Tried ls1tech for some ideas... just curious what you guys over here think.

theres a couple dyno graphs posed through the thread....

https://ls1tech.com/forums/dynamomet...raph-like.html

thanks,

Blaine

 

i would try a lower boost, say 8psi and see how it does.

 

I am running 14* timming and 9psi for DD and it does the same thing.... should have a tranny soon to see if thats it....

Not spark, boost leak, exhaust restriction, tune, valve float, turbo, fuel

So it has to be the tranny, the cam wasn't installed dot-to-dot (i even double checked that befor i put the timing cover back on),

its enough to drive a person crazy....! lol

I might try mobile 1 synthetic just for *****-and-giggles

 

seems like those 317's would drop you compression a little too low. No?

 

My first guess would have been valve float like many others mentioned. I have seen that same condition at work though due to a slipping 4L60E. The tune show's you locking the converter at 87MPH. That could create a problem with a 60E. If you make a pull with the converter locked you want to lock it early so that when you go wide open it is already locked and doesn't unlock. Does it feel like the dyno show's on the street? Curious, why a TR8 with such low cylinder pressure?

 

Valve float would be my guess. How are your springs set up?

5.3L with 317 heads?? Really?? The combustion chamber has to be hanging over the cylinder bore pretty badly!

 

It does feel on the street like it shows on the dyno... pulls really hard to 5500 then almost stops pulling hard lol

I switched to autolite 103's (same as tr6's) and it didn't help...

 

I have TSP dual valve springs with titanium retainers good to .660 lift... they should be more than enough, they have less than 8000 miles on them also.....

There are other guys pushing over 600 with 317's...

 

The 317's aren't the problem. They are part of the reason you didn't make more power since 8.5:1 compression is great if you're going for 30psi, but at less than 20psi you'd have made more power with the stock heads and stock compression. Don't take that as an insulting comment, I admire your build. Going for big power for little money is a fun project. In your tune I see you took alot of fuel out at the higher rpm, do you have a chart of your AFR? I see that some of the boost begins to flutter during the rpm that this is happening. Is it possible that you have an intake leak? You could try to open the wastegate fully and pull the tube off of the throttle body to see if it does the same on an N/A pull. If it does that will narrow alot down. Make sure to post up as you're working on it though as I am curious as to what you're finding.

 

ya thats a good idea! Im gonna do a few logs of NA and see how they compare. I really should have done an NA run on the dyno!

I though about bumping the boost up quite a bit when at the dyno... but started with 14psi and had issues and seen no reason to push it any farther...

I know this setup has 600+ hp in it, I just have to get it figured out. Im getting the th400 in a week or 2, so ill know if that solves the problem.