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."
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.
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
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!
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
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.