Sports exhaust

[Iansparky]

Hi All
My car is currently fitted with standard manifolds but has the 2 inch straight through sports exhaust, whilst it does sound incredible and makes a fantastic growl when you accelerate it is a tad tiring after anything longer than 20 mins, a friend of mine has the 1 3/4 standard baffled system but I am keen to hear the 1 3/4 straight through sports system before I decide what to do, is there anybody that has this system fitted not too far from solihull, south birmingham preferably in an OTS that would be willing to take me for a drive as a comparison.
Many thanks
Ian

[mgcjag]

Should be lots of Jags at Oulton Park this weekend...Steve

[Iansparky]

Unfortunately I can't go to that this weekend, although I did go to the brdc at Silverstone 2 weekends ago with the hope of speaking to someone, the reality though, is that even though there were loads of e types there, most were unoccupied, the owners somewhere on the circuit, and even if they were there we wouldn't have been able to go for a drive as there was no vehicle movement during the day,
Ian

[rfs1957]

If you search « exhaust » and rfs1957 you should find a post I made 10+ years ago about this.

I tried running straight pipes in place of the centre boxes, keeping just the tail silencers, and it was embarrassingly noisy, aside from destroying the nature of the care for anything longer than a 10 mile drive.

I refitted the central silencers, but before I did I drilled out - with a « carroteuse » - or sleeve drill (?) the single thickness baffle that is visible inside the silencers.

I think it is on the way in, not at the exit.

10 minutes work.

This added EXACTLY the right amount of zing when you cane the car over 3000 rpm, without taking anything away from its suave magic-carpet drivability - grace did Jaguar called it ? - for the remaining 95% of my usage.

If I want to hear what it COULD sound like, I go to the Revival and listen to Jenson Button, Adrian Newey, Rob Huff and C°

[Iansparky]

Thanks I will search for your post

[40GT]

There are a few different manufacturers of 1.75'' systems, my car was fitted with stainless restrictive baffle type centre boxes as rfs1957 has mentioned, way to quiet and certainly no roar, but boring these made no difference as they were multi restrictively blanked. So I then bought straight through centre boxes ( still 1.75'' ), thinking these might be on the loud side I opted to match these with the early 3.8 long resonator style tails in mild steel ( having the utmost hatred of the sound of a cheap stainless tin can sound ), the car now is actually on the quiet side and will only make '' the E sound'' at 3k plus, but is a pleasure on a long cruise.

I would say go for a stainless system of 1.75 straight through centres with later length ( short resonator ) tails, if I come across a pair of Mild steel short resonators I may ditch my long versions for a touch more volume.

[Iansparky]

So would you go mild steel throughout or just the rear resonators
Ian

[40GT]

I would go all Stainless with Mild steel resonators, that's what I have at present and there is a nice depth to the note with no '' ting ting ''.
Finding a system with straight through 1.75 centres is a must, mine are made by Falcon, good quality but I'm not sure they are still in business.

[Heuer]

You can go with a full mild steel system (P D Gough in Nottingham have original patterns) and they do sound superb. I had a mild steel exhaust on my Elan S4 and it lasted from 1995 and is still going strong I believe.

Rust is not a problem on a classic car which will only have selective use and a mild steel system will outlast your ownership of the car. I agree on a straight through centre box but not on a FHC as the booming is painful in the cabin.

[johnetype]

I have the same arrangement as RFS1957 describes above created by taking the standard mild steel system bought from Jaguar and then drilling out the two baffles.

Sound is as he describes and for me is the perfect balance given the standard system with the baffles left in the centre boxes is just too bland - and restrictive.

The baffles are at the ends of the inlet pipes to the centre boxes.

I'm 30 miles from Solihull but have a FHC rather than a OTS. However, given how few door glass rubbers and I have and no roof lining I suspect the audio experience is more akin to an OTS car

[Iansparky]

If we are drilling out the baffles in the standard silencer are we not creating a straight through box or are there more baffles inside
Ian

[TGN]

I’ve also got a jaguar mild steel exhaust, if you drill out the baffles at the inlet of the centre silencers you can see straight through. It’s not at all boomy in a FHC

[johnetype]

There's definitely wadding inside, can't recall over baffles, so you're left with more than just a straight through pipe would be. Somewhere I've seen a drawing/image of the standard centre box cut open but can't find it.

[Heuer]

A true 'straight through' silencer design is a single perforated tube from one end to the other surrounded by fibrous wadding much like the E-Type's original resonators. Drilling the baffles will alter the sound and allow freer flow of exhaust gases but no idea what affect it will have on performance. Engineering tests at the factory showed the standard exhaust system reduced power output by 10% (23bhp) and the air silencer reduced power by 6% (12bhp). Fitting a correctly designed straight through silencer and inlet trumpets can potentially give you an extra 35bhp.