Installed on Friday.

 

ok i wanna see some vids, 0-100, burnouts, you name it. I think i can say that for all of us following this thread

 

Haha. I'm still running on a base tune, I need to work on it a little bit. Hopefully after not too long I'll be shimming the WG spring to get some boost back, and then later turning the meth on to get some timing back. Took a quick video the other day in the rain. It was pushing up to about 5-6psi cause I couldn't load the turbo enough, but it was still pretty damn fun. Spools much quicker now, I'm definitely liking it. Got a little squirrely at the end there



In the next couple weeks or so, Joey (chevyboy520) and I should be getting his gopro and making some nice burnout videos. Strap on some beater tires and let 'em have it!

 

Little update...today was my first time getting on the highway with the smaller turbo, and with the higher load from wind resistance and whatnot I was actually able to see 9psi. 1st gear never climbs above 6psi cause it doesn't load it enough. I'm impressed the smaller exhaust housing, even still being a T6 is making enough back pressure to drop boost in 1st gear...
Ran some numbers, and if I add 1/4" of washers underneath the WG spring it should add a little over 2psi to max boost. So 11psi next weekend, turn the meth on with some more timing and should have some new videos

 

Made a log on the highway tonight just to check up on things. Zero KR, meth is working well, and its running strong. I caught the low boost issue in the log, though. Check out frames 968 and 7915. These are two spots that I actually go WOT, but don't hit full boost. Only makes it to maybe 7psi. If I roll into it I can see the full 11. Maybe the sudden surge in manifold pressure and back pressure shoves the WG fully open? I know shimming it with washers doesn't change the springrate, but I expected it to raise WOT boost a little more than 1psi lol. I'm a bit confused.

 

Those 2 spots look pretty normal to me....does your WG valve slide freely....take it down and push it with your fingers to see if it sticks or not...with that said I know you know wastegates can be easily modeled by spring-dampener systems and a simple second order differential equation, which makes the manifold pressure look like a decaying exponential, changing the spring just changes the steady state value, not really the time it takes to reach that value.

 

Yeah it slides freely, works smoothly. The steady state value is fine...I can still hit full boost, just not at WOT. I didn't change the spring, just added washers to it for some preload. In the ODE, that changes the x(t) value, but not the coefficient. Thats telling me that the pressure buildup on the wastegate is still forcing it fully open even though the spring has more preload. According to the ODE, it looks like I need to change the spring rate in order to get that steady state value everywhere, not just under low exhaust back pressure.

That WG is a pain in the *** to put back on!

Edit: After painfully looking at several log files, it seems that this turbo is already maxed out on the 6.0. I must have underestimated how much this heads/cam combo flows on the high end... I don't think adding a heavier spring to the WG is going to fix the boost drop. So that really blows...

 

interesting....so why did you put on a smaller one anyway?

 

Quicker spool. I bought that thing with oversized in mind cause of the twincharge stuff but maybe it wasn't that big afterall lol.

 

off idle


WOT on the highway, about a 60 roll


rolling into it on the highway, same 60mph roll. notice the much higher boost...

I'll update with videos once I do the compressor upgrade.