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MG MGB GT V8 Factory Originals Technical - Mufflers for V-8 with centered tank

I have centered my tank and am trying to figure out exhaust. I have a 67 with a V-6 conversion. After centering the tank I only get 4 1/2 inches on each side between the tank and leaf springs. The car has been lowered 1 inch and I don't think I can safely put flat mufflers under the car. I am running 1 1/2 inch duel exhaust straight back with a crossover. If anyone has any ideas please let me know
Garret
garret

Have you looked at some of the moterbike ones. The big ones would probably do the trick and sound and look rather nice with it
Stuart Robson

So garret, is your car a V6 or V8? If V6, could you tell us more about your exhaust system? Where did you get it? Are you making it yourself? Are dual systems common on a V6?
Thanks,
Dana
Dana

You could try Borla (in US). They make everything you can spec. I ordered a set of silencers for my twin unlinked system and it was no problem, even though the diameter of the pipes is rather large.

Frank
Frank de Groot

FlowMaster has flatter versions that may possibly fit vertically next to the tank. That's what I'm considering. Look here:

http://www.flowmastermufflers.com/web10/SePerfMuff12.html
Michael Willis

Garret
I have the fuel tank centered on mine. I am using glass packs on each side with resonator tips. I tried it with plain stainless steel tips, but it was a bit loud for me. With the resonator tips it has a nice mellow rumble to it.

Bill
bill jacobson

Flowmasters will have that deep chest pounding rumble too, which really makes your V8 stand out. A Friend of mine has a set on his 3.9L car and it sounds burlier than my 302!!

I bought a cheap set of "turbo" mufflers they fit fine right under your seats. then all you have to do is run up and over (or under) the axle and out the tail. The part that most MG's drag exhaust is just behind the front wheels when going over speed bumps. This is becaust the chassis dropping off the speed bump actually bounces on the front springs and thus the undercarriage bottoms on the speedbump just behind the front wheels. That is why hitting them at an angle helps, you only have one wheel at a time dropping of and thus the car rolls side to side more than up/down...
Larry Embrey

I have a centered gas tank on my 75 B with Rover 3.5, hugger headers exiting under the motor to a crossover and then the Flow Masters under the seat, from there as straight a run as possible under the axle running beside the tank (not much room to spare) and out. All 2” pipe. This gives me about 4” clearance

Bruce

What I am thinking about doing with my V8 conversion is to have dual exhaust (one pipe from each header collector) and having one dump in front of each rear wheel. I would use a bullet style dynomax muffler (small case + they sound great) and a balance pipe to synchro the exhaust pulses. And then, some nice 2.5" or 3" chrome tips. That would be sweet
Jarrod

Jarrod,

Have you measured the ground clearance just in front of the rear wheel? Three inch tips would do a lot of scraping, to say nothing about being riceboyish.
George B.

Garret, Glasspacks are ok to use with your swap, if you go with glasspacks use Monza tips with the mufflers, otherwise it will be to loud.
If you are using one battery only, then you could cut the battery box out and install a Camaro, fiero muffler in that empty space. You could also install two dynomax or Edelbrock Mufflers for dual exhaust.
Borla is a Stainless glasspack and it's overprize.
Dynomax has the same construction minus the high cost and stainless.

r/Bill
Bill Guzman

Please can anyone enlighten me on the theory of exhaust systems. The exhaust system on most cars (eg std MGB) has a middle box (muffler) and a rear box. Some custom made systems also have two boxes, but some only one. Are there any technical reasons for two being better than one? If a single box system is used, is it better to have it in the middle section or near the tail pipe? If a single box will do, I would assume that putting an oval unit under the seat area would help to alleviate the fuel tank clearance problems?
Custom mufflers are obviously popular in the US. Does anyone have experience of sourcing exhaust components in the UK? Cherry Bombs were all the rage in the 70's....I don't know if they are still available? (So were Thrush Sidewinders, but thankfully they went out of fashion!!!!). Any guidance would be very welcome......my ideal system would offer a nice V8 burble but not upset the neighbours. A twin pipe system appeals.
Pete
Pete Green

Jarrod,

Don't put on those big 3" tips! My V8, even with two in-line mufflers, is a little loud; I tried fitting a resonator on the end and it just looked tragicomically out of place on an old British car. I think you oughta just leave it plain and take it like a man!
Terrence

Pete, you are asking a question that would take a textbook to answer.
In simple terms, one box (muffler) is a silencer and the second a resonator (noise reducer)
By removing the resonator you would get a burble as you call it. An effective system doesn’t have to be loud; it’s how you exit the gases that matters.
By placing a muffler (box) at the end of the exhaust pipe, will produce the max torque in the middle will create a choke on the gases thus reducing the noise and power.
A proper matched muffler with the right size pipe can produce a nice tone and increase power.
A stock V8 with dual exhaust pipes of 21/4 inches with a crossover of 2 inches or the same size as the pipes with two dynomax or turbo mufflers mounted at the end of each pipe can produce a nice note and power.
Hence this is not possible in the MG then mounting the same mufflers ahead of the rear axle with 21/2 inches of tail pipe, should produce the same results.

I hope this helps you Pete.

r/Bill
BTW the crossover pipe helps to reduce noise.
Bill Guzman

Terrence, would you be speaking of straight pipes? ;-)
Jarrod, ground clearance will always be a problem if you have a CB or CB ride height or lower. Even the stock pipe could be grounded at times. I have that problem solved, but it takes fenderwell headers (custom), sidepipe glasspacks (custom) and some fairly extensive bodywork to make it blend in acceptably (mucho dinero custom).
http://www.foresight.cc/Graphics_Content/MGB-DF-5-01.jpg

Jim
Jim Blackwood

Pete,

Try MGBV8 Development Exhausts
www.mgcars.org.uk/v8_conversions/files/engine/rv8dev

Should be a lot more options but I do not have info to hand but I believe Mike the Pipe has retired.

Cherry Bombs etc are available from Demon Tweeks.

Be warned that a twin system can imitate Concorde and ear plugs are advised.

Paul

Paul

Paul,
Thanks for the Concorde tip! Yes, I remember looking at the V8 Developments site some time ago. They may have ceased trading? as none of the web addresses seem to work (including www.v8dev.freeserve.co.uk/ or www.mgcars.org.uk/mgdev/
I've been doing some digging and have found that Jetex (www.jetexlimited.freeserve.co.uk) offer a good range of boxes and pipes at reasonable cost. Their range covers 2" and 2.5" and is worth a look if anyone is interested. They do very long/thin cylindrical boxes which ought to fit either side of a centralised fuel tank.
Pete
Pete Green

This is for Bill Jacobson and Bill Guzman.
I have been trying to get in touch with both of you on your verizon addresses and they keep comming back undeliverable.
I have some questions for both of you on completing my conversion.
If you could drop me a line I will try to use REPLY to get the message thru
Thanks
Garret
Garret

This thread was discussed between 28/06/2002 and 03/07/2002

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