Ben26

Ok no problem. Feel free to PM me details.

Fuel system price drop - $200 Blitz front pipe - $50

Nistune sold. Price drop on fuel system to $300.

R32 gtr standard fuel pump, rail and injectors all working and in good condition. Just pulled off my gtr making 410rwhp with these items. $400 for all 3. Nistune chip on standard ecu, was running with standard fuel system, -5s etc making 410rwhp. $250 Blitz front pipe, damaged. Still works fine but as you can see in the pictures there is a fairly large indent. $100

haha agreed Dose Pipe!

Ok yea, Im not sure on the entry and exit effects so I don't know how that would impact flow in a manifold. Yep that makes sense what you are saying, thanks for explaining!

I am considering the whole system. I understand what you are saying and I do not think that in the circumstance of an exhaust manifold, halving the length would double the flow rate, because the other variables in the equation of fluid flow are also changing. My point was that length does have an impact on fluid flow, and that if all else stays that same, there is an inverse relationship. Yep I have done a little CFD and understand what you are saying!

Hey gtsboy. Im not talking about resistance, only what the hagen-poiseuille equation says regarding flow rate and length of a pipe. Of course I was assuming all else is remaing constant, as I previously mentioned, so if there are other variables in the formula changing than that would affect the relationship between flow rate and length of the pipe. Hmm thats an interesting example but something that to me cant be quantified without measurement in my mind. Awesome that we can have this discussion!

If the pressure differential was 0, wouldn't that also mean the flow rate is 0? That's what that equation says. I'm happy to be wrong and learn something new, but going by that equation and researching pipe flow vs length, thats what im reading!

I disagree mate, if you rearrange for Q . Ie they are inversely proportional if all else stays the same. Maybe I'm missing something but I just typed pipe length vs flow rate into google and this was the answer as well "Flow rate varies inversely to length, so if you double the length of the pipe while keeping the diameter constant, you'll get roughly half as much water through it per unit of time at constant pressure and temperature."

This is the hagen-poiseuille equation. Am I interpreting wrong?

I don't think there would be a benefit from lower flow rate, although im not sure. However lengthening the runners may have a benefit via timing exhaust pulses and scavenging? That is the trouble most of the time right, we try different modifications but dont always have the time or money to do direct back to back comparisons! It doesn't work comparing different cars with different setup, because there are far to many variables. Ah well, hopefully one day someone will on here and post the results for all to see!

Yep, understood and agreed with both of you, diameter of the runners has more influence on the pipe velocity, however flow rate varies dramatically with length of the pipe. Half the length of a pipe and expect double the flow rate. All very interesting, now who has the budget and time to test all of this with different length runners and pipe diameters on the same turbo setup and see what happens!

Well the velocity of gas coming out of the manifold drives the turbine right, so you would think different velocities of air would have a different effect on the turbine in my mind? Yea im not going to pretend that some modifications I make are for aesthetics or sound haha. Most are functional but hey the whole experience is not just about perfection otherwise we wouldn't own skylines!