Vintage Speed 48 mm Exhaust

[rwalker1296]

Anyone running the Vintage Speed 48mm exhaust? I like the look but not sure if it would work good with CB Ultra Wedgeports. I'm currently running a 1 3/4 A1 with and A1 stainless fat boy.

[jl_1303]

It's a bit off the topic, but is the A1 you run quiet?

[Clatter]

It will work, but be prepared to leave a lot of power on the table.

Everyone is all excited abou these new VST exhausts these days,
But nobody has dared do any back-to-back dyno runs with them.
_________________
Bus Motor Build

What’s That Noise?!?

[Alstrup]

I have.
It will kill the top 20ish hp on a prpoperly set up engine with Wedge ports. Torque will suffer with about 10% Also the torque "delivery" in lack of a better word, gets funky if the cam duration is in the 256ish & up range (@ 0,050")
If you have or are building a large slow reving engine with peak hp at or below 5500 rpm it is ok.
If it has to be VS I actually like the the equal length Super flow better, apart from it being noisy. But then again, an A1 or CSP will be too. With the super flow you can actually exploit the shorty header design and make the engine pull nice torque and power up to about 5500 rpm.
The odd pairing of the cylinders with the 48 mm version will never work optimum. It WILL kill torque no matter what you do. The plenum on the secondaries may actually help HP a tad at higher rpm, I have not tried with and with out.

In general the finish of these systems are very nice. Some people call them eye candy. On the down side I am very disappointed with the hardware delivered with them. First thing to do it to throw those bolts and nuts in the trash and replace them with something with the right quality. Grade 6 isi 304 hardly holds across the sidewalk. Next I have seen several mufflers that cracked in the weldings and exhaust tips (bus versions) that breaks off due to very thin material thickness.

There is a guy or company in Australia that made some tests on the VS, CSP and other header systems some time ago. These tests actually showed significantly less difference between the varius systems than I have noticed. One of the wildcards was though, that I for one do not know the engine combo, only that it was an engine that pulled 155-160 hp at best. That may have something to do with it, because if you do not test the headers at their max performance capabilities along with a test where it would be at say 75% you will never know the real behaviure on the system. This is without getting into the multiple engine combo solutions, which of course also will affect the overall system reaction so to speak.

Anyway, to the OP, if you believe that your engine is set up properly, and that you are in the 180-200 hp region, and want to maintain the power and ability to pull above 6 grand, you should think twice before taking the plunge.

My 02c.

T

[rwalker1296]

Thanks for the info guys. It looks great, that's the only reason I'm considering it.
I'm running a SLR EXR 310 cam and 12.2:1 C/R. The motor made a little over 200hp on Jaycees dyno. Jack built the motor for me. I don't want to give up hp so I'll stick with what I have.