Joesixpack
Pull'n it.
X2. My twin set didn't have the divider. Made quite a difference putting it back.
interesting - with both springs, I assume? I got antsy and installed it without using your test setup I love the thing, regardless!
Nick, I'm glad you took some time to spell that out.
Also, what are you guys using to lubricate the o-rings on the piston?
Try a header manifold and get back to me on that. All the extra volume kills pulse energy.
The easy check is to cap the gate.
I'm interested how it turns out.
I wonder what would be cheaper - 'remaking' the divider or just selling and getting a new plate/pipe/flange from E.D. ...that or finding someone that would be willing to trade (that would be a gem!).
I've already done just that. I increased the manifold volume by about 5-7 times, and gained 31 hp and 34 ft/lbs.
I thought this was a discussion involving diesel engines?
I'm thinking the larger manifold plus the divider missing is killing spool from a pulse perspective.
And you are saying the difference in exhaust pulses vary enough that the principles no longer apply?
no just found it kind of funny that a dyno chart from a gas burner was put up to explain how a larger manifold will not increase spool times. Even your chart shows that power dropped off down low due to less velocity of the exhaust entering the turbine wheel. This would correspond with it taking longer to spool, no?
I've already done just that. I increased the manifold volume by about 5-7 times, and gained 31 hp and 34 ft/lbs.
With your gasser there is a lot more residual head in the exaust even at idle due to it being throttled, and a hotter burn, way more heat in the exhaust right from the get go.
One of the trucks I pull against put a chitload of time into building a equal length header, into a large collector with no divider. Was a work of art.
Spooled like chit.
More on top.....maybe, as a peak, BUT it would snuff the charger way early as well.
All that open pipe was a huge heat sink, so from that angle, lost a bunch of heat.
All the extra volume, killed the pulses.
In the end, gave it away and I see he has one of the new t4 manifolds this year.
Well lets see some photos of how its supposed to be done. Know of two others on here that tried header style manifolds and both said the same, spooled significantly slower off idle.
Yeah I'd like to know more about this since I'm kinda struggling to believe what you're saying. Many of the Dmax sledpullers with fancy headers got rid of 'em real quick.
And I don't know about your EGT statement. I don't have a gasser with a pyro but I understand at idle they can be 800-900 F. My truck at idle is like 200F.
What would you like explained?
I know after I put headers on a gas motor truck I had, they would read about 600* if you let it idle for about 5 mins on a hot day. Thats with a lazer temp gun.
Well, you're trying to make the point that it's "about flow" and "low pressure".
Obviously if you took that to an extreme, you'd make 3" primaries and have infinite flow and nonmeasurable pressure drop. And they would spool like ass.
So somewhere in between is the balance point. I have been told by a Garrett application engineer that spool is all about gas velocity. Temperature does come into play because the loss of it, reduces the volume it occupies, which slows linear velocity if everything else is constant.
And the thing I still don't understand is how could several apprently skilled header builders have terrible luck with V-8 headers on Duramaxes to the point where you can buy pretty much anything BUT a set of race equal-length headers. That experience is the direct opposite of what you have seen on your Cummins stuff. So were they just all doing it wrong? I'm kinda skeptical on that.
I'm not calling BS or anything, just trying to have a good conversation on this.