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I read that and thought the same thing.
That said, I think the the OP has done something pretty cool. I have questions but not about if it has aero benefit at speed. I don’t look at a tire and ask if it’ll roll. But I do look at it and ask if it’s appropriate and cost-effective for MY use of the car. In my case the full under-tray is probably not.
I want to stay above the fray, but I do have a legitimate question since I don't know a lot about undertrays other than what I have read through the years( which is quite little to be honest). It would seem to me using logic that ours cars put out much more heat through our exhaust system than most piston engines, barring true race cars and many high HP street pistons with NO2. If any full undertray traps that much heat between the tray and the car floor and all the intervening components including the trans, drive shaft, U-joints, etc., that cannot be good long term. It would be like putting these things in an oven, particularly in hot climates, and baking them for hours on end. Am I missing something here, if I am please enlighten me.
Mike
You definitely want proper ducting in the engine bay, including the hood. Although I imagine that if you are at speed, enough "cool" air (even if being heated by the radiator and intercooler, but still cooler than the heat coming off the turbos and downpipe) somehow makes it way out of the engine bay through the trans tunnel area (if a flat bottom restricts it to that area.
With or without a flat bottom, a properly ducted system, incorporating a vented hood will help mitigate under hood temps.
I am talking about the entire area from under hood, to the mid body region and all the way on back. It seems to me as an analogy is that if you seal a metal box on all sides and then put a fire in it, the contents get pretty much cooked to a crisp in very short order, i.e. a barbecue but we are not cooking food in this case. I just don't get it.
Mike
Last edited by mikejokich; Feb 4, 2019 at 11:47 PM.
Reason: grammar
It's not really sealed. Air will move through the tranny tunnel to the back of the car. It will also escape other areas. Cabin air temps may increase. If it was really sealed and prevented flow from entering the engine bay, I think you'd feel it when driving.
If any full undertray traps that much heat between the tray and the car floor and all the intervening components including the trans, drive shaft, U-joints, etc., that cannot be good long term. It would be like putting these things in an oven, particularly in hot climates, and baking them for hours on end. Am I missing something here, if I am please enlighten me.
Mike
That is a common downside to adding a full flat undertray.
You just have to weigh whether it is worth the added stress for lowering the lap times and take care to duct hose from your NACA ducts to the most critical components.
Its also going to be harder to put out a fire from common race situations like transmission rear seal, diff axle seal or even the vent failing and dumping oil onto the exhaust.
Another downside is occasionally cars with full flat bottoms take flight.
I wondered about heat. Also about noise from vibration and noise that might be reflected from the exhaust and drive-train, ease of access, and the inability for me to just visually check stuff when it’s on the lift for maintenance since it’s mostly a street-driven car.
Originally Posted by TwinCharged RX7
I do understand this is a car forum mostly consisting of middle to older aged men haha
Yeah, those old bastards probably still hold doors open for women and think “manly” and “lady-like” are valid descriptors. But what can you expect from “old guys just being old guys” when they never got participation trophies as kids. haha
Jin-74 my offer still stands if you change your mind. I do run a factory with laser/press brakes/powder coating etc in NJ so i can do them and even offer them with variations in exhaust cutouts etc.
I wonder if you just want a set for yourself . Just kidding though, you guys should really do it.
Originally Posted by Montego
You mean real men who don't have a ***** that gets all bloody from being called a little girl over the internet? Then yes, you are correct.
Yep.
Originally Posted by BLUE TII
Can we please STOP with all the school girl talk?
This. Why do good threads always turn into a pissing match?
Last edited by FührerTüner; Feb 5, 2019 at 08:20 AM.
I wonder if you just want a set for your self . Just kidding though, you guys should really do it.
Well jokes aside i do want one for myself and i did show my interest above when i said count me in for a set. Not because i cant make them (or design them) but I respect the development from a company/individual who "wasted" their time and money to make a part.
I don't and never will copy someone else's work but if the OP wants to work out a deal i do have the capability and capacity to produce them as a "job-shop" .
As for getting one for my self it will be a major task to ship it half way around the globe .. My car is not here in NJ with me lol
Whole thread seems to be a rehash of the Atomic Rex thing from 10 years or more ago.
If you think a flat floor (or the usual japanese diffuser) on a car with road car ride height will make a difference - other than add heat and make access more difficult - you're furiously abusing your old fella!
I'd like to explain a few things.
1. NACA duct & many louvers has been placed as showen in figure for cooling of center tunnels and exhaust lines
2. louver's angle was adjusted by the user.
3. aftermarket brace(ex; autoexe) was cannot be used together or will require mod.
4. under panel was placed above the front subframe. therefore lowest ride height was front subframe.
5. for maintenance, front & rear central panel can be separated easily.
thank you for opinions for improvement.
Jin.
Id imagine some gussetting in critical areas would be fairly necessary anyway, and could be done in such a way the flat bottom itself lends a fair bit of rigidity to the chassis.
a bit like when building a house with a truss frame roof, the trusses by themselves seem flimsy but as soon as it has the plaster (drywall?) which is also very flimsy, screwed on (let alone the roof sheets) it becomes incredibly stiff and rigid.
hi there~
I don't know if it's okay to advertise here. I'm ready for online sales.
The final mass-production type undertray can be ordered on the following web page.
. Just kidding though, you guys should really do it.
.. My car is not here in NJ with me lol
