To go straight through or not??

[1nando]

Okay, so ive got a 2.2 110 puma. It has a Bruce Davis alive tune and bigger cooler and egr removed.

Now i was reading the Bowler defender specs and they have a stainless steel 3inch exhaust. I currently have the standard exhaust system with the egr blanked, decat, and rear muffler removed. I only have the centre muffler left on.......

My question is whether to remove the centre muffler or not?

I have done many google searches on vgt turbos and exhaust back pressure and cant find any negative info against the idea. My reasoning is to reduce any potential egts, quicker spool with greater torque......

Thoughts welcome

Sent from my SM-G925I using AULRO mobile app

[cripesamighty]

I saved this off the Lancer Forum many moons ago. I can't vouch for everything he wrote, but some of it might help with your queries, esp. backpressure. I'm sure the more knowledgeable ones here will be along soon enough to give you a definitive answer.

[n plus one]

Okay, so ive got a 2.2 110 puma. It has a Bruce Davis alive tune and bigger cooler and egr removed.

Now i was reading the Bowler defender specs and they have a stainless steel 3inch exhaust. I currently have the standard exhaust system with the egr blanked, decat, and rear muffler removed. I only have the centre muffler left on.......

My question is whether to remove the centre muffler or not?

I have done many google searches on vgt turbos and exhaust back pressure and cant find any negative info against the idea. My reasoning is to reduce any potential egts, quicker spool with greater torque......

Thoughts welcome

Sent from my SM-G925I using AULRO mobile app

Straight through with decat on a puma is reported (by BAS from memory) to risk turbo over speed/clipping.

For this reason I went straight through but kept the cat - nice note, heat wrapping to reduce cabin heat and is nice and neat under the truck too.

[PAT303]

I wouldn't go straight through because of the drone. Pat

[1nando]

Straight through with decat on a puma is reported (by BAS from memory) to risk turbo over speed/clipping.

For this reason I went straight through but kept the cat - nice note, heat wrapping to reduce cabin heat and is nice and neat under the truck too.

I dont ubderstand the turbo oveespooling as the actuator is electronically controlled.

I have a drag racing background, my understanding has always been, and this is a simplistic way to put it:

The quicker exhaust gases are removed from the engine the greater the amount of air you can get into an engine thus producing more power with lower egts.

The other thing is, how would a straight through 2 and 1/4 inch pipe make a turbo overspool but not a 3 inch pipe like on the bowler defenders when they are using standard turbos?

Sent from my SM-G925I using AULRO mobile app

[1nando]

I wouldn't go straight through because of the drone. Pat

I could put a hot dog in it to reduce noise whilst still increasing flow....



Sent from my SM-G925I using AULRO mobile app

[dromader driver]

my hotdog just fills up with soot. Would use just a straight pipe next time. only replaced the centre muffler due to fatigue cracks. :)

[1nando]

my hotdog just fills up with soot. Would use just a straight pipe next time. only replaced the centre muffler due to fatigue cracks. :)

Do you mean you replaced the centre muffler with a hot dog?

Sent from my SM-G925I using AULRO mobile app

[n plus one]

I dont ubderstand the turbo oveespooling as the actuator is electronically controlled.

I have a drag racing background, my understanding has always been, and this is a simplistic way to put it:

The quicker exhaust gases are removed from the engine the greater the amount of air you can get into an engine thus producing more power with lower egts.

The other thing is, how would a straight through 2 and 1/4 inch pipe make a turbo overspool but not a 3 inch pipe like on the bowler defenders when they are using standard turbos?

Sent from my SM-G925I using AULRO mobile app

Dunno, only report what I found in my research.

Maybe give it a go and find out? A replacement hybrid isn't that dear?

[GypsySamuraiAnt]

I come from a bit of an amateur racing background and have good experience with small hybrid turbos. And BAS is right a wrong at the same time. Right in the fact to small turbos when pushed can easily spike. Wrong in the fact that with live road mapping under real load (not Dyno) and consequent tune that any spikes can't safely be tuned out. The key as always is keeping the AFR and EGR's safe and dandy.

My last project was a VW Polo 1.8T with a factory Ko3s Borgwarner turbo (tiny town). Stock power was 110Kw and 280nM. With changing the turbo wheels to larger ones and a ceramic ball bearing cartridge combined with a 3" street legal exhaust (stock was 2.25") and custom tune with road mapping from Custom Code in the UK we got 180Kw's and 440nM's ATFW's. That's right at the front wheels of a 1000kg fun machine :p No dangerous spikes at all tested time and time again at Lakeside and QR with stock rods to prove the safety of the tune!

So my guess is BAS went for the economical off the self mass produced tune option as you would for the stock exhaust diameter.

By the way the whole back pressure myth has been dismissed in the racing world for quite some time :cool: Speak to anyone at Magnaflow to verify. Any exhaust diameter resistance is not your friend.

I miss those days

https://www.aulro.com/afvb/images/imported/2015/11/798.jpg

https://www.aulro.com/afvb/images/imported/2015/11/799.jpg

https://www.aulro.com/afvb/images/imported/2015/11/800.jpg

[barkingmad]

My last project was a VW Polo 1.8T...we got 180Kw's and 440nM's ATFW's

Did it pass the emissions test?? :wasntme:

[GypsySamuraiAnt]

Did it pass the emissions test?? :wasntme:

So not my problem anymore lol! No it was petrol :cool:

[dromader driver]

1nando,
yes exactly.

[GypsySamuraiAnt]

Sorry forgot to mention I used a Magnaflow 3" resonator to kill the drone which had no effect on performance. And that's 3" straight from the turbo outlet to the rear 3" cannon outlet :)

[rick130]

If a Tdi with a 3" pipe is anything to go by, the noise and drone is horrific (and I used to race)

At a minimum you need a resonator otherwise the cabin literally becomes your resonator.
It isn't good. :(

After about three years I just couldn't stand the noise anymore with just the resonator and fitted a centre muffler too, much better now