Finally...twin turbos for my LFX

[Tajefe Couple]

Sorry to hear that's not cool at all. Hopefully it's not as bad as it seems and is a simple fix as it can be. I'm also sure you'll be back at the track soon probably pulling 11's too.
Keep us posted and the best of luck my Camaro brother.

[MagnumForceGB]

Holy crap that sucks. I was out there last night but didn't see you, I did my runs early then was talking to Stephanie for a long time. How much boost were you running? Starting to wonder if I have a time bomb on mine now.

[JantzenOKC]

Originally Posted by MagnumForceGB

Holy crap that sucks. I was out there last night but didn't see you, I did my runs early then was talking to Stephanie for a long time. How much boost were you running? Starting to wonder if I have a time bomb on mine now.

I figured since I couldn't beat you to the 11s I'd at least beat you in the race to blow our motors up. At least I didn't oil the whole lane down like most people do when their motors blow. I'm surprised it let go though I really wasn't expecting it, especially since you beat on yours so hard and so many runs. But with me trapping 120mph with my horrible launch and 60ft I'm probably making a little more power than the pistons and rods can handle.

Its hard to tell what kind of boost I was running I'd say around 14-15psi.. I had my boost controller set to 55 duty cycle.. Obviosly too high. I was trying to turn it up to 11 like in Spinal Tap.

The bad part is that I was so worried about getting my car off the track and getting a tow that I forgot to get my timeslip for that third run. Just my luck would be if I ran an 11.9 and don't even know it. I ran a 12.1 the run before and then turned the boost up a little.

[MagnumForceGB]

Originally Posted by JantzenOKC

I figured since I couldn't beat you to the 11s I'd at least beat you in the race to blow our motors up. At least I didn't oil the whole lane down like most people do when their motors blow. I'm surprised it let go though I really wasn't expecting it, especially since you beat on yours so hard and so many runs. But with me trapping 120mph with my horrible launch and 60ft I'm probably making a little more power than the pistons and rods can handle.

Its hard to tell what kind of boost I was running I'd say around 14-15psi.. I had my boost controller set to 55 duty cycle.. Obviosly too high. I was trying to turn it up to 11 like in Spinal Tap.

The bad part is that I was so worried about getting my car off the track and getting a tow that I forgot to get my timeslip for that third run. Just my luck would be if I ran an 11.9 and don't even know it. I ran a 12.1 the run before and then turned the boost up a little.

Depends on when the engine really let go, if you had your datalogger running you could see exactly where. You will also have to see if it was too much power or you had pre-ignition, so spark plugs first.

Mine runs only 8 PSI at peak torque where the max cylinder pressure is, then goes to 13 at max RPM. If I remember correctly, Turbo's will hit max speed at the peak torque so it might have also spiked the PSI. Engine tear down will tell the story.

[JantzenOKC]

Got it up on the rack and the holes are in the oil pan not the block so maybe I'll get lucky and I can salvage the block and heads for a build up. Probably not though. I'll pull the plugs after while and see what they look like. It seems to be the front cylinder on the passenger side, which is the same cylinder that had the injector failure before, not sure if that has anything to do with it or if it's just a coincidence.

[JantzenOKC]

Definitely front cylinder on passenger side. Plug looks pretty good considering.... Looks like the piston slapped it and closed the gap. I can see the piston somewhat with my boroscope, pretty scared up but seems to be intact and not melted or anything. Its hard to tell but the valve reliefs look crooked like the piston twisted. I'm thinking the rod itself broke or the end cap came apart. I'm anxious to tear it down and investigate. Maybe if I get some free time tomorrow I can yank the motor.

Here's the plug as it came out and after cleaning the oil off it.

[JantzenOKC]

Hopefully nothing made it through the exhaust valve and hurt the turbo...

[MagnumForceGB]

Looks like you found the limit on the boost for the LFX. Just have to see exactly what piece failed. Wonder if the wrist pins or ring land went. The LNF guys said the ring land was the weak point on the piston for their engines, same exact construction as ours.

If you have the cash, might as well do some upgrades to the transmission as well, a 3,000 RPM stall and a trans oil cooler will help out. Trans will be out anyways if the engine gets pulled.

[JantzenOKC]

I've heard that about the ringlands too, I guess that's possible. I did have a lot of oil smoke out the exhaust when it went. I can actually see down into the bottom end through a gap between the cylinder wall and piston. Maybe the gap I'm seeing is the ringland gone. I don't know it's hard to tell with my crappy boroscope. It almost seems like the piston went down too far about out of the hole. It's pretty far down there. Just need to tear it down.


Carnage pics:

[Tajefe Couple]

Please correct me if I'm wrong but thought these motors where factory built to withstand about 500hp at the flywheel not at the rear wheels. Most of the twin turbos are closer to 600hp at the flywheel are they not? I ask because I've been kicking around the idea of twins and don't want to spend 7k to set on a time bomb. Gretchen bombed at around 750 at the flywheel and had a lot in to that motor. Thoughts anyone?
Once again sorry to hear about your bad luck.

[MagnumForceGB]

Might have also been runaway detonation, usually when the boost goes up timing has to be reduced and you might have been right at the limit on the lower boost. The spark plug look is hard to tell since there was oil all over it, but the insulator is a lot darker than what mine is.

Water/Methanol injection is probably what is keeping my engine alive, it helps so much cooling the chamber. I want to say that anything over 12 PSI on stock internals will require WMI for longevity.

Going to look at replacing it with a 454 LSX with twin turbo's?

[smithnc]

What WMI kit do you have? Seriously considering adding this to my build.

[MagnumForceGB]

Snow Performance stage 2. I want to get the new VC-50 controller since it's also a boost gauge. Also want the AIS trunk tank since it looks cool and factory.

[JantzenOKC]

Originally Posted by tajefe

Please correct me if I'm wrong but thought these motors where factory built to withstand about 500hp at the flywheel not at the rear wheels. Most of the twin turbos are closer to 600hp at the flywheel are they not? I ask because I've been kicking around the idea of twins and don't want to spend 7k to set on a time bomb. Gretchen bombed at around 750 at the flywheel and had a lot in to that motor. Thoughts anyone?
Once again sorry to hear about your bad luck.

Idk what the engine was built to withstand but we already knew the rods and pistons were iffy at this power level. This wasn't a surprise to me as ive been pushing it a little harder than I should have without forging. I wasn't really planning on crossing this bridge yet but oh well. Don't let this stop you from buying the turbos though, you can always just skip the boost controller and run 7psi on the wastegates it's still lots of fun, not a night and day difference between 7psi and 12psi. Not like I thought it would be anyway.