Tri-Y vs 4:1 Header

[Al Seim]

Has anybody ever compared a Tri-Y (4:2:1) header to a 4:1 header on a dyno?

My ITC Scirocco came to me with a Tri-Y. If I was building from scratch I'd use a 4:1, but I've never convinced myself that I knew for SURE that it was worth $400 to toss the Tri-Y and buy a 4:1.

Conventional wisdom has always been that the Tri-Y had better mid-range at some expense of top end. Since an IT engine is hardly a high RPM screamer, maybe appropriate? OTOH, the fast guys don't typically run them.

Anybody have a thought?

[VW16VRacer]

Al

I have had a conversation with Stu at BSI and Collin at TT and they both recomend a 4:1 and a short exhaust. My understanding is that if the collector is in the firing order and you use a small resonator then the exhaust will dump out on the ground just behind the driver for the best HP.

Just my .02

Jon

[This message has been edited by VW16VRacer (edited December 05, 2004).]

[madrabbit15]

As having run both a tri y and a 4-1 header, I now run the 4-1 header. BSI talked me into to it, does it really make a difference, I cant tell you, but I will say that the torque is better with the tri-y header, so it depends on your gearing and track that you run at. Everyone that has access to a dyno has always told me to run a 4-1, an honestly if you turn the rpms that you should if you are a competitive VW that I suppose that it makes sense. I just know that I had really good luck using the tri-y when a ran a taller gearbox because I run a roval every once and a while, and that is the only place I would use it.

[Bill Miller]

Conventional wisdom says that 4:1 is better for the track and Tri-Y is better for the street. Talk to Walt Puckett if you're interested in getting a custom 4:1 built. He's got lots of experience w/ VW exhausts.

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[Knestis]

Walt has also expressed real interest in building a header for the MkIII if anyone is shopping. Good stuff.

K