Side Pipes-Pro & Con

[Guest Anonymous]

All,

 

After some correspondence with Pete Paraska about one of my newest design projects, he encouraged me to take my questions to all of you on this forum.

 

I've had ideas about installing custom, recessed side pipes into a S30 body every since I got into Z's back in '84. Recently, I have begun several new, preliminary concept drawings to rough out visual approaches for some of my fellow customizers to review and comment on.

 

As would be expected, many early comments zeroed in on the technical concerns of loss of structural integrity to the body and excessive heat inside the car. I have mulled over many solutions, too many to list here, but at the urging of Pete Paraska, I thought I'd put the topic out for discussion at Hybridz to see what many of you may have to say, pro or con, about the feasibiltiy of side pipes.

 

I have seen very few examples of side pipes on S30 bodies, but of those I have seen, all have been external designs which, I feel, spoil the the compactness and integrity of the original Z body design.

 

What I would like to achieve is an integrated, recessed design inside the hollow area of the Z's lower rocker area similar to the image below.

 

If any of you have actually built and integrated side pipe into a Z or have experience in dealing with the loss of structural integrity from removing a rocker cover or about the heat related issues, I'd like to hear your comments or suggestions.

 

For now, here's one of my first concept illustrations to give you all an idea of where I am headed. The concept is of a louvered cover over a 3" chromed, cherry bomb style laker pipe. The forward part of the chrome pipe would reach aprox. 5" into the fender section before turning inward and entering through the unibody through a welded in heavy metal pipe. The design may have only one large oval exit tip or as many as 3 large oval outlets (click on link below) toward the rear area of the rocker section.

 

Hope to hear your ideas & comments, pro or con.

 

Thanks much,

 

Eric Neyerlin

 

3 large oval, curved,outlets

[DavyZ]

You asked for it:

 

Aside from possible compromises in the structural integrity of the car, the side pipes are an intriguing idea. A louvered or vented valence covering them would add to the appeal, but bare pipes would be a recipe for burned skin---no fun IMO.

 

Having grown up in San Jose, I don't like the three outlets because it smacks of lowriders--but that's just a cultural and asthetic thing with me. I guess they would be open at the ends vs the closed ones found on many older Chevy Impala lowriders.

 

What might not be practical, but would look "raw" would be the twin pipes that some of the Cobras and Daytonas used to run. Those look great in white on the sides of the car, although I think they might look strange covered.

 

I'm not sure that for the amount of time & money involved in the modification that I would embark on such an endeavor, but I'm sure that many would since this has been a topic that comes up every so often from different people.

 

It'll work out and I'm sure there is demand.

 

Davy

[Guest Anonymous]

I would love to have plain sidepipes on mine if I didn't have to worry about getting burned every time I get out of the car. Something similiar to the Viper would probably look preetty cool on a Z,especially one with big flares or a good aero package like the one Motorsport sells.

[Guest John Adkins]

Hmm.... your design reminds me of the 60's Corvette stingray side exhaust

 

The Corvette side exhaust covers are slotted aluminum and attach to the rocker panel if I remember correctly. Could these be used on a Z?

[Guest mtj71Z]

side pipes look so sweet on a Z definatly getting some, i think it makes them look better external - gives it a lower appearence like most front airdams are.

[Guest Anonymous]

Exactly what I was going to say John, it does look like the vette's design. If they are properly boxed in, I don't see a problem structurally, I'd put in frame rail connectors anyway from the front to at least the back rollbar main hoop (being as I'm using someone else's wallet.. )

They would look real good if they don't stick out very far IMHO. I'd probably use a diameter of 3" or something like that, perhaps a pair of Car Chemistry inserts inside of each pipe should quiet it down enough (Actually the inserts don't look that tough to make really, but they're fairly cheap and being mechanical baffles won't wear out). Oh well, just an opinion, done right I think they'd look smashing.

 

Regards,

 

Lone

[pparaska]

Of course, there are water jacketed side pipes. I saw that recently, can't remember where. A custom rod, I believe. That ought to keep a bit of noise down also.

 

(tongue-in-cheek)

[Guest Anonymous]

All,

 

Just wanted to thank all that have generously added your thoughts. Perhaps if I add a bit more detail to my goal and design philosophy and some examples to the discussion, it will get even more livelier.

 

Beauty, in the case of side pipes, is in the eye of the beholder, and perhaps, influenced by one's early automotive influences, as Pete stated, but to my eye, an external side pipe design is too bulky to compliment the sports car design and road height of the S30 body. This is why I feel the proper approach should be to tuck at least half of the pipe's tubular mass into a recessed area of the rocker panel or into a ground effects style lower body piece to make it worth doing.

 

Because I wish my design to look fresh and complimentary to the relatively small S30 body, I have purposely avoided researching examples of side pipe designs used on other popular performance cars. Certainly, I am aware of such examples as used on early Corvettes and fifties hot rods, but I don't think they will work visually on an early Z body.

 

For that reason, I am attempting to design a relatively unique styled solution from scratch, cost and difficulty be damned. If the technical solutions to structural loss of integrity and heat can be solved, I will proceed, but only if a design can be fashioned that is both functional and aesthetically pleasing to my eye.

 

I wish I had time to work up more detailed illustrations of what I have in my mind's eye, but that kind of work takes lot's of time to execute properly. Perhaps, in the next few months, I will be able to show everyone many variations on a theme that I have already envisioned, but for now, I'll have to rely on descriptive word.

 

Until then, let me point some of you to a few examples of side pipes actually installed on Z car bodies, even though part of altered Z based body modifications. In the past year I have photographed a certain Z body kit, named a Tomahawk Z, that uses side pipes as one of it's basic visual features. Here are some links to pages that have unrelated text on them that will show you many angles of the Tomahawk's approach to side pipes. This Tomahawk was built on a 1977 280Z body.

 

Vincent Hudson's "Purple Candy" poster image

 

Vincent Hudson's unpublished "Featured SideBar" page with 5 photos

 

Another Z that I photographed last year that offers a fresher approach, but which suffers from pipes being routed awkwardly under the car from a cross over dual design, is that of Jim Darnell's very unique custom 240Z.

 

Note, a full feature article on this car may appear later in SZM

 

One added complication and important factor in my side pipe design that I failed to mention in my first post, is that my primary objective is to add these side pipes into the lower rocker area of a 2+2 Z car custom convertible that I have long wished to build. Whether time, energy and money will allow me to complete it is uncertain, but I've had a fixation on the idea for a very long time. The illustrations I have been working on to show the basic concept are not quite finished, but as reference for food for thought, here's a basic outline illustration of mine showing the stock outline of a 74 260Z 2+2 without bumpers added. The only customization is that of the wheels which I designed hastily to illustrate the lowered body riding on relatively large wheels and low profile tires.

 

In my earlier post I alluded to possibly using a design that had 3 large oval exhaust tips at the rear of the side pipe design. DaveZ commented that he had some problems with the idea due to associations he had to other car communities that seem to place extreme show as a priority over aesthetics derived from "form following function" Although I feel the same uneasiness about 3 outlets from one pipe creating similar visual cacophony, I feel, that for aesthetic reasons, 3 oval exists might be justified if a large side pipe were installed into a 2+2 body starting aprox. 8" aft of the front wheel well and running all the way rear of the door. look at the 2+2 outline and try to envision both one large 3" oval exhaust tip and then 3 of them separated by aprox 4-5 inches each.

 

OK, that's enough design philosophy for tonight. What you'all think so far?

 

Eric Neyerlin

[Guest Anonymous]

Eric have oyu thought about using oval shaped tubing for this project? I believe that this would help greatly in being able to fit the pipes close to the car. Les

[DavyZ]

Hmmm, throwing a 2+2 into the mix makes things a bit more interesting. I think you could avoid the association I alluded to in my earlier post with the proper stance and the use of the large, low-profile wheels & tires, in keeping the three outlet side pipes. Suffice it to say that I believe your idea has merit, especially taking into consideration the careful process you are implementing in doing the job "correctly." Good luck, Eric.

 

Davy

[Guest Anonymous]

Les's idea of oval side pipe enclosures had not crossed my mind, but because I may bolt in a heavy chrome cherry bomb looking chrome enclosure to the rocker hollow area as a structural replacement for the removed rocker cover, the oval pipe might not provide the structural reinforcement that may be required. I believe that an oval pipe might be prone to collapse before a thick walled round type. I will take the idea under consideration, however. Thanks.

 

DaveZ and all, I have now published a preliminary web page and related index to the growing number of illustrations and photos that I am generating related to both the 2+2 convertible concept project and the one custom feature of integrated side pipes. For those of you that want to follow my progress or accumulated suggestions and discussions around this topic from others not on the HybridZ forums, I'd like to invite you to visit that page occassionally.

 

Please bookmark Sleek Z Projects

 

Last night I got busy and worked up a sketch of a modestly styled version of a 2+2 convertible concept based on a S30 body showing a simple, long chrome side pipe with one oval tip. Unfortunately, I did not have time to show how it would recess into the rocker area's holllow area nor did I bother to add front and rear seat outlines. Please use your imagination.

Here it is:

 

Thanks for all the good suggestions and interesting comments.

 

Eric Neyerlin of Z PARTS

[Guest John Adkins]

One thought about recessing the exhaust pipes into the rocker panels: heat in the interior. Recessing the pipes into the rocker

panel would put the exhaust pipes awfully

close the seat cushions.... I hope the heat would not start any carpeting or interior insulation on fire or melt the seat covers!

[pparaska]

John, Eric, I was just half kidding about the water cooled pipes. I think a pipe-in-pipe setup would do wonders for keeping the heat out of the car.

 

A bolt on rocker cover is not going to give the kind of stiffness that a welded rocker gives, IMO.

 

Here's an idea that might solve both problems:

 

1) Cut off the outer rocker panel.

2) Install a steel tube in the inside area of the rocker box. This could be a square tube. Have it accessible from in front of the door, where the stock rocker tapers down under the front fender.

 

There's not alot of room here. but if you were to put a 3.5"x3.5" square tube against the inner rocker panel (you'd have to remove the vertical sheet steel that is in the midst of this opening at the front and rear).

 

3) Weld the square tube into the inner rocker and tie it to the rear wheel house and the front door pillar.

 

4) With the pipe welded in place, the outer rocker could now be just cosmetic. Now make it a bolt on outer rocker panel.

 

5) Access into the pipe. Two ideas:

a) Leave the pipe intact and "load" the sidepipe into it from the front. I'm thinking of a chambered 2.5"pipe. You could paint the inside of the square tube with some of that shuttle tile paint that the NASCAR guys paint their floors with before installing them. Or slide some kind of rigid flat insulation in before or after the chambered pipe goes in. You'd of course have a cutout in the square pipe for the outlet turnout of the chambered pipe. And some bolting points for the ends of the chambered pipe to the square pipe.

 

(Chambered pipe is going to be loud. Putting an H-pipe between the sidepipes should help.)

 

Before welding in the square pipe, cut it in half, down the length. You'd have two channels now. Weld one channel into the inner rocker having the legs stick outward. Arrange some flanges top and bottom with a welded in row of nuts top and bottom, to bolt a mirror image piece to to put the square tube back together. Now you have easy access for installing exhaust. If you can arrange some sheer pucks/pins along those flanges, all the better for stiffness.

 

If you want I can sketch this and post it.

[Guest Anonymous]

Any thoughts on how this will all hook up to the exhaust headers? Under the TC rods isn't very big (well maybe oval tubing with one of those braided stainless flexible exhaust pieces so the engine can move but the exhaust system is stationary), thru the inner fender will put it in the brake tubing. Just curious how that would work on the hookups so it wouldn't reduce your ground clearance anymore than necessary.

 

Regards,

 

Lone

[pparaska]

I don't have my car handy but you bring up some good points, Lone (as usual).

 

My first though isto reroute the brake line and do primaries through the inner fenders, with a collector in the wheel well .

[Lone Star 1]

I didn't read all the post on this subject, but keep in mind that a fare amount of wiring runs down the right side in the door rails. These wires would more than likey need to be relocated.

 

[ July 11, 2001: Message edited by: Lone Star 1 ]

 

[ July 11, 2001: Message edited by: Lone Star 1 ]

[Guest Anonymous]

Yeah, I agree Pete, thats probably how I would want to do it. Just like the cobra's (well if I was going through the trouble of doing set in side pipes, I'd build custom headers through the fenderwell (they'd have to be darn fancy to, to get by the steering column!)) A flange type joint in the fenderwell where the four pipes come together. Alot of work thats for sure, but would look sweet. LS1 makes a good point too, there is a bundle of wires down that side, probably just run them down the center of the tunnel while I was putting in the Painless harness.. See, its easy when its someone elses wallet!

 

Regards,

 

Lone

[Guest Anonymous]

Eric and I have e-mailed a bit directly, and he suggested I post some of my comments to you-all.

 

You see, I work for an exhaust manufacturer.

 

I agree with all of the comments made about the appearance of Eric's design, and have some functional points.

 

Here's what I posted to Eric:

 

Material choices will be 'critical'. I suggest naturally enough that you

have the system coated to hold the heat down.

 

How about ceramic infused material for the cover? Something from the space

age that will definitely deflect heat or disperse it very quickly. CF won't

do the job, but F-1 cars' exhaust systems utilize something that does.

 

Exhaust pulses etc. The VG series firing order is 123456, so cylinders in

one bank fire one after the other.. It's a true dual pipe system, with a

'balance tube' H-pipe assembly after the cats. That makes dual pipe systems

easy. More complex with an L6 or V-8, though. But you knew that........

 

Tube size, primary length and resonance of materials: my engineers here

would be challenged by such a project. If you are exhausting (!) an L

series, are you thinking of mating the exhaust runners by firing order or

opposite of firing order? Pipe bending for collection and so on would be

'interesting'.

 

 

One of the posts here suggests using double tubing. That's a good idea! Getting air to circulate between the two tubes, however, is difficult, and that's one reason my company worked with Chevy to design the slotted covers over the 'Vette's side pipes (or so I am told by an old-timer around here).

 

If we could combine several of the points in the posts, here's what I come up witH

 

- Figure out how to split the exhaust stream into equal parts and design the runners to be as near equal length as possible. Tune it so that you get the best exhaust gas scavenging you can (L6, V6, V8 - it doesn't matter).

 

- Coat the inside and outside of the entire exhaust so that it keeps the heat inside the system, until you get to the mufflers.

 

- Use 'sausage tube' mufflers (we make these things too...) in the rocker cover area.

 

- Put grates or some form of slotted cover over the mufflers.

 

- Add heat resistant coating to the floor pans inside the car. (I'd suggest heat-reflecting coating to the underside of the floor pans also.)

 

- Make it LOOK good!

[Lone Star 1]

Has any one thought of doing like some of the Mustang do it. Fake side pipes down the side rocker panels. or a replacement rocker panel that looks like side pipes. While the real exhaust system runs down the tunnel and turns out in front or the rear wheels and into the fake oval side panel outlet. That little triangle area behind the seats might make a nice location for the muflers. The post that follows this post is the same as I'm talking about. I believe these are fake sidepipes with the real exhaust just terminating at ovel end.

 

[ July 12, 2001: Message edited by: Lone Star 1 ]

 

[ July 12, 2001: Message edited by: Lone Star 1 ]

 

[ July 12, 2001: Message edited by: Lone Star 1 ]

[Guest Frank Rich]

Eric, are you familiar with the "sidepipes-enclosed-in-side-skirts design of Roush Mustangs (the street versions, not the fullrace machines)? There's a convertible Roush Mustang that's always parked on the third level of the parking garage at my office building, and the sidepipes run along the rocker panel inside a fiberglass side skirt, then exit through a "wedged oval" shaped tip in front of the rear wheel well. I haven't crawled up under the car to see how they've handled heat shielding, etc. (didn't want the owner, who I haven't met yet, to come out and find me half under his car !!)This is part of the Roush body treatment, and looks darn trick ! You might want to see what you can find on the web about Rooush Mustangs - there are some pics at: http://www.wendel.com/roush/roushmustang.htm

and apparently you can buy a repro/knock-off Roush body kit, including side skirts with the openings for sidepipes at autoaccessory.com

 

I don't know how keen you might be on the idea of using these pieces as a starting point, but personally, I kinda like the shape, even though I'm sure that the rocker panel length difference and differences in ground clearance between a modified Z and a newer model Mustang would make any kind of direct swap a little dicey at best. Take a look and see what you think - apparently Roush has solved the problems of heat, etc. - I'll try to find the onwer of the convert. in my garage and ask if I can do the "crawl" for purposes of fact-finding . I mean, the guy's got to be a gearhead, right?

 

"Lead me not into Temptation, I'm getting there just fine on my own"

 

Frank