This is pretty cool
Cast manifold vs mid length vs long tube

 

Thanks for the pics. It's nice to see new ones not the usual beat up discoloured ones from wrecks.

Notice how the branching is different between the left and right bank? On the right side the pairing is cylinders next to each other; front pair and rear pair, on the left bank the pairing is changed to separate the adjacent cylinders. This is exactly what I keep banging on about in regards to the firing order, it's done this way for a reason...

 

I would absolutely LOVE to see the same tests done with a supercharged engine because that's the kicker for us.

I am not convinced that the gains on a naturally aspirated engine translate directly to a supercharged one.

 

I'm with you on that one

I'm going out on a limb but I would have to say that the s/c would be lucky to see a gain of 10-15whp ..probably double that amount for n/a engines

 

The engine master series really isn't that good. Frieberger and company are car guys, not necessarily engine guys. It makes nice video for the couch potatoes. The video on X vs H pipes could have moved the conversation forward but fell flat because they don't understand how it work. The goofy guy with the DB meter was the smartest of the group but he seemed to just be there for comic relief.

 

Jaguar has announced a $170,000 hot rod XE with supercharged V8 producing well over 600 hp. I think it would be interesting to compare our superchargers, camshafts and intake/exhaust manifolds with this new motor's components. I wonder if Jaguar is using the same exhaust manifold?

 

I assume others will chime in here but based on posts about pulley and tune I think it is fair to assume that they have achieved the same 600 hp numbers. Let's hear the form guys explain.

 

An engine is an air pump and is only as efficent as it's biggest restriction. Why would exhaust extraction on a supercharged engine be any different than on a naturally aspirated engine?

 

The difference between a naturally aspirated engine and a supercharged engine is that the naturally aspirated engine is sucking air in, the supercharged engine is being force-fed air instead. So you have an air pump feeding an air pump.

Quite how that changes the exhaust side of things I'm not clever enough to understand.

But so far I have not seen anyone show me the same gains from fitting headers to a supercharged engine, as a naturally aspirated one. Like Steve's examples...

 

Cambo,

Concerning the BadCat Headers, I read some of the information on his Website and found that he did not design them as he had some other Engineers work out the design considering how close the space is in which to put the Header on the Engine and hook up all the Cats and rest of the Exhaust system. So, it appears that more thought and work went into these Headers than we anticipated. Avos has a point though and that said, I would like to see some Dyno Runs that show what they are doing...... When I talked with him several months ago, he said he wanted around $2,400.00 for the Pair.....At that point, I sorta forgot to ask about Dyno Runs! Sorry!

Billy Clyde

 

The answer is that under boost the engine theoretically becomes larger. 14.3 psi is one atmosphere, what we walk around in. Add another 14.3 psi of boost and you've effectively doubled your engines power output (less drive losses for the blower). Unobstructed flow is actually more important upstream from the blower vs. downstream from the engine because it's easier to blow through a straw (restriction) than suck through one.

 

I believe the terminology you're looking for is "achieves a larger mass flow rate." The engine stays the same displacement no matter what.

14.7 PSI, actually. That's only on a standard day at sea level, though. Various factors such as temperature, elevation and humidity have a lot to say in what the atmospheric pressure is at the point of measurement, which is referred to as density altitude. Rarely will you ever find yourself in a location where the DA is exactly 14.7 PSI.

Roughly, sort of. In reality, nope. Pumping and thermal losses come into play. What you propose is what's referred to as a free lunch.

Wrong. Restrictions downstream are as important as upstream. All you have to do is look at the CTS-V crowd that's tuning the LSA engine. It's the same supercharger as ours, but on a 6.2L engine. A decent set of headers, 200 cell cats and free flowing exhaust won't gain those guys much power... because the reduction in restriction lowers the boost pressure. Where you see gains with that setup is when you spin the SC faster to regain the lost boost. Furthermore, freeing up the exhaust side will allow the engine to run cooler and lower IATs. Win win, right?

Getting back to my original post in this thread and the point I was trying to make: Until we know how big of a restriction the stock exhaust manifolds are, developing headers is pure fabrication ****. Given the current numbers the tuners are getting from these engines, all of which are under 700 crank HP, I feel that the gains from correctly designed headers won't justify the cost vs. extrude honed stock manifolds. When Jaguar guys start swapping the R1900 for a 2300 or larger and start making BIG numbers like the LSA and modular Ford guys are doing, I can see the justification for a set of headers that will require the removal of the engine to install. Until then, it's all just shots in the dark.

 

I think avos got about 700HP with the 4.2 and its existing headers, in which case they can't be much of a problem.

 

We could have an interesting discussion about all this but honestly I don't have the time right now. For arguments sake, take your mouth and nose shut, poke a 1/4" hole in it and go for a run. Try it again with another 1/4" hole, this time with a flap over the outside that acts like a check valve, that's your free flowing exhaust. Finally flip the valve around. Then your intake is free flowing and the exhaust isn't. I think you'll find it's a lot easier to breathe in through both holes and only push out the little one.

Kind of like breathing in through your mouth and out the nose while running to control your breathing.

 

Intake V Exhaust flow...... that's why intake valves are larger than exhaust valves, especially considering the post-combustion increase in gas volume.

 

Ouch !!!

 

 

Thanks Steve_k_xk & jahummer,

Now this Header system is more like it! This is a true 4 into 1 system...I haven't found it on their website yet but I'm still looking....? It appears to be made for a Range Rover....How can I find out more?

Billy Clyde in Houston

 

From Supersprint. It's also about $5k USD!

 

jahummer, It appears that they don't want to make their "Money" a little at a time..... for a few dollars more, you could get one of AVOS's Kenny Bell Kits! Now we're talking lots of HP per dollar not just a little......The maximum HP they could make is what? 20 to 25....No way for me! Although they sure are pretty!!

Billy Clyde in Houston