Progress Thread Grover: Window motor replacement & OEM rebuild

Here's a little dMap action. You can see that the computer is giving it 43%, and it pegs the meter rich at 9.2:1. I have since pulled about 10% from that cell in dmap enrichment. I probably need to pull more, but I should also take the dTPS into consideration as they are both adding to the problem.

dMap.webp


By the way, if you refer to our back and forth about the transient tables in your tuner thread, I posted a bunch of pictures showing each of the transient tables and I think there's one or two of the lean spikes I was experiencing that will be illuminating.
 
Woohoo! My hunch was right about the Viper spec T56 being a 6 tooth speedo drive gear. That means it's one of the early Viper specs. Anyways, I put a 17 tooth speedo gear in, adjusted the speedo needle like I think @Mustang5L5 had said to before, and bingo! I actually didn't get the needle perfect, but that worked out even better. With the current tires on the car, the 17 tooth should read 98.4 mph. The needle is still very slightly high by maybe at most 1 mph. So, it kind of offsets the difference and it seems to be spot on by 55.
 
Last edited:
Just dropping in for a boring update.

BLUF: new starter, powersteering pump, hood supports, & reconnected exhaust.

Details.
After blowing the clamped exhaust apart, I've reconnected it with the band clamps in place. Really need to eventually figure out a more permanent solution like V-band clamps. But this solution should work for the time being until I can get to a less busy lifestyle.

I also installed a new starter. Sometimes it just clicks now, but I just try again and it turns over fast. Hopefully, that click issue will go away as the solenoid breaks in (does it?). The old starter was turning over very slowly like it had a dying battery, even when the battery was just topped off.

I put in a new power steering pump that Joe provided when he sold the car (thanks, Joe). I planned to replace the lines, but holy cow those are hard to get to without dropping the steering rack. So, since it was just the old low-pressure hose that leaked, I just cut it a little shorter and reinstalled, this time with a spark plug heat shield clamped on it and I also ordered some Heatshield Products Armor Exhaust Heat Shield to wrap the driver's side pipe, which is touching the hose. Hopefully, that will keep it from cooking the hose again. It also got new Quicklift hood supports.

Took her out for a cruise with a buddy, and it reminded me that there's still some tuning work to do. For the most part it drives very nicely at idle, part throttle, and WOT. However, it still goes lean on tip-in sometimes, and I'd like to keep it from stumbling at any time, because that's just embarrassing when someone else is riding along.
 
Last edited:
So does it drive better now then?

I've only driven around the block, so far. It was on and off rain, yesterday. The replacement was due to readings that were jumping all over the place. I thought I had a static injector, but it just turned out to be a bad O2 sensor: see link. After swapping the O2 sensor the readings have returned to normal.

The car has always had some minor low rpm/high load stuttering that felt a bit like a miss, and I'm interested to see if there's a difference there. I'd assumed was in the tune or due to the cam. But really, the car never drove badly. I could only tell by watching the AFR output closely.

Chris
 
Well hopefully that addressed the issue with the bad O2 sensor.

You get that wet stuff that falls from the sky in Cali? Wow are you sure your not seeing things ...lol
 
180608.JPG

So, check this out. I think I modified these cells in the box once since this log. So, the numbers in the cells are not exactly what the computer used in this run, but it serves the purpose. It's the same run as before. As you can see, the boost spike goes through the 3500 column and when it gets levels off, the top cell is 98. The one to its right is 91. Even with the 98 at the top, you can see that where the spike apexes, it still goes slightly lean. Now, we're only talking about 12.2:1, and that exact lean spike occurs at the 100 cell in the table (it was 98 at the time of this log). I have to be careful where it initially goes too rich, because I must also consider that at higher boost levels, the spike will go through this cell on the way up, and I don't want it to lean out there. So, the 98 cell at (4000,13.6) is causing it to drop AFR deep into the low 10s. Way too rich. It does transition up close to the desired AFR when it gets into the 91 cells.

If I transition through these cells at flat boost, the Actual AFR is far richer than if I'm transitioning through with a vertical boost line. Transient should be what I'm using to compensate, but the MAP transient tables just aren't getting the job done. So, the only thing I know to do is compensate in the main table. It puts me in the position of either running too rich when the boost levels off, or running too lean when boost is still going up. I choose the safer option.
Note to self for future tuning. I want to revisit I/O times. It occurs to me that if the I/Os that I plugged in are too low, it might be causing the lean issue as RPM & voltage rise. Just a thought to revisit when I get back around to tuning.
 
Since I got her, the ol' girl has burned something like a quart of oil every 500 miles or less and I've finally gotten to the bottom of it. Borrowed a buddy's bore scope today, and found a big problem. Boo! But, I'm very fortunate to have found it before any major carnage.

I'll get a pic of it soon. Pulled the head.

Broken ringland! No melting. No other signs of detonation. Every other piston looks good. I've never lost a plug strap or had any other indication of detonation or a tuning issue. My best guess: I think that when it made 954rwhp, it just overcame the integrity of that piston at it thinnest point. Or, possibly there was a defect in the piston. Or maybe there was some detonation at some point that cause enough pressure to do it in. I've been driving/racing on it like this for over a year! Wow.

Not sure what I'm gonna do, yet. I may pull the motor and do the CP pistons I want with 8.5:1 compression, and do an ED C cam. Or I might just try and replace that specific piston and slap it all back together cheaper and quicker.

More to follow.
 
Last edited:
holy :poo:.

Those are diamond pistons, no idea wtf happened there...

kinda off topic but why do you want to drop the comp and or change the cam?


Pull the motor, install the firewall plate, maybe figure out the PS too?

I am super bummed
 
holy :poo:.

Those are diamond pistons, no idea wtf happened there...

kinda off topic but why do you want to drop the comp and or change the cam?


Pull the motor, install the firewall plate, maybe figure out the PS too?

I am super bummed
Well, the lower compression and cam would allow me to cruise at lot lower RPM for one. It opens the tuning window. Also, it allows more pump gas power, and I get the impression that E85 is dying.. Then again, I found all of the part numbers for the pistons, thanks to your copious record keeping, and a single piston is a lot easier. Will call Diamond today.

If so, you're more bummed than me. These things happen. I look at it as a blessing to catch it before it got worse.

The PS is addressed. I used the back up pump for a while and had a belt issue that took out the front seal on that pump. Bought a new LMR pump and wrapped the header in heat shield, and put a spark plug sleeve on the hose.. Now it works great and no leak.
 
Bummer, The cratering look usually means water leak or way to little octane, that's Detonation. Its interesting that it is also the intake side. Note the peppering on the top flat of the piston, this thing did get run lean for a bit to cause the sand blasting or peppering look also detonation. I would pull the valves too, if you got some debris between the seat and valve it will need a valve job. Also it can transfer debris during over lap so you may have some other valves that had will need to be touched up. How is the turbine wheel? Any nicks? Might be hard to tell on the exhaust side without a full tear down and cleaning. So there was detonation, no doubt.