Exhaust upgrade advice

[marsh]

And so it begins...

The car hasn't even arrived yet and thoughts are turning to potential upgrades for my 3.8 FHC.

First on the list is the exhaust and in an ideal world, I'd like to go the whole hog with a full system from Classic Fabs, but common sense tells me to hold fire until I've got to know the car a little better.

It's currently completely stock, so I'm thinking that for the time being, I just substitute the stainless resonators with mild steel ones, or just remove them altogether and run the car unsilenced to get a fruitier tone and then subject to how happy I am with that, then consider a Classic Fabs system a little further down the line, once the car is ready for a mechanical refresh and I can configure upgrades to compliment a fast road set up.

My objective for the time being is to liberate a little more noise than standard, without upsetting the current mechanical specification.

Any advice is welcome!

Marsh

[Dave K]

Just for info I believe E-Type fabs are now making exhausts and manifolds again.

Can't help you with what exhaust to get for your car, you need to speak to the manufacturers and they will sort you a system out. I wouldn't run without the rear mufflers driving it at any speed I imagine will be unbearable and not the done thing in an E-Type

I do know someone who replaced the rear mufflers 1. 75" or whatever the original size of the pipes were with copper tube, that was back in the 70's so I never heard it run but he said it was loud.

Dave

[kingzetts]

I have the SNGB sports system in SS on my 3.8. Very satisfied with it - a nice fruity increase in noise but still civilised. I know some folk prefer the tonal quality of mild steel over stainless, but I do not have a sophisticated ear and am quite happy. I personally would not countenance running anything louder, out of consideration for French villagers and my own ageing ears.

[1954Etype]

Agree with John. Nothing worse than a loud exhaust on a long journey.

[cactusman]

And stainless steel will last many times longer than mild steel. My MGB Stainless exhaust is still hole free after 24 years.....although the silence baffles are a bit gone....now sounds lovely...

[marsh]

Thank you gentlemen for the advice - update to follow...

Marsh

[abowie]

Headers will not improve the power of your engine and actually can decrease torque between 2500 and 3000. Search the archives.

There are those who swear that mild steel systems sound better than stainless. I'm not one of them.

I have fitted 3 of the Bell stainless systems to my cars. I see no reason to recommend using anything else. They are well made, are a good fit and are well priced. They offer a "sports" muffler that gives a ballsier sound. Their standard muffler on my FHC is if anything a little quiet.

[BRM]

I agree with all the above. I wanted a S1 system for my S2 FHC. I thought about mild steel because of the supposed better sound but the quote I got from P D Gough was simply ridiculous - over £900 - plus VAT !

For half the price I bought a Bell stainless system from SNGB and am very pleased with it. As Andrew said they are good quality and fit nicely. I bought the sports system with straight through main silencers and to me it sounds wonderful. When driven with enthusiasm it makes a lovely deep growl but when pottering through villages or cruising at the legal limit the sound is satisfying without being obtrusive. I wouldn't want anything louder for touring.

[neil4444]

I'm very pleased with my Ecosse Motorsport system (original manifolds plus 2" stainless) & Ian who runs it is a great guy to deal with.

[Heuer]

My Lotus Elan had a mild steel system fitted in 1995 and it still works perfectly. Mild steel sounds different to stainless and returns the car to the exhaust note it had in period. I have mild steel on my FHC and stainless on my OTS. Some people like the original sound as do Jaguar themselves who are now offering mild steel systems for the E-Type. You can expect about 20 years life out of a mild steel system provided you don't use the car on salted roads. My own tests, which you can find on the Forum, suggest the following:

1. Using anything larger than the standard 1.75" exhaust tubes will cause a torque dip between 2,250 and 2,750rpm unless you install venturi's. It will also make the car very tiring to drive over distance because of the bass boom. OK for the race track (although even there noise restrictions are usually in place) but not for the road. They will also reduce the already low ride height so you may loose the silencers over speed bumps.

2. Tubular headers should be avoided as they reduce torque, increase under bonnet heat that can bubble your paint and make a horrible tinkling sound at low revs. The Jaguar cast manifolds are perfectly designed to optimise the XK engine and act as gas extractors at low revs. Big tubular manifolds will produce more power above 5,000 rpm but are compromised on the road.

3. If you want more power (Jaguar tests suggested 10%) order 'straight through' rather than baffled silencers for a 1.75" system. Noise is increased but remains tolerable and is probably the best compromise for road use.

4. The resonators are straight through as standard. If you want the 'original' E-Type exhaust note use a stainless steel system and fit mild steel resonators as it is they that determine the exhaust note.

So the 'ultimate' system will use cast manifolds, standard 1.75" stainless steel down pipes and straight through silencers mated to mild steel resonators.

[64etype]

The build specification for my car is for a cool, reliable cruiser in Texas summer temperatures. In addition to an air conditioning kit, I focused on defeating heat intrusion into the cockpit. For starters, the factory heat deflectors were replaced by a full belly pan fabricated from polished honeycomb aluminum. The next major item to be addressed was the exhaust system. With the exception of the chromed resonators at the end, every component has been coated in ceramic. The manifolds are black, of course. The mild steel down pipes, mufflers, and tail pipes are all done in polished bright silver/aluminum. I've had excellent prior experience with these coatings, both in terms of heat reduction, and longevity. I might have to run the heater for most of the summer....

[marsh]

Thank you David - that's what I'm thinking too.

Update to follow...

Lee

[Barry]

I agree with the general comment about stainless v mild steel, it really gets down to personal choice. However, I tried a 2" stainless systems against the 1.75 st st system with standard manifold it came with on my Series 1 3.8. There was no drop in torque on the new manifold and 2" system. In fact it was developing 7lbs ft more torque at 3500, and similar extra power at 5250. The car came with a Bell system, which is ok, but if you want something better made and extra attention to detail, I would go to Ecosse. Great service. The manifold I have is a FIA tubular as homologated in 1963 and also made by Ecosse. They also have heat treated it. No problems then with paint peeling. I have since had my engine rebuilt, with the head flowed, bigger valves, same cams, SU's, but using slightly richer needles. Lighter flywheel, and balanced crank etc. So, Mildy tuned, and with the Ecosse exhaust and FIA manifold as above. On the synopsis, 267bhp at 5500, max torque of 310lbs at 3250, then 290 from 4100 and still 273 at 5000. It sounds lovely to my ears, but to keep the resonators otherwise it will be hard work.....

[dal2.0litrefrogeye]

I'm very pleased with my Ecosse Motorsport system (original manifolds plus 2" stainless) & Ian who runs it is a great guy to deal with.

This , not fitted yet, but a work of art and a very nice guy to deal with

[Dave K]

I was talking to Uryk of E-Type fabs the other day about exhaust systems and since I beleive he originally designed the systems that Classic fabs and Ecosse now sell, he sold the exhaust side of the business to Classic fabs, this is what he has to say:

Cast manifolds are right - that's why we spent a lot of time and money making the stainless versions with "cleaned up" internal porting.

We're now starting to make heavy wall 1 7/8" systems as I feel the 1 3/4" dia is a tad too small - the new size doesn't lose the small dia's torque but allows a bit more flow at speed - and no booming or tinkling as its heavy wall. Tests so far don’t indicate any loss of torque.

We always use internally baffled middle boxes (with continuous ceramic strand), as the straight through system is way too loud and contributes to booming under certain loads / engine speeds. I've tried to make it as unrestrictive as possible, and for a fast road car with plenty of torque, this is absolutely fine.

The intermediate pipes are squashed, but only on their top side - so you don’t lose the appearance of round pipes and severely restrict the flow as in fully squashed pipes.

The tails are more or less std - stainless perf and packed with stainless wool - but one piece to ensure they don’t look cross-eyed under the reverse light.

We now use stainless poly mounts in the style of the originals - with an integral fail safe on the rear mount.

The reason exhaust systems get scraped is because the middle boxes and inter pipe are hung too low - probably as they've been made wrong with crap fixings and incorrectly positioned down pipes.

For a fast road car, you need more mid-range range torque (drivability) even if it's at the expense of high revs & BHP (high speed). I always work the engines to provide as much torque as poss in the lower rev range and gear the car accordingly - on our cars, 5th gear with a 2.88 CWP feels like a std car running a 3.31...and it never runs out of steam, just pulling all the way to the red line, and burning off those nasty little Porches in the process:-)

[essbee]

So the 'ultimate' system will use cast manifolds, standard 1.75" stainless steel down pipes and straight through silencers mated to mild steel resonators.

Thank you David! Brilliant reply. I will take your advice and go with exactly as you suggest.

[Dawnpatrol]

All very interesting stuff. Particularly wrt the resonators, the works long systems as used 61-64 ish, had only the resonators fitted but in front of the axle. Slightly squashed tubes under the axle and slightly splayed out towards the rear. If you look closely at period photos you can normally tell a works system as the end of the system is scarf cut, not squared off, if that makes sense.
The rear mount was sprung and used an inverted rear of engine tie rod for attachment.
I know this because I still have one strung up in the garage, rusty but sound.