Exhaust tuning

[SHOTANG]

So I know ya'll aren't familiar with me but I lurk a good bit 'cuz you guys seems pretty bright. I was doing some deep thinking while sitting on the throne the other night. I was mulling over the VE of the SHO engine which IIRC is over 100%, something like 114% (someone correct me otherwise). I think this is attributed to the intake manifold design, which uses pulses to aid in cylinder filling. Right? Hokay, so our SHO engine's got that kickass intake but because of packaging constraints the exhaust isn't nearly as exotic. There's a lot of literature out there on tuning of the exhaust pulses to aid in evacuation and cylinder filling too. From what I understand it's possible to tune the exhaust to a fairly narrow window using the heat of the exhaust gases and length of the tubes to calculate when the pressure waves arrive.

So, all that to say.... The SHO has two exhaust valves, why not separate them with a port divider or something and have two primaries at different lengths, tuning for an even broader pressure wave curve?

So what am I forgetting? I already know it with be a PITA to weld this monstrosity up but I'm more or less just thinking out loud on a theoretical level.

 

[Phoenix]

2.5 or 3'' exhaust will solve that for you.

But what you really looking for are equal length headers. Good luck.

 

[SHOtime2511]

Just boost it.
You will save time and $ in the long run.

 

[SHOTANG]

Yup, they would be equal length. But there'd be two primaries, one for each exhaust valve. Allowing twice as many pulse waves to come in and out, dig?

Nice 2002 swap, that thing is sweet!

 

[SHOTANG]

And the two primaries would be two DIFFERENT lengths (but equal to their mirrors on other cylinders), maybe I didn't stress that before.

Boosting is a viable option, but harder on drive train components, fuel, more moving stuff, more weight, complexity.... I knew you boost junkies would chime in

 

[Phoenix]

Yup, they would be equal length. But there'd be two primaries, one for each exhaust valve. Allowing twice as many pulse waves to come in and out, dig?

Nice 2002 swap, that thing is sweet!

Thanks , and whats in there is a cammed , ported , 3'' exhaust , 3.2 mtx , and 1.75'' headers home made. Not equal length , just making them is something - for the minimal gains you might get (if any) Im not sure if its really worth the effort. But , its your money , not mine.

If you do get this in the works , let us know.

 

[SHOspazz92]

You can just buy my headers






-Sam

 

[illSHOyou]

I really think the stock collectors are good. What is needed in my opinion is good length of pipes after the collector with a merge point near the rear of the car before the fuel tank. The extra length could provide more wave action and low end torque.

 

[SHOTANG]

Those headers look nice and curvy....how I likes it Unfortunately they won't fit my longitudinal ranger. I know the name's SHOTANG, but I came to my senses somewhere along the way and realized that my vulcan ranger already has a lot of the parts needed for rwd SHO fun. From what I gather, firewall issues for the ranger swap are due in large part to the coil packs and heater box on the other side. I'll hopefully mitigate those issues with a COP sequential Megasquirt, a 97(?) heater box from a 4.0, electric Davies-Craig pump and controller...... Oh, and 12.5:1's + port propane, muha!

 

[Phoenix]

Nice , well keep us posted , looks like an awesome project.

 

[SHOTANG]

It'll be a slow evolution to be sure. I'm not going to dive in headfirst and yank anything as long as my vulcan is running well. It seems like it'll probably never quit as I'm at 206k and I've never had the valve covers off. When I reach critical (parts) mass I'll start a build thread.