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914World.com _ The Paddock _ GT louvered front cooler vent
Posted by: Charles Freeborn Mar 6 2020, 10:52 AM
I've got an aftermarket front cooler that currently vents up through the hood. I want to change it to a more discreet set up to get past vintage tech.
Does anyone have access to photos of how the original GT's were done? I understand they blew out the bottom of the front trunk area through a louvered panel that created vacuum when in motion.
I do have access to sheetmetal working equipment to build the shroud around the cooler. Cutting louvers is a bit of a different story - would prefer to buy that panel, but making it is not out of the question. I recall a segment of "Binky" where they punched louvers. Will never show so doesn't have to be pretty.
My alternative is to fab a box with round vents ducted into the wheel wells.
Thx.
Posted by: stownsen914 Mar 9 2020, 10:18 AM
Here's a thread from Pelican from a guy doing what appears to be an accurate GT repro (or maybe resto?). It doesn't look like he did the louvers on the bottom. And honestly I think I'd skip that too. Louvers won't have as much open area and may not vent the cooler sufficiently (you want the cooling exhaust to be at least the size of the cooler and preferable 1.5x the size). A low front spoiler will "trip" the air to create the negative pressure you need for the oil cooler exit in the trunk floor, or you can add a lip at the leading edge of the opening, worst case.
The accurate metal GT ducts I see look very expensive (over $1000). I'd fab something similar if it were me, or I think I've seen fiberglass ones that are cheaper. Try mb911 here on the forum - I seem to recall he has GT repro stuff that is nice and reasonably priced.
http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/632760-last-new-914-6-gt-project-5.html
Posted by: Charles Freeborn Mar 9 2020, 11:04 AM
Here's a thread from Pelican from a guy doing what appears to be an accurate GT repro (or maybe resto?). It doesn't look like he did the louvers on the bottom. And honestly I think I'd skip that too. Louvers won't have as much open area and may not vent the cooler sufficiently (you want the cooling exhaust to be at least the size of the cooler and preferable 1.5x the size). A low front spoiler will "trip" the air to create the negative pressure you need for the oil cooler exit in the trunk floor, or you can add a lip at the leading edge of the opening, worst case.
The accurate metal GT ducts I see look very expensive (over $1000). I'd fab something similar if it were me, or I think I've seen fiberglass ones that are cheaper. Try mb911 here on the forum - I seem to recall he has GT repro stuff that is nice and reasonably priced.
http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/632760-last-new-914-6-gt-project-5.html
Excellent. Lots to work with there. Now I see why the PO of my car simply blew a hole in the hood and winged together some ductwork ... Many thanks.
Posted by: stownsen914 Mar 11 2020, 03:00 PM
Charles - I'm curious, did the vintage tech folks give you a hard time about venting the oil cooler in a way that doesn't meet the letter of vintage SCCA regs? (Or are you just playing it safe?) For the old EP car I'm going to be fixing up, I think it currently vents the oil cooler to the fender well, which I think may not be SCCA legal technically. I've also heard that sometimes the vintage groups aren't sticklers on such details.
Posted by: brant Mar 12 2020, 08:44 AM
I have a front hood oil cooler on my street car
It used to be a PCA race car back in the time that this car was.
I used to race against this car.
I'm also an Eligibility technician for rocky mountain vintage racing
I have been for over 10 years, and I'm the only Porsche tech on eligibility for our club.
We wouldn't allow it
We wouldn't come after you for your floor cooler or fender cooler because those don't show from the outside
but anything that does show from the outside would be scrutinized
that's how our vintage club handles it
and it is more forgiving than SCCA by far.
brant
Posted by: Craigers17 Mar 12 2020, 06:26 PM
I'm not exactly sure what you're looking for, but I think it's something like this. This was a thread I started on a somewhat different topic, but member Cairo94507 posted a few pics to give me some ideas. The relevant part for you starts on POST 13 of the first thread.
Anyhow, take it for what it's worth....I'm sure he can answer any specifics on the setup.
If you look on PAGE 70 of his build thread, on the second link below, it shows more details of the setup. Hope this helps.
http://www.914world.com/bbs2/index.php?showtopic=343084&hl=
http://www.914world.com/bbs2/index.php?showtopic=313869
Posted by: Charles Freeborn Mar 14 2020, 12:18 AM
Exactly what Brant says. I’ll run with a couple vintage groups up here (PNW) who mostly want t car to look correct. Eventually I’ll have to address the box flares too. I’ll also run with ICSCC which is a regional body. They follow SCCA rules so we’ll see where it falls. It’ll be one of thu production classes or SPU.
What surprised me about it’s build is how lax some of the safety gear was. Cheapo plastic drag race fuel cell. No diagonals in the cage to name a few. Those are all going to be addressed.
Posted by: stownsen914 Mar 14 2020, 06:29 AM
Gotcha. Some vintage groups are a bit looser than SCCA. Did you run with any groups up there and get a temporary pass on the flares and hood vent? Or just re-class your car until those items are addressed?
Posted by: Charles Freeborn Mar 14 2020, 05:41 PM
Gotcha. Some vintage groups are a bit looser than SCCA. Did you run with any groups up there and get a temporary pass on the flares and hood vent? Or just re-class your car until those items are addressed?
There are a few mitigating factors. With entries down somewhat they're more eager to find a class for everyone.. that said it's sort of a no-harm-no-foul scenario - at least with SOVREN, which is the smaller of the PTW vintage groups. If there are visible, or even not-so visible mods they'll bump you up a class. If you're still shellacking everyone they have a talk with you to see what's going on and probably bump you up again. I'm relatively new to this, so I can't say with authority how they handle "repeat offenders". It is, after all, "gentleman racing". SVRA, I'm not sure of yet - haven't been involved with any of their events as a driver - SCCA vintage either. ICSCC (conference) follows SCCA guidelines with weight regs, etc, but also has a no-foul sort of attitude. If another driver doesn't protest they let it sort itself out. I'll let y'all know how it all goes.
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