I did verify timing with the head off, marked balancer, etc. Then put an offset in megasquirt. It took 15 degrees to make everything agree.

I rechecked it recently. Loosened rockers, piston stop from both directions, then ran timing light. Dead on. Just did it in case I made a mistake somewhere the first time.

I didn't degree the cam. Just dot-dot and bolted down. Never actually degreed one before.

 

Interesting situation for sure!
Are you running an intercooler and is it restricting boost/flow?
Are you measuring boost at the Turbo or Intake manifold?

Since you’re only seeing 10% converter slip and it seems to take to long to hit shift points shows it doesn’t seem to be blowing through the converter. I notice you’re foot braking 3000-3100 on the launch, are you able to hold it higher and are you seeing boost?
I truly feel you’re not getting the boost to the engine but more investigation is needed. JD

 

There is a member here that struggled to make power with an Ls, and I believe the timing set running dot to dot was retarded enough to make it run like garbage. It was a Jared 12/12/12 cam, and they even tried another cam before realizing it was the timing set. It's a long shot, but don't rule it out. Another thing you may want to check is lifter preload.

 

Brakes won't hold any higher. Agree on not blowing through converter. With the lower gears (3.9) i saw maybe 0.5-1psi at launch. Going to work on this.

I'm more concerned with the soft shifts that take waaay to long.

Typical Chinese cheap intercooler with 3" inlet/outlet. I'm measuring boost off map sensor. Not sure what the pressure drop is across intercooler.

No argument from me, its pretty open up front so I bet I could have the front of the motor disassembled in an hour or two and check it.

I'm half tempted to bolt in another stock 4.8 and try it. $300 could rule out what's going on pretty quick.

The trans is out, on a stand and stripped most of the way down. A fresh layer of friction material in the pan isn't promising. Curious what I find when I pull the pump and clutches out.

 

You don't even need to pull the front to check it. A dial indicator on the intake push rod, a degree wheel affixed to the front of the crank, and a piston stop.

 

Then no excuses, once I get through this th400 I will do that. I can borrow a 0-1 indicator from work so the only cost will be a degree wheel.

 

I can't find my piston stop so I ordered another one and a degree wheel. Really curious to see what the results are.

I found a thread from 2014 about a 6.0 that was down on power but couldn't find the conclusion. It was something like 430rwhp at 17lbs.

Also, I tore down th400 and it was not a fresh stock rebuild as indicated. Completely worn and all clutches except forward drum were smoked. I ordered a rebuild kit, direct drum with sprag, and a new converter just for fun.

 

https://ls1tech.com/forums/forced-induction/1755681-cam-timing-experts-come-inside.html

This was the thread I found.

 

Forcefed86 is the user here who I was referring to.

Denmah is matt from sloppy.

 

They are both in that thread. I didnt know who you were referring to before.

I was just looking for examples, and reading about cam degreeing.

 

Sorry, I didn't read the other thread, and didn't realize they were both posting there. I don't go there much.

 

Your compression test numbers look like the cam timing could very well be an issue.

 

I'm anxious to figure this out. Waiting on degree wheel but I will update as soon as I know something!

 

I can tell you that I was overly cautious with meth and it killed a ton of power. I took some advice from a guy who told me not to bring it in until around 10-12 psi and my car came alive. W/M can be tricky and even distribution is a huge factor. If your serious about not intercooling, I'd be looking at doing direct port.

 

I have an intercooler, and don't really have any issue with turning off the w/m system or activating it at a higher boost level. I'll certainly experiment with it once the car is back together.

 

Ok, so minor update.

I checked and all pushrods are straight.

Also, found the card and degreed cam. Tdc with piston stop, then checked angle at intake .050" open. It appears cam is 2.5 degrees retarded.

So my question is this enough to make a big difference?

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Howdy. Pete from Hughes here. Happy to help with the converter side of things if needed. Did you originally purchase our GM30B torque converter?

 

Hi Pete. I bought the converter I have a long time ago. I'm going to have to look to verify exactly what it is.

I appreciate the offer for help. I have a 4000 stall Freak Show on the way, hoping it improves things for me. Will reach out depending on the results

 

No worries. We can easily adjust your current Hughes converter if needed. Easy deal. Our lower cost shelf-stock 3,000 RPM model for GM 30-spline applications is not ideal for turbo use, but we can change the stator and adjust the impeller fin angle in that converter to make it work extremely well with a combo like yours.

 

Short update: car is still slow but slightly faster

Long update:

Trans rebuild with all new frictions, direct drum, sprag, etc. and 4000 stall Freak Show converter. I ended up taking it apart again to fix an intermediate clutch snap ring issue but all is now good.

Cam was advanced to +4 degrees because why not.

The two runs in the video were both my shakedown runs at low boost (4 and 8#) and I was ready to turn up the controller when the starter let the magic smoke out. Got it towed home and all is well.

I was able to take >.5s off my 60ft and beat my previous best time on half the boost. I'm anxious to try a bunch of things and hope to make it back to Milan before the season ends. t

Car is infinitely better than when I started this year. Thanks to all who have replied!

1st run:

1.96 60ft
8.57 1/8th
83.0 1/8th
13.30 1/4
103.3 1/4

2nd run:

1.85 60ft
8.13 1/8th
84.6 1/8th
12.79 1/4
105.2 1/4