Twin Turbo C5Z
#22
Drifting
Why are you dropping compression anyway? Not sure, do you want it to run safer on straight pump gas or what? If you were running meth or e85 I would just leave the stockers bolted up.
#23
Burning Brakes
Thread Starter
Just to have a bit of wiggle room. I've had meth nozzles come apart on me in the past so not much faith there. When I get around to doing the fuel system the way I want i'll switch to E85. For now a drop in compression is a cheap easy way for me to provide a margin of safety to the stock bottom end, and for the occassional turn of the ****.
#27
Burning Brakes
Thread Starter
A tube runs to the bottom and then the can is packed with SS Scotchbrite pads. Also I think I may have found the cause for the issue I'm having. Pretty sure bank 1 has an exhaust leak at the t3 flange. I've stopped tuning until I can get a chance to address that.
Last edited by jimbos'ss; 10-21-2014 at 12:41 PM.
#28
Burning Brakes
I didn't used inner tubes, just packed with copper scotch pads between inlet/outlet bungs. Mounted horizontally though to force air across stock pads. I get almost zero oil at all in there. 98% is water.
#30
Burning Brakes
Thread Starter
I got the new air bridge installed thanks to Jon. Next up is some exhaust leaks near the O2 sensors that are really throwing things off. Waiting on a set of V bands to come in. Also going to tear it back down and have each flange machined flat. At the same time I'll be wrapping and shielding everything to keep the heat down. A bunch more pics to follow in two weeks. Time for refinement and cleanup.
#32
Burning Brakes
Thread Starter
Added the vband flanges. Resurfaced all the flanges and added copper gaskets. Wrapped manifolds downpipes and the first section of the Hpipe so the narrow bands function properly. Also used the DEI heatwrap sealant. I'm hoping it doesn't burn off.
#33
Burning Brakes
Thread Starter
Exhaust wrap sealant turned into a hard candy shell when it cured. Pretty happy about that. Finally got around to cleaning the engine bay and waxing the car.
#36
Drifting
I know you said those were e covers, but do you know the turbo wheel sizes, turbine size or have a link to them? I'm just curious to what you to and how the response turns out for you. Great job getting it up and running so fast. What springs did you use in the heads? I know some people have made good power with the stock cats, but you have a lot to gain without them. Running as rich as a boosted car will/should they probably won't last all that long unless you really take it easy on it.
Last edited by slow ride; 11-12-2014 at 08:39 AM.
#37
Burning Brakes
Thread Starter
I know you said those were e covers, but do you know the turbo wheel sizes, turbine size or have a link to them? I'm just curious to what you to and how the response turns out for you. Great job getting it up and running so fast. What springs did you use in the heads? I know some people have made good power with the stock cats, but you have a lot to gain without them. Running as rich as a boosted car will/should they probably won't last all that long unless you really take it easy on it.
I believe the turbos are 58/60. I can look up the specs later. I still haven't installed the 317 heads yet, kind of on the fence. If I do i've been hearing good things about Brian Tooley springs. As far as the cats, you are absolutely correct, I'm just waiting for some money to purchase a good set of spun metallic cats.
#38
Drifting
I suppose if you HAVE to have the cats Seems like they all melt at some point, but those cars are probably at extreme levels or more than you want to push it. Turbo cars tend to really pick up without the cats.
Hard to say on the heads. You have 243's now with basically the same port style/cc runner, titanium intake valve and a slightly smaller more efficient chamber. At some point soon you will need the valve springs for either head anyway. I would use either Tooley spring package. The steel retainer ones are almost as light as some others titanium retainers at a better price (I run the titanium version).
I like compression, but a stock ls6 being around 10.5 is a little high if you want to start leaning on it with straight pump gas. The 317's will get you down to 9.7 or so and if it were me I would install SS valves, a little bowl work/cleanup on the 317's, check the guides out and install the springs all at once. I enjoy porting things so our idea of fun might differ
Hard to say on the heads. You have 243's now with basically the same port style/cc runner, titanium intake valve and a slightly smaller more efficient chamber. At some point soon you will need the valve springs for either head anyway. I would use either Tooley spring package. The steel retainer ones are almost as light as some others titanium retainers at a better price (I run the titanium version).
I like compression, but a stock ls6 being around 10.5 is a little high if you want to start leaning on it with straight pump gas. The 317's will get you down to 9.7 or so and if it were me I would install SS valves, a little bowl work/cleanup on the 317's, check the guides out and install the springs all at once. I enjoy porting things so our idea of fun might differ
#39
Burning Brakes
Thread Starter
I suppose if you HAVE to have the cats Seems like they all melt at some point, but those cars are probably at extreme levels or more than you want to push it. Turbo cars tend to really pick up without the cats.
Hard to say on the heads. You have 243's now with basically the same port style/cc runner, titanium intake valve and a slightly smaller more efficient chamber. At some point soon you will need the valve springs for either head anyway. I would use either Tooley spring package. The steel retainer ones are almost as light as some others titanium retainers at a better price (I run the titanium version).
I like compression, but a stock ls6 being around 10.5 is a little high if you want to start leaning on it with straight pump gas. The 317's will get you down to 9.7 or so and if it were me I would install SS valves, a little bowl work/cleanup on the 317's, check the guides out and install the springs all at once. I enjoy porting things so our idea of fun might differ
Hard to say on the heads. You have 243's now with basically the same port style/cc runner, titanium intake valve and a slightly smaller more efficient chamber. At some point soon you will need the valve springs for either head anyway. I would use either Tooley spring package. The steel retainer ones are almost as light as some others titanium retainers at a better price (I run the titanium version).
I like compression, but a stock ls6 being around 10.5 is a little high if you want to start leaning on it with straight pump gas. The 317's will get you down to 9.7 or so and if it were me I would install SS valves, a little bowl work/cleanup on the 317's, check the guides out and install the springs all at once. I enjoy porting things so our idea of fun might differ
I will probably eventually install the 317's just for a measure of safety, this motor is really low miles and would like to keep it alive as long as possible. If I can find a nicely priced forged 347 I might pull it and sell it complete though. I actually looked at the steel retainer package since I'm not planning to rev it higher than stock. I agree the valve springs need to go before I break one.
I'll probably just clean up the heads and run them like they are. I don't know enough about porting IMO. I'd likely ruin them.
Really just happy the car is running well now, and hoping to enjoy it for a little bit and work on the small things like the custom radiator shroud i'm making. I appreciate your input, if it weren't for yours and JDS99's build threads and info, I would probably have supercharged the car for simplicity sake.
#40
Burning Brakes
Thread Starter
Finally got around to doing a couple of pulls on the highway. I'm still about .05 lambda to rich in most areas. The maf maxes very early in the pulls so it's time to switch to SD or lower the boost. Blowing oil out the seal on the turbos. Pretty sure the crank case isn't nearly ventilated enough and it's pressurizing the center cartridge of the turbos. Other than that, she's a beast and i'm starting to have some fun with her again.