I agree that there are several contributing factors to having an issue there. I'll state that my fuel systems that include rails all use -8 plumbing up to a Y split to twin -6. The rails bores are smaller than I desire for adequate fitment in a type space. We aren't going to see -8 rails fitting under a stock intake manifold so while I won't argue that it could be an alternate fix, it's not an option for the typical VQ. (BTW I know of a 370 with custom manifold and -8 rails and it's suffering rail resonance hesitations). My kits on the DE all used -6 Aeromotive regulators which I find appropriately sized for the general walbro 255 that the majority of customers use. I personally tried different fuel pressures in my 350z to no remedy. Having to make new rails was the last thing I wanted to do as i had concerns of being overwhelmed with people asking for replacements.

I'd go out on a limb and say that I doubt most race cars have them because they don't spend much time at those RPM/load sites where it causes hesitation. It is my opinion that there are probably many people suffering of the resonance and completely unaware as they probably credit it to tuning or other issue.

Good post it did a lot to back up your arguments, I understand the point of dampeners and i don't disagree with you on them, just that not every car needs them to perform and drive well. Also since if they happen it is at a point when the engine usually isn't getting a lot of boost and so low in the range that to a lot of people even if they notice it, it really isn't even that big of a problem, to some it is, hell the factory traction control is WAY more annoying.

I wish I had a video to show you how bad my 350z would buck and hesitate if you tried to hold it at 2400 or 3100 rpm. Just standard cruising around town you pass these rpms all the time. It's annoyance was cumulative and you sort of learn to drive around it. But I'll tell ya, it was bad! 17s AF and jerking and bucking until you either push thru the RPM or backed off it by up shifting. The potential for this severity of problems is why we just said skip it and put the dampers back in. Tons of my customers never did have a noticeable problem though. In that thread linked you can see the guy who started to chase it and datalogging it noticed that while putting the setup back to stock dampening solved the drivability problems, but he could still see it in logging and he eventually added one more additional damper over stock.

Great here we go again...

I managed to get a little more prep ready for the engine to be pulled out tomorrow. Here are a few pics and yes that is metal chunks sitting on top of the valves..

What part broke, piston or rod?

Damn!

Sent with TapAhoe

Wellllllll... If need... I have a left side valve head assembly


Good luck, I hope you won't need it

Im sure it looks worse than it actually is, but that process looks like a nightmare lol.

The motor will be out tomorrow and I'll will know for sure but I'm guessing a rod. The valves are intact... :tup:

It's not that bad at all since I have done 4 Twin Turbo installs.. :tup::tup:

I'm curious to see if I find any Cracks on the exhaust manifolds... Stay Tuned!!

How long have you had your FI setup? Those valves are clean. I need to get catch cans for mine since I have this paranoia with oil blow by. I need to pull stuff apart to clean it once the weather gets warmer.

I have about 3-4k on the TT Kit..

As if I don't have enough things to do already look what came in today from Z1.. lol :tup::tup: