Major potential stumbling point retrofitting an LS7 :>(
07-06-2005, 10:14 PM
#21
Originally Posted by John B
New for '06? The '05 LS2 doesn't use this....
Also, check out this thread... page 9 post 81 by Poltergeist... about the LS7 PCM being math based and not table based... hmm... very interesting stuff
Originally Posted by Poltergeist
One problem with getting a PCM is how are changes going to be made? The LS7 PCM uses a Math based setup instead of Table based. It might take a take a while before an edit is avaliable for it. Steve1969LS1 told me this after his trip for Pop Hot Roddin to build an LS7 for an article. The GM engineer that told him this said that they figured the aftermarket would come up with a way to control the motor.
Last edited by billreid1@cox.net; 07-06-2005 at 10:33 PM.
07-06-2005, 10:44 PM
#22
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What about a trigger wheel crank sensor or optical sensor mounted on the front of the engine externally and take the reference off the front pully? Maybe you would have to machine a crank pully to do it? Might be easier to do than internally, just a thought.
07-06-2005, 11:01 PM
#23
Originally Posted by StickSS
What about a trigger wheel crank sensor or optical sensor mounted on the front of the engine externally and take the reference off the front pully? Maybe you would have to machine a crank pully to do it? Might be easier to do than internally, just a thought.
07-07-2005, 12:54 AM
#24
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If it is true that the LS7 uses the Electromotive-type 60-2 timing wheel, then it should be fairly straightforward to generate the 24x signal required by the Gen III PCM. The signal generated by the Gen III reluctor wheel needs a reference every three degrees of crankshaft rotation. This reference could come from a frequency doubler phase-locked to the 60-2 timing wheel. The reference signal would be used to clock a shift-register that is loaded with the 24x code sequence once per revolution.
-Gary
-Gary
Last edited by Gary Z; 07-07-2005 at 01:08 AM.
07-07-2005, 01:10 AM
#25
Originally Posted by Gary Z
If it is true that the LS7 uses the Electromotive-type 60-2 timing wheel, then it should be fairly straightforward to generate the 24x signal required by the Gen III PCM. The signal generated by the Gen III reluctor wheel needs a reference every 3 degrees of crankshaft rotation. This reference could come from a frequency doubler phase-locked to the 60-2 timing wheel. Once you have the reference signal, it can be used to clock a shift-register that is loaded with the 24x code sequence once per revolution.
-Gary
-Gary
... just kiddin' with ya 
. I have an Associates Degree in Electronics and busted out my old text books to start refreshing my memory on this stuff
07-07-2005, 01:48 AM
#26
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I don’t think I’ll have a complete circuit soon - not even if I stayed at a Holiday Inn. My electronic gobeldy-gook explanation was poor. As Builder commented, there are many solutions. The key observation is that 60 times 2 divided by 5 equals 24. This is a fun problem to think about but since detailed information is lacking, I don’t think it will be possible to work out all the details without access to a running LS7.
Last edited by Gary Z; 07-07-2005 at 09:43 AM.
07-07-2005, 10:57 AM
#27
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Originally Posted by Gary Z
...I don’t think it will be possible to work out all the details without access to a running LS7.
It's a real surprise that the PCM is apparently not available, at this time, with the crate engine (hope GM reads this). Since my application is so far removed from needing the full functionality of the stock PCM, perhaps an aftermarket system is a better answer anyways. (Justified!) Perhaps GM will produce a reduced-function box, like the ASA box for the LS6?
Regardless, I think we all have to wait and get our hands on the engine and PCM before too much can be done. I won't be throwing a carb on my LS7 just to drive around. I'll get a forged, stroked 402 LS2 instead.
07-07-2005, 04:12 PM
#28
This may be a bit premature but does anyone know if there is a part # for the new trigger wheel (60-2) and does anyone know what crank angle is represented by the missing two teeth? This may end up being a pain for the stock PCM guys but may be good news for anyone who wants to go aftermarket.
07-08-2005, 06:59 AM
#29
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the reluctor ring is on the back end of the crank. if I am correct. why cant you just replace it with an ls1/ls2/ls6 reluctor ring??? this may be a stupid idea but it is worth a shot. or just while building using an ls7 block and heads etc. I was going to use the block and heads but swap out to all forged goodies for the internals. so that it will hold for the healthy amount of boost I wanna use. hope this helps.
07-08-2005, 09:07 AM
#30
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just another reason to get a stand alone, and **** seriously with all the extra features in a stand alone ecu, and the money being spent on the engine itself how cant someone justify spending the money on a ecu.
07-08-2005, 09:12 AM
#31
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Originally Posted by Sbertolone
just another reason to get a stand alone, and **** seriously with all the extra features in a stand alone ecu, and the money being spent on the engine itself how cant someone justify spending the money on a ecu.
wesley
07-09-2005, 03:35 PM
#32
Take a look at this thread...
http://forums.corvetteforum.com/show...2&forum_id=100
A nice compilation of shots on the new 06 Z06 thats been hanging out at the proving grounds in Mesa... and being allowed to tool around town and get cozy with folks at car shows and clubs...
BTW, I watched Horsepower TV today and they had a MUCH BETTER motor assembly video than Motortrend did awhile back. DEFINITELY the new reluctor wheel. I couldn't tell if the snout of the crank is longer (or a different diameter)... except the lower cam sprocket looked longer than normal to accomodate the twin rotor pump... and assuming you got to leave enough room on the end of the crank for the harmonic balancer... is doesn't look feasable for a retrofit using the LS7 crank... unless someone comes up with custom harmonic balancers and custom electronics.
http://forums.corvetteforum.com/show...2&forum_id=100
A nice compilation of shots on the new 06 Z06 thats been hanging out at the proving grounds in Mesa... and being allowed to tool around town and get cozy with folks at car shows and clubs...
BTW, I watched Horsepower TV today and they had a MUCH BETTER motor assembly video than Motortrend did awhile back. DEFINITELY the new reluctor wheel. I couldn't tell if the snout of the crank is longer (or a different diameter)... except the lower cam sprocket looked longer than normal to accomodate the twin rotor pump... and assuming you got to leave enough room on the end of the crank for the harmonic balancer... is doesn't look feasable for a retrofit using the LS7 crank... unless someone comes up with custom harmonic balancers and custom electronics.
07-10-2005, 07:15 AM
#34
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yeah I seen the pics. for my application I dont think I will have many problems with that. just gonna buy the block/heads/intake and use forged ls1 goodies to make it all happen. only thing now is the dry sump system. if we can change it to the oiling system on the fbody. just gonna take some time.
