Lotus Elan Central
Exhaust Downpipe Replacement

The Elan is an incredibly wonderful car and I wouldn’t trade it for anything at present! This said, the car has a few notorious design flaws. We all know and love the Cam Angle Sensor—Well I’d like to introduce you to your "downpipe."

Down What??

The downpipe is a simple bent pipe that connects the downward-facing turbo exhaust flange to the forward-facing catalytic converter pipe. Being stuck between a vibrating engine and a long, relatively immobile exhaust system, this pipe takes some punishment. Furthermore, this pipe is one of the lowest parts in the front of the car and is easily scraped if the car rides over road dips and speed-bumps too fast! If you look under the front of the car you can see this pipe a bit and maybe get an idea of its condition.

downpipe image 1

Symptoms of a failed pipe:

If the pipe fails, you will know it!! Mine failed spontaneously while driving on the highway. Your quiet exhaust note in the rear will turn into a howling roar, emanating from under the front of the car. You will likely worry that something horrible has happened, but I assure you that a failed downpipe will NOT change the car’s performance significantly in any way!! A quick visual inspection under the front of the car will confirm your misfortune, but let you know it was not anything worse.

You could theorize that the decreased backpressure in the exhaust system will actually improve performance, but I noticed no real change in the car other than the howling exhaust note. I found the sound pleasing at first, as it was very rough and "throaty," but setting off every car alarm in town and not being able to hear your stereo on the freeway will get old after a while. It definitely gives the Elan a different character though!

My pipe failed at the front flange weld; and I suspect yours will have the same fate. This happens because the front joint is immobile, and years of vibration and rust add up to no good. The rear joint actually has some built-in play, using a spring-loaded bolt construction. The rear of the pipe is also not as prone to rusting as the front. Late model cars sometimes have a braided, flexible stretch built into them (pretty ingenious, in fact)—to remedy downpipe failures like ours.

Bonus: I pointed out the metal exhaust pipe hanger in the above picture for a reason. This piece broke on my car and has done so on others’. It breaks at a weld (likely for reasons similar to the downpipe) and causes a metal vibration sound. It can be remedied, as in my case, simply by removing the bolts and metal bracket altogether!

Replacement Components:

Pictured below are the parts I used for the replacement. I would recommend everyone to get at least these parts! If your Rear Flange nuts and bolts are in poor shape, you may want to get them too. Your turbo exhaust flange will have rust on it, and NO DOUBT, like mine, your front flange nuts and studs will be rusted heavily. If they are not heavily rusted, they may be reusable—but I think you should be safe and get replacements. My old front seal was crushed, rusted, and fused to the old pipe. My old rear seal was blackened and crumbling. I’m glad I decided to pay the extra money for the seals—you should too!

downpipe image 2


Check with your Lotus dealer and perhaps on-line Lotus parts companies (see my links page) with regard to availability and prices. I checked with R.D Enterprises and JAE and they both had the parts in stock. As I remember, the downpipe cost about $100, each seal cost about $25, and the nuts and studs were a few dollars each. Not a truly cheap job, but unless you want to spend MORE money to upgrade to a custom, flexible, braided pipe or an entire exhaust system upgrade, you’re stuck with a stock replacement. Perhaps this will be the encouragement you need to upgrade to something ‘better.’


So I get the parts and diagrams and go to attempt to put the damn thing in myself, and to keep this part short, even using a half bottle of 'liquid wrench' I was unable to get the rusted nuts off the front flange. I'm thinking, "my tools are weak, I need to find someone with an air-wrench or a nut breaker." I've now given up—the freaking car is just too low to EVER get under well enough to get good leverage on anything! Even jacking it up makes me think I'm going to break the bottom of the car each time. So I call a few local muffler/exhaust shops and take it to the one who says they can help me out. They have a nice ramp type lift (wish I had one) and I show the guy exactly what needs to be done. So the guy goes to work and gets the front nuts off after a struggle with the air-wrench. The other nuts are then off and the pipe is taken out.

Then after wrestling with the rest of the exhaust line, using another guy to pull the cat converter back to allow clearance to get the new pipe in, the pipe goes into place and the nuts are put in place. All this took the guy 20-30 minutes, and he was under the car with the right tools and had help from someone else!! I'm thinking, "there was NO WAY I could have ever done this at home with my little tools, and I'm going to tell everyone not to try it unless they are VERY good and have very good tools!" The Bottom Line: don’t try the replacement yourself unless you have very good access and leverage to the bottom of your Elan and have some good ratchet wrenches with long handles—patience, ‘liquid wrench’, and a nut breaker might come in handy too!

So now I have a quiet car again—my stereo is audible once more, and I don't have to push the clutch in when driving by cops anymore! So be careful driving because when you scrape the bottom front of the car, you are scraping the downpipe and putting extra stress across the weld joints. My pipe had its share of rust, but it gave at the weld of the front flange when I was just driving on the highway.

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