Spawn Aerodynamics - Bullittes CF build thread.

[miguez]

Gents, interesting info, but let's try and keep it civilized (so far so good, but I can see where this is going).

A question to both of you guys knowledgeable in composites, as well as to John from Spawn Aero: When making parts for a car such as this, what are the differences between using prepreg (which I understand is carbon cloth pre-impregnated with resin, but not yet cured) and a dry cloth with resin and vacuum-bagging applied on the mold? And which is Spawn using? I think a lot of people here are interested, but not very knowledgeable, like me, so we'd very much appreciate the information coming from either of you.

[njmike]

Spawn is doing a wet layup, as seen by the roll of dry fabric. There is absolutely nothing wrong with wet layup, 90-95% of the work I do is wet layed & cured under vacuum..

Prepreg has the advantage of consistency, but is not necessarily stronger. Some can be, and at the high end (fighter jets, f1 tubs), everything is made from prepreg for controlled resin distribution and because some of the high temp resin systems used simply aren't available separately.

This really is all a moot argument, as there is absolutely 0 reason to use prepreg for street car parts. Unless people are going to start paying $4k+ for a hood, there simply isn't a demand for it, and the quality difference is negligible.

I don't know what the deal is with Seibon's "dry carbon" parts is (hate that term, noone in the industry uses it). I haven't seen one in person, but since their normal line consists of fiberglass hoods with a carbon overlay, I can't imagine what their "dry carbon" line is like.

It looks like Spawn is on the right track. I'd love to check out some of his work in person.

BTW, anyone can feel free to PM me with any questions. I've been working with composites for over a decade, and have built parts for 100's of race cars, NHRA stuff, formula cars, drift cars, Grand Am cars, you name it.

[njmike]

Originally Posted by CCCLXXZ

Indeed, the new copy/paste feature on the iphone works rather well. Why would l make my own claims about another corporations products? I was just working on my works cited page, you just beat me to it! I'll cite my other references in the future, right after I go enjoy my cwoffee.

I'm not sure why you quoted me then. What you copy/pasted didn't really have anything to do with what I said.

Yes, in the future, you shouldn't present someone else's writing as your own.

[RCZ]

John can you make us a set of these for us Stillen G3 owners

[FuszNissan]

^^ Isn't that in the worng area thought. Shouldn't it be closer to the middle and lower.

[SpawnAeroJohn]

The lip or the inlets on top of the bumper? The 2 carbon fiber inlets?

[WShade]

Originally Posted by SpawnAeroJohn

The lip or the inlets on top of the bumper? The 2 carbon fiber inlets?

They are talking about the inlets.

[miguez]

Originally Posted by FuszNissan

^^ Isn't that in the worng area thought. Shouldn't it be closer to the middle and lower.

Hi Fusz,

Not necessarily. These are actually curved inboard. You don't want openings pointed straight into the Stillen G3 air filters otherwise you run the risk of getting water in your intake when it rains.

[wstar]

Originally Posted by WShade

They are talking about the inlets.

Yeah, the inlets. I'm sure one of us Gen 3 owners could get some measurements re: where the filters lie in relation to the bumper itself. Just looking at the pics, the height on the Mine's probably about right. But yeah, there's that whole thing to consider about whether you'd want the holes directly over the filters (probably best on a dry day) which are close to the center, or positioned further out for indirect airflow and avoiding rain.

What would be complicated but ideal (to me anyways) would be to position the inlets about where Mine's ones are, but do a shaped tube from there that goes in and up, then lets the air out on top of the filters in the center. Light rain wouldn't make it through the upwards tubes much, and you could always make little snap-in covers for those occasions where the car has to be driven in harder rain.

[RCZ]

Would be perfect to have something maybe not directly in front of the filters, but maybe just to the side of them with a couple of rams (or not) on the inside. Here is where they sit.



And finally, excuse me STILLEN for borrowing your pics, but here is a see through.


They MAY actually already be perfectly positioned to suit us. More to the middle and its right over the filter. I know you are trying to keep the air trapped in that section and to ram it in there guys, but the air needs to flow somewhere to create cold air flow over the filters. Otherwise it fills up with turbulent air and actually defeats the purpose for having the vents on the front as wind wont flow in as easily. Then again it is going through the radiator too...so there is flow and we should try to ram the air into the intakes... discuss?

[Endgame]

Originally Posted by SpawnAeroJohn

The lip or the inlets on top of the bumper? The 2 carbon fiber inlets?

What about the lip??

[miguez]

Originally Posted by RCZ

They MAY actually already be perfectly positioned to suit us. More to the middle and its right over the filter. I know you are trying to keep the air trapped in that section and to ram it in there guys, but the air needs to flow somewhere to create cold air flow over the filters. Otherwise it fills up with turbulent air and actually defeats the purpose for having the vents on the front as wind wont flow in as easily. Then again it is going through the radiator too...so there is flow and we should try to ram the air into the intakes... discuss?

There is some flow behind the bumper, so openings like Mine's would work, even if they don't ram the air on top of the filters.

If someone is interested in ramming air into the intake, then ModShack's approach, modified for the Stillen intake, is the easiest/cleanest. Using the openings by the fangs, and a hose to connect those to an air box (a cylinder) that fits right around the filters. In that case, since the route has a large vertical displacement from the bottom to the top of the bumper, very few droplets of water would actually make it to the filter, and those would be caught by the filter element.

Trying to ram air from somewhere like the Mine's openings would require a path that would first travel down or back, before turning around, so that the water would be trapped there through gravity or inertia, respectively. There is room to travel down, but in that case once again ModShack's approach makes more sense. There is little room to travel back, so that's probably out of the question.

My opinion then is that the Mine's openings should be considered but not in the ramming fashion, simply to get fresh air behind the top of the bumper, and therefore into the Stillen intake. One could even optimize it a little by having a simple 90º elbow turned inboard from the opening, but without an extension or hose connecting it to the filters.

[Caravanshaka]

My idea regarding the vents in the dual vent discussion post:

Titek Dual Front Air Vents - Opinions

[RCZ]

Originally Posted by Caravanshaka

My idea regarding the vents in the dual vent discussion post:

Titek Dual Front Air Vents - Opinions

Good point, I got way off track, I apologize John! Will continue discussion on the other page.

[Caravanshaka]

Originally Posted by RCZ

Good point, I got way off track, I apologize John! Will continue discussion on the other page.

off track is ok as long as it stays in the grass...you only have problems if you find a wall