Euro Exhaust - US Bora

I'm not sure of all the pros and cons but I do have an original Euro Bora and we are not that far apart if you need to compare notes.

 

As there's sometimes little choice as to whether to replace aged and very tired rusty mild-steel exhaust systems, and "Euro" seems tempting somehow, I wonder if the MIE product is the same or much at all different from the polished SS units sold by Jacques??

Contemplating same, I lately drove another 73 Bora that was equipped with the latter (installed last year). It looked and sounded excellent and the owner reported it FELT as tho' it had a bit better power/responsiveness. This set-up includes SS304 headers and the two cross-mufflers at the back, but NOT the corner L-shaped resonator/mufflers/whatever. Sound was reported as a bit louder but sounded good, not intrusive. These headers have the air-injection nipples on each path within the first 15" or so of the head, but NOT an O2 sensor port (provide that yourself) for proper tuning. Now I hope to install these on my car. I'm ignoring the 'pure stock' notions, as I drive the car regularly, hard.

Consider your use of the car, and whether you intend all else to remain 'stock'. Eg, the airpump, advance curve, etc. Being an early US model (and in CA, past the smog inspection limit--applicable now only to 1976 and newer) the latter items might be optional in the minds of some.

Then too, some US4.9 model owners have also opted to replace the front-bumper/grille with Euro'. I'm not sure where this stops, quite. I'd like the know the FULL SET of potential changes that would be 'respectable' and performance-enhancing, while not actually being value destructive. However, I'd bet this is not a unified profile for all potential buyers, and that most might be more highly influenced by other factors related to condition and potential future uses. Drivers might be influence by rather different considerations than 'Polishers'.

There's so few Bora units available for sale at any given moment that it might be foolish to be TOO choosy, lest one never actually buy and enjoy the car (particularly driving it).

Please keep up this thread regarding your decisions, your findings re others paths chosen and the results of each. I'm going to do the Jacques' units, despite that I don't know the difference from the MIE units nor if there's any actual measurable performance increase (that will ever get dyno'd). The weight savings alone could be worth it, let alone appearance (deleting old rusty leaky stuff).

NE

 

Just to add my bit to the discussion, I've never seen anyone who actually cared about the originality of a rusty leaky exhaust... even the most die-hard originality experts accept a replaced exhaust on such an old vehicle.

I replaced the exhaust on one of my cars. I gave the original to the mechanic and I told him to make an exact identical copy with stainless steel. The result was perfect. The sound note changed a bit, because the original exhaust was like a cheese full of little holes.

 

Wow! Impressive. Just what is always discussed but 'never' done! What happened to said replica in SS? RE-installed? Bora? Any other insights, comment on change from Euro' to USA or reverse, or any mod's at all? Still have the car?

NE

 

I don't know what MIE is offering these days. The original euro swap out they offered were plain steel and not terribly well crafted (1987).

The earlier US cars do not have the thermal reactors but they do have air injection which can be capped and the difference in performance isn't as dramatic when you swap the headers as the late cars. If you've already had the cam timing changed and you're no longer running the vacuum retard distributor setup then you've probably accomplished most of the european performance upgrades. Getting the distributor recurved is what's left.

You probably will have to make new S pipes from the headers to the rest of the exhaust system at a good exhaust shop due to fitment issues or if you're dumping the thermal reactors the joint is completely different. BE VERY CAREFUL HERE. Clearance and proper heat shielding around the suspension arms as well as those CV boots is important. Don't let a run of the mill Midas guy do this for you.

I originally did my swap with the engine in the car and used the distributor inspection panel (pass seat out) to assist but it's not an enjoyable job.

I think a lot of people make headers for this car now.

 

Go for the real thing. These are produced by the former guys of Ansa who took over all the original drawings and castings of the factory. Correct materials and weldings. I bought from them the exhaust for the Ghibli.
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Those are crap as well. Note the lack of shielding on the S pieces. I have a set of those from ANSA and they are not correct either for the Bora.

 

Also - no lateral mufflers. If you, Dean, (or anyone) has an original exhaust system, can you tell me if the connecting pipes (5 & 6 in the parts manual) are actually flexible tubing as the drawing implies?

Thanks.

 

Just took down my old exhaust system, which was 'done'. 1973US, no cats, air-ports all capped. It did have nice (but 'worn') shielding/cladding at headers, not present on Jacques' system replacements. Now no longer any L-shaped muffler/resonator cans at rear corners. NOT any flexible connectors (which seem a bad idea anyway). Alas, no new and pretty S-connector pieces with the Jacques'-sourced system, tho' they do look nice, and desirable. Using fabbed SS custom bends to complete the connections. Nice or not, ANSA or not, no shielding where passing the CV's boots. However, many excellent heat-tape solutions now exist from hot-rodding suppliers, and wrapping just these connector pipes (and not the polished SS parts necessarily) seems to be the best solution... per the heat-suppress numbers I think can be found for same. Better, longer-term solution than ceramic coating. However, take best possible measures to heat-insulate critical components in area, nearest said components. PS.. did install O2 sensor port to get objective read-outs for later tuning of carb mix, etc.

Also, be aware, the Jacques'-sourced tips attached to final lateral mufflers are far from perfect in positioning and are requiring 'adjustment'--as did the hanger fitting positions. OK, but I'd hoped someone taking all that much trouble in the first place might have used a serious (near-perfect?) alignment jig. Oh well, it's going to be MUCH better than the 'corked-up' and internally rusted 40-year old stock 1973 system--adios. MPG had been falling off lately, and now will see if this improves it (or just makes driving harder too much fun to worry about it).

Bob: I'd love to make certain re my cam-timing, distributor advance, etc. (anything easily adjustable), are all best set up for most power/efficiency. Not clear to me what exactly to do if anything re vacuum advance for 1973US distributor, except perhaps just disconnect. The Swain diagramme curves are interesting but I'm not quite sure what those may mean with respect to my particular car. Having Distributor "re-curved" seems to imply I'd be using a DYNO set-up to know what/when/how-much? Probably a prior full discussion exists of all this but unknown to me--please advise if you recall any/all re how to discover.

I keep thinking there should be some way to create a better 'weather pattern' inside the engine area to move the heat OUT and AWAY much more quickly--eg., possibly somehow venting/louvering the inner fenderwells for induced airflow drafts and/or setting up a kind of not-too-obvious diffuser set centrally, post-axle line.
Best,
NE

 

Are they crap at all or are they just missing some parts which, maybe, shouldn't neither be sold along with the exaust system? Are heat shields consumables? How old is your ANSA system?

I really can't understand.

If you need info I can talk with the guys so i could tell them "hey, some say your Bora exhaust systems is crap because of this and that" so maybe they can give me an helpful answer.

Edit. Just spoken with them, they told me that the heat shields, as well as the mainfolds, were made by Maserati itself and not by ANSA which was the official supplier. They consisted in a sheet of asbestos wrapped by metal. I asked them to send me a photo of the system, so we could see if in Modena they don't know how to do things for cars made in Modena.

 

Just to clarify folks, those "S" shaped pieces that go under the CV boots were not flexible exhaust pieces from the factory. That's an aluminum spiral wrap over some asbestos covering that's tack welded in place.

Of course we can do much better than this today. That was the point of my comment. Don't just throw some "Ansa" style system on there and expect everything to work well long term.

Back then this was considered a performance system but it's noticeably noisier without those large L shaped cans. This was meant to be a long distance GT car and not a Pantera. So decide what you want.

The Ansa setup I have is from the original time period and it's not on my car.

All of the factory original exhaust rear of the headers is heat shielded. For the early and late air injected cars there will be shielding on the headers as well. It just doesn't work right. None of the air injection headers did.

Over the years I've had plenty of exchanges with folks putting aftermarket exhaust systems on these cars. None of them just bolt on. One of them even resulted in a lawsuit.

Also, this is pretty typical for aftermarket exhaust fitment on these old Italian supercars. I've had the same exact fitment issues with my Espada. You have to be prepared to do some extra work to insure that you get a good fit that lasts.

 

Dean,

If you get someone to make a really nice set of pipes out of stainless then there are a couple of things you can do. Just make sure that they form them to the best clearance so that when you wrap them there won't be any clearance issues. Afterwards you could send them out for inside & outside ceramic coating - Swain Coatings. You could also use some of the many header tape style wrap products out there as well. Now given your rather probable "normal" driving of this car, no road racing or extended track stuff in hot weather, I think you and most people will be fine with the basics of a header wrap tape.

If you want to go anal then after the tape wrap have a good metal fabricator & welder guy spiral wrap it with the aluminum strip and tack each seam just like the originals.

Pebble beach stuff!

For extended hard and high speed driving the headers and those pipes can glow red and that's when the trouble starts. Not many will be doing that though. But if you do decide to drive to Monterey this August for the 100th and go through Nevada for some terrific road experience just know that you can cause trouble for the car driving it at high speed for long periods.

 

This is the Stebro system I bought to finish the Euro bumper conversion on my car. I am NOT endorsing that company, but neither am I panning it just yet. You can find many unhappy Stebro customers on the web. I'll wait until I see how well it fits and sounds.

What this picture shows is the kit as delivered with the lateral mufflers and connector pipes. I did a trial fit with the engine still in the subframe and I think the rear section will hang properly, but the S pipes are worthless.

There are two other S pipes in the picture. They're from the Stebro US style exhaust that was on the car. It seems clear that the previous installation required custom fabrication, but at least it fit well afterwards, sounded good, and was not too loud on the highway. That system had lateral mufflers as well as a single big transverse one.

I asked about what appeared to be flex pipe because I was planning to use a modern equivalent in the new S pipes to solve one known and one perceived problem. The known one is heat rejection near the CV joint. With triple layer construction the new style flex pipe should, like a double walled exhaust manifold, reduce radiated heat in that area. I can also make the pipe stay as far away from the joint as possible. The other reason is that I see there's very little room for the exhaust tips to move in the grille. I think the flexible section will allow the rear mufflers to stay relatively still while the engine/transmission rotates under torque. We'll see... assuming I ever get around to it.
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After several burst CV boots out in the middle of Nevada going faster than I should I did figure out that having the joint completely sealed is a no no. Providing for a filtered vent that doesn't spin grease out of it fixes that problem but the concern about heat stress for my situation still led me to look for other solutions. There are silicone versions of these boots available somewhere? Though I never found them I did see some installed on Herb Kaplan's Bora. He and his son Brad modified their Bora extensively. I believe they're both gone now. I have no idea where that car went.

The other idea I had was to place a tuna can style shield over the joint by attaching it to the joint with the 4 bolts and letting it spin with the joint. Balance would be an issue but that would shield the joint from the radiant heat when those pipes glow red.

 

Until you mentioned it, I'd forgotten about these.

U-JOINT GREASE GUARDS

They're grease shields, but I wonder if they can be mounted to the bottom of the side plates and serve as heat shields?

 

Sort of the other way around but I can attest the MF mess that grease makes of one's detailed engine compartment! I had to clean it twice from this stuff but once a boot lets loose no wimpy guard is going to prevent the big mess. Best to prevent.

Yes this is the idea just a complete circle and it rotates with the joint. There's not a lot of room to do much else as far as I could tell.

 

Great to see all these responses and comments, TLA (true life adventures), and informed speculations. Also, particular thanks to GLB for posting that picture of complete SS replacement mufflers system (sans headers). Somehow I'd not seen anyone's offer of SS L-shaped cans being available, so presently have omitted same (but will have to find and buy them if too loud w/o).

Meanwhile, a very experienced and competent hot-rod, motorcycle, and LSR car friend sent this as one of the tape sources possibly worth considering >>
Link to an interesting heat insulation from DEI:
Titanium Exhaust Wrap with LR Technology 010128 | Purchase DEI, CryO2, Ny-Trex, Boom Mat & SPA Turbo Products | Design Engineering, Inc. - Thermal Performance Products

May it be so. Further thoughts all appreciated, as the CV area seems weakest (which is mainly where I thought I'd try the said tape idea, on the pipes as they pass by--actually entire pipe from headers back to mufflers.) I thought I recall he said he'd seem some data indicating much better heat suppression than with ceramic... but both couldn't hurt either.
--NE

 

Looks interesting but keep in mind that besides the protection from radiant heat when those pieces get glowing red (not likely for most of you) you also need basic thermal insulation so that the CV joint doesn't just toast on a hot day.

So find out how effective it is at basic thermal insulation. There are a ton of very neat products out there now.

I vented my CV joints with a pin prick punch hole in the center of the inside cover plate cover with a piece of glued on felt over the hole towards the inside of the joint. Grease isn't thrown out at the center of rotation and there's enough of a gap between the CV joint and the transaxle flange to allow for some expansion flow for the air.

Another tip I got was to insert a part of a spray tube from a brake clean can inside of the shaft side of the boot before clamping down. That can be done by anyone but I have no idea how well that holds up.

 

Thanks for all prior inputs/opinions/experience/tales.
Did install Jacques' sourced SS headers and mufflers (latter hangers needed adjusting}. No intermediary L-cans. Heat tape as pipe passes CV joints, entire distance between headers and mufflers inputs. All is well. Good sounds at idle and driving modestly, pleasant bass note. Higher revs and more agressive throttle sounds 'agressive' but not stupid. Now to see how CVs survive the experience. Did insulate around starter etc., but nothing over the headers, per se. Go faster.
--Engine seems to breathe lots better, with better acceleration take-up. However, can now hardly help but think of how to get better cold air source to the carbs' intake, w/o intrusion of heat from headers et al below. Bora and all mid-engine cars nifty on 'balance' but difficult packaging for cold air in. Ideas??
--NE

 

How was the RH header? The one I got from him had an enormous indentation in one of the runners, supposedly for clearance though my original steel MIE headers have none?

Without cutting up the car and dramatically changing the appearance there are none.
You've done enough already, enjoy the car. You can see some of the attempts in the Norbye book and a few more in the Bora Picture thread. Look at the Bora in my avatar ... you really want to spoil that?

Add some heat shielding for the shift rod linkage under the LH header. The heat dries out those needle bearings. I enclosed and sealed the assembly with seals at each end and straight piece of silicone radiator hose between the two supports with a breather and packed it with grease.

Add a shield to block the radiant heat from the headers to the fuel pump and improve the one on the gas tank. You should be fine then.

A fuel cooler would be a big help too. I think some Meraks run one behind the RH rocker panel? I even insulated my rubber fuel lines with that super flexible rubber foam AC cover but it looks like hell.

I tried a lot of experiments during my high speed sojourns to the desert. The most interesting one was to add air scoops, ears really, on those rear corner vents and use 2.5" hose to force the air into the air cleaner. Looked like absolute hell of course. But the sound of the burbling webers when the window was down was fabulous.

I ran into a bit of problem one night coming into Ely Nevada. The car ran great but then it began to drizzle. The car drove just great all the way to our hotel. But the next morning I had to pull all the plugs and dry out the engine. So a water trap needs to be incorporated if you really want to do this.

It really did look like crap though and I had to leave the spare at home.

Performance? It was cool out that night anyway.