Oval Exhaust

PostPost by: Certified Lotus » Wed Feb 20, 2019 4:50 pm

Frank, appreciate the offer but I have a complete Tony Thompson stainless steel 2 inch exhaust system (headers to silencer) on my S1. Although I only have 150 HP at the crank, it?s a beast :D
Glen
05 Elise - Back where I started
65 Elan S2 - 26/4055
72 Europa - 74/2358R
69 Elan S4 - 45/7941
64 Elan S1 - 26/0379
12 Colin 30 - Lotus Racing Kart
07 Exige S - Wicked Road/Track Car
07 Exige S - Fast Road/Track Car
06 Elise - Track pack
User avatar
Certified Lotus
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1233
Joined: 04 Aug 2014

PostPost by: JohnP » Wed Feb 20, 2019 5:46 pm

I'm guessing that quite a few people have ended up with thier circular exhaust turning slightly oval (not elliptical) over time and speed bumps!
Incidentally, don't confuse oval with the Oval, which is actually nearly elliptical and the esteemed home of Surrey country cricket club.
JohnP
Second Gear
Second Gear
 
Posts: 93
Joined: 25 Feb 2015

PostPost by: GLB » Wed Feb 20, 2019 6:17 pm

Frank, I had an S2 in 1974 or so. It had the original oval pipe and a Stebro muffler, which I think was a dealer option. It would shatter windows on the overrun. I thought it was great as a young man then. My son has a nonrunning early S3 with a round pipe and a Stebro muffler. I hope he at least tries out the Stebro just to see if my memory of it is correct. Gary
GLB
Second Gear
Second Gear
 
Posts: 154
Joined: 31 Jan 2018

PostPost by: Famous Frank » Wed Feb 20, 2019 7:06 pm

Gary,

I agree. those Stebro mufflers were anything but a silencer. More like a Megaphone. I've had two over the years also. One was on a S2 SE I purchased from my good friend in Chicago. His name was Carl Grabowski. He always thought that a small car should have a loud exhaust ! I think Stebro called them the Stebro Bazooka. Three inches in diameter, chrome plated with a slash tip. The packing on the inside did not stay there long.

John, you are correct that many round exhaust pipes turn oval over the years. Although its only on one side.

Frank
Famous Frank

67 Elan Coupe
66 Elan S2 SE
65 Elan S2
65 Elan 26R
69 S2 Europa
06 Elise
67 Barracuda
User avatar
Famous Frank
Fourth Gear
Fourth Gear
 
Posts: 627
Joined: 29 Apr 2004

PostPost by: Famous Frank » Wed Feb 20, 2019 7:14 pm

Glenn,

That TTR system is beautiful! I've hot one of his hipo mufflers also. And they work good. At 150 hp, yours is right on the edge. I think he states his headers are good up 150 hp.

When you want to build one of those stock screaming 105 hp motors, my exhaust is just what you'll need! Ha!

Frank
Famous Frank

67 Elan Coupe
66 Elan S2 SE
65 Elan S2
65 Elan 26R
69 S2 Europa
06 Elise
67 Barracuda
User avatar
Famous Frank
Fourth Gear
Fourth Gear
 
Posts: 627
Joined: 29 Apr 2004

PostPost by: mrdoow » Wed Feb 20, 2019 8:39 pm

My 72 Sprint has 26R springs, thus dragging my round pipe on the ground was bothersome. So, I went to an oval pipe in the middle. Spintech makes the pipe and may have it in stainless. They also made the silencer.
Attachments
dsc00975.jpg and
dsc00978.jpg and
dsc00979.jpg and
dsc00983.jpg and
mrdoow
First Gear
First Gear
 
Posts: 17
Joined: 08 Dec 2010

PostPost by: tedtaylor » Wed Feb 20, 2019 9:06 pm

mrdoow wrote:My 72 Sprint has 26R springs, thus dragging my round pipe on the ground was bothersome. So, I went to an oval pipe in the middle. Spintech makes the pipe and may have it in stainless. They also made the silencer.

what are those extra shiny steel sheets next to the frame in the mid section all about?
TED
"Driving a Lotus is a triumph of bravery over intelligence." Stirling Moss
"TaylorMadeClassicCars" on WWW and Facebook
tedtaylor
Fourth Gear
Fourth Gear
 
Posts: 608
Joined: 09 Dec 2012

PostPost by: mrdoow » Wed Feb 20, 2019 9:53 pm

Heavy gage aluminum straps anchored to the rear and forward body mounts to provide a forward seat frame anchor point other than FRP. Also added layer of carbon fiber to the inside and exterior side of the tub for added strength. The yellow areas are Kevlar for impact issues. The floor tub is not flimsey now.
mrdoow
First Gear
First Gear
 
Posts: 17
Joined: 08 Dec 2010

PostPost by: nmauduit » Wed Feb 20, 2019 10:23 pm

mrdoow wrote:My 72 Sprint has 26R springs, thus dragging my round pipe on the ground was bothersome. So, I went to an oval pipe in the middle. Spintech makes the pipe and may have it in stainless. They also made the silencer.

nice! I am thinking of something similar (just for the center section) ... how does the square exhaust sound ? looks a bit modern to me... are there tuned pressure cancellation traps in it?

it looks like the Y is the low spot, maybe they should have custom made it wider rather than using a round output there...
S4SE 36/8198
User avatar
nmauduit
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2037
Joined: 02 Sep 2013

PostPost by: mrdoow » Wed Feb 20, 2019 11:30 pm

A bit on the loud side for sound. The Y is an older Bean system that I already had, so I had to work with it when installing the oval pipe.
mrdoow
First Gear
First Gear
 
Posts: 17
Joined: 08 Dec 2010

PostPost by: Famous Frank » Thu Feb 21, 2019 3:26 am

mrdoow, Nice installation. Your oval pipe is substantially larger then mine for early Elan originality. And a transverse muffler on a S4 Sprint is not something you see everyday. And those long secondaries coming off the headers should give a good bump in midrange torque! Very nice indeed. Beautiful installation!

Frank
Famous Frank

67 Elan Coupe
66 Elan S2 SE
65 Elan S2
65 Elan 26R
69 S2 Europa
06 Elise
67 Barracuda
User avatar
Famous Frank
Fourth Gear
Fourth Gear
 
Posts: 627
Joined: 29 Apr 2004

PostPost by: Andy8421 » Thu Feb 21, 2019 6:01 am

theelanman wrote:as the overall cross sectional area has not been changed I cant see that the flow rate would be altered........
you could put fairings on the inside to start the gasses spinning in order to create a vortex allowing the gasses to escape faster.........but then stutter as you get to a box...........lol


I seem to recall a circle encloses the largest area. As the cross section moves away from a perfect circle, the cross sectional area decreases. An oval pipe will flow less than a round pipe of the same circumference - though in this case i have no idea how significant that is.
68 Elan S3 HSCC Roadsports spec
71 Elan Sprint (being restored)
32 Standard 12
Various modern stuff
Andy8421
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1162
Joined: 27 Mar 2011

PostPost by: el-saturn » Thu Feb 21, 2019 7:47 am

famous frank - here you can get both OVAL (aerofoil profiles made in 120kg/mm2 stee)l as once used for f1 suspension parts OR FLAT-OVAL tubes as you just made in inferior steel (60kg/mm2) sandy, alps
el-saturn
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1374
Joined: 27 Jun 2012

PostPost by: zog » Thu Feb 21, 2019 2:35 pm

I've done 7 S1/S2 restorations plus a couple S3 types and a Coupe. Only one had a rusty oval exhaust and I thought someone had just squished it themselves on some rail road tracks.

I have 3 S2 projects pending. One is an early S2 that was parked in 1969 with 21,000 miles on it. I will have to crawl underneath and see what lurks below!

Thanks Frank for continuing to pursue perfect original styled parts! I'll be needing some interior parts again soon.

Bob Herzog
zog
Third Gear
Third Gear
 
Posts: 233
Joined: 15 Nov 2003

PostPost by: h20hamelan » Thu Feb 21, 2019 3:58 pm

Mrdoow
Your third photo shows some Yellow where the hoist/lift pick ups are
Are they reinforcements, or simply yellow
Born, and brought home from the hospital (no seat belt (wtf)) in a baby!
Find out where the limits are, and start from there
Love your Mother
Earth
User avatar
h20hamelan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1918
Joined: 25 Sep 2010
PreviousNext

Total Online:

Users browsing this forum: No registered users and 24 guests