• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Exhaust systems/ mods

Share this page

TonyPanchot

TonyPanchot

Jedi Trainee
Offline
Hi all

I have a Monza system that I installed a few years back
and wow is it still loud even though I dont drive the 250 that much, was wondering what or if I could install a glass pack prior to the Y pipe
would this quiet things down a and any recommendations on a brand ??

THX,

Tony
 
Glasspacks:
100_0325.jpg

Baffle:
100_0480.jpg



The glasspacks are just about as freeflow as you can get and pretty loud. I took a page from motorcycle drag racers book and installed baffles both to add some back pressure and quiet the sound.
The baffle as pictured was still a little too loud so I wrapped the smaller diameter part with asbestos webbing that I've had for years and that gave me just what I wanted , a nice drone at cruising and a mean sound on hard acceleration. I think the added back pressure improved acceleration too.
I suppose header wrap or even fiberglass in one form or another would work just as good as the asbestos webbing.
 
If your Monza's are not rusty, you can probably just add baffles to your tailpipes and notice a difference.
100_0322.jpg
 
Thanks PB, my Monza's are very fresh, where might I acquire such devices
kinda reminds me of the spark arrestors that always rusted out on our motocross bikes back in the day
 
Glasspacks vary, I suppose. Many years ago (ok, 26 years ago), a buddy and I resurrected an old G-prod '64 Spitfire to use as an autocross car. Knowing that we'd be running mostly parking lots, and that some had "sensitive" neighbors, we used some straight pipe from the header and hung a small Thrush muffler under the boot. Turned out really to be no more offensive than some of the "stock" cars that showed up!
 
Ebay Motors. just search for "baffles".
You'll find them in various lengths (mine were 4" long) and various diameters.... And various versions.
I imagine that some cycle shops would have them as well.
 
did have a thought !!
what about simple glass pack forward the Y pipe
would this retain too much heat under the floor pan ??
 
You could install a muffler between the downpipe and the Monza system you have. I think item 2 on the moss diagram would work for your 250.

Midpipe Silencer

I went this route on my 4A with a Monza exhuast (using the 4A midpipe silencer which has two inlets) and it helped considerably.
 
When I had a 4A I added the monza exhaust and thought it was too loud, I added the midpippe silencer as shown on the moss page referenced about, item 26, I believe this would be the one you want if you have the dual downpipes.

It went from too loud to just right, louder than stock but not obnoxious, with the additional muffler.
 
One possible solution, although maybe pricey, is to copy the silencers used on current performance cars. For example, a friend of mine here was looking for an exhaust system for his MG and came up with the silencers (mufflers) from a new MINI Cooper JCW exhaust system. I think he found it at MINI Mania.

The JCW (John Cooper Works option with reworked head, exhaust, headers, etc.) system is compact and the actual mufflers are relatively small. It has a very sporty sound, and is louder than the MINI S that I drive, but it's acceptable. Maybe a bit too loud for my tastes, but he wanted something sporty and is very pleased with the system.

Most importantly, it fits nicely under the MG. I suspect it would fit under other LBCs as well.

Maybe worth investigating? I hope this is helpful, let us know what you decide.
 
I've installed one of these: https://www.jegs.com/p/Dynomax/744696/10002/-1. It's only an 11" case and is installed right behind my 4 into 1 header and before my stock TR4A "Y" pipe and stock twin resonators. It got my exhaust volume and tone to where I wanted, plus was economical ($24.00) and it looks like it was designed for the space available.
 
Back
Top