I remember dealing with that, the best way to describe the difference from the reflash to the htp fake 2.5 bar is night and day. I constantly have traction issues and spin em through 2nd/3rd and chip them into 4th on occasion, You'll be happy. What other supporting mods does the fire have?

What does using the 2.5 bar MAP sensor achieve in this approach if the system remains Alpha-N and not speed density? Please bear in mind, I'm not trying to disparage this setup, just learn more about it for my own curiosity and to assis my customers who are seeking tuning solutions for their turbo J's.



Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

JUCNBST wrote:I remember dealing with that, the best way to describe the difference from the reflash to the htp fake 2.5 bar is night and day. I constantly have traction issues and spin em through 2nd/3rd and chip them into 4th on occasion, You'll be happy. What other supporting mods does the fire have?

at the moment, nothing but the blower and a heat exchanger setup.

Now that being said, I am planing on changing that, hence my interest, and my understanding that this reflash is not going to cut it, and is holding me back



** FOR SALE** http://www.j-body.org/forums/read.php?f=24&i=110879&t=110879

I boost, therefore I am wrote:To all: the E67 PCM (in Cobalt, HHR, and others) is a great example. It can be tuned to accomodate boost rather nicely on airflow only, for it can readily compensate for this 70% difference using measured MAF airflow. Even without a TMAP (it features a stock one-bar MAP), it performs this purpose very well, and very repeatably, as it should...GM's strategy for boosted cars is to use MAF for the primary fuel calculation, with the TMAP sensor only there as a backup should the MAF fail. The Ford vehicles we add turbocharging to also achieve proportional boosted fueling via MAF exclusively.

Actually, the bold above is a false statement. With the E67, it can read up to 80kpa (roughly 11.6psi) boost in stock form, BUT, it must have a 2bar (or higher reading) MAP sensor, and it must be scaled correctly under the MAP Sensor Linear and Offset tables... If this is not done, the Fuel Flow Rate VS KPA will only read from -80 kpa to 0 kpa only. The MAF itself will read the air flow, but the injector flow rate would not be there at all......





P&P Tuning
420.5whp / 359.8wtq

QWK LN2 (needs an @ss whoopin) wrote:

I boost, therefore I am wrote:To all: the E67 PCM (in Cobalt, HHR, and others) is a great example. It can be tuned to accomodate boost rather nicely on airflow only, for it can readily compensate for this 70% difference using measured MAF airflow. Even without a TMAP (it features a stock one-bar MAP), it performs this purpose very well, and very repeatably, as it should...GM's strategy for boosted cars is to use MAF for the primary fuel calculation, with the TMAP sensor only there as a backup should the MAF fail. The Ford vehicles we add turbocharging to also achieve proportional boosted fueling via MAF exclusively.

Actually, the bold above is a false statement. With the E67, it can read up to 80kpa (roughly 11.6psi) boost in stock form, BUT, it must have a 2bar (or higher reading) MAP sensor, and it must be scaled correctly under the MAP Sensor Linear and Offset tables... If this is not done, the Fuel Flow Rate VS KPA will only read from -80 kpa to 0 kpa only. The MAF itself will read the air flow, but the injector flow rate would not be there at all......

No, my development efforts over many years and many vehicles would indicate it's true. The car will still fuel very effectively and repeatably under boost. In such a case, the additional fuel flow rate needed under boost is calibrated via MAF scaling. Fuel flow rate vs KPA is altered to accomodate the larger injectors, but it will remain constant at the 0 kpa value throughout boost. However, as a determinant of actual fuel being delivered, the fuel flow rate vs KPA only varies a small percentage. It is not a large factor in fuel being delivered...look at such a table and you'll see that its variation is actually rather small from one end of the range to another. Nonetheless, tuning for AFR achieves the the same desired outcome. Were the Fuel Flow Rate VS KPA also active in boosted conditions, we'd still just tune MAF to compensate for this small percentage of fuel added. The end result is the same, with an identical injector pulse width (and AFR) achieved.

While it is true that recent software developments now also allow the use of a boost-capable MAP sensor on the E67, we've proven that it can be boosted very effectively without one. Having done so on hundreds of E67-equipped vehicles, we're very confident in that statement, and all the way to 450 HP. Now, certainly, if a car tuned this way does experience a MAF failure, it will not be able to compensate for boosted fueling, whereas one tuned with the newer software feature and a TMAP will (at least all the way to 11.6 PSI). Thankfully, such MAF failures are extremely rare.

But we wander off-topic...as per my question above, can you or anyone anyone answer what it is the 2.5 bar sensor achieves in this "fake 2.5 bar" approach with the Alpha-N J-body PCM? Again, I am not trying to cast an ill light on it, just trying to understand it.



Edited 1 time(s). Last edited Thursday, October 14, 2010 4:10 AM

Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

I boost, therefore I am wrote:

QWK LN2 (needs an @ss whoopin) wrote:

I boost, therefore I am wrote:To all: the E67 PCM (in Cobalt, HHR, and others) is a great example. It can be tuned to accomodate boost rather nicely on airflow only, for it can readily compensate for this 70% difference using measured MAF airflow. Even without a TMAP (it features a stock one-bar MAP), it performs this purpose very well, and very repeatably, as it should...GM's strategy for boosted cars is to use MAF for the primary fuel calculation, with the TMAP sensor only there as a backup should the MAF fail. The Ford vehicles we add turbocharging to also achieve proportional boosted fueling via MAF exclusively.

Actually, the bold above is a false statement. With the E67, it can read up to 80kpa (roughly 11.6psi) boost in stock form, BUT, it must have a 2bar (or higher reading) MAP sensor, and it must be scaled correctly under the MAP Sensor Linear and Offset tables... If this is not done, the Fuel Flow Rate VS KPA will only read from -80 kpa to 0 kpa only. The MAF itself will read the air flow, but the injector flow rate would not be there at all......

No, my development efforts over many years and many vehicles would indicate it's true. The car will still fuel very effectively and repeatably under boost. In such a case, the additional fuel flow rate needed under boost is calibrated via MAF scaling. Fuel flow rate vs KPA is altered to accomodate the larger injectors, but it will remain constant at the 0 kpa value throughout boost. However, as a determinant of actual fuel being delivered, the fuel flow rate vs KPA only varies a small percentage. It is not a large factor in fuel being delivered...look at such a table and you'll see that its variation is actually rather small from one end of the range to another. Nonetheless, tuning for AFR achieves the the same desired outcome. Were the Fuel Flow Rate VS KPA also active in boosted conditions, we'd still just tune MAF to compensate for this small percentage of fuel added. The end result is the same, with an identical injector pulse width (and AFR) achieved..

I call bullsh!t! My research of this on many cars, on and off the dyno, shows otherwise. Further more, it also shows how many people have NO BUSINESS touching this PCM. I've see a lot of HACK tunes from E67 PCMS, but the most recent one I have pulled takes the cake.... Makes me want start yellin, "Hide your kids, hide your wife, and hide your husband, because they rapin everybody!" With that being said, alot of these are coming out of shops with reputations for knowing what they are doing, I beg to differ! These shops/tuners don't know sh!t..... If this is your process, I can see why there are so many complaints on CSS.net about your E67 tunes blowing sh!t up. Also, before we get in a pissing match, I'm not saying this is all 100% factual information from people posting, but based on what I'm reading above from you, and their complaints, I can see a pattern....

I boost, therefore I am wrote: While it is true that recent software developments now also allow the use of a boost-capable MAP sensor on the E67, we've proven that it can be boosted very effectively without one. Having done so on hundreds of E67-equipped vehicles, we're very confident in that statement, and all the way to 450 HP. Now, certainly, if a car tuned this way does experience a MAF failure, it will not be able to compensate for boosted fueling, whereas one tuned with the newer software feature and a TMAP will (at least all the way to 11.6 PSI). Thankfully, such MAF failures are extremely rare.

This to be says that you are basically raping the MAF/anrd or injectors with no proportional fuel being added due to due the flow rate VS KPA table not being able to compensate. Is this the reason why you sell your "boostfueler" and advertise "Conventional tuning procedures do not work well on this platform. The Hahn Racecraft BoostFueler makes performance tuning an easy reality." ??? With this being quoted directly from your website, this tells me that maybe you are selling/adding more equipment to compensate for your lack of knowledge on this particular PCM. I know myself and other reputable tuners have had no issues tuning boost on the E67 and have never had to use these components you are adding/selling.....

I boost, therefore I am wrote: But we wander off-topic...as per my question above, can you or anyone anyone answer what it is the 2.5 bar sensor achieves in this "fake 2.5 bar" approach with the Alpha-N J-body PCM? Again, I am not trying to cast an ill light on it, just trying to understand it.

I guess I'm having a hard time understanding exactly what you are trying to ask? Its been stated in this thread and in other threads what the Fake 2.5 bar tune achieves....





P&P Tuning
420.5whp / 359.8wtq

Since its so hard to reply to that simple question, the bar map on a alpha-n controls timing, not fuel.

Well, you are certainly free to call "bull@!#$", but frankly, I've yet to hear of the complaints you mention with our product. You're also free to call my attention to them, here or otherwise, but it's going WAY off topic to do so here. FWIW, I would not consider css.net to be an infallible source of information about my customers and their experiences with our products, for I do not participate there, and the companies that do are notorious for seeding negative information about others.

I too don't wish to get into a pissing match, and I'm sorry if my quest for knowledge about this "fake 2.5 bar tune" inspired you to move in this off-topic direction, apparently a "tit for tat" approach. It was not my intention to inflame you or portray your work in a negative light, as I also outlined in the PM I sent you about this, a PM you've yet to reply to. It's merely my intention to learn more about the possible options that exist for users of our turbosystems.

I'd be happy to discuss more about the E67 tuning approaches we're debating, but again...this is not the appropriate time or place on this thread. If you wish to start another thread to do so, I'll gladly participate; just let me know when and where.

As an aside to all: It's not uncommon for independent tuners such as Ryan to "take on" the larger companies such as ours. This is not the first instance, and it's sure to not be the last. Whether it's Vortech, ProCharger, or even Hahn RaceCraft, we primarily provide hardware solutions. While we do strive to make our software tuning solutions adequate for the task at hand, we freely admit that tuning specialists can and will employ different methods than ours, and may well be able to delve deeper into a particular application than we deem safe and necessary for a production turbosystem. Today's PCM's are amazingly complex, and available tuning technology advances rapidly. Simply put, a custom tune from a tuning specialist should always be superior to a "canned" tune such as we provide, and the customer will pay additionally to attain this higher level of service and features. We typically provide our canned tunes at no charge to our turbosystem customers, and encourage those who are looking for more power and/or different features to seek custom tuning services if they like. We even refer to custom tuners for this very purpose, and have good working relationships with many of them.



Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

Vic28 wrote:Since its so hard to reply to that simple question, the bar map on a alpha-n controls timing, not fuel.

Thank you Vic. So, in the case of the "fake 2.5 bar" tune, what is achieved is boost igntion retard, but no fueling is associated with the 2.5 bar sensor?



Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

As stated before, Not going to get into a pissing match with, its pointless... Also, you must of failed to read the part where I said this is just information I have read/observed.... It was not an attack, just simply observations. I don't want misleading information being spread... Did not see the PM as I do most my posting from my phone...

I boost, therefore I am wrote:

Vic28 wrote:Since its so hard to reply to that simple question, the bar map on a alpha-n controls timing, not fuel.

Thank you Vic. So, in the case of the "fake 2.5 bar" tune, what is achieved is boost igntion retard, but no fueling is associated with the 2.5 bar sensor?

Actually, I did answer this previously. As stated, You have to re-scale EVERYTHING related to the MAP sensor, therefore the IPW vs VAC(or KPA) would be affected... Last time I checked, that would adjust fueling via pulse width if adjusted accordingly and scaled properly... The VE tables would still be TPS based, but the pulsewidth would be boost referenced now.... I hope this is a more clear understanding for you....





P&P Tuning
420.5whp / 359.8wtq

I wish I didn't live all the way down here in Alabama I would love to have my car properly tuned by HPT using the TMAP =( I hate the reflash so hard