So when willyou be offering a whole conversion swap kit? :lmao: That is so wicked... I was looking to do the same thing, but with a TDi motor, but money, little to no fab skills, and school put an end to that right quick. :rolleyes:

Clive, I'm glad you brought that up. How sure are you that that idea is true? If you're 100% I'm gunna have to change my thinking, I used to think the same thing. But the more I understand about aerodynamics, the less I think this is likely.

When I was down at 034 I explained my idea of the ducting, strictly the pathway, not mentioning high and low pressure areas. The tech who worked on my car, Mike, mentioned he thought NACA ducts in the side windows ducting into a plenum then out the vents would work great, said NACA ducts flow serious air. Then Javad, the owner, said he thought scoops would be a better bet, really trap air and force it through. Finally, Christian (Miller, KONI Challenge Series points leader) said he thought scoops and make sure that the exit duct to the rear vents was very well sealed, as he figured the vacuum created in that location was actually going to be pulling more air through the intercooler than the pressure from the scoops.

All of these guys are SERIOUSLY into motorsports, Javad has been racing and setting up racing cars for years, and Christian is a professional racecar driver with a lot of R&D experience. ALL of them had the same idea as I did regarding high and low pressure areas and airflow in general. We could all be totally wrong, so I'm going to have to do some R&D of my own, build the setup in cardboard then put little red yarn pieces on the ducts and see which way they blow.

When I think about the stock idea of those ducts, I actually think they may be there precisely to pull the hot air out of the engine comparment! Regarding the NACA ducts, I spoke with a drag racer at Bugorama a few years ago, and he had actually tested the pressure from the duct placement in the quarter windows, and he said he was seeing 5psi!!! I don't know, I hope the old idea isn't true, but if it is I certainly stand corrected. My little test should let me know if it'll work or not.

Jason

What are you talking about, all I DO is beat this thing!!! How do you think I break stuff?!!!!

Jason

Hi Jason,

I'm not at all sure about the high/low pressure areas but this was my logic:
The rear vents are the only visible inlet for cold air to the normal single carb? The flutings behind the grille imply (to me)an airflow into the engine bay whilst protecting from rain penetration. I would expect the shape of the beetle body to create a laminar airflow over the rear window. This was I understand Dr Porsche's original intent to create a tear drop shape. If he had required a solid negative pressure area behind the rear window then he would have created a kamm tail. In general all the aerodynamic aids I have seen for beetles do take advantage of the laminar flow by placing wings etc hung out of the back including integral intercoolers. If there was a low pressure area at the base of the rear window then I would have expected a roof lip spoiler above the window to enhance it.

With regard to the side scoops, I agree that they are in the logical location but I would have expected the airflow to be reasonably turbulent not least because of the flow from the edge of the front screen. The shortness of the beetle body would, I would have thought, prevented the airflow becoming laminar again to create a positive pressure. The half moon vents in the rear quarters of a beetle body are to demist the rear screen, in other cars they are extract vents. If they are inlet vents (as would be supposed with +ve pressure at that point) then where is the air extracted from within the car?
I have no proof that any of those thoughts of mine are correct and I would be pleased for someone to correct me.

Clive

PS If my suppositions are correct then the air will flow through your intercooler but in the opposite direction???!!!

Well I'm glad you are as unclear as I am, it's the bug shape that puts a real clink in the deal. If it had a flat roof or this or that, it might be more predictable, but you are absolutely right, it might flow backwards!!! I'll have to run some tests and I'll post my results!!!

Jason

I'm very interested in how this goes. Those vents behind the rear windows on the side are quite a mystery, I would love to know definitively if they flow in or out.

If all the UK contributors clubbed together we could get a bug in the wind tunnel at MIRA (Motor Industry Research Association) that's no more than 3 miles from here. From that we could get all the data we need but unless we have an aerodynamicist on board I doubt whether we could interpret the data. Ho Hum!

Clive

Exhaust
 

Finally got something going with the exhaust, and it actually turned out pretty good. It's all tacked up, and then I'll take it to a welding shop and have it either stainless MIGed or TIGed, not sure which will be a better option. I had a brainfart and ended up overtightening the V-band clamp, so after it's welded I'll have to get a new one as the nut gaulled...

Jason

http://images.thesamba.com/vw/gallery/pix/632786.jpg

http://images.thesamba.com/vw/gallery/pix/632785.jpg

http://images.thesamba.com/vw/gallery/pix/632788.jpg

http://images.thesamba.com/vw/gallery/pix/632787.jpg

http://images.thesamba.com/vw/gallery/pix/633485.jpg

http://images.thesamba.com/vw/gallery/pix/633486.jpg

Love that exhaust Jason. Magnaflow uses MIG on their mufflers, but TIG would work too (just takes longer).

Well I'm going MIG then, there are enough gaps that need some fill that a TIG would get REALLY hot. Thanks for the kudos, after welding I'll get it polished again and it should look pretty good.

Jason

That is off the hook, what would it cost to get a ride in your bug? My bro and I keep wanting a ride in a fast bug, ours are anything but fast, and we're torn between a big T1 motor and some type of water conversion...

I continued the build thread HERE

Jason