John's EZ36R H6 818R Build

[Hobby Racer]

Finished the rear wing support today. It will also double as support for the rear fiberglass section.

[Hobby Racer]

Here is a peek of the top exit exhaust with the rear deck laid in place. I have Mechie's "Hump Vents" to cover them.

[Mitch Wright]

Ok your exhaust looks pretty cool.

[AZPete]

Smart design and nice work.

[flynntuna]

looks great! one year in and making great progress.

[lsfourwheeler]

Do you think exhaust fumes in the cabin will be an issue? Looks awesome though. More 918 than 818

[Hobby Racer]

Do you think exhaust fumes in the cabin will be an issue? Looks awesome though. More 918 than 818

Should not be a problem, been through that here.

And yes, the 918 was part of the inspiration!

[longislandwrx]

looks impressive... maybe I can stop by sometime and eat off your floor

cant wait to hear you rev this lady up.

[UnhipPopano]

"cant wait to hear you rev this lady up."

With the exhaust tips right behind your head, you better be wearing so serious noise protection.

[Hobby Racer]

looks impressive... maybe I can stop by sometime and eat off your floor

My brother in-law does say I spend as much time cleaning up the garage as I do working on the car

[longislandwrx]

are you going to modify the vents?

that exhaust blasting on the fins is going to turn the whole thing into a heat sink and roast that fiberglass.

on the Porsche the whole assembly is inconel or titanium iirc... its also triple walled and has a cooling duct... how are you going to control heat?

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[Hobby Racer]

are you going to modify the vents?

that exhaust blasting on the fins is going to turn the whole thing into a heat sink and roast that fiberglass.

on the Porsche the whole assembly is inconel or titanium iirc... its also triple walled and has a cooling duct... how are you going to control heat?

Well I'm not sure yet. But the Porsche exhaust is quite a bit shorter and the that engine is boosted, putting out way more power/heat than my naturally aspirated EZ36. My pipes should be much cooler at the exit.

If it cooks the fiberglass, I guess I will poke the exhaust pipe out the top about an inch to push the exhaust out past the fins and fiberglass. I'm hoping to not have to do that as it kind of ruins the look I'm going for

[flynntuna]

So this isn't the look you had in mind?

[turbomacncheese]

Why am I not surprised to see a Florida plate on that thing (the semi-piped mustang)....

[redbudrr]

Very impressive!!

[Hobby Racer]

I've been thinking about what longislandwrx said about the exhaust heating up the aluminum fins and he has a point. The top 2 fins are right on top of the exhaust exit and will get hot. So what to do about it...



First idea is to remove the top 2 fins and either leave the hole which would allow the exhaust to escape and not heat the aluminum or fiberglass. I could also cover the hole with some stainless steel mesh for looks and to keep large debris out. Here is a mock up of what it might look like.



Second is to leave the vents alone and route the exhaust out the sides of the humps. Take a look at the two black circles outlined in green for a visual of where the exhaust might exit. I could route the exhaust into the center of the humps OR direct them out towards the sides of the car. I would then trim the holes out with some stainless trim rings.

Which way would you go and why?

[lsfourwheeler]

I would think going out to the side would give you the benefit of not encouraging things to fall down the exhaust. Even if you did add mesh, small things may fall down there and in that case how do you remove them? For aesthetics, I think going out to the sides of the hump facing the outside of the car would better than the inside face and it leaves the design of the nice hump vents intact.

[Zach34]

I like the idea of going out the vent, but have a heat shield around the exiting pipe - totally imitating the Porche. I think you'll need a heat shield to keep from burning the surrounding fiberglass and also to make sure the exhaust doesn't collect in the engine compartment, making everything hotter and sooty in there. Maybe not the intricate custom formed sheet metal on the Porche, but something more rudimentary.

By the way, what products did you use to bond the engine cover together? Looks like a gray filler under the fiberbglass cloth? Did you use epoxy or polyester resin? How's the strength/flexibility. I'm going to try to do mine this weekend.

[VicariousJ]

First,this build is amazing and so much fun to watch! Innovative ideas and excellent execution...

Concerning the heat-soak/vents issue...would ceramic coating not work like on the pipes themselves? Another idea that could help save the fiberglass could be a phenolic spacer between the aluminum and 'glass hump. Extension of this idea (kind of extreme), phenolic wafers covering the underside of the top two fins.

Just a couple random thoughts...

Otherwise, my vote would be exit the humps facing centerline...keep the hidden exhaust idea alive. Plus soot trails on the body are less visible.

Whatever you come up with, I look forward to seeing your results. Good luck

[STiPWRD]

Which ever path you take, I would highly discourage obstructing the exhaust with anything (i.e. fins, mesh, etc.). I know you're going for a clean look but anything you place in front of the exhaust gases is going to get very, very hot (especially on a race car) and potentially divert some of the gases into the engine bay. Personally, I would get rid of the fins but retain the openings in the humps then fab up some nice stainless shrouds. It would be a good chance to show off some custom sheet metal work and provide a heat shield over the fiberglass at the same time. Like others have said, it would mimic the 918 but still be unique.

[Hobby Racer]

By the way, what products did you use to bond the engine cover together? Looks like a gray filler under the fiberbglass cloth? Did you use epoxy or polyester resin? How's the strength/flexibility. I'm going to try to do mine this weekend.

I used vinylester resin with alternating fiberglass cloth and mat for total of 6 layers on the back and 2 layers on top. Vinylester is better for heat and chemical resistance than polyester and more flexible than epoxy. The strength / flexibility is excellent, I can lift the deck from the front or rear and cantilever the rest out without stressing the glass.

First,this build is amazing and so much fun to watch! Innovative ideas and excellent execution...

Thank you, its nice to hear. I hope some of my ideas are helpful to others looking to solve some of the same issues.

Personally, I would get rid of the fins but retain the openings in the humps then fab up some nice stainless shrouds. It would be a good chance to show off some custom sheet metal work and provide a heat shield over the fiberglass at the same time. Like others have said, it would mimic the 918 but still be unique.

I think I'm going to try a hybrid. I will remove to the top 2 or 3 fins and come up with some stainless shrouding to bridge the gap between the exhaust and the hump holes. But I will keep the rest of the fins to vent ambient heat out of the engine bay.

Thanks for the input everyone!

[Hobby Racer]

Getting ready for the next big stage in the build, paint! I am lucky enough to have a heated garage large enough to construct a spray booth inside. I have ~ $100 invested in lumber, plastic sheeting, hardware etc.



The door will contain 4 furnace filters to filter incoming air. The window will have 2 filters before 2 box fans to exhaust air out.

[ben1272]

You going to drive the car through the door sideways? :O

Nice paintroom. I assume a wall will come down, or you plan to paint the panels off the car. I always heard that panels should be on or mostly in-place on the car to reduce variations due to spray paint angle of application and metallic particle distribution, etc.

What's your plan stan?

[Hobby Racer]

You going to drive the car through the door sideways? :O

Nice paintroom. I assume a wall will come down, or you plan to paint the panels off the car. I always heard that panels should be on or mostly in-place on the car to reduce variations due to spray paint angle of application and metallic particle distribution, etc.

What's your plan stan?

Panels are coming off the car. I've panel painted 3 cars this way, including my Cobra, and I find it much easier to get at all the the bits when they are off the car. As long as you watch your gun to panel distance, angle, and travel speed, the metallics come out beautiful. The important thing is to paint them in the right orientation. I.E. paint the hood laying flat and not hanging vertical. That way the metallic particles flow out properly.

Since the paint booth is temporary, I wanted to build it as inexpensively as possible and yet meet my needs. Here is a picture of the box fan / filter setup in the window. I will use plastic to seal off the filters to the wall section so my nice white windows don't turn orange!

Hopefully I will be painting later this month. I am still waiting for my rear wing to come so I can mount it and cut the holes in the rear deck.

IMG_20180201_173402.jpg

[Wayne Presley]

What rear wing are you using?

[Hobby Racer]

What rear wing are you using?

I went with the 67" APR GT-250 single element wing. I felt the GT-1000 was a bit overkill

[Sgt.Gator]

DIY at it's best!

[RetroRacing]

I wish I had pics of the 4 different paint booths we built

One, the finished garage of a buddy of mine, taped poly to the ceiling and installed a scroll fan on the floor. ceiling is still Mazda Laguna blue.
second, in his warehouse. Hung tarps from the trusses by standing on the last forklift stage, rigged with pulleys to the ground so we could raise and lower them. Taped cardboard to the floor. Had to wet sand a ton of dust out of the paint....
Third, built a 24x24 scaffold structure in my warehouse. Used a 48" fan, with 8-10" round ducts and filters "down draft" the booth. Used astroturf on the floor, baaaaad idea!
Fourth, bought a big out door tent and erected it in the new warehouse, with cardboard on the floor, two scroll fans in a sealed box with filters. Best one yet, very little color sanding required.

And that is why we vinyl everything now!

[Canadian818]

Old trick is to wet the floors just before painting, or run a hose if there’s good drainage. All the dust and overspray lands in the water and doesn’t get stirred up.

[Larry J W]

Be careful with the wet floors because the 2 stage paint is moisture cure and it really affects the flow and cure. In general the relative humidity should be less than 50%. With wet floors I had a lot of orange peel. Also the over spray sticks to the plastic and just opening or closing a door shacks it loose. Turning on the fan does too. Unfortunately I am an expert of what not to do!
Larry

[Hobby Racer]

Old trick is to wet the floors just before painting, or run a hose if there’s good drainage. All the dust and overspray lands in the water and doesn’t get stirred up.

I tried that once, didn't like the results. The paint and wet floor made a nasty slurry on the floor and made a mess of everything! I like using construction paper on the floor. You get it in 36" rolls at Home Depot in the paint department. Its absorbant and your just fold it up and recycle it when your done and your floors don't get messed up.

Be careful with the wet floors because the 2 stage paint is moisture cure and it really affects the flow and cure. In general the relative humidity should be less than 50%. With wet floors I had a lot of orange peel. Also the over spray sticks to the plastic and just opening or closing a door shacks it loose. Turning on the fan does too. Unfortunately I am an expert of what not to do!
Larry

The humidity issue is also why I like painting in the winter, very low humidity and no bugs to land in the paint! I know what your saying about the over-spray on plastic! It just flakes off and floats into your paint I try you use paper to mask off anything on the body to avoid that as much as possible.

[RetroRacing]

We did the wet floor thing, not good with base-clear, had to sand out the orange peel. Used the paper on the floor for some body parts we did for our ep cars, and yes, better than cardboard

[Wayne Presley]

My painter uses this stuff
http://like90.net/floor-coatings/pig...ticle-control/

[Hobby Racer]

My painter uses this stuff
http://like90.net/floor-coatings/pig...ticle-control/

Wow, that looks like a much better solution. Thanks Wayne!

[Hobby Racer]

While I'm waiting for the wing to arrive I sealed off the radiator so all air coming in the grill is forced thru the radiator core.



Started by forming up the bottom then the sides and then the top last.
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Here is a pic through the front grill.
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This shot is from the underside looking toward the front of the car. I reshaped the FFR aluminum piece so that if I need additional cooling I can open up the laser cut vents to get more air from the underside.
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And finally the top. This piece is not riveted, but fastened instead using #10-32 button head bolts so it can easily be removed to get at the radiator.
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[Hobby Racer]

I attached the rear diffuser and pushed it out 4" from the rear bumper
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Next I'll make some panels to seal off the rest of the underside in back.

[flynntuna]

I see you're using an after market radiator. How did you attach it to the frame?

[phil1734]

Holy cow I never realized how comically small the diffuser is. I guess I'll scratch that off the wish-list.

Can I ask how you arrived at leaving it out 4"? With a full race wing it seems like you'd be wanting to move your pressure center as far forward as possible. (Rules permitting of course )

Also love the exhaust but don't forget a provision to keep water out when it rains!

[Hobby Racer]

I see you're using an after market radiator. How did you attach it to the frame?

I knew from the start I was going to skip the OEM radiator and go for something better. I found this Griffin double row, dual pass aluminum radiator fit perfectly. Since I was also using a water to oil engine oil cooler, I needed the extra cooling capacity. Anyway, I mounted it using simple bent strips of metal welded to the lower radiator support and a 3/4" square tube to span between the left and right sides . My radiator sits nearly vertical as opposed to laying at a steep angle to promote better flow through the core. The top is held by a bent piece of aluminum sheet that is secured to the top radiator support.

Here is a close up of the left side and two of the right side.
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[Hobby Racer]

Holy cow I never realized how comically small the diffuser is. I guess I'll scratch that off the wish-list.

Tell me about it. I got it because it was only $100 in the FFR attic sale at the time (scratch and dent).

Can I ask how you arrived at leaving it out 4"? With a full race wing it seems like you'd be wanting to move your pressure center as far forward as possible. (Rules permitting of course )

I pushed it out the max I could and still have it close to the lower bodywork when clearing the lower bumper. Nothing scientific I'm afraid! And yes I will be moving the center of pressure just forward of the rear wheels by adding additional under body trays that meet up with the CF diffusor. I'm still making those, but I'll post pics of the completed under-tray when they are done.

Also love the exhaust but don't forget a provision to keep water out when it rains!

Other than a car cover I have not thought about the rain issue. Although I never leave the car outside, and if its raining I'm not driving