Saturn bellypan

[orbywan]

Hi,
This is my first post with ecomodder so here goes. I have a 99 Saturn 1.9L DOHC 5 speed. Great car. So far I've blocked off the front grille completely (no overheating even with the A/C on), made covers for the headlight nacelles, removed the side view mirrors and installed cameras instead.
I posted some photos of some of the mods, I hope they load OK.
My average 14 mile commute has been 43.2mpg on the scan ga. before the mods. After the mods I'm still collecting data but the average is around 52-53 mpg.
So, the reason for the post is I'm thinking about a bellypan since the body is about as low drag as it's going to get without major surgery. I found the post by lovemysan concerning belly pans. He said he used polyboard and like it better than coroplast, but I'm not sure plastic is the way to go down there.
Anyone have any suggestions for the bellypan material? Aluminum sheet will have to be ribbed to keep it from rattling, etc., but problem I would think with anything plastic is the cat will melt that in short order.
He refers to Hucho's post on belly pans, can't find it, does anyone have a link to that? Any info on belly pans would be greatly appreciated. Thanks!

[CigaR007]

Looking good so far, especially the headlights covers.

Concerning the bellypan material, I think most people would agree coroplast is the way to go; lightweight, easy to cut, easy to work with, resists the elements etc..

[cfg83]

orbywan -

Welcome to EM! Fantastic first post. Is that a 3-door SC2?

Here's a concept car belly pan :

Ecomodded Kia Ceed. Factory fit ecomodding!!!



CarloSW2

[orbywan]

Thanks 007, so what do they do, just leave the cat a wide berth (hole)?

[orbywan]

Thanks for the link cfg83, great photo of the belly pan(s) on whatever that is. Yes, it's a 3 door SC2. Great little car.

[orbywan]

So that's a diesel KIA, pretty cool, segmented pans, I like that. Reading some of that text they refer to engine management. Speaking of that, does anyone know how to keep a Saturn from fast idling when in moving in neutral, that bugs the hell out of me, wastes fuel big time I would think.

When moving at all, in neutral, the ECM boosts the idle to about 1300 - 1400 RMP's, instead of the usual idle of about 900 RPM's. Unless there is something going on with the EGR I'm not aware of, this can't be efficient. This thing is so much cleaner it will coast forever in neutral, at a fast idle. None of my other vehicles do this. Is there anyway to lower the idle when coasting?

[aerohead]

Originally Posted by orbywan

Hi,
This is my first post with ecomodder so here goes. I have a 99 Saturn 1.9L DOHC 5 speed. Great car. So far I've blocked off the front grille completely (no overheating even with the A/C on), made covers for the headlight nacelles, removed the side view mirrors and installed cameras instead.
I posted some photos of some of the mods, I hope they load OK.
My average 14 mile commute has been 43.2mpg on the scan ga. before the mods. After the mods I'm still collecting data but the average is around 52-53 mpg.
So, the reason for the post is I'm thinking about a bellypan since the body is about as low drag as it's going to get without major surgery. I found the post by lovemysan concerning belly pans. He said he used polyboard and like it better than coroplast, but I'm not sure plastic is the way to go down there.
Anyone have any suggestions for the bellypan material? Aluminum sheet will have to be ribbed to keep it from rattling, etc., but problem I would think with anything plastic is the cat will melt that in short order.
He refers to Hucho's post on belly pans, can't find it, does anyone have a link to that? Any info on belly pans would be greatly appreciated. Thanks!

Whatever fits your budget can be used.
* the materials you've alredy mentioned
* door skin will last a few years if sealed
* fiberglass/foam composite
* ferrous sheetmetal
* fiberglass sheet
* ABS plastic
* the thin sheets will require closer center-to-center distance on supports to prevent sagging
* of course,carbon fiber/epoxy as Ferrari has used.
Just let the free span rigidity determine your support distance.
* hot areas can be dealt with with special shielding/venting
-------------------------------------------------------------------------
As to Hucho,he has published a series of books: Aerodynamics of Road Vehicles.Worth every penny!
In his text he goes into the science of the belly pan and diffuser and cites research which has fixed the dimensional criteria for successful streamlining.
I recommend you splurge and get a copy.It's the difference between being given a fish to eat or learning to fish.

[dennyt]

Originally Posted by orbywan

Is there anyway to lower the idle when coasting?

Yes, that's your Idle Air Control (IAC) valve boosting the idle because the computer is telling it to. I'm not familiar with Saturns, but here's what I did on my Subaru to restrict it. A 3/16" orifice plate worked for my 1.8L engine.

Disconnected Idle Air Control - for lower RPM after a cold start

[arcosine]

My sc1 would overheat closed off like yours is.

See belly pan:


sc1 aero mods

[cfg83]

orbywan -

What dennyt said. When the car is warmed up you can disconnect the IAC and it will stay in the same position. What might be better is a switch that would disconnect the IAC at your will. The IAC could rev high when the engine is cold. When the engine warms up, flip the switch so that the IAC will be stuck in the same RPM position.

I really like the headlight covers. Can you post close-up pictures of the connections? What kind of plastic and thickness did you use? Do you think they will have a negative effect on headlight refraction/visibility? I don't think they will, but I always ask this stuff. The execution reminds me of mcrews' rear wheel-skirt pictures.

CarloSW2