View Poll Results: Which exterior mod
I would leave the extrerior unmodified even if it means less effective intercooling
1
4.17%
I like wider smile as in the doctored picture, modify the stock part
16
66.67%
I'd go with the Strosek piece
4
16.67%
Something else, see my post below
3
12.50%
Voters: 24. You may not vote on this poll
Would this exterior mod be tasteful?
06-29-2010, 08:54 PM
#46
Administrator - "Tyson"
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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.
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.
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.
06-29-2010, 09:21 PM
#47
Nordschleife Master
Thread Starter
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.
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.
06-29-2010, 09:40 PM
#48
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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
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
06-29-2010, 10:08 PM
#49
Nordschleife Master
Thread Starter
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.
06-30-2010, 10:44 AM
#51
Rennlist Member
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.
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.
06-30-2010, 11:19 AM
#52
Been selling Twinkies on Ebay,
have some extra cash right now.
Rennlist Member
have some extra cash right now.
Rennlist Member
The intercooler setup is designed by John Kuhn, so it will not come as a surprise that the air flow is throughly considered. The intercooler faces the spinning tire. The moving tire has air spinning fast with it, creating a significant vacuum. This vacuum sucks air, and the easiest way it's going to get it is thru the intercooler. Thus, at high speeds, there will be a positive gauge pressure zone in front of the intercooler (ram effect) and a negative gauge pressure zone behind the intercooler. As a bonus, the radiator and air intake air flow is left undisturbed.
(2) The wheelwell has significant vacuum. I took a ride on the freshly paved route 2 with silicon hose run to both the existing bumper cover vents and inside the wheelwell front of the tire. Watching the radar detector, the road, the traffic, and my home made water manometer proved challenging, but the water column clearly moved. The pressure at the front bumper vent is high enough that one can feel it and the vacuum inside the wheelwell is also high enough that I could feel it. So venting the intercooler flow path from the front bumper, a la ketchmi and JK, is a great idea from the flow perspective.
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.
