Jump to content
SAU Community

Recommended Posts

So I just fitted a di fillippo 2.5inch twin system to a VU SS ute with ls1, everything else is stock..

The problem is its droning pretty bad on idle and upto 1500rpm, after that its very quiet but with a nice V8 sound coming thru, so I'm after any advice

on what to do with it. I just want a throaty, rumble without a drone , it sounds like an RB30 with no mufflers.

I've called the manufacturer and supplier, both say they've never heard of the system droning, so suggest it must be vibration of the body or touching something, well seems pretty good to me , i think its the rear resonator that maybe isn't doing much?

I have a few things in mind

1) replace rear resonator with a quality muffler like magna flow

2) see if an exhaust shop can make up a J pipe

3) add some 100cell cats and 2.5inch pipe from the manifold back,

4) the tail pipes are well over a foot long, should they be shorter?

Ive read all the commodore forums and nothing mentioned about this system except its the best etc...

Link to comment
https://www.sau.com.au/forums/topic/454175-ls1-exhaust-systems/
Share on other sites

When I bought mine it had an xforce system with 2 hotdogs at the back. Too loud especially at cruise Rpms.

Since putting in the cam (232 at 50) it was unbearable. Ended up squeezing 2 of these in at the back, not much room in a sedan, not sure if ute has more or less.

I welded the 2 mufflers together as they have to touch each other to fit. Massive reduction in volume

http://pages.ebay.com/link/?nav=item.view&id=171273988910&alt=web

Besides the cam high flow cats will make a big difference to the sound. It sounds like your system is a cat back only, correct?

I had full Di Fillippo 2.5inch twin system including headers and cats in my V2 Monaro and it sounded brilliant, much better than my R34 ;)

This was with a bigger cam and ported heads too so hard to say how much those contributed to the note...

EDIT: Also -> www.ls1.com.au

Edited by V28VX37

Its very confusing reading all the commodore forums, they all say this system is the best, so ive spent $800 thinking that it would sound nice and meaty, it does on the youtube clips,

the local supplier and the main business in Melbourne both say its very unusual and unheard of that the system would drone..

Ive had several opinions, probably all biased because they are business's that want some $$ spent at there shop.. they all agree that adding extractors and cats will make it worse and seem to think that the system is a rebranded redback system and just shit, the company says that's not possible as they only supply the "di fillippo" label to be welded to there system and cant be just bought and rebranded....

Ok so , latest word from the company is, " We have a VU ute here with same system and no drone or issue's, but first run the exhaust for 1000km's to "bed it in" and then let us know and we'll try to fix it".

so do you guys think, will this exhaust stop droning once it has done 1000km's?????

post-70965-0-65315600-1424867196_thumb.jpg

post-70965-0-32880300-1424867238_thumb.jpg

post-70965-0-59326900-1424867263_thumb.jpg

post-70965-0-54991100-1424867291_thumb.jpg

Edited by AngryRB

Once the packing in the mufflers bed in it will sound different, but not that different. Doubt it will happen in 1000k either.

Lol @ their response of never hearing one drone and blame fitment. So their exhausts have fitment issues?

Take a video and send it to them.

Ben- that looks like a good idea,

what did it sound like with them on the back? I still want the V8 rumble etc just not the drone, at the moment Its all engine above 2500rpm, which is almost silent.

Edited by AngryRB

Stegea97- at first it wouldn't fit up, but then I loosened the bolts on the cat pipes and manifold to cat pipes and it seems to bold up ok, but it does seem to hang quiet low at the rear, could do with being tucked up as theres almost a foot clearance above the rear resonator, as seen in pics.

I'm talking about the rear muffler, replacing that with two. Hooker aero chamber mufflers are sweet but wouldn't fit at the rear, and are slightly tricky to fit in the center of a commodore, as you really need offset in and out. And more expensive.

I'm surprised to see the exhaust uses slip joints at the back, that's a bit crusty. A proper bolted flanged connection like factory (and xforce ) is heaps nicer.

Do these engines need such large exhausts? a single 3inch on a skyline is enough for over 300kw's, the plan was to get the cat pipes and cats done next and then OTR plus tune and be happy with whatever that puts out, maybe 220-240kw's..

I have a single 3inch X force muffler that sounded good on the skyline, seeing as the rear muffler is so far back from the engine, would this work without

suffocating the flow?

Edited by AngryRB

what is 'best' is mainly subjective, as is perception of drone. I have a twin 3" Xforce on mine with 100cpi cats, 4 into 1 extractors and a H type merge. Sounds good, but at 100km/h on a slight incline in 6th it will drone. I'm not worried because I generally turn the music up louder. Sounds great otherwise, and not insanely loud unless you stand on it.

You don't lose anything down low with bigger pipes, but you will gain a little bit up the top and it gives the LS a deeper note.

I wouldn't be f**king with a DF exhaust unless you already had cats and extractors and it still sounded crap. Bear in mind that you'll want a tune after that point.

Whatever you do' don't drop the rear resonator, it'll make it drone terribly. Remove centre mufflers if you intend on removing anything.

I also used to run no cat and a straight pipe on my Skyline though haha.

Oh and Commodore forums are pretty ordinary for the most part. Grumpy old men on LS1.com.au and mang machine warriors on JC.

Edited by bozodos
  • Like 1

hmm, just took off the resonator off the rear, and Fark!!!! thing sounds like a V8 for the first time,

been told by local exhaust shop that its illegal and if i weld straight pipes to the back it will drone big time. arrgggghhhh!!! :domokun:

Question- If a 3inch exhaust can make 300rwkw's on Skyline, can an Ls1 make the same 300rwkws? if not how much?

Question- How would a Jap muffler, eg. HKS hi power silent with silencer sound on a LS1? same same or epic fail haha

Take into consideration that 250kw's is the target max power and just after a decent sound with no drone.....

Edited by AngryRB

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Put a fuel pressure gauge on it. Replace the turbos. Probably completely separate issues.
    • What copper washer do you guys use on the bleeder bolts? The existing one I have I had no idea where to find it in a local store, I did buy some online but that are only 1mm thick whereas my old one is 2mm+ thick and when I put the new washer out and squeeze the top radiator hose I can hear a bit of air but not with the old one. Does this matter? The new one doesn't leak, but the inner diameter is a bit loose whereas the old one threads on the bolt.
    • Howdy all, after being out a few weeks ago on a spirited drive in my GTR I have 2 issues that oddly have appeared at the same time. Whilst accelerating quickly through the gears all of a sudden i’ve lost power at the top of third gear (below redline around 6000rpm) for no obvious reason.    From that point onwards the car has been running rich on idle, won’t really rev under load without a ton of black smoke and the odd backfire, and dying as a pull up to a set of lights unless I keep the revs up around 1500rpm. In addition when shutting down the car that same night (I was 10 minutes from home) I noticed one of the turbos was significantly noisy on wind down when shutting off the engine. After letting the car cool down overnight it starts up fine, although once it gets to temp the revs start to creep up and down, the exhaust is darker than it should be and it also sounds like it’s running rich (fat note) I’ve put a new set of plugs in it - no change, the old plugs all seemed OK with two of them being somewhat richer/fueled up than the other 3 with 1 being borderline. I’ve smoked tested the intake system via the front of the Turbos, found a split vacuum hose going to the factory boost gauge sender, which I have since replaced.  Also found another leak on the gasket coming off the rear turbo outlet, have also replaced this. After fixing both of these leaks - still have the running rich issue. I’ve also tried another pair of AFM’s - no change here After pulling off the front turbo intake pipes, there is obvious shaft play in the front turbo, which now hisses loudly on light revvs although I can’t see why this would make the car run funny even under idle. I’m curious to know why it’s running rich before I potentially replace/rebuild turbos. The car is completely stock <50,000kms  other than an exhaust. Oil and coolant are all clear. I haven’t bothered with coil packs as it looks like they won’t be the issue due to condition of the plugs. Any help appreciated as I cry myself to sleep!
    • No probs at all. I used to love trying to dig up obscure info for those in need where possible going back 20+ years on SAU.  I did have another look and couldn't come up with any closer match. I'm leaning towards those skirts in your first pic are custom fitments, cut down/extended or from another car entirely and modded to fit an R34 sedan. I would've thought someone in Japan had them and taken a photo at some stage over the last 2 decades but there's nothing. Someone out there must know surely.
×
×
  • Create New...