With the steering system having caused more headaches than anticipated and research taking a long time, actual progress on the V8Mongrel has been very slow recently.  With a nice, temperate weather forecast, I decided to put down the books and get back into the garage.  There is still a lot to be done other than the steering, much of which can be accomplished without any need to consider the final steering solution.  The temperate weather is also better suited to working with composites, so the rear fender flares were a natural choice.  Having previously purchased the raw materials (which incidentally have a limited shelf life, providing even more motivation to work on this particular project) I could (theoretically at least) get to work without having to wait on anything.

There are posts in the exterior category where I have provided links and information regarding different methods of making fender flares.  I am not following one specific method, but amalgamating the knowledge I have gained and doing what I feel will work best for me.  So far I have created the very basic outline of the flare using insulating foam and blue painters tape.

I taped down a piece of foam in the front to act as a base.  I still have to figure out how to trim that leading edge. The foam is easy to work with, but can make a fluffy mess if cut too quickly or the cut edges are handled roughly.  Heating the knife blade makes for a cleaner cut, but if it is too hot, material close to the blade melts and can remove a lot more than the knife will when cold.

I plan to have the big, flat rear space be cut out and filled with mesh.  The reason for this is twofold.  First, I have seen it done on many professional cars, presumably to relieve pressure; thus another case where I am following the ‘when in doubt, copy the pros’ mantra.  Second, flat is a lot easier to make than curved.

After taking the first pictures, I added an extra support at the leading edge.  From the bottom of that extra piece to the bottom of the fender, I still have to figure out.

Not much to look at so far, but that took a couple of hours since it was my first shot and on the steepest part of the learning curve.

Anyone who knows me will tell you that my kids are a huge part of my life.  Power tools, metal shards and harsh chemicals can make it difficult to get them involved in the V8Mongrel project, but there are still ways.  This past weekend was hot, humid and raining; far from an ideal weekend for getting work done on the car.  The kids usually can play outside while I turn the wrenches.  Even though that wasn’t an option, with a little creativity and some help from the kids, we had some fun and put together some ideas for what the Mongrel might one day look like.

When I first got the car, I searched online and found an outline drawing of a first generation RX-7.  I don’t know who drew it or where it came from, but I’d like to say thanks.  My kids have spent countless hours coloring copies of that picture and I occasionally join them, as I did this weekend.  While I won’t embarrass myself by posting what I did, I will show what it lead to.

I was toying with ideas on how to make the nose of the car look a little more menacing.  Here is the current look.

On top of the hood, you can see the raw materials for the project.  Red construction paper.  I was working with the kids and wanted to stay in familiar territory.  Some painters tape, a little measuring, a little trimming of the paper and we have the start of a new look.

The kids both thought it looked good and it was a nice way to spend an hour or so on a rainy day.  Paint is not even on the priority list at this point, but when the time comes, I might add something like what is pictured.  My son, Colin, had a cool idea of turning the triangle into a V, to fit the V8Mongrel motiff.  I like that.  Next time the kids take out the colored pencils, I am going to join them and see what it looks like on a drawing.

Part 1
Part 2
Part 3

While the air pan may not be how I want and ultimately determined that it is not fit for use on the car, that doesn’t mean that it is useless.  More so than an air pan, this has been a learning experience and the learning isn’t complete until every step in the project is done.

The next part of the process was to cut the air pan so it can be attached to air cleaner base.  The plan is to use rivets to attach it to the underside of the air cleaner lip.

The other side of this face is the surface on which the air filter sits, so the rivets head will face up to allow the filter to seal properly.  Since the filter has a rubber body, it should conform to a small surface imperfection such as rivet head.  If not, well, I’ll cross that bridge when I come to it.

I made a centering mark and then placed the air cleaner housing in the proper location in order to trace a circle around it.

Of course, that is the outer diameter, which were I to cut around, would leave no lip in the fiberglass to attach to the air cleaner.  The cleaner base would fall right through.

The solution is to measure the width of the lip on the air cleaner base and measure inwards from the circle drawn on the fiberglass in a number of places.  Connect the dots and you get the above.  It doesn’t have to be perfect since it is just a guide for a rough cut that will need to be finished after the cutting is complete.

Lesson 4 – A wide tipped marker works better to mark GRP than the pencil tip Sharpie.

Time to cut, but first:

Important note:
Cutting fiberglass creates a lot of dust.  That dust is hazardous to your health.  Wear a good dust mask.  The first time I worked with fiberglass I didn’t and by the end of day, I was coughing up little specs of blood.  Wear eye protection. I have had fiberglass in my eye and it was one of the single most painful events of my life.  Look online for a picture of fiberglass under a microscope and you will understand why.  Learn from my experiences and protect yourself.

I tried to use hand tools to cut the fiberglass to minimize dust production and spread, but found nothing that worked for this part of the project.  On the edges, a hand hacksaw and high leverage metal snips worked well, but neither of these work well cutting a hole out of a panel.  So I went to the Dremel with a drill bit in it.

Lesson 5 – Start on a slow speed with the Dremel as high speed will melt the GRP.

While cutting I could feel the bubbles as the cut rate would suddenly speed up.  I am still looking into the solution to that, but I am now convinced that it is a problem that must be completely rectified before I continue.

Only step left is to make sure things line up properly.

Not too bad for an experiment.  I am glad that I took it to the end as I found a potential problem.

There isn’t a lot of clearance around the neck for the PCV hose.  I will have to clamp the final air pan to the cleaner base before final riveting so that I can mock it up on the engine with the hose attached in order to be certain that it will clear.  A fiberglass edge will slice a rubber hose in no time, so the clearance will have to be generous.

The next fiberglassing installment might not be for some time as I have the research to complete, but I will report what I find out and my new game plan.  Back to metal for the time being.

Part 1
Part 2

Time to lay some glass!  With the preparations done it is finally time to lay some mat, mix some resin and make a part.  For this entry, there isn’t the usual level of detail I try to provide.  This is for two reasons.  One, the pot time of the resin (how long it takes to become gel) is such that in-progress pictures aren’t going to happen until I have someone with me to operate the camera while I work the fiberglass.  Two, I am still learning this process and I don’t want to post up what I do until I have finalized my own procedures.  This is why there are no resin to catalyst ratios, cloth weights, specific set times or other details.  I am not sure I have it right so I don’t want to make any suggestions until I feel more confident.

Step 1 – I laid out the mat dry to make sure that it wasn’t too small.  Too large is OK, but excessively so just gets in the way, so trimming it to only slightly oversize makes sense.

Lesson 1 – Mark the cloth so that you know which way to lay it when the time comes.

Step 2 – I mixed a batch of resin.  I made an extra large batch; larger than was calculated for the mass of the mat because I needed extra for step 3.

Lesson 2 – Have everything ready before you add the catalyst to the resin.  You want the entire pot time to work with, not waste it looking for a brush or your gloves.

Step 3 – I spread a layer of resin all over the mold.  In this case that was the aluminum foil.

Step 4 – I put the mat over the wet mold and tried to press it into the corners as best I could.  You will see later that I am not exactly an expert at this part.

Step 5 – I then wet down with resin the top side of the mat.  I am still developing my own application technique.  Getting the resin to be even can be a challenge.  This step used up the remained of the resin made in step 2.

Lesson 3 – Be gentle with the brush.  As the resin starts to thicken slightly it gets sticky and a hard brush technique will pull apart the mat pretty badly.

Step 6 – I added natural fiber reinforcements (mixing sticks), mixed up more resin and put down another layer.  This may have been a mistake as I think it generated too much heat, causing the bubbles you will see later.  Perhaps I should have let it dry first.

Here is the wet layup.

Step 7 – Next, I let it dry.  Took about one hour in the upper 80° temperatures of North Carolina in August.

Step 8 – I pulled it off the table and then removed any of the aluminum foil still hanging on.

Now time for the real analysis of the experiment.  This was a learning experience, so the bad parts are going to be more instructive than the good.  Here is the catalog of problems that I need to determine resolution of before continuing with more GRP projects.

Problem 1 – The aluminum tape didn’t release like the aluminum foil.

Problem 2 – The corners didn’t form properly.

Problem 3 – Bubbles.  Lots of bubbles.

Time for some research on how to fix each of these problems.  Although there are obviously some issues, I am still pleased with the progress I am making.  The aluminum foil mold release worked really well.  I am getting a much better handle on pot times.  My application technique has improved.  Overall, I am gaining skill and feel like I am not far from being able to tackle the fender flares.

Link to Part I

Next step in the experiment that is to become that air pan was to set up the mold.  Slightly more complex than a flat panel, the pan still wouldn’t require any other than straight lines.

First thing to do was make sure I had a flat surface.  Unfortunately, I didn’t do this first, as the pictures will show, but I did do it early enough so as not to impact the final product.

The wet lay up process will take place on a rolling metal work table I got free when an office building was cleaned out.  The metal top is not level like a machinist’s ruler, but it is certainly close enough for this project.  There were a couple of lumps in the surface that needed to be taken care of.

They look like someone drove nails into the top, but there is nothing on the underside indicating that to be the case.

Since I didn’t want to risk damage to other parts of the surface, I kept the power tools in the drawer and took the offending lumps down with a hand file.

Halfway done.

Finished.  Lots of dust needed to be cleaned off afterward, but the surface is now smooth enough for my purposes.

Important note:
I am doing this entire project in an attached, two-car garage and chose a rolling table for this step so it can go outside once I start using chemicals.  My sources tell me that the smell of polyester fiberglass resin can permeate food quite easily.  Furthermore, the dust from dry fiberglass mat and sanding the composite material is irritating to airways.  This is a job best done outside.

The pictures above show glimpses of the next couple of steps, but here is the process in greater detail.

After measuring the underside of the hood and the filter base, I put up fences that would make the perimeter lip when duplicated in GRP.

Just some steel tube I had laying around, held with welding magnets.  Nothing fancy.

Next, I sealed the corners with tape so that when I put down the aluminum foil, there would be a smoother radius.  Not sure if this will make any difference, but in metal working sharp edges are a weak point, so I just followed my old habits.

Again, nothing out of the ordinary, just standard blue painters tape.

All of this was just the base for the aluminum foil that would be the surface against which the fiberglass would be laid up.  This is the same method as used by the guys on Muscle Car.

The only thing I did differently than the guys on TV was to not glue the foil in place.  Since they were using a disposable foam mold, that made sense for them, but since I want to keep this table and use it again, I just taped the edges down and sealed the seams with aluminum tape.

Here is the approximate location of the air filter housing on the mold.

All set.  Up next, time to lay some glass.

Since the car now has wheels, the need for fender flares has become very obvious.  I am not ready to dive right in and start with such a big composites project, so I have decided to start small.  I have previously made some flat fiberglass panels for purposes such as an undercar splash shield, but that allowed me to make it extra large and then cut to shape.  With the fender flares, I won’t have the luxury of avoiding bad areas, and I will have to follow curves, raising the difficulty level considerably.

I brushed up on my GRP (Glass Reinforced Plastic, aka fiberglass) knowledge by reviewing the resources I posted over a year ago.  Once I felt like I was up to speed, I looked for a good starter project.  Having gone through all the trouble of making a cowl induction system, I decided that having the air filter sit open to the engine bay made no sense.  Cold air makes any engine run better and provides more horsepower, so an airbox of sorts makes sense as a functional project.

I wasn’t sure that I could do a full box, but since I didn’t want to do another flat panel project a flat pan was out of the question.   I decided that an airpan with a lip around the edge would provide both good practice and function.  Something like this, but in GRP.

I would need a way to seal the pan to the underside of the hood; a function performed by the rubber door seal material in the picture above.  While cowl induction is supposed to provide a steady stream of cool air to the engine, I am still not confident that a rubber seal like that would last under the hood.  Perhaps in some applications, but I have very little room and precious few escape paths for heat, so I am going err on the side of caution.

I found that Moroso sells air pan kits for certain carburetor combinations, and that if you read the fine print, the fire retardant foam is available separately as part number 97070.  At just $12.95 from Summit Racing, I decided to pick up two boxes worth.  The beauty of the foam is that not only am I going to be using it for what is designed for (shocking, I know) but it will easily conform to the underside of the hood, which, because of strengthening ribs, is far from flat.

For materials, I will be using chopped strand mat (CSM).  The one square yard bag made by Bondo and sold in nearly all autoparts stores.  I don’t even know the weight, but I assume it 1½oz/ft².  The resin is polyester and from Elmers.  I got that at Lowes Home Improvement.  Once I feel like I have a handle on the process, I am going to find an online supplier that I can use to order in bulk to save money as buying piecemeal is never cost effective.

I will be using the aluminum foil method I saw on the Muscle Car TV show instead of a chemical release agent.  It has served me well in my flat panel trials, is cheap, available, and about impossible to mess up.  Since I don’t have a part to copy, I will be making a box without a top to serve as my mold.  Nothing fancy, this is about the learning experience more than anything else.

Hopefully I will end up with a usable part and the skill set needed to flare the fenders.

As promised in my previous post, I have added a gallery of images from the 2009 VIR Gold Cup.  It was a great trip: beautiful weather, beautiful cars and the fun, welcoming atmosphere that is a hallmark of the annual Gold Cup.  Obviously, the Hemi Challenger was the highlight for me, but there were other cars there that sparked my imagination and offer potential ideas to make the V8Mongrel even better.

One of my favorite cars of all time is the 1968-1982 Corvette.  The C3 has the classic Coke-bottle shape, aggressive fender arches and a stance that just screams performance.  There were three beautiful C3s on display at the 2009 Gold Cup.

While the SA22C RX-7 isn’t a C3 clone by any means, the two designs do share certain elements.  Both are tw0-seaters with a compact cabin and hide-away headlights.  It is in the Gold Cup’s C3 headlights that I found some inspiration.

The RX-7 headlight actuator motors are heavy and take up space in a place that is perfect for getting cool air.  As the engine compartment is cramped, cooling airflow is a major consideration.  Removing them seemed liked like a good idea, but I still want working lights so the car can be registered for street use.

An easy solution to a lack of headlight motors was found at Granny’s Speed Shop.  Their shop mule is a first generation RX-7 like mine and they came up with a clean, simple solution for having working headlights and no motors – removable brackets.

Should be easy enough for me to duplicate, and while that is the solution I will use for now, the Gold Cup Corvettes presented a much more aesthetically pleasing possibility.

Those clear covers and fixed headlights look tough and would fit the look of the V8Mongrel well.  I have absolutely no idea how to make them, how to mount the lights, or anything else, so this project is well down the priority list.  But I always keep my eye open for inspiration like this because you never know what you can take away and how you can apply it to your own project.  That is part of the joy of seeing all these race cars each year at the Gold Cup.

As I said in the last post, one of the greatest joys of the V8Mongrel is the fact that it allows me the opportunity to do all sorts of projects that I might not otherwise. In fact, there are certain things I get to do that I would never even thought about doing previously. And, for me, that is very much part of the fun of having a project car.

“Shakedown 1979,” and apparently a passenger side mirror is a luxury item that a budget sports car such as an RX-7 doesn’t get. On track, this simply isn’t acceptable. The previous owner got around this problem by running a multi-panel Wink mirror. This allows almost 270° vision once you get used to it. Having a single mirror provide five images can be somewhat overwhelming, particularly if you don’t drive the car regularly.

So I decided it was in my best interest to find a mirror for the passenger side. Problem is, the matching Mazda mirror is expensive and, well, kind of frumpy. While not as bad as the ridiculous Japanese market mirrors mounted half way to the headlights on the fender, they look like they are about the cheapest mirrors ever made. While the Mongrel is all about go, for the mirrors, I went with a little show since I had the opportunity.

I picked up some universal mirrors on closeout from Summit Racing, for the princely sum of $17/pair. Adding some interest to them are the integral turn signals. Unfortunately, this was also the source of the only real problem.

The paint that covers the portions of the lens that need to remain opaque was flaking off. Since I had purchased these mirrors about a year prior to installation while they were on clearance, I had no recourse. It could have been that they paint was exposed to something during the course of the project. No problem, some time, a little bit of sand paper, add some masking tape, a quick spray over, and it was good as I needed.

Mounting the driver side was very easy since there were two mounting holes with threaded bungs already in place for the OE mirror.

The mirrors I bought have a range of adjustment in the mounting that allowed them to accommodate the factory mount spacing. Between them, I drilled a hole and inserted a grommet.

The wires for the turn signals were passed through the grommet and await Mike “Mr. Wizard” Westerfield to come and make them work like they were there from the factory. I am sure I could ugly my way into getting them to work, but Mike really knows what he is doing, so his way won’t melt wires and burn fuses like mine will.

After that, it was a simple matter of bolting the mirror on.

Certainly a big improvement.

The passenger side, due to the lack of a factory mirror and mounts, was more of a challenge. I measured the holes on the driver side in an attempt to get them to match.

I put painters tape over the area before drilling in order to minimize paint cracking. I stepped up the drill bit diameter gradually.

The metal was thicker than I was expecting, but not think enough to tap and use as the sole method of mounting the mirror. Notice that the paint chipped over what looks to be Bondo.

So a quick trip to the BORG yielded me some well nuts. While I wouldn’t use these to mount anything critical, a mirror is not a big deal. Plus, since it is a rubber mount, it should be able to reduce some vibration. Pity I didn’t think of that until after I had mounted the driver side!

Another mounting hole was drilled, a third for the grommet, and the mirror was ready to go. After a couple of attempts, I found it much easier to thread the rubber wellnuts onto the bolts rather than than put them in the holes. That way, I could pre-tension them and ensure a fit snug enough to stop them from turning while the bolts were fully tightened.

I used stainless steel, button top, socket-head cap screws on both sides. The factory metric thread was so close to the SAE that I couldn’t tell the difference. The hex drive is better than using a Phillips head, and the stainless steel should never rust.

The finished product.

Driver side

Passenger side

The Mongrel now has mirrors. It was a fun little project, and certainly a change of pace from the usual mechanical mayhem.

After looking at some pictures of RX-7s with fender flares, I had a pretty good idea of what I was going to be working towards. And, thanks to ProdBodies, I have the option of purchasing the parts if I decide not to expend the effort on the DIY solution.

I found that there are some good resources for people looking to lay their own composites. A lot of it is focused on aircraft, so here I will limit myself to the automotive resources.

Yugo Flare Tutorial – This is a site that shows how to do a very simple flare. Honestly, this is the resource that started me thinking about doing my own fiberglass work. While maybe not as high quality as some of the others shown, this is definitely the resource for doable fender flares.

Project e30 blog – I was shown this site by Chris Brown (who has his own e30 blog) and it really shows what composites can accomplish when used on a production based race car project. My congratulations to the builder; that is some impressive work. The carbon-fiber roof is amazing. Maybe one day the Mongrel will be have those kinds of . He uses some interesting techniques, like fleecing, that I need to investigate more.

Grassroots Motorsports, May 2004 Volume 21 Number 3 “The Glass Slipper” by Noel Omer, Velocity Racing 1988 Toyota MR2 – I am not sure that this particular back issue is still available, but the article I reference covered a $2003 Challenge MR2 that featured extensive GRP (fiberglass) body work, all done at home. There are some great details on how to make molds and bucks.

Grassroots Motorsports, November 2004 Volume 21 Number 7 “Performance Plaid” by Ed Lenahan – This article gives good details on how to make carbon fiber parts at home. The technique used is more involved, and while not explicitly stated, I believe that it is for components that will experience some load. This article convinced me to stay with fiberglass. It also provided links to two suppliers:

Aircraft Spruce
FibreGlast

Competition Car Composites, A Practical Handbook, by Simon McBeath, Haynes Publishing ©2000 – This is a great book, as are most of the Haynes hardbound technical books. It covers, in significant detail, the use of different materials, techniques and results. This book, like Lenahan’s article, has made me about certain that I will use just fiberglass. The cost of the alternatives aren’t worth it for my application.

Muscle Car (TV) – As part of their road race Mustang series, the show detailed how to make fiberglass fender flares. Thanks to Mike Westerfield for bringing this to my attention and Kendt Eklund for the digital magic so I could watch the Amazon Unbox copies the way I wanted. Later on, they had a feature on how to make molds from existing parts. Both of these episodes showed how to do fiberglass with minimal tools and in exactly the way I plan to.

I am still not 100% sure what I am going to do. The idea of buying full fenders for the front and adding my own flares to the rear has crossed my mind. An add-on flare seems like an easier proposition than a whole fender. Plus, the fronts I have are pretty dented up, so wouldn’t make a good basis for a mold any way. Obviously the full fender would be the way to go from a weight standpoint. If you have an opinion, leave me a comment and let me know what you are thinking.

While planning and test fitting the front suspension it became clear that even with moving components as far inboard as possible, the wheels just weren’t going to fit under the stock fenders. This is no surprise; I didn’t buy 15″ diameter, 10″ wide wheels expecting to slip them on a car that came equipped with 13″ x 5.5″ wheels from the factory. However, the extent of the problem I might have slightly underestimated.

This picture represents the worst case scenario, and subsequent suspension work has allowed for components to be located closer to the centerline of the car compared to what is shown in the photograph. Regardless, of the extent, the fenders and the tires will attempt the impossible task of occupying the same space if I do nothing.

My first step was to find some pictures of other RX-7s with fender flares. My elder brother, Paul, proved quite resourceful and came up with a link to an amazing site, Racing Sportscars. All the images are copyrighted, and since I would rather err on the side of caution, I am going to provide a list of links to pictures hosted there, rather than embed the images here.

Number 71 – I like the side pipes but the nose looks very wide.
Number 47 – I think I prefer the box type flares.
Number 53 – I am not sure what to think of the front flares that have no back part. Easier to make perhaps?
Number 92 – Looks a lot like 47. I think the wide nose would be easier to make than those graceful curves up front.
Number 76 – Looks good and also relatively simple.
Number 66 – Probably a team car to 76 above. Overall a nice look and not too complex.
Number 55 – I will have to research if the leading edge of the front flare configuration to see why it would be the two configurations (curved and wide nose) might exist side-by-side.
Number 38 – And now I know how much material to remove behind the flares, at least at the rear.

The entire site is a treat and I am sure that there are more images to be found therein.

Paul and I also used Google Images and came up with some other example. If these images belong to anyone, please let me know and I will be happy to give credit.

I think that one is my favorite. At least in the front it seems to be the most subtle of all. I believe that the car was run by Racing Beat. If you have more details on it, let me know.

This car appears very similar to some in the links. The IMSA GT sticker makes me think that perhaps is is one of those cars that someone found. I think I would like to avoid a rear flare that needs to be blended in to the door.

These images served the purpose of showing me what had been done before. For what is being done today, I found a company that is only about an hour away from me. ProdBodies which has a number of options available for the Mazda RX-7. Based on their name, my guess is that their target market is SCCA Production class road racing. The parts seem reasonably priced and since they are local, I won’t have to pay shipping. With the high prices of diesel driving freight cost skyward, that is no small consideration.

With a basic idea of the possible options, I still have more planning to do. Next up, I will share a couple of links of fellow amateurs and how they made their own flares, plus my research into composites to determine if I can perform the fender flares in house.