6pack
[Top] [All Lists]

Re: exhaust recommendations???

To: "Matt M." <afterburn27@yahoo.com>
Subject: Re: exhaust recommendations???
From: "Robert M. Lang" <lang@isis.mit.edu>
Date: Tue, 27 Nov 2001 16:43:55 -0500 (EST)
On Tue, 27 Nov 2001, Matt M. wrote:

> Which exhaust system do you think is the best in terms
> of performance, looks, and sound. 

First note that performance with respect to Triumph 6 cylinder motors
means LOUD. But, not all loud systems give better performance. 

> I think performance
> is the top item on my list, then sound and looks
> follow pretty close after. 

If you want performance, then a good header (with "proper" primary tube
length) will terminate into a single 2.5 inch pipe that runs straight to
the back of the car with a megaphone at the end. This setup can be louder
than an unmuffled Mazda rotary... Not very practical and generally frowned
upon.

The key is the scavaging done by the primaries. I'm not an expert in this
area but I can offer the folowing: The Gp 44 car header is a "tri-y"
design. It has three tubes terminating into two tubes and then into a
"box" under the tranny (more or less). It then has two tubes coming out
all the way to back of the car with two megaphones.

I recall a Temple of Triumph article on how to calculate the length of the
primaries and secondaries. The bottom line is that you need that "box" or
a single pipe to get the best scavaging effect (and therefore the most
power). At least one reference (Kastner) says 2.5" pipes all the way after
the collector.

Driving around town with this setup would be annoying at best and frankly
would lead in short order to hearing impairment.

So - what do you do?

Get a good header. Get the part that terminates into one pipe. The rest of
the system should be "custom". Cut the flange on the 2 to 1 collector and
install a 2.5" flange. Then have a custom shop fabricate the rest of the
system. Use a "glasspack" if you want _LOUD_ or a "turbo style muffler" if
you want relatively quiet performance. You should be able to rig something
up for well under $300. But remember that the more muffling that you do,
the more power you rob from the motor.

> I think the TR6 engine will
> sound good with almost any exhaust on it, although
> some will be better than others. 

I'm sort of partial to the TR6 sound myself.

> I was looking at the
> Monza exhaust, but I read a comment that it really
> wasn't that great. Any suggestions? 

Stay away from Monza. They are cheap, they don't flow very well (2 inch
pipes in the 2 -pipe "later system" and 2.25 inch in the "early style"
single pipe. This is nowhere near ideal to this car. In fact, the wrong
size pipes interfere with the power, especially at the top end.

The other minus for Monza is that they are LOUD and really annoying on
long trips. I have a Monza setup on my street TR6, and I actually keep a
set of earplugs in my map pocket for any trip longer than 10 min.

If you want a closer to stock system, the Falcon systems are built very
well and the stainless will last a long time. Whether you use the "sport
version" or the "stock appearing system" is up to you...

If you really want power (and have the coinage to back it up), then after
your custom exhaust is setup, pull the whole thing and get it ceramic
coated inside and out. There is a def. power advantage to this process.
Not cheap ($200 for the header, more money for the rest of the system)
and is also looks great (and will stay looking great).

> Also, how do I
> determine if my '74 TR6 is a '74 or a '74 and 1/2?

The bumper height. There's also a few other hints. I'm not sure when they
"reinforced" the bumpers, but the later cars added structural steel to the
backside of the bumpers to make more collision resistant. Another easy way
to tell is on the early cars the rear bumper "forward extensions" exactly
follow a body line in the rear wing... on the later cars the extensions
sit higher than that body line.

> Thanks ahead of time...
> 
>                                   -Matt McKeever
> 

regards,
rml
------------------------------------------------------------------------------
Bob Lang              Room N42-140Q            |  This space for rent
Consultant            MIT unix-vms-help        |
Voice:617-253-7438    FAX: 617-258-9535        |
------------------------------------------------------------------------------

<Prev in Thread] Current Thread [Next in Thread>