I wanted to measure the power loss from my new Tangerine Evo Stage II 914 silencer.
The graph below shows that the performance was identical between the Stage I and Stage II silencers, yet there is a huge difference in sound. The Stage II is very streetable.
I didn't bother tuning the engine since I will have to re-tune at the Glen anyway, so in both tests the AFR was only 12 to 1. My EGTs never even reached 1200F.

Power would have come up quite a bit if I had leaned it out.

Chris is the stage 2 like the smart racing looking muf?

Damn Chris!

You have been alot with that amount of power!

The "A" engine is going on the dyno tomorrow- The weather here has been horrid and really screwing up things or I would have fired it today....

The graph looks odd to me.. The actual plots go over 120 but it states max power at a lesser value... same on torque by quite a bit...wonder if something was out of cal on that machine?? I would think judging from your performance against others that you had a bit more than the dyno states...

We'll see how much you lose from my dyno to theirs- my 914 lost exactly 25HP from the flywheel to the rear wheels and so did the 3.0 in the bug..

BTW- Their plots do not cross at 5,252 RPM- There is something wrong with that dyno... All dyno graphs must cross at 5,252 thats the mathmatics. You might want to ask them about that and see if they'll re do the runs for you after they cal the machine..

They should have caught that!

This is what it should look like..... Same dyno software

Jake, The scales for hp and torque are different. Look all the way to the right for the torque scale. I don't kow why they have it set up that way.

oops

Chris, The numbers still do not cross at 5252- something's wrong.... call and quiz them on it.

damn dude, I went and flipped it for ya and you flipped it back

QUOTE (TimT @ Jul 7 2005, 10:44 PM)

Chris is the stage 2 like the smart racing looking muf?

a pic of the Tangerine Evo Stage II 914 Silencer

QUOTE (Jake Raby @ Jul 7 2005, 11:08 PM)

Chris, The numbers still do not cross at 5252- something's wrong.... call and quiz them on it.

Sure they do. Both traces have a value of about 110 at 5252rpm. Hp is still rising and torque is just past peak.

Sean,
Damn thing won't save correctly..... it won't let me flip it... can you try it again?

I think you may be confused.. The way their graph is set up thats very easy to do...

I see the cross at more like 5800-5900 revs, not at 5252...

compare it to my graph and you'll see what I'm talking about... The runs from my dyno are the same, everything crosses at 5252..
Hell, maybe I'm confused by their set up- who knows!

QUOTE (Jake Raby @ Jul 7 2005, 11:21 PM)

I see the cross at more like 5800-5900 revs, not at 5252...

I know what it looks like but the value of both torque and hp plots is the same at 5252. You have to read the torque on the scale at the right of the graph.
I think the software chose the scales but didn't coordinate them, and the operator didn't force them to be identical. One has a full scale value of 120 and the other is 130.

The thing that really interests me is the dip at 6400 - 6500 rpm. What causes that?

The dip may be from tire slippage or some sort of interferance- dunno... I'm not super familiar with chassis dynos anyway...

The values just don't add up on the graph so I think I'd quiz them on it.

Here's one from my dyno... trend is the same, same engine too..

Chris & Jake: Here's what I see.

Torque seems a fair amount over 110 at the crossover point. Unfortunately the hash marks along the bottom are not easy to use (4 marks for .2). So the values may be correct, we just can't choose where 5252 is accurately, so they look wrong. Margin of error sucks.

Yeah, I agree- The scaling is way off. It may be easier to read for some guys that have a -8 that way though due to the curves.....

It definately plays with your eyes, especially the first time you look at it.... But maybe thats because I have been playing with a data logger for 14 hours already!

The real point is that the Stage II makes the same power as the Stage I!, and its not real loud!

Oh yeah.

I'm excited. Sounds like just the kind of muffler I'll want on my CFR Header.

Cool... I'd really like to try it out here in comparison and see how it effects BSFC and how it behaves on an engine with a lot more air volume out the tail pipe..