?'s about Cam surge
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?'s about Cam surge I have a 357 LT1 with a 236/244 608/609 110 lsa cam and TFS 195 heads. Mo-Hp has done alot of work on my mail order tune and couldnt be happier with the C.S. my question is with a cam this big in a street car (not d/d tho) is cam surge able to be tuned out completly? Its alot better than it was but still has some surge crusing aroud 45-60 mph 2-2.5k rpms.After 60 mph its fine. I dont want to keep trying to fix something that isnt going to get better. When it does it it makes a clunking noise in the rear pinion/gears/driveshaft area. More annoying than anything. Its a auto with a 4.4k stall and 3.90 gears.
My two cents.
The bigger the cam, the harder it is to tune cam surge out assuming you want a closed loop tune. My tuner determined that the root cause for the surge in the problem areas, was a lean condition. The motor simply wants more fuel that the PCM will allow. Remember the PCM forces 14.7 A/F ratio in NON WOT conditions.
When my tuner ran a open loop tune (no O2 sensor feedback forcing corrections), the surge was gone. The engine was getting more fuel and was happier. I still choose to run an closed loop tune to get the best MPG's and and other benefits of maintaining 14.7 A/F ratio.
Might have to run an open loop tune.
The bigger the cam, the harder it is to tune cam surge out assuming you want a closed loop tune. My tuner determined that the root cause for the surge in the problem areas, was a lean condition. The motor simply wants more fuel that the PCM will allow. Remember the PCM forces 14.7 A/F ratio in NON WOT conditions.
When my tuner ran a open loop tune (no O2 sensor feedback forcing corrections), the surge was gone. The engine was getting more fuel and was happier. I still choose to run an closed loop tune to get the best MPG's and and other benefits of maintaining 14.7 A/F ratio.
Might have to run an open loop tune.
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Is unplugging the o2's the proper way to check this? Would/could it do any harm? I cant get my innovative wideband to work. It just flashes. To many wires. Its there a wideban meter that just hooks to a power source and plug in the o2 bung and ur done?
My AEM wideband plugs into the cig lighter and the O2 and works that easy.
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Thanks for ur input henry but i just spent $$$ for my dynaspark and at this point in sticking with the stock ecm and opti. I have very little time to mess with it. Just take it for a spin a few times a month and i hope to make it to the track a few times this winter.
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Not possible to completely tune out the surge. Surge is basically the camp loping under light load conditions, and with a cam that big on stockish cubes there's not much you can do.
