New 3'' Manta exhaust,does it quieten down after carboning up

[kleanphil]

Does anyone else notice any rattle from an open aftermarket system with bimodal closed?

Hi, like this ( X-Force)

I managed to get both replaced after a year under warranty , the other butterfly got stuck

 

[abuch47]

Hi, like this ( X-Force)

I managed to get both replaced after a year under warranty , the other butterfly got stuck

Can't watch but more so just tinny rattle sound when bimodals are closed, probably just the gases vibrating the flap creating metal on metal sounds.

 

[dimetime]

Does anyone else notice any rattle from an open aftermarket system with bimodal closed?

yer my dpe 3inch system rattles with the bimodels closed, ended up taking out the fuse so it's loud thought the whole rev range rather then 3k onwards

 

[abuch47]

yer my dpe 3inch system rattles with the bimodels closed, ended up taking out the fuse so it's loud thought the whole rev range rather then 3k onwards

There is a $150 relay/fuse tap on ebay that allows fully on/off bimodal with remote. Really easy to turn off when you get home or driving past cops.

 

[Jackel]

If it's any help, I've just had a new exhaust system installed and as others have said, will get louder if anything. Now have 1000ks on it.

No blower or cam on mine, but with engine-back 3" with 1 7/8 headers (all DPE) bimodals made a decent enough difference.

Not sure if its the same as the pictured muffler design above, but for me makes enough of a difference to not worry the neighbours, which is really the only reason I had them fitted - that and being able to relax at stop lights with a copper behind you.

Big enough difference at idle with this setup to make it worthwhile.

Ive got a Vf ssv ls3 S2. No cam & no supercharger. Just a custom tune & otr.
Ive thought about doing the same thing but 2.5 inch instead from engine back. 1 7/8 headers all Harrop/HM with bimodals.
How much of a difference do the bimodals make in terms of noise reduction at idle and full throttle? Do the bimodals quieten the car down heaps?
I want it to be reasonably quiet but roar when i put my foot down.
Maybe 200 cell cats?
Dont want to piss off the neighbours, the mrs or the coppers.

 

[Jackel]

Mines similar set up, LS3 with Magnuson supercharger and a cam.

It had a full 3 inch Pacemaker system ( 1 7/8 inch headers, 100 cel cats). hideously loud.

Put a 2.5 inch Hurricane cat back with quite restrictive mufflers. Noticeably quieter when driving, though still too loud at idle, which i'm guessing due to the cam.

Like Stooge said you could be wasting your time putting the bimodal flaps on your mufflers. Try blocking off one of the outlets and see if it makes a difference

Hypothetically if u didnt have the cam or had a mild cam and 200 cell cats instead of 100 cell cats would it be much quieter?

 

[MY17DIR]

Ive got a Vf ssv ls3 S2. No cam & no supercharger. Just a custom tune & otr.
Ive thought about doing the same thing but 2.5 inch instead from engine back. 1 7/8 headers all Harrop/HM with bimodals.
How much of a difference do the bimodals make in terms of noise reduction at idle and full throttle? Do the bimodals quieten the car down heaps?
I want it to be reasonably quiet but roar when i put my foot down.
Maybe 200 cell cats?
Dont want to piss off the neighbours, the mrs or the coppers.

Mate of mine has pretty much same setup as strattos on his director and he said exactly the same thing. Bimodal makes a good difference and worthwhile enough to install it to keep the noise down when required.
I'll be doing the same. DPE big boy system has 3" 200 cell cats anyway. 3" mid section but tapers to 2.5" after the big center hotdogs.

 

[mpower]

consider J pipes as well.

changes the exhaust characteristics quite a bit and honestly imo improves them into something much better.

 

[dimetime]

Listen to that with headphone and you'll know what you need to do!

 

[Jackel]

Listen to that with headphone and you'll know what you need to do!

What are the mods to the DREMSE?
Full exhaust, high flow cats etc?
Sounds great.