26 replies to this topic

[Struggler]

Personally I would go with 1 3/4, but you may make more power with 1 5/8 if using a 4:1 design.

If building tri-Y's use a 1 7/8 primary.

JMHO

[Tiny]

Have a chat to LXCHEV, I know that he went though the whole saga with 4-1s and also Try Ys.

There is a BIG thread on it somewhere!

From my memory: It made the best performance gains with the 4-1s on, but for accessiblity he went back to a custom set of Tri-Ys and has struggled a little bit to find the max grunt that he got from the 4-1s.

But again, that's just by my memory! Drop him a PM, i'm sure he'd be more than willing to lend some advise!

[LXCHEV]

Yes I've tried 3 different sets sets of extractors and exhaust systems on my 383 Chev - what I would describe as:

1. Small Tri-Y's
2. Big 4-into-1's
3. Medium Tri-Y's

From my personal experience, each set have all produced 'similar' performance. The 4-into-1's certainly made a tiny bit more peak HP on the dyno (perhaps 10kW), and my fastest ever 1/4 mile time was run with them too. But we're only talking about one tenth here compared to times I've run with Tri-Y's!!

I also found the 4-into-1's made life very hard in my LX - impossible to remove without effectively pulling the engine, bugger all ground clearance, harder to access starter motor and oil filter etc. My Tri-Y's are much more user-friendly for the above problems.

I have gone into detail on this before in another topic - let me try to find it to save me typing it all out again.... stay tuned....

Edited by LXCHEV, 12 May 2008 - 11:57 AM.

[LXCHEV]

Ok this was the thread from last year... I notice you've already posted in it, but have a re-read of my post to refresh your memory:

http://www.gmh-toran...showtopic=22779

Keep us posted with what you decide....

PS. My engine is probably making a tiny bit less HP than yours (I've estimated mine at somewhere around 460HP, maybe a bit more. And it makes peak power at approx 6200 RPM), but I've revved it way past that many times.

[LXCHEV]

If Struggler recommended 1-7/8 primaries above for a Tri-Y design, I'd trust him!!

I personally have no idea on collector size - but my engine builder LOVES big collectors (eg. 3" or even as big as 3.5" on Chevs that make big HP like we're talking here).

Custom pipes are certainly not cheap - if you have the skills to build them yourself, it'd be a good way to save some cash. I got mine built for an awesome price, but unfortunately he's shut down his workshop now. Just for interests sake, here are my current Tri-Y's (custom job):





Cheers,
Brett.

Edited by LXCHEV, 13 May 2008 - 10:39 AM.

[RIM-010]

That's a nice looking 'zorst you've got there, Brett

Tim

[LXCHEV]

It's kinda like a jigsaw puzzle hey!!! HAHA

[LXCHEV]

From my 2.5" collectors, I have a twin 2.5" system, running twin Supercat mufflers (these are straight through, but with an interference/expansion chamber in them). Then twin 2.5" tailpipes. I also had two 10" hotdogs fitted prior to the mufflers.

With this system, it's still loudish - but not obnoxious like other systems I've had. I can happily cruise the streets with no problems. I don't think it'd pass the Victorian 96dB test though. If I run my dumpers at the diff, it's way louder again, obviously.

You could try the restrictor in the collector flange and/or a tiny set of tailpipes (assuming it's flanged at the rear just swap them on and off). Tailpipe size seems to have a huge influence.

[MRLXSS]

How loud is yours brett?

It sounds VERY NICE!

[LXCHEV]

And Go Pedals are FUUUUUN!!!!

[MRLXSS]

And Go Pedals are FUUUUUN!!!!

They sure are!

[LXCHEV]

I paid around $1100 - $1200 for mine.

Lostit is right - depending on who makes them, and if they're clever - you could still get 4-into-1's to fit easily.

[racean69]

They look good.... are you running a sbc or vn type holden engine?

[LXCHEV]

Great looking pipes LJ!