My 1973 TVR 2500M : Renew and Restomod

TVR Scott said:

Stu flatter-shamed me in his thread, so I had to get off my ass and get a few things done.

First some minor stuff:

All the TVR guys were posting pics of their horrible bonnet-frames, and I took this one real quick today.  The cave-man former owner of mine clearly did some repairs here:

Yup, some Home Depot engineering there.  Kudos for the bird-turds holding it all together.

Another unrelated activity: I found some scrapped aerospace parts today that I grabbed from a job 10 years ago.  I had forgotten that they had some 10-32 nut-plates mounted, so I spent a few minutes with a drill and punch:

MS21059 FTW!

I'll admit you have to be a pretty serious hardware nerd to appreciate these.  But I am one.

On to the hood hinges.  No, I'm not going to duplicate the stock frame.  That 30 deg hood opening angle just doesn't do it for me.

First off, I'm adding some bulkheads to stiffen the structure and direct cooling air in the right direction.  Some wood-based cad:

These will need to be trimmed out quite a bit to fit around the intercooler tubing - at least in the middle.

I wanted to do a super slick internal hinge, sort of like this:

Imagine a rod end on the end of that, pointing straight down to allow some vertical adjustment.  This *might* work, but it doesn't really clear the intercooler tubes, and there's not a ton of space inside the hood for mounting arrangements.

So, I'm probably going to go sort of crude and mount a subframe below the front of hood.  Something like this (binary CAD):

This is essentially the same as the hinges on the front end of my old Spitfire.  This could potentially look sort of terrible, so I'm going to give a lot of thought to how to make it pretty.  The whole thing could be inset flush with the hood.  Or the tubes could go up at an angle and get partially inset.

Big advantage of this frame is that it offers an absolutely bomber mounting point for a front splitter, should I decide to add one.  And that is floating around in my head.

So some progress on the hinge question.

That's it for now!

I like option B.  I think that's actually a lot cleaner than A.

I stock flat head solid rivets to anchor MS21059. Little formula cars ae full of them.

TurnerX19 said:

I stock flat head solid rivets to anchor MS21059. Little formula cars ae full of them.

I totally would have expected that!

What are your thoughts on putting rivet-nuts into frame tubes?  Weaken the structure?  Tend to spin and create problems?  Do it all the time?

Sweet! Thats a pretty complete CAD model you've got going.

You've got my wheels turning about my own hinge system. I think I'm just going to stay pretty close to the original design but move he hinge point forward about two inches so the vertical comes down pretty much right at the back edge of the bonnet under tray. Extend the frame tube and include front to back adjustment pretty much how it is now. Ugh I wish I could get going on it this week! 

CoolHandMoss said:

You've got my wheels turning about my own hinge system. I think I'm just going to stay pretty close to the original design but move he hinge point forward about two inches so the vertical comes down pretty much right at the back edge of the bonnet under tray. Extend the frame tube and include front to back adjustment pretty much how it is now. Ugh I wish I could get going on it this week! 

I think you're on the same track I'm heading.  I gave the remains of my hinge assembly to the welder to duplicate, but I've been thinking that 2 0r 3 inches forward set with corresponding extension to the frame ends would solve the issue nicely without "reinventing the wheel" (i.e. the Scott approach).

Hey, just kidding, Scott!

In reply to Stu Lasswell :

I'm not reinventing the wheel.  Those are totally stock.  Everything else I'm reinventing.

In reply to TVR Scott :

Touche!

Finally did my airbox layup today, so here comes a big photo dump.  You've been warned.

The technique I did here is a little different than just a "regular" wet layup.  The process is a bit like making big gooey stickers.  It works really well for a project like this where I have templates and want to make the part nice and smooth with clean edges.  I wouldn't do this with much more than the 4 plies you see here.  Too much trash and wasted epoxy/carbon.

First thing is to trace my templates onto plastic sheet.  You'll want one top sheet with the templates and one plain bottom sheet for each ply.  This sheet got split in half for two top layers.

Plastic backer layers are prepped, so time to cut up some money:

I used about 1-1/3 linear yards of carbon fabric for this project, so maybe $70 there.

Then I set aside the top plastic layer and wet out the carbon cloth.  The carbon is laying on top of the bottom plastic layer here.  This technique really keeps the weave stable as you're working.  No random threads pulled or ragged edges.

Top-side plastic sheet with the templates goes back on, and everything gets all smoothed out and pretty.  Now's the time to add in a little epoxy or work the ply further if you have any dry spots.

Snip, snip with scissors (which reminds me to go back outside and clean my scissors) and I've got big carbon fiber stickers:

The stability of the plastic sheets makes cutting the plies really easy and precise.  This is especially so with Kevlar that likes to slide away instead of cut.

Here's the first ply down on the mold.  Bottom-side plastic gets peeled first, then the top is removed after some smoothing:

Top layer of plastic peeled off, and the edges smoothed down:

First layer fully down here:

Lather, rinse, repeat for the next three layers.

I did pre-prep all the fabric and plastic layers, though I wet-out, cut, and applied each layer one at a time.

All finished, with the first layer of perforated film on.  You'll notice I cut darts along the edges so that they'd fold down pretty flat.  This film doesn't like to stretch really at all.

Here's all the perf ply down and gently taped with some masking tape:

And put to bed in the vac bag that I made the other day:

Tune it tomorrow after it's cured and popped off the mold!

I can hardly wait to see how it looks, nice work!

That looks so stressful. Trying to get four layers nicely applied like that and get it bagged before it starts to kick any. Very nice work. I continue to envy your composite skills. 

regarding the hinges, look at BMW trunk hinges. these are E39

In reply to Rigante :

Your picture just looks like a big white box to me.  I've definitely looked at my wife's Jetta truck quite a bit in this process.

Ninja edit: I did get your pic to open in a new tab.  Four-bar linkage.  Hmm.

edited my comment, should work now

In reply to TVR Scott :

I would not put a riv-nut in a small diameter frame tube. They don't like the radiused grip zone. Think about how much total wall is exposed simultaneously with less of it exposed to the teeth. The little ones won't fully deform to the radius when installing  The threads pull out too easily. I will avoid them in any application I can. Nut plates for the win.

Edit...Sorry for late reply, I was out playing with cars!  Track day in EVSR, the first time I have driven my design.

In reply to TurnerX19 :

You're good!  Track day is definitely more important than any pendantic questions I might have!

Cool.  You confirmed my thinking.  I was worried about the big holes reducing bending strength too.  And twist-out is always a concern.  No nut plates in this specific spot - since no back side access - but I'll maybe add gussets that will then allow it.

Meanwhile, she's putting up a fight...

Ugh.  Part stuck to the mold.  I had to slit the end corners to get it off:

It's a bit banged up in a few spots, but I think it's repairable and usable.

Shouldn't have used any-rando-spray paint as my mold top layer.  Should have sprayed on gel-coat.  This stuff - either mechanically or chemically - was not up to the job.

Oh well!  Worse things could happen in life.

Otherwise the part looks decent, is pretty stiff, and very light.  It'll work out.

TVR Scott said:

MS21059 FTW!

I'll admit you have to be a pretty serious hardware nerd to appreciate these.  But I am one.

I have a tub of those, from dissecting a DC-6, or something like that. 

I've been knee-deep in building prototypes for a customer all week, so today was the first day the TVR got some love.

I did a big clean-up and threw a bunch of junk away, and then...

Body is back on:

I need to fit the hood back on to make the hinges and stuff, so it was time.  I did it alone this time, and it really wasn't that bad.  I can see the value of keeping the body and frame systems fairly separate, so that I can retain the ability to easily remove the body later on.  Sort of the F-250 diesel service-method!

My buddy Rob came over the other day and helped me make a fiberglass panel.  This will be for the front bulkhead plates that I mocked up in cardboard.

He brought his old Jeep too.  It's maybe 1950s - I forget.  But it's old and lots of interesting features.  It's got a separate knob to control the throttle, that's somehow also linked to the gas pedal.  Vacuum wipers.  Neat stuff.

Wow, awesome composite work, nice to see how its properly done.

It looks nominally like a car again!

I think my hinge plan is going to work out ok.

I might tweak the ride height a bit right now.  That front end seems way too high.  And most of the front end weight is in right now.

TVR Scott said:

I might tweak the ride height a bit right now.  That front end seems way too high.  And most of the front end weight is in right now.

That's what losing 460 lbs. of cast iron will do.  The EcoBoost must weigh at least 150 lbs. less than the stock engine.  If you decide to start it up, let me know and I'll drive up to hold the fire extinguisher, not that you'll need one.

Yes, would definitely agree that is the difference between the TR6 engine weight and the ecoboost including the transmission. Great to see this looking like a car again!

Yeah, 150 lb weight loss is probably about right.  And I'll be adding hardly any more weight to the front end.  Maybe 100 lb more?

I just spun the coil-over mounts down to the point where the springs are just about loose - I dropped it about a half-inch.  I feel like these springs are just going to be wrong, rate and length both.

The hood actually needs to tilt up in front a little bit more.  The panel gap on the back side of the fender isn't right at all right now.