Brake ducts in R-package front lip
 

Has anyone ever tried and had success with molding brake ducts into an r-package front lip?

I'm thinking of trying to use ducts like these: https://www.pegasusautoracing.com/pr...p?Product=3624

And molding them in to the r-package lip such that they're kind of like this (the brake ducts would be on the backside of the lip).

Of course, some modification to the r-package lip would be required.

I've considered something similar but with a GV replica lip.

The question is will you be able to flow enough CFM through that opening. Most brake ducts use a 2.5" outlet so choking it with a 1" inlet would be a waste IMO. See if you can find a similar inlet with a cross sectional area closer to the equivalent of a 2.5" diameter.

Is that all the bigger the front lip opening is? I just ordered one yesterday and from the pictures I figured the openings were at least a couple of inches tall.

Dang. I may need to rethink this.

Here is a couple that have 2.5" outlets. but are probably too tall to fit nicely in a r package lip

https://www.merlinmotorsport.co.uk/s...r-intake-ducts

the 1 in outlet will help cool your brakes some. It just would choke at the inlet and would not work nearly as good as a larger opening.

2.5 in diameter = 4.9 in^2
1 in diameter = 0.78 in^2

That's an 84% smaller opening.

I don't think your adapter thing is necessary...

I used a 3" sceet hose on my r-style lip and bent the opening of the tube into roughly the shape of the back/exit side of the holes in the lip and tape/zip-tied it all together.

It works well- tested up to 125mph. :)

I'm definitely going to go with the 2.5in duct. It's just a matter of how much I have to hack up the bumper and front lip to accommodate it. I used a similar setup on my E30 and it was nice not having to ever worry about brake fade.

I guess another option is to just cut out openings in the bumper but it seems like this could be such a clean install that I don't want to abandon it yet.

Hornetball has done it. Go through his NA car build thread and you'll see a fairy detailed how to.

subscribed. I plan on making some for my GV style lip this spring using carbon fiber sleeves which can expand to form the correct shape in a smooth profile. I know that area of the bumper isn't the best for flow, but its better than nothing for a light duty HPDE car.

I've always said that the Track Dog 'splitters' (just ABS plastic lip) were useless, but actually if one were trying to pull air into the stock R-package lip openings for brake ducting, one of those little ABS extensions would actually help to build up some pressure at the duct opening.

-Ryan

Or you could put the hoses in the corners of the mouth, as God intended. :party:

I've been thinking of doing this myself. My plans were to 3D print a little converter that would sit over the intakes on the 'R' package lip. The oval intakes would need to be trimmed back to a certain point with the 3D print rivetted over the top them to the tabs either side.

I need to check the size of the intakes but I think they are just large enough to be converted to a 2.5" round hose.

I'll have a look at it again tonight and see if I can get something that might work.

oh man. why are you guys over-engineering this?

1. bend hose opening into an oval.
2. attach hose to holes that ALREADY EXIST on your lip (I hear duct-tape works well on ducts).
3. enjoy cooler brakes

+1, simple and effective.

Why did you make me drill holes into my bumper cover? It was so innocent before it met you. :qq:

+1 i did this, happy with results, A++ would cool brakes to the max again

Post up the cad files if you do. I have 3d printing capabilities.

Mine are routed to the R package lip. Just the hoses with some nice gorilla tape sealing them up. As people have said, don't overthink it. Sure you won't get 100% perfect airflow, but it definitely won't hurt

Just to give a link:

https://www.miataturbo.net/build-thr...8/#post1130011

Even though I used the R package lip ducts and it seems to work OK on my normally aspirated track car, I agree with Andrew. If you're going for max airflow, 2.5" hose routed into the radiator inlet gives a more direct, larger path that will flow more air.

With the wheels turned, the R package lip ducts are inline with the tires. That means that the path for the flexible hose has to go inboard to the frame rail/undertray side before turning back outboard to the hub. Not ideal. And, as others have noted, the R package lip ducts are smallish.

Thing is, it gives me a reason to make something on the 3D printer which I enjoy. When I get the time I'll model up a little adapter that will sit over the lip and transition it into a 2.5" and / or 3" round. 3D modelling will only take 15 mins, its getting the tolerances and figuring out the angles that takes more time.

I'm just finishing up a printing a complete rear wing with a custom profile. It's been using up my printer time as I've had to print 12 sections, each one around 12 hours or so. Once I've finished that project I'm going to look at printing a custom airbox or maybe do the brakes ducting first.

I realise I could mount it all up with gaffa tape, but if I applied that theory across the whole car I'd end up with something hacky. I find it enjoyable to build nice custom parts...

Post up pics when you get around to doing this