Originally Posted by nitrodann
(Post 1213423)
Thats correct.
Ive never seen overshoot on an MX5 with a T2x turbo or EFR using competent boost control, and CERTAINLY not with only the wastegate can for boost control. Dann
Originally Posted by Savington
(Post 1213420)
Someone should probably explain the difference between boost overshoot and boost creep. I'm pretty sure Dann is referring to creep (boost rises with RPM regardless of wastegate spring pressure), while everyone else is referring to overshoot (boost rises rapidly past the wastegate spring pressure which creates torque spikes that can damage stock engines).
let me google that for you Dann http://lmgtfy.com/?q=what+is+boost+creep |
also see my buddy's fastivab25mr (or whatever his sn is) 300whp BP with stock rods that ejected them with ewg and only a can for boost control.
haven't seen much? tune more BP's PS: my buddy's rods all ejected PAST peak torque. that should blow your mind |
Reread what sav wrote, retard.
You failed at being a smartass. |
Originally Posted by 18psi
(Post 1213431)
see keiths build thread because I sure as heck am not about to post dozens of links to prove what we've all already known since 1995
e: This thread is basically a clusterfuck of nomenclature. Boost creep (boost rises with RPM, max boost at/near max power) doesn't put any additional stress on rods if it doesn't move the torque peak up. Uncontrolled creep is still not desirable because you can outrun the fuel injectors and it generally means the wastegate setup is pretty piss-poor. Boost overshoot (boost immediately rises beyond the desired level, max boost at/near max torque) is seriously undesirable in all cases and, by definition, is never induced on purpose. Most of you are talking about overshoot, but saying "creep". Dann is talking about creep as I've defined it. Can we get back to talking about how kludgy exhaust restrictors are now? |
Originally Posted by nitrodann
(Post 1213351)
What is the point and why.
Seriously, spell the point out and justify it. |
Originally Posted by nitrodann
(Post 1213458)
Reread what sav wrote, retard.
You failed at being a smartass. Are you back to neg propping every single one of my posts again? Is it that time of the month for you again?
Originally Posted by Savington
(Post 1213460)
You should probably post a link, because from where I'm sitting you sound like someone who doesn't actually understand the topic you're attempting to talk about.
:bowrofl: |
fuck all your strawman semantics arguments. That includes you vlad.
this is what we are discussing:
Originally Posted by nitrodann
Seriously, why do we give a fuck if we get 5psi of creep past peak torque?
If its past peak torque then its not putting any more stress on any components than peak torque already did. Which is why its called -peak- torque. Nitro's theory is that peak torque on a dyno plot is the peak load of an engine's conponents, so he tunes his cars to increase boost after peak torque to keep the torque output flat to redline. talk about that. |
But bro, he's tuned so many cars.
..and set so many records:laugh: |
Originally Posted by Braineack
(Post 1213503)
talk about that.
will not fit into brain because literally nothing past peak load matters. nothing bro. nothing. no stress on the components, just run ALLOFIT on an upsidedown dyno and your stock rods are fine |
Originally Posted by Braineack
(Post 1213503)
Nitro's theory is that peak torque on a dyno plot is the peak load of an engine's conponents, so he tunes his cars to increase boost after peak torque to keep the torque output flat to redline.
talk about that. |
in regards to tensile or total inertial loads, yes. total compression or power loads, no.
if you're inducing "creep" to maintain peak torque to redline, you're putting more load/stress on the rods the greater the rpm. |
More tensile load/stress, yes, but not more than a stock motor can handle (unless you rev it past 7k, which nobody has suggested). The compression load is what the stock rods care about, and the peak compression load happens at peak torque.
IOW, if the motor copes with 230wtq at 4000rpm, is 210wtq at 7000rpm going to break it? I think not. |
i dunno, i suppose. way to ruin it.
|
Originally Posted by 18psi
(Post 1213499)
Are you back to being a complete and utter child and lashing out again?
Are you back to neg propping every single one of my posts again? Is it that time of the month for you again? Dann |
Originally Posted by Braineack
(Post 1213650)
i dunno, i suppose. way to ruin it.
|
My dad did always tell me: "never let the truth ruin a good story"
|
Nitro, Hang in there.
Vbad, ??//?????///??? 2D: You need V clamp? I Make V clamp. A/O can do both. Loads: Get a plot of chamber pressure vs crank angle. Multiply piston area times chamber pressure at every degree and plot. At each degree of crank angle, calc the inertial loads. Plot. Add the two loads together for every degree for a total load. Calc column buckling strength of the con rod. Take worst case compressive sum and adjust boost (reflecting pressure load) and rpm (inertial load) to stay below the column buckling load. It appears nitro has figured this out, its just hard to get past the accent. Subject for the next thread: In what month of the year do the Aussies drink the least amount of Tequila? corky |
Originally Posted by Savington
(Post 1213638)
More tensile load/stress, yes, but not more than a stock motor can handle (unless you rev it past 7k, which nobody has suggested). The compression load is what the stock rods care about, and the peak compression load happens at peak torque.
IOW, if the motor copes with 230wtq at 4000rpm, is 210wtq at 7000rpm going to break it? I think not. In terms of compressive loads, 230wtq at 4000 vs 230wtq at 7000 is always going to be harder on the rods, because they have to endure that compressive load for nearly twice the amount of time. |
Originally Posted by Mobius
(Post 1213745)
Andrew r smart and understand physics.
In terms of compressive loads, 230wtq at 4000 vs 230wtq at 7000 is always going to be harder on the rods, because they have to endure that compressive load for nearly twice the amount of time. |
Originally Posted by Savington
(Post 1213671)
I like you because you never let the truth get in the way of a good internet pissing match :giggle:
:brain: I haven't really read up on loads in a quite a while--it's probably been over 10 years. I was thinking that if you added boost to redline and since tensile load is a function of rpm^2 that the loads would significantly increase as you reach redline, compared to if you held it steady. But that was wrong because that extra boost doesn't really factor into those loads and any increase in boost is really just making up for the loss of combustion pressure due to the speed of the explosions relative to the crank angle and all that business. Plus I really just wanted to argue about something. it takes a brave/strong man to admit he was wrong--remember that. |
All times are GMT -4. The time now is 09:58 PM. |
© 2024 MH Sub I, LLC dba Internet Brands