Blown Motor, Engine Rebuild/Replacement.

elperuano

Stock block 12psi 534/500. I've been skirting the danger limit for awhile now. I've been researching built projects because I'm sure it won't last long at this power and I drive the car pretty hard with tons of Street racing. Finally saved up enough money to start my project. Not popped yet but I'm not sure if im used to the power or car is losing power cuz it don't seem fast to me anymore.
Wanna push the stage 2 to the limit. Believe it said was rated for up to 700hp.

I'm very interested because I have the same system as Cosmo and I probably will use his builder as well.

Rusty

The Z feels not as fast because you got used to it's power. Now you need more power. You addict! Damn horsepower junkie. LOL

__________________

浪人 - 殺し屋
"The Difficult Anytime, The Impossible By Appointment Only"
http://www.the370z.com/members-370z-...o-journal.html

Nissan370

lol a dude named cosmogirl

__________________
370z vsr motorsports single turbo/built motor 9.1cr 525rwhp/450rwtq @ 10.5psi (stock maf maxed out)

COSMO

It's a sick world out there....

kpjc4eva

Anyone need turbos? I have two 6262's for sale.

COSMO

Hey thanks for the offer but you should put them in the For-Sale section...

phunk

As stated in my post, some cars experience the side effects, some do not. There has been no pattern found to determine which cars will. You didn't notice any side effects, and that is a happy story. Unfortunately, that has not been the case for many others. This is why I have found it prudent to take action and reconstruct a product that already sells and improve upon it for the better of my customers.

Experience of a single example doesn't tell the same story as the experience from hundreds of samples. Your undampened rails did the job, and that is a pretty frequent experience. That doesn't change the fact that there is a better option. It's not hype.. It's just better.

__________________

faceglide

Lean Spot At ~2400 RPM...What the? - MY350Z.COM Forums

Here is where Phunk says to the Nissan gods "I shall dampen thee".

No speculation, it is a feature that was found a long time ago to fix a problem that may randomly occur and if not addressed cause people to question his kit(AAM rails still have to live with this to this day). Yes, I pulled this thread up before dealing with CJM and found it was all I need to trust this man and his design for MY fuel needs. Instead of just dropping a product and blaming the customer for **** installs(you know who you are), he fixed the problem, make it available and handed it out.

Now, the real question. If these dampeners greatly improve low load driveablity, can eliminate lean spikes and hesitation, and provide another safety net. With ZERO performance, flow or other drawbacks. Why live without?

Let's just add to the fact that you do not need to spend $50k with CJM to get their attention...yeah I went there.

faceglide

And yes, I run them on my e85 build, and it is OEM daily driver smooth with the walbro 485.

phunk

Funny thing about that thread.. At that time it seemed like the problem was extremely rare. Eventually it was like people were coming out of the woodwork reporting that they always had that problem and just didn't know what it is.

STILL a pretty small percentage of people that spoke up... I am going to estimate maybe 5%. But that's just who spoke up to me. Who knows how many cars out there have owners who never found the thread. The last thing that would come to your mind when you experience it is a problem with your rails. I lived with it for a couple years in my 350 and it never even occurred to me. I was positive that my FCON was having an intermittent issue with the crank trigger or something. Too many years I had just disregarded the purpose of the FPDs that every single automotive manufacture puts in their cars.

__________________

1slow370

all i'm saying is it's common knowledge in the rest of the fuel injected community that dampers are not necessary in a good fuel system. only utilizing hard line for return flow so that supply pulsations are dampened in the line, bigger rails (rail pulsations are worse when a huge injector is put in a small rail, the standard rail size for aftermarket rails on the z is so small ~.4, compared to the .5 and up most other aftermarket rails are), and utilizing a quality fpr with, a line for each rail, capable of flowing the supply volume to the engine in return flow, is a sure fire way to get consistent fuel delivery. When you start compromising line sizes and routings, using a regulator too small for your pump and supply line, or using too small of a rail diameter, you start getting these issues. I very rarely see race cars with FPD's because rail resonance is greatly effected by rail size, and size/type of supply line and regulator, and most race setups involve -8 or -10 supply and returns, with 5/8 rails, and large high flow regulators. often a small tweak (5-10psi)to base pressure at the regulator can cure it too because the pressure effects the way the fuel moves in the rail.

__________________
ANSWER PRICE LIST
Answers - - - - - - - - - - - - - - - - $0.75
Answers (requiring thought) - - - - $1.25
Answers (correct) - - - - - - - - - - $12.50

phunk

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.

__________________

1slow370

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.

__________________
ANSWER PRICE LIST
Answers - - - - - - - - - - - - - - - - $0.75
Answers (requiring thought) - - - - $1.25
Answers (correct) - - - - - - - - - - $12.50

phunk

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.

__________________

COSMO

Great here we go again...