General Supercharger Thread

- Hot idle like poop, the banks afr would oscillate (seen below on the screenshot), you can hear the misfires.
- few times when cold start, the oscillation would get so bad that I would get misfire codes.
- it stalled a few times when coming to a stop.
- while cruising and I give it a bit more throttle, you can hear the misfire then suddenly it downshift and pick up and go.

It never behave like this until the 750cc/340lph/2.3" pulley went in, been spending last 2-3 months trying to solve this with various help, if you guys can help, please let me know but otherwise I feel like only other choice is try with the 650cc injectors.

 

How are the plugs looking, age? Air leaks, vacuum? Pcv valve? Dirty injectors, MAF and TB? Air filter? I know a few dealt with the oscillation but not misfire. Hmmm

 

Brand new IKH22 plugs, we ran smoke machine, no vacuum leak, pcv looked good, injectors were relatively new, TB was cleaned, new filter, new Denso O2, new MAF.

When driving, it's generally really good, only time it ever gave issue is when giving bit of a go you feel slight hestitation and hear couple misfire then it downshift and afr goes into the 12s.

 

Mine has the same AFR oscillation at idle since installing the ARH headers. I also noticed misfires idling and at low RPMs since going back to naturally aspirated, probably need to change the plugs and gap for NA until I get the blower back.

Harrop responded, they don't have the means to bench test the unit so they are going to ship it to SCOL for diagnostics and repair if needed...I guess I should have sent it there first.

Made more progress on the Interchiller installation, my liquid line fits perfectly, and I mounted the dryer and interchiller to the crash bar. I need to take the brackets off and paint them, then plumb everything up. Now I need to move my power steering cooler since it's effectively blocked by the interchiller.

 

Do you have the primary o2s mounted in one of the primaries or collectors? I've reached out to Keith, he said the O2 position is usually the cause of oscillation problem, this also seem to be confirm by Prospeed and Ekanoo.

 

Currently in the collector, I had them in the primaries when ProSpeed tuned it, they welded in bungs and put them there. I moved them to the collector when tuning and troubleshooting with @snivilous, but the reason escapes me, need to review emails. I can move them back and see if that changes anything, but might be a couple days.

 

Yea, unfortunately for me is I have to get them added...............

 

Off the primary (close to the head) was giving really weird AFR readings as I recall, off the collector was more consistent though had the oscillating issue. The oscillating seems very common on all header setups I've tuned, I suspect the feedback loop of the time delay from the exhaust leaving the combustion chamber and getting to the O2 sensor, and the computer calculating the fueling adjustment based on that time delay, gets messed up enough with headers that you end up with the AFR oscillating. In other words, the truck sees the AFR change, adjusts the fueling, but that information is based on out of date AFR data since the exhaust takes longer to reach the sensor, so now the whole fuel trim logic gets messed up since it's constantly delayed so keeps swinging back and forth.

The oscillating of the AFR also coincides with the short term fuel trims maxing back and forth as it tries to get it under control, but by the time the fuel trim has done its job the command to relax the fuel trim is now delayed so the truck is now over/under injecting fuel and keeps repeating. Increasing the idle speed I think helps this because the exhaust gas flow/speed is increased, so the time delay is diminished enough to not matter---that's why it only happens at low idle and normal driving is for the most part unaffected.

I don't know if there's a way to fix it with the (simple) tuning in HP Tuners. Moving the O2 sensor to the same distance as factory on one of the primaries I would think would fix it, but you're now basing all your fueling off of one cylinder which has its pros and cons. In Armyoffoo's case the O2 sensor was mounted barely off the head as I recall, so seemed to have weird behavior from the opposite effects of it being mounted so close to the head versus overly far away.

This is all speculation, I'm not an expert. Take it with a grain of salt.

 

I heard back from Whipple this morning: Coupler bushings failed.

The repair list says they will replace basically everything but the rotor assembly, which they will clean and reinstall in the new housing. Yikes. Luckily, they are taking care of me under warranty, so props to Whipple. Hopefully I can get it back up and running in a month. I'm going through withdrawals...

 

I believe 12-16 inches fron the head is ideal in the primary. Too close and the heat will really make the readings off. I was concerned at first by not having it in the collector but been running it in the primary with no issues for the past 13 years. The back pulse of clean air can throw the o2 readings off a bit.

 

WAT VB is in. Initial impressions is that there is nothing “extreme” about it other than being extremely livable. I’m all for that if they’re telling me it will hold the power all the same. Overall, it provides quicker and slightly firmer shifts throughout, with less of a lazy feel. I don’t see the point in going to a Nomad after my limited time behind the wheel with the extreme though. I didn’t rip it WOT through the gears yet, but 75% throttle or so felt good. The best feeling is the peace of mind knowing I made a change to help the transmission longevity…hopefully.

 

I'm hoping too! I'm glad it's in and "done!"

 

How long and how bad is a job did you feel it was?

 

I’d love to tell you but I did not do it at home, my trusted mechanic did it. Sadly no free time right now, coupled with fear of F’ing it up before my first camping trip of the season. Once that concrete is poured in that garage though this type of job is definitely in my future purview going forward. I’ll never be the take my trans apart in the driveway kind of guy, I require plenty of space and a nice clean work environment to feel confident in the work if I’m unfamiliar.

 

Does grass covered gravel count as a driveway ? @bflooks A good 3 hours should suffice. I did mine in about 2 but I've taken a few out/install.

 

Nice! What fluid did you end up going with? I feel like the hard shifting etc is so old school hot rod days. Much rather have it this way and know it’s holding etc

 

I stuck with the Toyota WS fluid since it hasn’t done me wrong yet. My Toyota mechanic would probably think me a fool if I put anything else in also lol, even though I know other fluids work just fine.

I just had a nightmare image of dropping small ATF covered VB springs in gravel as tiny pieces of dirt and stones stick to them, and to my ATF covered hands and forearms. Just shoot me.