3" exhaust clearances

[blueoval]

Just wondering who here has a 3" exhaust system fitted to their car (non IRS) and if so, have you got clearance issues around the diff area to contend with?

Reason I ask is I will be getting mine soon and was told to be aware of diff clearance issues of 3" single exhaust systems on an already lowered car. There may be a chance of the exhaust hitting the underside of the floor or it getting 'pinched' against the diff housing when going over large bumps in the road.

My car is 35mm lowered all round and already has a 2.5" system with no problems of clearance even when fully laden with people that I know of. So should I be concerned if I fit the 3" system?

What other options do I have? Could I go with a muffler that accepts a 3" inlet and dual 2.25" outlets side by side over the diff and out the rear so it clears the diff and doesnt restrict flow?

Constructive responses would be appreciated.

[FTE72]

Keep in mind that you still have bump stops on the diff, so the minimum clearance you have is what is there when car is on the bump stop. Lowering does not change that clearance unless the bump stops have been cut.
I would think that single 3" would fit without too many dramas.

[blueoval]

thanks for your reply.

I doubt my bump stops have been modified in any way.

Do you think there would be any point going for a different setup like what I have suggested to be safe? I'd hate to get the system fitted with the single only to be caught out and it not clearing 'well enough'.

[StealthAu]

Had no issues on my old AU, when are you getting yours done? wil be keen to see what gains you get.

[FTE72]

You are really only adding 12.5mm or so to the overall diameter, IMO that will have less clearance/place to fit issues at full suspension compression than fitting the twin.

[blueoval]

Brendan - Am waiting on a nice tax return to help pay for the new exhaust. Will get that done and then the cam fitting at the same time.

FTE72 - That sounds logical. Is there anyway I can keep the system quiet? My current 2.5" mandrel system is pretty quiet and I love it that way. from the cat, I have a hotdog, glass pack straight thru offset muffler, to a mandrel tailpipe with a resi on it. There is no drone, and its very stealthy but offers good flow....well it offered good flow in NA form...lol. How can keep the 3" quiet without it affecting overall flow?

[The Monty]

I had the 3 inch on SL's in my old car, no problems at all.
I have 3 inch with standard height now and still no issues.
I have a Ballistic cat, and single rear muffler, but no res, and its deffinately quite loud, but not over the top, and deffinately not droney.
http://www.youtube.com/watch?v=4xcccxG6l3o

[AUIIPURSUIT]

i have a 3 inch on super lows.. have noticed some scrapes up near the tranny from previous owner not having enough clearance, but it all seems fine down the back end (im in a ute though ,so nfi what difference that makes)

[blueoval]

thanks lads.

The Monty - That sounds awesome, but too loud fwiw. Appreciate your comments on clearance too, but does you car have IRS or live rear??? What would you suggest to tone the Db right down to a quiet level?

AUIIPURSUIT - Im not sure on the difference of the utes to sedans other than leaf spring rear in yours. But essentially it would be similar clearances.

I think it will come down to making sure the exhaust is fitted with adequate clearance to begin with.

[5L]

why not go to ET and get your 2.5" exhasut sleeved with 3" piping haha.

[The Monty]

Live rear Shav. One way you could quieten it down is put a turbo on it as well, lol.
Seriously though, a res and an extra muffler would do the trick.

[Auturbo6]

3' system fits with no issues what so ever. As for muffler no idea, don't run one on mine, just small resinator at rear. Later.

[blueoval]

thanks fellas.
Shane - lol @ ET. I'm not setting foot in that place.

The monty - yes I share your thoughts.

Auturbo- cheers for the confirmation of clearance.

Looks like the extra resi and hotdog idea like I have already on my 2.5" is what i'll be doing to the 3".

My next question though, cost aside, is it worth going stainless or just go a mild steel redback mandrel setup? Is there any note differences between the 2 materials?

[WiggyMK2]

Stainless just lasts longer mate

[AUIIPURSUIT]

stainless definately has a different note to it as well. youd need to hear both to decide which you prefer.. its a personal preference. i think stainless sounds good, vehicle dependant.

[SLO AU XR8]

Shav, I know that a 3.5" system fits with a live axle.

[The Monty]

Mines mild and Ive had it for 4 years, and it was very used before I bought it.

[Stattic]

I'm lead to believe stainless sounds a bit more crisp can anyone comment? I'm getting my 3" same time as shav

[blueoval]

That was my thoughts too with stainless, not just with longevity. The different material seems to strike a different note, a note that to me sounds better. I have heard this on V8's with stainless systems and I love it. What it comes down to is cost. Is it worth 2-3times more than mild steel???

[Stattic]

Yeah I was quoted double the price for a stainless system so yeah the material itself is about 3 times the cost. It's also lighter if you care about 5kg or whatever it is haha :P

[blueoval]

5kg is neither here nor there Cory. I think I'll go the cheaper option at this stage. Most of the mild steel piping comes with a rust protective surface these days anyway. Forgot what its called.

[POELWYK]

got 3ich from extracters right though it dose not hit or anything i think i have somes pics on the build thred im lead to beleave stainless is the way to go as sound gose

[The Monty]

Whenever Ive heard 2.5 inch AU's with stainless they sound like poo for the 6 cyl, just my experience.
I wouldnt worry about rust on the mild system. It will get surface rust, of course, but seriously, mine would be about 6-7 years old and its fine.
And thats including going sand driving down the coast, lol. No lowered height makes for great fun sliding around in sand and over big humps, hehehe.

[blueoval]

Originally Posted by The Monty

Whenever Ive heard 2.5 inch AU's with stainless they sound like poo for the 6 cyl, just my experience.
I wouldnt worry about rust on the mild system. It will get surface rust, of course, but seriously, mine would be about 6-7 years old and its fine.
And thats including going sand driving down the coast, lol. No lowered height makes for great fun sliding around in sand and over big humps, hehehe.

Cheers mate. i never have taken my cars on the beach or anywhere with sand so I dont need to worry so much about this. That being said, I still want this build to be done on a budget. This rules out s/s at this stage. Had my car been show car worthy then it may be a different story.

Originally Posted by POELWYK

got 3ich from extracters right though it dose not hit or anything i think i have somes pics on the build thred im lead to beleave stainless is the way to go as sound gose

Cheers mate, thats good to hear. Im feeling more confident that I should be able to get the exhaust in with no problems. How much is your car lowered by?

[POELWYK]

Originally Posted by blueoval

Cheers mate. i never have taken my cars on the beach or anywhere with sand so I dont need to worry so much about this. That being said, I still want this build to be done on a budget. This rules out s/s at this stage. Had my car been show car worthy then it may be a different story.



Cheers mate, thats good to hear. Im feeling more confident that I should be able to get the exhaust in with no problems. How much is your car lowered by?

mate i dont know im in 2 minds i brought the car with it allready done

it could be

Super lows
or lows

my white au was on super lows and the mont is at the same lever i think

ill have to pull the wheel off and have a look if u like

[Stattic]

I think I'm going to go for a centre muffler and a hot dog I definitely want it a bit louder than my 2.5 system. Poelwyks mont is pretty quiet (not quiet but quiet considering) so maybe he can find out what sort of setup it is
if I can get my car sounding anywhere near as awesome as josh's I'll be happy with no power gain lmao

[vermiltina]

should fit with plenty of room. i have made myself a 4inch mandrel bent stainless system for my EA and it fits great. plus it is sitting very low

and there is simular room from what i have been looking under the wifes AU

[POELWYK]

Originally Posted by Stattic

I think I'm going to go for a centre muffler and a hot dog I definitely want it a bit louder than my 2.5 system. Poelwyks mont is pretty quiet (not quiet but quiet considering) so maybe he can find out what sort of setup it is
if I can get my car sounding anywhere near as awesome as josh's I'll be happy with no power gain lmao

quiet quiet quiet!!!!!!!!!!!!...................


i think its louder then my white car but i like it

[blueoval]

Poelwyk - i dont want to put you out mate, but i appreciate your offer to pull your wheel off. Dont worry at this stage, I think it should be fine based on the replies alone in this thread.

Stattic - Cory, Im sure you'll achieve a level of loudness from a 3" system you'd be happy with. From what I hear, they are louder than you think.

vermiltina - thats some awesome fabrication skills u got there. well done.

[Stattic]

Mate that exhaust is super cool!