FE-FC Holden Discussion Forum

Hi all,

I need a new exhaust system on my FC as the system I have on their now has rusted out.

My question is - what's the best system for overall performance/sound?

I had my heart set on a two inch twin system - I think it would look sweet, but a few people have said that it makes the motor 'bark' and sound unpleasant.

Another option was a single three inch dump pipe that finished just before the diff and aimed at the ground.

Basically I want a tough sounding FC - something that will sound really lumpy, grumpy and tough, that will be heard before it's seen. Like a cammed up car without the big cam. It's powered by a warm 192 Red (hopefully soon with triple Dellortos).

What's the best set up to got for? Is it beneficial to go with stainless or not? How about a hot dog?

I heard a couple of XU1 Torana's racing at Baskerville a while ago and those old things sounded mighty tough. Something like a grumpy Bathurst racer would be pretty sweet.

Kind regards,

Ol_Girl_58

Ive had a few different exhaust systems in fc's it just depends on what your after twin pipes have a bark to them if you run a 3 inch pipe i wouldn't have it dumped at the diff as it is really noisey and quite unpleasant on the ears but if you run a 3 inch all the way to the back they have a really nice deep sound. A single 2.5 inch exhaust would probably give you the best in alround performance and sound this is the one that i would go for.
Hope this helps
Ben

Gee Ben, i never thought anything could be too loud for you, have you tamed down since getting a chick or what?
 as ben says twin pipes are barky, i would just go as free flowing as possible and make it quiter with soundproofing.
 performance and economy wise, a smaller pipe has no advantage other than being less likely to scrape, the rest is old wives tales, some people say they get less economy but its becuase they floor it more to make a big noise.

sounds like you are after a 2.5" with 1 x 12" long straight through offset muffler.

FCCOOL thats my system except 14'' straight through muffler ... Who has built there own extractors with 1 7/8'' primary pipes ???? I need to go down this path soon as the old extractors were inadequate for the blown engine .......FC427.......

mark, ive got a set of extractors lying around with what appears to be larger primaries, i'll check the size for you tomorrow if yoyur interested.

as far as systems go i am running a 3 inch straight through system on mine with turbo muffler and the souns is nice and deep as ben said. mine will be dumped just before the body ends, just to clean the rear apperance up a bit.

dean

 Hi Dean Let me know what size they are Thanks ....FC427......

OL Girl, those Toranas you talk about would most likely have basically open exhausts. The Appendix J guys have a very small hot dog with the exhaust coming out under the left rear door. The hot dog is only there to get under the 97 dB limit.
Colin.

I used to run a 179 with Genie Extractors, 24" Lukey muffler placed well forward, close to the extractors, and a 2.5" system all the way to the back. It sounded really sweet and distinctive. Then I tried a twin system using hot dogs with no balance pipe. This was loud and barky but I wouldn't say it sounded any good. I will be using the lukey on my FC ute which has a 186. Regards Bob

G'day,I run a slighty warm 202 with extractors, a 2 1/4 exhaust with a hot dog , sounds pretty good.
                                             Cheers Rusty

"magnaflow" mufflers sound great IMO

nice tone without the bark.

Cheers

Ed

you won't get a lumpy idle with out a lumpy cam

Ol girl,if you want to hear a nice sounding FC,go to Alex's' (custom FC)post "making of a bad girl" and watch the videos...actually just realised his is a grey so might sound a little different...Great sounding car just the same.FCCOOL has a nice sounding RED motor also and has some videos posted on his thread.Cheers,Jamie.

Josh, I run a warm grey but its extractors 2 and quater cut off at diff with a louvered hotdog and sounds sensational.

Hey Leon
Na i haven't "tamed down after getting a chick" :) :)I'm still running dual 3 inch exhaust on my wagon which is real load.  Its just when i had my fc with a single 3 inch cut at the diff it had a real terrible drown which was unbearable at certain revs.

Ben

good to hear ben, two 3" pipes sounds like the go.
 i still remember hearing the HR approach my house, from a few blocks away, chev v8, gear drives, stally and loud exhaust.

Hi Guys,

Thanks for the replies.

So what would the best size to have if I want to dump it at the diff? Would it be beneficial to have a hot dog on it - I want to get as close to a circuit-racer sound as possible, but still be legal if the cops pull me over.

Cheers,

Ol_Girl

i would still be a bit cautious about dumping at the diff, as ben stated the resonance would be pretty terrible but if you were to angle the pipes so they were to aim outward from the car say like "chevy dumps" behind back wheels it would be better, maybe? i still think you would want to push the gasses away from the car as best you can.

I think from memory the exhaust has to finish 100mm past the last passenger door opening to be legal, that was why Ute's and Van's were allowed side pipes but not sedans and wagons .....FC427.....

that was my understanding too, i guess if you wanted to you could weld the back doors shut, and then you could dump it out the side :-\ :-\
seen it done but not a big fan of it.

Yeah, it'd make it hard for the passengers to get in and out  :-X

easy fix, put a roll cage and wheel tubs= no beckseat passengers
seems like a long way around for an exhaust though ;D ;D ;)

yeh but a good way and hey if your going to do that why not put something decent under the bonnet too ;D ;D ;D

You'd also have to fix the windows shut.

i think its more like 50mm past the last welded seam and some distance past the nearest opening window.
 i think there is a rta error, or maybe its only in ACT that allows sedans to run side pipes without the rules but wagons, utes and vans have to comply.

no we are pretty much the same here leon, im pretty sure its 100mm past the last opening door.

Hi again guys,

Thanks again for your input.

I'm leaning towards a twin system, mostly because the car had a twin system long before I had it back in the 70's/80's - and I like the sense of nostalgia harking the car back to its roots. Plus it will keep everyone guessing when I'm stopped at traffic lights  ;)

So, two questions follow:

* What set up/exhaust size etc. is best with a twin system so that it won't sound raspy/sound horrid at idle or full noise?

* Where is the best place to split the exhaust?

Thanks again,

Ol_Girl_58

Hi Josh cut the collector off the extractors and start your twin system right from the front as for size of pipes twin 2''pipes would be large enough for a 350hp engine with no problems but I like the look of 2.5'' exhausts .......FC427......

i've been told i shouldn't go  bigger than 2 1/4 for my 186 cause i will lose bottom end power.is this somewhat true?

ive heard of it but you never seem to dyno evidence, A bigger pipe gives most of its advantage when rpm is high but why would a restriction give more power down low?
 

i guess you lose bottom end torque  i meant to say
guess it depends if ya wanna drive it or race it or both(then its just a compromise)

i am not a exhuast expert but afaik there is no advantage of a small pipe, the only disadvantages of a big pipe is they are harder to weave through all the other stuff under the car and they are louder, more expensive pipe and less ground clearance.
 has anyone really seen a dyno improvement down low when a smaller exhaust is fitted, what do the exhaust systems look like were low down torque is needed, what do they look like on tractor racers or those 4wd comps were they pull loads, do they fit a smaller pipe, what do they do on ski race boats were there is no db limit and they can have what ever size pipe they want.
 a lot of exhaust shops say big pipes loose out down low but were is the proof, i think its a mix up from hearing big pipes give more high up, i am sure big pipes give just the same down low.

Ahhhh... This is a topic that interests me greatly, I have tried many pipe length/diameter combinations based on research on exhaust scavenging\pulse tuning.  There is a book called "the scientific design of intake and exhaust manifolds"  that was written some time ago and contains heaps of great info and formula's.  In a nutshell A primary header pipe 1 size too big can produce roughly  a 20% decrease in torque!!! You are better of one size too small than one size too big...

Diameter of pipe determines how hard your engine will scavenge (come on pipe) and the length will determine when scavenging will occur...Its a complicated and often miss understood science.  Have a look at the "Headers by ED" website for some more insight..

All my work has been done with x2/xu1 style headers...i have tried different combo's on the dyno with different engines....

so here goes.....

For a 202 the best street/torque combo is 1" 3/4 mandrel or 1" 7/8 crush bent and sixty inches long from header flange to muffler.  Your 2 pipes must enter a very large volume hollow design muffler immediately at their union and must be same length (1" difference is acceptable). Muffler to be at least 2 1/4 inlet and pipe afterwards doesn't matter as long as it is 2 1/4 or bigger.   I like the sound of 2.5"... This will produce  great power/torque  from 3000 to 6000 rpm

For a 186 you need same setup but with pipes 45" long for a sweet spot of 3500-7000....

An old timer speedway mechanic, since dissapeared, got me hooked on this about 10 years ago and it's taken a long time figure out.....

I was hesitant at first to share this info but i know it can be put to great use....

My current 186 produces 117rw/kw and runs a standard port head,a monster 308 duration solid cam and a 465 Holley.   Its entirely streetable idles at 800rpm and pulls hard from 3300-7000rpm and happily revs to nearly 8000rpm. I run a 2.92 diff and it will still pull in top gear from 1200rpm

hope you find this interesting/helpful

2door350

Thanks 2Door350.

This info is both interesting and helpful!  ;)

Cheers,

Ol_Girl_58

In my opinion ,whatever you decide, go see shane at City Car Centre on brisbane street, he does the neatest systems by far....good luck, have fun

Sorry to get back to this topic but i believe a smaller pipe which obviously is hotter, somehow draws the gasses out better than a too large diameter pipe or whatever.cold air somehow minimises the flow.perhaps at low revs the bigger pipe ican't create this vacuum effect aswell(i'm no physicist)

all i can say is just drove my car basically stock 202 with open extractors, then had a muffler 2" conected, but from muffler back is standard size 1.1/4"-1.1/2" exhaust and the difference was noticable

ratbox,were you towing ?haha this is what i'm curious about not that i am going to  what i always have been told is this bottom end stuff,which never bothers me cause i love the revs .can see how a smaller pipe works better in a towing situation you're not speeding off from the mark.i wanna go 2 1/2 but everyone tells me otherwise.heard also ya need a huge cam for a huge exhaust .