ss.slp.ls1

iTrader: (36)

What was the spring rates of the new springs? I want to know how they compare to PRC duals or Patriot Extreme duals...

Bob@BruteSpeed

iTrader: (16)

We've seen quite a few cars fall on their nose with 50/50 as the water puts out the flame, you're lucky that you didn't have problems with it. Bob

Boo"SS"t

iTrader: (2)

I can't remember exactly, but I think it's 155lbs @ the seat and 428lbs@ .650lift. It's not really that high of a rate compared to other springs that I've seen around here, but I did'nt want the hassle of pulling the heads off to have the seat machined for a bigger diameter springs.

ss.slp.ls1

iTrader: (36)

The Patriot Extreme duals are rated at (per Patriots website):

Spring Pressure Closed: 155 lbs. @ 1.800"
Spring Pressure Open: 410 lbs. @ 1.140"
Coil Bind: 1.090"

MrDavid

iTrader: (11)

Pretty sure thats not an issue on my car as the meth kicks in @ 4lbs and no issues occur until it hits 11.5-12lbs.

Bob@BruteSpeed

iTrader: (16)

You might want to try 100% meth though before you swap out valvesprings just to rule it out. Bob

MrDavid

iTrader: (11)

I'm nearly 100% positive thats not causing the problem. If it were, the car would get extremely rich right after the meth kicks, which is probably around 3000rpms. All the symptoms point towards valve float.

I am now looking to invest in the Livernois Motorsports LS dual valve spring. Its rated at .690 lift and has 150lbs of closed seat pressure. If that doesn't solve it, i will try 100% meth just to humor you.

Sluggish

iTrader: (10)

I have the same issue with the same springs but with a bigger cam, dyno graph even looks the same

MrDavid

iTrader: (11)

To any of you who were still following this thread the problems have been resolved.

To start out, all the springs were changed to Livernois Super Duty springs (150lbs seat pressure). This didn't fix the problem though. Symptoms were still the same.

So I called Bob and we talked about it for a while and he convinced me to try a shorter belt and I also purchased a new idler pulley from him since mine was a little dinged up from the previous owner. I also went with 100% meth instead of the 50/50 mix.

Car got back on the rollers last Wednesday and put down an impressive 730hp 640tq. I was pretty happy with these results. It made 17lbs of boost.

Graph can be viewed from my tuners website here: Dyno Graph

Hopefully those of you who had an interest in this thread will remember these problems and be able to point someone else in the right direction if you see a problem like this arise again. Thanks.

tomz28

iTrader: (20)

im glad to see you fix it. that always makes my day to see something fix after so much work and BS. i know your pain
congrats buddy

ss.slp.ls1

iTrader: (36)

Wow, that's a lot of psi from a D1SC.

Bob@BruteSpeed

iTrader: (16)

Thanks for the call to update me, I appreciate it! Bob

MrDavid

iTrader: (11)

Yea, its a little more than I was hoping for. In the near future, i'm going to swap the LS6 intake for a LS2 and upgrade to a Nick Williams TB, change my exhaust to a setup with cutouts and also upgrade to a larger intercooler. Hopefully drop it to 14psi.

Aster

iTrader: (9)

What pulley combination are you using to get you 17 psi? It doesn't sound that far out of range on a forged 347.

MrDavid

iTrader: (11)

3.40" blower pulley, 7.53" ATI Super Damper