Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: johnnyboy on April 22, 2016, 12:44:17 PM

Title: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: johnnyboy on April 22, 2016, 12:44:17 PM
As it says in the title, I need a new exhaust for a CJ7 304 v8 - and I would appreciate suggestions.

The engine is stock, and I am not in search of more power...

I am however in search of "reasonably priced" and fairly quiet (provided it sounds like a V8 :greggmo:).

I am also old enough to want the pipes to run inside the chassis rails and out at the back.

According to the internet, the standard cast iron headers are OK unless I start doing engine mods, which as I say I am not (currently...) planning. - is the internet right?

Presumably a dual pipe system front to back?

Any recommendations as to pipe diameter, muffler makes and models, stainless vs not? etc. etc.

And above all, a recommendation on somebody to make it?   


Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: 5536paulj on April 22, 2016, 03:17:49 PM
Nothing wrong with the standard cast manifolds,apparently they flow well, if you want duals you'll have to make it yourself or have it fabbed up. Agree on keeping the exhaust with in the frame rails, as side pipes are loud, however well you silence them.

Doesn't need to be big bore, 2 1/4 or 2 1/2 is quite big enough, the silencer (s) will dictate how it sounds, plenty of options there.
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: JamesH on April 22, 2016, 03:50:41 PM
3" pipe and cherry bombs  :icon_super: :003:

Or, in the world of wanting some hearing left and not setting off car alarms - 2.25" to 2.5" pipe and cheap silencer box unless you want some nice sounding Flowmaster or even Borla boxes.

The headers, large pipe, no cat and cherry bomb did sound sweet on my 4.0 though so you might want to indulge your inner hooligan with how awesome it will sound on a V8. 
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: Bulldog67 on April 22, 2016, 04:00:03 PM
Upgrade to hei if you want cheap n easy power increase

Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: Dave69 on April 23, 2016, 12:26:30 PM

cheery bomb 3" overall od and 24" in length as a minimum or pair up two smaller cherry bombs per side should decrease the noise level a bit
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: wildwood on April 23, 2016, 01:37:42 PM
Using an H pipe or letting them meet in an X after the trans case apparently is good for scavenging and gives an exhaust note that is pleasing......

After that back to two pipes and mufflers of your choice :icon_biggrin:
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: isle of man on April 23, 2016, 05:31:22 PM
Just pipe and MOFOing exit !!!
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: STUARTF on April 24, 2016, 08:45:21 AM
Maybe a little toooo far to travel for you.
Silver Systems, Leek Staffordshire. They fabricate all my cars exhausts, stainless is the way to go.
And for sounds well they can make it as loud or quiet as you want
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: Bubba on April 24, 2016, 08:51:32 AM
there is one in walsall with a very good reputation John something possibly when running possibly take it there ?
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: STUARTF on April 24, 2016, 09:32:39 AM
Or even loan a trailer and drop off. It would only be a half a day job
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: johnnyboy on April 29, 2016, 06:09:01 PM

Silver Systems, Leek Staffordshire. They fabricate all my cars exhausts, stainless is the way to go.
And for sounds well they can make it as loud or quiet as you want

Thanks for thiis. What sort of money do they talk about
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: johnnyboy on April 30, 2016, 02:46:45 PM
there is one in walsall with a very good reputation John something possibly when running possibly take it there ?

I was feeling sorry for your neighbours :icon_eek:

Also wondering about pipe diameters.

A V8 304 is low revving (by todays standards...) and half of one is only two and a half litres... - do I really need a 2.5 inch pipe for the equivalent of a low revving 2.5 litre 4 cylinder engine?

(I am fretting about clearance past the Quadradrac/TH400 box)

Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: 5536paulj on April 30, 2016, 03:38:44 PM
2 1/4 or even 2"will be plenty, and give you clearance past the qtrac
Title: Re: New exhaust needed for a CJ7 304 v8 - any suggestions?
Post by: LairdScooby on May 13, 2016, 11:49:08 PM
If you're anywhere near East Anglia, Demand Engineering in Ipswich are pretty good and will tailor the sound and look to your ear drums, wallet and neighbour-scaring activities :D

http://demandengineering.co.uk/

A friend had a stainless system (including manifold) made for his 98 Rover 820 (different car i know but gives you a ball-park figure) for £380 i think he said. The workmanship is excellent, it looks and sounds great, a bit sporty without being intrusive at speed or even when he hoofs it and even his neighbours don't complain!