L92/VVT in C4 vette LS/T56 swap
#63
Here's a lame rear bumper video. The motor needs a bunch of tuning and the Open headers are limiting time out of the garage and thus tuning time. I'm working on getting the shop scheduled to have the exhaust made soon.
Note, no cats, emissions related or real, were harmed in the making of this video...
http://www.eecis.udel.edu/~davis/z28...y/L99Vette.mov
Note, no cats, emissions related or real, were harmed in the making of this video...
http://www.eecis.udel.edu/~davis/z28...y/L99Vette.mov
#64
TECH Enthusiast
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Here's a lame rear bumper video. The motor needs a bunch of tuning and the Open headers are limiting time out of the garage and thus tuning time. I'm working on getting the shop scheduled to have the exhaust made soon.
Note, no cats, emissions related or real, were harmed in the making of this video...
http://www.eecis.udel.edu/~davis/z28...y/L99Vette.mov
Note, no cats, emissions related or real, were harmed in the making of this video...
http://www.eecis.udel.edu/~davis/z28...y/L99Vette.mov
#66
Still waiting for shop time to have the exhaust system made. I have the idle tune working, still tons of tuning to do once I can it out on the road. Trying to get it road worthy to make the Ocean City, MD Corvette Weekend in October.
Video clip with open headers, idling, ECM Scanning and dash tach, and some exhaust temps taken soon after startup.
Video clip with open headers, idling, ECM Scanning and dash tach, and some exhaust temps taken soon after startup.
Last edited by 85MikeTPI; 09-07-2012 at 08:49 PM.
#68
Tach is 400-500rpm low, actual idle was 900-1000 (tuned up because of the open headers). I was actually trying a 500ohm pull up in this test to see if it got better, because the 1K pull up read the same 400-500 lower.
I do pretty well just tuning using HPT and the stock O2s. For fine tuning, I have a zeitronix ZT2 WB-O2 in my camaro that I can pull out and tune another vehicle, and I picked up a barely used PLX Devices WB-O2 that I need to get a cable for. Probably leave the PLX installed in the vette if it works out.
#69
I found one more setting in HPTuners to try, but haven't had a chance to test. I know the VSS is working because I have it wired to the C4 ECM/CCM and the digital display works. (Just way out of spec. Still has the stock 4000ppm while the T56 is putting out around 45000ppm)
#72
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on my vet,i fed the vss to the new ecm and the output to the speedo. it works and hptuners can then be used to match speedo to gps for accuracy. ecm's dont like to share inputs.
#73
"What pins on the E38 ECM did you use to feed the VSS and output to the speedo ? "
I tapped into the wire going to X1-71 for my VSS signal. In my case that is the TOS signal coming from the 6L80E. My car is not running yet so I don't know for sure that will work.
I tapped into the wire going to X1-71 for my VSS signal. In my case that is the TOS signal coming from the 6L80E. My car is not running yet so I don't know for sure that will work.
#75
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Have you tried running the VSS as a dedicated into the E38 without the older ECM in play? Might be worth a shot - I agree with you it isn't a blanket statement, but may not be too hard to test just by disconnecting the old ECM.
Is there something special about the VSS used in the newer TR6060s compared to the T56? They do use the same ECM between the LS3 and L99 gen 5 Camaros right? Maybe having no communication with the tranny is upsetting things. Please keep us posted - eventually I'll run into the same issues.
Is there something special about the VSS used in the newer TR6060s compared to the T56? They do use the same ECM between the LS3 and L99 gen 5 Camaros right? Maybe having no communication with the tranny is upsetting things. Please keep us posted - eventually I'll run into the same issues.
#76
Have you tried running the VSS as a dedicated into the E38 without the older ECM in play? Might be worth a shot - I agree with you it isn't a blanket statement, but may not be too hard to test just by disconnecting the old ECM.
Is there something special about the VSS used in the newer TR6060s compared to the T56? They do use the same ECM between the LS3 and L99 gen 5 Camaros right? Maybe having no communication with the tranny is upsetting things. Please keep us posted - eventually I'll run into the same issues.
Is there something special about the VSS used in the newer TR6060s compared to the T56? They do use the same ECM between the LS3 and L99 gen 5 Camaros right? Maybe having no communication with the tranny is upsetting things. Please keep us posted - eventually I'll run into the same issues.
#79
Well I'm eating Crow tonight, with a side of humble pie.. After doing a couple more OS tweaks, and grounding the P/N pin of the E38 PCM with no success, I pulled the VSS pins going to the Factory C4 ECM and the E38 started picking up a good VSS MPH signal. (Although I've split the VSS signal before, the C4 has the VSS feeding the ECM, the CCM, ABS, ASR, and FX3 shock controllers and hindsight is always 20/20)
So I'll have to dig back into the harnesses and schematic to play around with back feeding the C4 ECM (factory dash speedo) from the E38 PCM VSS output signal.
Note that I never had the 158mph reading in the E38 scanner as others did, my mph always read 0mph. I will try some other tests since I have to be in the harness again anyway, to try and get mine to read 158mph now that I know it works otherwise..
Finally, My tach now reads correctly too. I was following the post on HPT forums and missed the part about the poster putting his autometer in 4cyl mode and halving the RPM resolution (15/15) in the tune. Since my factory tach is in 8cyl mode, I doubled the resolution (7/7) and it now reads within 5% of what the Scanner tells me..
So I'll have to dig back into the harnesses and schematic to play around with back feeding the C4 ECM (factory dash speedo) from the E38 PCM VSS output signal.
Note that I never had the 158mph reading in the E38 scanner as others did, my mph always read 0mph. I will try some other tests since I have to be in the harness again anyway, to try and get mine to read 158mph now that I know it works otherwise..
Finally, My tach now reads correctly too. I was following the post on HPT forums and missed the part about the poster putting his autometer in 4cyl mode and halving the RPM resolution (15/15) in the tune. Since my factory tach is in 8cyl mode, I doubled the resolution (7/7) and it now reads within 5% of what the Scanner tells me..