Actually yes, the responses? Not so much...
Ah...the good old days.
I never realize stating the fact that some potential customers could be turned off by making the holes, would be taken as disparaging the overall product.
Silly me..... Especially since this was expressed to me by potential customers.

99 isn't really that many, especially when you consider track guys can use them to upgrade their brake ducts.
Or even $100 for something nice that fits good.

What are the dimensions?

One of my relatives does CNC plastic stuff, he's been bugging me to give him some work to do that's car related. Not sure that's really the best way to make something like this though.

 

I think it is necessary to make holes to the front of the car to make the system function properly and deliver close to 600 rwhp with a completely stock long block. I think everyone shooting for that power level with a stock long block will *demand* holes in the bumper if they understand the engineering of it. The physics of the situation are such that intercooling is simply necessary at those power levels with stock long block and the air flow from the stock bumper openings will not be enough. I in particular will want *more* and bigger holes in the bumper -- that's the point of this thread!

If the compression has been lowered by some means in a FI car then it may be possible to make 600 rwhp without extra holes in the bumper. But such a car would make even more with proper cooling air flow. Fans help at low speeds but they hurt (or are at best neutral) at high speeds.

I agree with you that people may reasonably disagree about what kind of holes they want and what kind of vents, mesh, etc, in them.

It would be a challenge to sell 100 of anything at $100 each to the 928 owners in this economy, be that diamond studded tooth picks or celebrity blow jobs.

I agree that anyone with a supercharger or turbo or extra oil cooler or anything *should* want a nice period-correct, factory-looking bumper vent pieces. But I am pretty sure that if I'd have 100 made, I'd sell 4 pairs over the next three years and be left with 95 pairs.

I think (but do not know) that the best way is to use the CAD / CAM / CNC to make an aluminum mold and then cast the pieces from plastic.

 

Tuomo, if you can get someone to draw a solid model of what you want, stereolithography shop with a 3D printer could make a small quantity from ABS plastic... If you want a price est, I know a guy...

I recently saw a formula car with titanium uprights grown in a laser-deposition 3D printer. The aluminum versions we made for a competing car weighed about 2 lbs, machined on a 5-axis mill, and took a week to program and machine- The Ti parts were .9 lb, took 2 days to grow, no expertise involved....kinda depressing for us machine-shop guys, but its the way of the future for prototyping.

At least they were ugly, and our car beat their car....nya-nya-nya!

Steve

 

Thanks, I'll think about it. The problem with drawing the piece (which I think even I might learn to do if for no complications) is that the the bumper cover is not flat. It's kind of concave and increasingly so away from the center. So if I understand this correctly, one would need to first scan the bumper cover before modeling the piece.

 

Yes, some form of digitizing of that area would be needed. I can also get that done...

 

Tuomo,
Coming in late to the show, but I like where you are heading. Your functional requirements is to get are to the intercooler, which you have done.
Your long-term solution is a more integrated concept. The 968 RS approach is really working for me.

This guy did some bumper mods to his 968...


I'm curious it's possible to graft on the 968 lower and mid-section to a 928 cover. See below.

Re front cover digitizing and ABS 3D print. Digitizing is pricey and UV-cured ABS is not suited for automotive application.

 

There was speculation back in the 80's in the Amateur Yacht Research Society that a boat could use a rotating cylinder for lift.
Here's a link to the mechanics of it, where you can adjust the rotation in a Java simulator:
http://www.grc.nasa.gov/WWW/K-12/airplane/cyl.html
So, I believe it's possible that there is substantial vacuum in the wheel well.
It would be kind of cool to actually visualize the airflow in there. Don't know how you'd do it, a static wind test wouldn't have the spinning wheel.

Anyway, it's kind of moot at this point.