I was hoping to find someone on here that uses a rear bumper difuser. The kind that go on the bumper facia itself. Do they help with times? Do they work? Pics?




Modified by badboyr66 at 8:44 PM 12/3/2005

 

They help a little if you're going very very fast with the wind drag..But it seems like most people do it for the "race car" looks..If I was gonna do it I would just use a hole saw on the bumper and make a couple holes put some screens behind them..

 

just my .02, but those look like **** on street cars

 

mm I could care less if it is fast enough

 

2 fast, 2.....

seriously though, are you going to honestly be going that fast?

 

gotta get to that sale before its over so yea he just might..

 

anybody have any pictures of these on their ef hatch's?

 

When you get down to drag racing... everything counts. Seems to me by getting rid of that pressure against the rear bumper would allow it to get down the track quicker

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by t3h WIN &raquo;</TD></TR><TR><TD CLASS="quote">just my .02, but those look like **** on street cars</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by t3h WIN &raquo;</TD></TR><TR><TD CLASS="quote">just my .02, but those look like **** on street cars</TD></TR></TABLE>

It does and that is why I am making a REAL diffuser for the rear of my CRX out of fiberglass.

 

You mean the type of diffuser they have on ferraris and whatnot? The parts that look moulded from a wedge? The reason those work as they do is because the entire undercarriage is a solid plate of CF or something, meaning there's a somewhat steady, as well as fast-moving, flow of air before the rear axle.

I don't have any data saying they don't work on drag cars, but I do know that the underbody of a typical honda has enough components to create severe turbulance. That, coupled with the vast vacuum behind the rear hatch/trunk and that most bumpers are higher than the suspension parts, is enough to really negate the any 'vast' gains you'd expect.

Think of them more as drag 'rice' or bling, just like a double-decker wing on a toyota tercel is going to produce mad downforce.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by t3h WIN &raquo;</TD></TR><TR><TD CLASS="quote">just my .02, but those look like **** on street cars</TD></TR></TABLE>

 

glad to see a bunch of geniuses speculating on how diffusers don't work. Funny considering most of the drag cars out there are using them so they obviously do something.

I agree that they don't look good, but there is a function behind them. I've been trying to figure out for a long time how to do it and make it clean but i don't know if it's possible. I have a couple pictures of better designs than a bunch of holes but i don't know if they'd flow air as well.

 

The ones this topic refers to are garbage. The ones ferraris and such use are what I'm referring to.

alot of the supra(MKIII and MKIV) owners build complete under diffusers or buy them. They start @ the front with a diffuser and then go and make the undercarriage completely smooth so that air just glides and isn't interrupted and then out the back in a rear under diffuser. It helps create downforce.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EGRacersInc &raquo;</TD></TR><TR><TD CLASS="quote">The ones this topic refers to are garbage. The ones ferraris and such use are what I'm referring to.

alot of the supra(MKIII and MKIV) owners build complete under diffusers or buy them. They start @ the front with a diffuser and then go and make the undercarriage completely smooth so that air just glides and isn't interrupted and then out the back in a rear under diffuser. It helps create downforce.</TD></TR></TABLE>

Yes, but the ones this topic is refering to do help in quarter mile times by reducing drag. They don't create downforce but they do help.

Here are some pics of Ferrari diffusers, it's amazing the crap i have on my computer:

and to get an idea of how they work: