Twin-charged Bonneville Update
#11
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In the old club, he possessed a little less knowledge than the senior administrator, or was able to play off to that requirement. LOL. This Senior Admins likes to surround himself with the best people available ( and it doesnt take alot of 3800 knowledge to know more than I) and gives members all the support they deserve for being here. I am totally amazed and impressed with what your doing Jeff. It would be my pleasure to bring you aboard Staff and help as you feel you can. No requirements or time constraints. We all have real life to attend to. I usually put this up for discussion in our Gearhead Section first, but your work and ability makes me want to fast track you into our organization.
#14
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Well, I fixed the issue, the knock sensor was way too sensitive and was pulling way to much timing way too fast. It pulled 12 deg out at 5500 which cost it 75hp! I "desensitized" it and lowered the max retard from 15deg to 8deg max. The next run out it only pulled .5deg to a max 1.3deg retard. I also think it was getting some false knock from the headers. Well strictly from a seat of the pants, the wall at 5500 is gone and it pulls hard all the way to the MSD-induced 6250rpm rev limit! I can;t wai to get it back on the dyno. One day next week. I'll post a new dyno graph as soon as I get it. C'mon 4xx HP!!!!
#16
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the whine of the */c is sweetly complemented by the whistle of the turbo! I'll see what I can do, I'm not good with video, I don;t really have any way to record and upload it exc. a digi camera that has a little vid capability.
#17
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Another run or two proved my fix, but another issue came to light. The turbo is boost-spiking at 5500 due to the restriction in the intake tract or possibly the blower itself. I have a N* tb I have been wanting to put on that might help. Better boost control of the turbo might help, too. The mass air values actually showed negative from 5500-6100, which means the air is reverting in the sensor (blowing OUT instead of in!) I might also try opening the */c bypass valve at 5500 and see if that'* helps level it out.
Still, same exact hp curve, just with no dip at 5500. And the curve looks like it'll end up about 385-390 if I can sort out this reversion.
Still, same exact hp curve, just with no dip at 5500. And the curve looks like it'll end up about 385-390 if I can sort out this reversion.
#18
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Can you scan the car while doing this? Any chance of posting a scan? You want the largest throttle body you can get on there, and the largest MAF. What size pulley you running on the supercharger? Might help if you increase the SC speed to off set any boost stack your getting from the turbo.
#19
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Ya, I scanned it w a tech2. That'* how I could see the MAF g/* values go negative at 5500. I have a 3.8" pulley on there right now. It made about 5psi without the turbo (empty turbine hsg with blockoff plate so it is an accurate idea since all the existing exh was hooked up), which is a 1.34 pressure ratio. I also have a 3.6 and a 3.4 pulley. I have a one-off DUB 8-rib setup he made to my order. With the 3.4 on it, it makes outrageous tq and spools like crazy, but the combined boost is a little high for pump gas. I will try the 3.6 to see if it gets rid of the current boost stack problem. Or just put the N* tb on it if I still have the same issue.
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What was the MAF reading when it tanked? What is the MAF rated at? If, for example, you have a MAF rated at 10,500 and you go over that the PCM will half the injectors causing you to go lean.