Sounds like bollocks. The hanger brackets are mainly towards the rear where the box is designed to be. You want it as free flowing and unrestricted as can be from turbo to the tip. If you want the box anywhere then it's at the back.
Spend the extra and get the quality of the JP exhaust and their knowledge too.

 

You want it as free flowing and unrestricted as can be from turbo to the tip. If you want the box anywhere then it's at the back.

Dunno bout that dude?!?! A restriction (box) is still a restriction no matter where it is in the system TBH!
It's far more important to consider HOW restrictive the box is rather than WHERE it is

 

JP. great quality, fits perfectly, and will stand a better chance of making a gain. Pays yer money.

 

Gains from an exhaust!

On a diesel no less!

 

Many people on here have powerflow systems and had no issues. Me included

Also a few people have had boxes put in the centre, a single box in the middle instead of the 2 at the back.

I have 2 very small boxes at the back as no one ever mentioned about a single box in the middle at the time.

The main reason people opted for a single box in the middle is for a more throaty sound

Ive had mine done a long time now and im still happy with it.

It comes with a lifetime warrenty but i do have to get it checked annually.

All in all its a very good system

 

Silencers on a diesel. NO THANX! Lol.

 

StuC, the exhaust gases slow down as they travel through the pipe. Welding ridges, bends and silencers all disrupt the flow creating negative waves. The less disruption the faster the flower and the better the engine breathes. The chimney effect at the end of the exhaust also increase the gas flow pulling the gases the last part of their journey. If you have to have a silencer then the end of the exhaust pipe is better.
Twin exit exhaust fitted to new cars tend to be a pipe leading to the silencer with two exhaust ports exiting them directly. Only snag in modern exhaust system effecting performance is Cats and DPFs which both require the heat from the exhaust fumes to operate efficiently so are fitted closer to the engine.

 

I understand the science behind it dude, its the effects on any standard road car I'm questioning!

Were only talking about a few bhp at the most (even on a highly tuned engine) and unless your flat out on a track I doubt your gonna notice.

Anyway we've been here before and..blah,blah,blah

 

Power wise on our cars it doesn't make much difference but response wise it has bigger effect. Going from the standard exhaust to the JP was as noticeable as having the car decat'd. It revs much more freely allowing access to the power you have more easily

 

Sigh, here we go again..... Think about the logic behind a twin exit system... Ideally it should be a True Dual system with an exhaust for each bank but thats not possible for most cars..... The single box before the y pipe is logically less restrictive than a system with two boxes at the end (or wherever else in the line).... Less boxes equals less restriction.... Simple

I'm back off to sleep now

ps I'm not questioning JP or anyone else's quality of exhaust systems... Just that the gains (real bhp or torque OR "Drivability") are a placebo effect!

 

Just like a K&N filter. -------Er sorry, sticker!

 

Hi

Just to add my tuppence worth, it makes no difference on number of pipes or silencers what affects performance is flow rates and back pressure.

With normally aspirated engines pipe diameters and capacities can be used to scavenge cylinders and valve overlap can be used to add flow of fresh mixture into combustion chamber.

With turbo charged engines things are a little different, energy and with it majority of noise is absorbed by turbo when under power.

Where silencers can kill performance on either engine is if they reduce noise by throttling flow by creating excessive back pressure. A well designed and presumably backed by dyno tested system should always outperform a few random lengths of tube and boxes joined together.

Peter

 

Some light reading here guy's. I have no comment to make except read and inwardly digest!

http://www.myturbodiesel.com/1000q/turbocharging.htm#turboexhaust

 

Some light reading here guy's. I have no comment to make except read and inwardly digest!

http://www.myturbodi...tm#turboexhaust

Geez man, can you not find us something a little more technical and comprehensive to read?! That'll never sustain me through my tea break

 

Diesels are not affected by back pressure as much as with petrol. A proper tuned exhaust has its length carefully measured so that the exiting exhaust pulse is at the point of the new intake of air so the one helps pull the other. These pulses are normally per bank to avoid interference which is why V engines have 2 pipes and straight 4's have one. A twin on a straight 4 is just for show. However. my understanding of the ST220 is that its twin exhaust joins at the middle (?) and this must be for a good reason. Maybe in tests they found that as they could not tune the length of the exhaust they found better results by joining in the middle but this is speculation.

At the end of the day it's a saloon car not a racing car and as people have found it improves the sound and feel but it's not going to knock seconds off your acceleration! If you like it great. That's all that matters

 

Hi

Correct there GT, the ST220 needs a correctly tuned system where our tractor engines just need an open pipe. Provided it is of a large enough diameter.

Peter

 

Ah! someone actually read this then?
http://www.myturbodi...tm#turboexhaust

 

Just as I had said that if you are going to have a silencer have it as far away from the engine as possible.

By the way the OP doesn't even have a 220 he has a TDCI. ST155king, save some more money and get the JP exhaust at least they know what they are doing and not just fudging a system together for show and noise effects. If you just want show and noise then get a fancy exhaust tip and CD track full of V8's at full chat, much cheaper

 

Hi

Sounds very similar to the sound mine makes, with the small straight through rear box I have fitted. Obtained from MIJ.

As there is a 2 1/2'' hole up the middle I doubt if it does any silencing!

Peter

 

After removing the cat the only restriction left in the system is that single silencer. I'm thinking when mine gives up the ghost, of having just a straight through box, Sadly my tail pipe is hidden and I won't cut a hole in the rear bumper so that means an angled outlet pipe. It might be better in my case to have the silencer further forward in the system to hopefully keep the noise down. Since it would be free flow, performance wise it wouldn't make any difference.Any thoughts?

 

IMO Pete you should just tell the custom exhaust builder what you want..... Loud but not too loud and not droney on a motorway cruise etc........ and they will build what you specify!

Well that's what a good custom builder does......

I've a single free flow centre box on mine but its tiny so its fairly loud..... What I wanted!

You might want a slightly bigger box to keep the stealth style

 

mines straight piped from the turbo with a straight through backbox tail piece 6"by 4" mine would sound like stc c described loud but not droney on the motorway mine being the tddi i had the extra sliencer when it was removed thats when the exhaust had the extra grunt(noise)

 

My JP is a downward exit pipe from the silencer and it just burbles in most cases but when you plant your foot you get a nice throaty sound. Best of both worlds in opinion as you can travel long distances at a good pace without the headache and ride around town without looking a tool

 

Did you have it custom made? Anychance of a pic -----obviously when the weather gets better!

 

Mine is the same as this but with a slightly longer flexi section because they modified it after someone had a problem

http://www.stdrivers.co.uk/forum/topic/15537-jp-exhaust-estate/

 

Many thanks mate very interesting. I don't need a back box yet but I'll have browse on the JP website,

 

Not much on their website your best giving them a call as they ate very helpful. If they're not too far go visit them for fitting and be amazed at the vehicles they are working on

 

I have decided to go down the JP route once funds allow hopefully with decat insurance depending(asda online). I hope the exhaust can survive til then and MOT