost boost artifacts. Next, we tried control boost with just one solenoid. Under steady state conditions it worked just fine. But under normal/dynamic driving conditions, we saw boost spikes, slow spool and all other sorts of wackiness. Turns out that there are two boost control solenoids in the stock car for a reason: To adjust the vacuum pressure in the wastegate actuator lines quickly. If the pressure in the lines doesn't change quickly enough, the wastegates dont respond quickly enough (hence, boost spikes and/or slow spool depending on what the vacuum condition was at that specific time).

Ok... back to having to use two solenoids it is. But wait... isn't it kind of silly to use 2 add on solenoids when there is a perfectly function pair already there? Ok.. so back to hooking up the factory solenoids and figuring out a way to design a system that allows the turbos to generate anywhere from 5 to 20psi of boost (our goal) depending on electronics (mapping). And more importantly, it has to be able to do this without the factory ECU driving the solenoids with any more or less duty cycle than it would in a completely stock car, running stock boost. We wouldn't want there to be any wierd logged data in the ECU, now would we?

I'm happy to announce that it looks like we figured out how to do it. And it doesn't involve adding on any solenoids. And it still retains the factory ECU's low boost-till-the-engine is warm feature. And it can still run anywhere from 5psi to 20psi. And it still doesn't over or under-work the factory solenoids while doing so. So far, we've tested in sea level conditions. This weekend, I'll go up to 4000' and test it again. But so far so good.

"So what about all the current kits of the road? How is this different/better?" you ask

The approach we've employed with the early adopter beta folks works just fine. But the range of available boost is only beteen stock (7-8psi) and 11psi. And boost doesn't seem to be as rock solid as with our new approach. Of course, early adopters will easily be able to retrofit this changes once we put the setup through its paces.

It's been a productive week and I just wanted to share it with you!

Cheers,
shiv

Awesome

[Ph3n0m73]

Holy hell Batman.

My hypothesis:

Race gas + 16-18 psi + dyno =

Can't wait to see the graphs.

Shiv, get on that.

Oh....

Springer

[edgarj]

Originally Posted by Vinobien

Sounds like the new setup provides more stable boost. Looking at the previous dyno graphs, you could see oscillations in power. It appears this has been corrected. I would think the beta testers would want any improvement that Shiv is offering - why not?

Shiv, are you considering running a slightly higher boost? Not to rush you, but what timeframe are you looking at delivery of the first wave, even on an order of magnitude?

+1

[Vinobien]

Originally Posted by Vinobien

Sounds like the new setup provides more stable boost. Looking at the previous dyno graphs, you could see oscillations in power. It appears this has been corrected. I would think the beta testers would want any improvement that Shiv is offering - why not?

Shiv, are you considering running a slightly higher boost? Not to rush you, but what timeframe are you looking at delivery of the first wave, even on an order of magnitude?

So Shiv, Not to rush you, but what timeframe are you looking at delivery of the first wave, even on an order of magnitude? Mine was ordered first week in Dec.

[lawdude]

Originally Posted by Vinobien

what timeframe are you looking at delivery of the first wave, even on an order of magnitude? (empahsis supplied)

That's the second time you've used that expression. I know what the standard definition is, but can't make it fit here. What, exactly, do you mean?

[Vinobien]

The project mgt term "On an Order of Magnitude" means a big picture estimate of a quantity or timeframe for a deliverable. It is often used to get answers or commitments from suppliers, engrs, contractors without pinning them down to a specific number or date. It is useful when you need info on a larger magnitude or scale so that you can assess whether your specific needs will be met. For example .. an acceptable response would have been mid Feb timeframe maybe the first 25 to 50 Xede's. A detailed response like ... the first 25 will be delivered and at your door Feb 1. Lawyersusually speak in Order of Magnitude and give worst case when assessing sentences and court dates since there are many unknowns.

[lawdude]

Originally Posted by Vinobien

The project mgt term "On an Order of Magnitude" means a big picture estimate of a quantity or timeframe for a deliverable. It is often used to get answers or commitments from suppliers, engrs, contractors without pinning them down to a specific number or date. It is useful when you need info on a larger magnitude or scale so that you can assess whether your specific needs will be met. For example .. an acceptable response would have been mid Feb timeframe maybe the first 25 to 50 Xede's. A detailed response like ... the first 25 will be delivered and at your door Feb 1.

Ah, jargon; to wit:

Order of Magnitude Estimate
(Accuracy -25, +75 Percent) This is an approximate estimate made without detailed data, that is usually produced from cost capacity curves, scale up or down factors that are appropriately escalated and approximate cost capacity ratios. This type of estimate is used during the formative stages of an expenditure program for initial evaluation of the project. Other terms commonly used to identify an Order of Magnitude estimate are preliminary, conceptual, factored, quickie, feasibility and SWAG.

Originally Posted by Vinobien

Lawyersusually speak in Order of Magnitude and give worst case when assessing sentences and court dates since there are many unknowns.

1. I'm a lawyer. I've never used that term in that context. I haven't heard any other lawyers use it in that context either. Must be peculiar to lawyers at your location.

2. I generally try not to speak in terms of worst case sentences. I found that clients fixate on a worst case sentence and I can't get them to focus on matters at hand. Besides, in most instances, a worst case sentence will not occur.

3. Sometimes in criminal cases, when a client bonds out, he is given a court date. I'm not sure what a worst case court date would be. Perhaps you could enlighten me. I try to be as up front with my clients as possible. I always give my best guess regarding court dates based on my experience with a particular court. If I don't know, I say so.

Thanks for your reply.

[Vinobien]

lawdude - I am definitely no lawyer. I'm an engr who used to work as a Proj Mgr. I was just trying to think of an example where it might be used in your profession - chow.

[lawdude]

Ciao.

[soma4u]

Originally Posted by lawdude

That's the second time you've used that expression. I know what the standard definition is, but can't make it fit here. What, exactly, do you mean?

de ja vu

[Vinobien]

Originally Posted by Vinobien

So Shiv, Not to rush you, but what timeframe are you looking at delivery of the first wave, even on an order of magnitude? Mine was ordered first week in Dec.

bump...So Shiv, Not to rush you, but what timeframe are you looking at delivery of the first wave, even on an order of magnitude? Mine was ordered first week in Dec