Complete under car floor or engine bay exposed?

[Frank818]

I went through the manual and couldn't have a good understand of if the entire under car is closed. I mean are there panels from nose to end of rear diffuser? Is there an engine bay floor, something that would be a complete flat floor like on race cars? Or is the engine bay floor totally open, like on most of normal cars?

[RM1SepEx]

no engine bay panel with the kit, Red demo does have a floor under the motor, only had a small cutout for the bottom of the oil pan

[Frank818]

Ok I thought our kits would be like the red, maybe that's why I thought about that. I don't know but without that engine bay panel I can't see how the diffuser could work to its optimum. Anyway we can always build one, but it's good that I know now cuz it changes a little bit some of my build plans. :) Tnx Dan.

[Santiago]

I don't know but without that engine bay panel I can't see how the diffuser could work to its optimum. Anyway we can always build one...

You're right - without the engine bay covered the diffuser will not work at its full potential. That's not to say "it won't work" to do "something" for you, but you're not going to realize the real performance potential of a proper diffuser without it.

Of course, the way things look at the moment the rear isn't having trouble with downforce, it's the front that needs to get with the program. Some folks will want to optimize the rear diffuser to get their downforce with a lower drag penalty - or to push their aero-load forward a bit (which may alleviate the front's work load in balancing the car at speed). So I think there are still good reasons to build an engine bay cover for a track car.

Best,
-j

[Bob_n_Cincy]

Hey Dan,
There is a engine floor aluminum. I have them with my kits.
Bob

[RM1SepEx]

none with mine... got a PN?

[Bob_n_Cincy]

none with mine... got a PN?
I didn't see them in the original order so I called, then they showed up.
Bob

[Frank818]

Bob by any chance do you have pix of that/those part/s?

If the car understeers I don't think I'll put an engine floor, but otherwise I might and if it exists it's good to know.

[nkw8181]

I'm interested as well as I don't recall having a lower bay engine cover on my list.

[Bob_n_Cincy]

Bob by any chance do you have pix of that/those part/s?

If the car understeers I don't think I'll put an engine floor, but otherwise I might and if it exists it's good to know.
I'll take a picture tomorrow.

[Mechie3]

I have the rear aluminum under tray. It shipped with my diffuser and not with the kit.

[Frank818]

I have the rear aluminum under tray. It shipped with my diffuser and not with the kit.

Hum, all I got are the diffuser strakes. Which is all on the POL as well.

[Bob_n_Cincy]

Here is a picture of the engine belly pan aluminum.
It is a trapezoid. With the front and rear edges bent. 36" wide at front edge and 23 inches front to back.
Bob
33050

[RM1SepEx]

Hum, all I got are the diffuser strakes. Which is all on the POL as well.

same here

[Frank818]

Tnx Bob, normally a pic is worth a 1000 words but maybe the different pictures make it hard to compare, I find that part looking like the battery tray cover, is it not?

33059

[RM1SepEx]

Frank, the under tray for the battery is flat, no bends....

[RM1SepEx]

Update: If you bought the diffuser, the under engine aluminum panel should have came with it. Ask and you will receive (Joe Scott)

[GUNS]

Thanks Dan, I'll call to get mine.

[Frank818]

Me too I'll contact Joe. I think we all contacted him at some point for something. :)

[Frank818]

Alu panel on its way. :)
I am very happy I started this thread, otherwise I may have ended up without the panel or buying alu to fab one myself. This forum is awesome.

Apparently there are some kits that got out without the panel and without having the part listed on the POL.

[Jim Schenck]

The goal with that panel is as smooth a transition as possible into the diffuser so you want it to form a nice smooth arc between the flat floor and the 12 degree angle of the transmission mount. Most cars will need the panel to be cut out around the oil pan but we didn't put the cut in there because there are different shaped pans (and some people run dry sumps that don't need any cut) and you want to keep panel fairly tight around the pan to help the diffusers effectiveness. I left 3/4 inch around but with a little more where the drain plug goes so i could fit the socket.

[dougkirkbride]

Update: If you bought the diffuser, the under engine aluminum panel should have came with it. Ask and you will receive (Joe Scott)

I am not there yet so this may be a stupid question but this diffuser you speak of,,, is this provided if you ordered a kit and specified turbo instead of na?

[JeromeS13]

I am not there yet so this may be a stupid question but this diffuser you speak of,,, is this provided if you ordered a kit and specified turbo instead of na?

No. The diffuser was a separate option itself.

[dougkirkbride]

No. The diffuser was a separate option itself.

oh...thats the carbon fiber thing in the back that goes accross and down.....I opted out of that option.

Thanks.

[CHOTIS BILL]

edit

[CHOTIS BILL]

From my experience in running a full belly pan there are several things to keep in mind. When it comes to aero changes anything done in the rear can also affect the front so smoothing out the air flow in the rear can increase rear downforce but at the same time increase the front downforce at the same time. If you completely cover the bottom of the engine you will gain the most but unless you have air moving past the engine from some other source the water and oil temperatures are likely the rise. Leaving just a small opening for the oil pan can have a large increase in turbulence and a pathway for the lower pressure on the lower surface to be lost and therefore a loss of downforce. To make changing oil easier you can make a removable panel. It is very hard to know for sure what any aero change will make unless you make and test them. For me making changes like this and then testing them is the fun part.

Bill Lomenick
P.S. Weight transfer is my friend.

[Oppenheimer]

For future engine service, would it make sense to mount the engine belly pan with screws, instead of rivets?

Maybe a job for threadserts. Or dzus fasteners?

[RM1SepEx]

For future engine service, would it make sense to mount the engine belly pan with screws, instead of rivets?

Maybe a job for threadserts. Or dzus fasteners?

yup

[FFRSpec72]

For future engine service, would it make sense to mount the engine belly pan with screws, instead of rivets?

Maybe a job for threadserts. Or dzus fasteners?

Quarter Turn or nut plates are what I will use