New Concept
Exactly right.
In the Y-car OBD II / PCM software engineering development meetings (circa late 1993 / early 1994), we were running into 'issues' because our (i.e. - "GM's") best processor couldn't do everything we needed it to do in the allotted time frame between consecutive cylinder firings. So, 'compromises' were made as it related to functionallity and features in order to comply with the future OBD II requirements.
I left GM right as the first OBD II vehicles were produced (1996), so I can't speak to what happened with newer PCMs, but I do know that those first generation OBD II PCMs were not adequate to the task at hand; so it just stands to reason that the newer PCMs would indeed do more and perform better.
As for the secondary debate on Cam position vs. Crank position - any Automotive Technician can tell you that timing chain stretch is always a consideration in highly stressed motors.
Think about it - Why are there double-roller timing chains? To reduce the load-per-chainlink by 50% and thereby reduce/remove the onset of chain stretch; so to argue about that fact is just silly.
You can't change the laws of physics. If the rotational position of the camshaft is dependant on a series of mechancial devices which wear and stretch over their usable life, then logically speaking, as these parts wear, the position of the cam realitive to the crank will change over time, and this variance will negatively impact power production.
I realize that by trying to add a little common sense into this discussion, I too will be labeled as "idiot" (and I have indeed had my moments of idiocy - ask me about my use [or lack thereof] of head bolt thread sealant
) but, in this particular case I must side with the majority, who have their facts straight - an updated / newer PCM is indeed better.
(Let the cries and howls begin anew!)
In the Y-car OBD II / PCM software engineering development meetings (circa late 1993 / early 1994), we were running into 'issues' because our (i.e. - "GM's") best processor couldn't do everything we needed it to do in the allotted time frame between consecutive cylinder firings. So, 'compromises' were made as it related to functionallity and features in order to comply with the future OBD II requirements.
I left GM right as the first OBD II vehicles were produced (1996), so I can't speak to what happened with newer PCMs, but I do know that those first generation OBD II PCMs were not adequate to the task at hand; so it just stands to reason that the newer PCMs would indeed do more and perform better.
As for the secondary debate on Cam position vs. Crank position - any Automotive Technician can tell you that timing chain stretch is always a consideration in highly stressed motors.
Think about it - Why are there double-roller timing chains? To reduce the load-per-chainlink by 50% and thereby reduce/remove the onset of chain stretch; so to argue about that fact is just silly.
You can't change the laws of physics. If the rotational position of the camshaft is dependant on a series of mechancial devices which wear and stretch over their usable life, then logically speaking, as these parts wear, the position of the cam realitive to the crank will change over time, and this variance will negatively impact power production.
I realize that by trying to add a little common sense into this discussion, I too will be labeled as "idiot" (and I have indeed had my moments of idiocy - ask me about my use [or lack thereof] of head bolt thread sealant
) but, in this particular case I must side with the majority, who have their facts straight - an updated / newer PCM is indeed better.(Let the cries and howls begin anew!)
My tuner, an L98/LT1 tuning wizard and former Engineer for GM in the 80's, said basically the same thing - he suggests aftermarket engine management for more aggressive high rpm builds.
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how do you enplane the numbers that I am getting out of my setup. 251hp 330fl/tq on the ground. sequential injection "should be good for at least another 10% in my estimation.
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[QUOTE=95 TA - The Beast;15449538]I really don't have to provide anything. It is a simple matter of fact, a sequential EFI system is a sequential EFI system. It supplies fuel, commands spark, reads O2s...
correct me if I am wrong here? but LT1 is batch fire NO??
correct me if I am wrong here? but LT1 is batch fire NO??
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well this got way off course, did it not?? "the plan" is to use the "window" wheel slightly modified, use a high speed sensor to feed the correct signal to the ECU. then use the OPTI distributor as if no changes were made. real simple, real cheap. real nice and dependable. I really do not care about where, what, how much gain, or who likes it. If you think it is bull, then stay off of my post!!!!!!, it is a theory, at this point anyway. Until either I build a new project or someone close to Wichita Ks steps up and says he's tired of the cost of the OPTI and is willing to let me play, it will remain a theory. there is a fella that was building a direct replacement for the OPTI, but there are two problems, where is he, and did it work?
I am an Electronic Tech with 32 years experience under my belt, and have been turning wrenches since 8 years old, now 52. I like to mix my two skills for a significant challenge, AKA "FUN". After all, where would be the fun of putting an LT1, LT1 wiring, and an LT1 ECU into a different vehicle, there is none to be found in my book. Change it up, make it a challenge for myself and everybody, including those of you reading my blog. Ya gotta admit, your gears are a turning?
p.s. if ya havent read my build blog it is here http://www.gmt400.com/forum/showthre...997-K1500-SBSS and yes it is rather long 7 months worth. but it is doing everything that I had hoped for
I am an Electronic Tech with 32 years experience under my belt, and have been turning wrenches since 8 years old, now 52. I like to mix my two skills for a significant challenge, AKA "FUN". After all, where would be the fun of putting an LT1, LT1 wiring, and an LT1 ECU into a different vehicle, there is none to be found in my book. Change it up, make it a challenge for myself and everybody, including those of you reading my blog. Ya gotta admit, your gears are a turning?
p.s. if ya havent read my build blog it is here http://www.gmt400.com/forum/showthre...997-K1500-SBSS and yes it is rather long 7 months worth. but it is doing everything that I had hoped for
Last edited by Tinbender59; Oct 1, 2011 at 02:09 AM.
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Been reading up on this as I am in the process of building up a '94 Z28 convertible that I got as a rolling shell, and I plan on running the 0411 (since I already have it, and an HP Tuner).
I know very little about Opticrap as I come from 3800, DIS ignition background. But it seems to me that, if all you want the Opti dizzy to do is to supply a cam position signal and nothing else, one could just fabricate a new shutter wheel that puts out a 4x signal to the 0411?
And to put in my .02 on previous statements...for some, changing the PCM to a different type is for the search of more HP. For me, and I'm sure I'm not the only one, it's in the name of tuneability. Given I could just plug my laptop into the OBD2 port, flash a neutered tune to the computer so my 16 year old son won't kill himself showing off or flash a different tune for different seasons, those reasons alone make the conversion worth it. But also given the fact that LT1 PCMs are getting harder to come by, and harder to tune, and the 0411 is easy to find a tuner for, and in much greater supply, a conversion such as this ensures the LT1 can chug along for another decade or two.
I hope what I just stated makes sense. It does to me, but then again I've been called "Murdoc" on more than one occassion, and I usually have a sock puppet talking to me when that happens
I know very little about Opticrap as I come from 3800, DIS ignition background. But it seems to me that, if all you want the Opti dizzy to do is to supply a cam position signal and nothing else, one could just fabricate a new shutter wheel that puts out a 4x signal to the 0411?
And to put in my .02 on previous statements...for some, changing the PCM to a different type is for the search of more HP. For me, and I'm sure I'm not the only one, it's in the name of tuneability. Given I could just plug my laptop into the OBD2 port, flash a neutered tune to the computer so my 16 year old son won't kill himself showing off or flash a different tune for different seasons, those reasons alone make the conversion worth it. But also given the fact that LT1 PCMs are getting harder to come by, and harder to tune, and the 0411 is easy to find a tuner for, and in much greater supply, a conversion such as this ensures the LT1 can chug along for another decade or two.
I hope what I just stated makes sense. It does to me, but then again I've been called "Murdoc" on more than one occassion, and I usually have a sock puppet talking to me when that happens
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Interesting discussion. How about a regular old school small block with a regular distributor and a decent intake and carb. Think a well tuned LT1 would outperform the same stuff in a carbureted engine? I'm just asking, I have no idea. But carbed small blocks will make 1.5 HP per inch with 10:1 compression and NO power adders without a lot of trouble.
Al 95 Z28
Al 95 Z28
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Off topic, but Lawhead....I just moved from Port St. John about a year ago, when I saw the writing on the wall with NASA becoming "Not About Space Anymore". Has it turned into another Detroit yet?
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As in deserted. I used to live on Greenwood Ave. Still have my home there, can't sell it unfortunately, so I rent it out. I do know of a Camaro that is turbocharged (STS rear mount from the looks and sounds of it) in the Titusville area, but I've only seen it once or twice.
After reading all of this. Someone with a dyno and a properly working stock 94-97 ignition/pcm would have to dyno the **** out it. I think alot of these gains come from people switching and then getting an extensive dynotune. And it sounds like with whatever that auto-tune is, it makes things alot smoother. If someone took the man hours and money to completly dyno tune the stock setup vs one of the 24x setups revving to 6400rpm...I think Beast is right. With the cars properly tuned, 100% dialed in, all your looking at is an a/f ratio, and aslong as those are spot on in either setup, it should make the same power since nothing has been changed.
However wouldnt ignition Coil strenght and plug wires and spark affect power as well?
However wouldnt ignition Coil strenght and plug wires and spark affect power as well?
Interesting discussion. How about a regular old school small block with a regular distributor and a decent intake and carb. Think a well tuned LT1 would outperform the same stuff in a carbureted engine? I'm just asking, I have no idea. But carbed small blocks will make 1.5 HP per inch with 10:1 compression and NO power adders without a lot of trouble.
Al 95 Z28
Al 95 Z28
Thats an interesting statement when you consider a 350lt1 with 10.44:1 compression ratio is making 285hp. Maybe im looking at the wrong information but shouldnt that be closer to 525hp?
As in deserted. I used to live on Greenwood Ave. Still have my home there, can't sell it unfortunately, so I rent it out. I do know of a Camaro that is turbocharged (STS rear mount from the looks and sounds of it) in the Titusville area, but I've only seen it once or twice.
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Come to think of it, it WAS green. Seems like all the freak cars in the area are green. I helped a buddy of mine install a 3800 Series III w/cam, ported intake, L67 TB, Bonneville PCM and 3.29 gearing into a '95 TranSport (also green). It's so funny how many Hondas he's killed, even hauling a load in the cargo area
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