TVR 2500M Teardown

Hi all, ive been lurking on this forum for quite a while looking at the interesting for sale ads and reading the project builds.  I finally have something worth sharing so I decided to make an account and start a thread.

My wife and I jettisoned our Miata after my little girl was born because we alternated using it as a DD and it just wasnt going to work with a carseat. Flash forward a few years and I got out of motorcycle racing, our family now both had reliable DDs, and I was getting an itch. I started searching for small 2-seaters and quickly realized I wanted a LBC. I specifically wanted a coupe so it limited me. I had been searching for TVRs, TR6s, MG GT, etc. I bid on some stuff, wasnt quick enough on some ads, and searched for about a year. A few months ago I found a '73 TVR 2500 in Maine that had been disassembled to paint and never reassmbled.  I responded to the ad within hours of it posting but lost out on it. A few weeks later it shows up on eBay for $1k more than it was sold for ($6k, I confirmed with the first seller). It never sold, never met reserve. I offered the seller $5K and he accepted, but it just didnt feel right so I ghosted him. A few more weeks pass and it shows up on ebay again with no reserve and I was able to snag it $3700. Like it was meant to be. A week later and its sitting im my garage.

As I received it the engine was out, the interior was stripped, and the body was just sitting on the frame.  Everything was in boxes, and it seems complete. Upon closer inspection the paint is not great, it has runs in several places and some body repair is noticeable.

The plan for this car is simple, a nice runner with modern components that can reliably be driven as a several times a week during the warm months and also capable of some track duty, HPDE, etc. To achieve this I will be doing something not so uncommon with these, a 2.3L Ecoboost with 5sp and appropriate suspension/brake upgrades.

Feel free to flame me and provide guidance along the way.  I do have experience in a wide variaty of car tinkering and I have done complete frame strip and engine rebuilds on bikes, but this will be my first large scale car project.

First thing I wanted to do is pull the shell from the frame to get a sense of what I was dealing with. I was able to remove the complete wiring harness thorugh the firewall gromet only snipping 1 singular wire that snaked through the firewall to the engine compartment, down to the trans tunnel, then back up through a hole in the trans tunnel connecting to the harness again for some reason..

Next, after about 4 hours of futzing around with an engine hoist, jacks, and blocking I was finally able to separate the body and frame.

In my next post ill show what I discovered inspecting the frame

Congratulations! 

So once the frame was out I found it had nearly ZERO rust.  It looks like it was either undercoated or at some point early in its life it was parted from the body and painted.  Even at where the jute padding was, no rust.

What it did have was an array of damage. 

on the passenger side outrigger, the leading square tube was bent downward past the angled support. It measures about 5 degrees out of level.  Inboard of the brace it is straight, my plan here is to slice the top edge just outboard of the brace, bend it up, then weld it back with a reinforcement on the sides of the tube. I will also cut out and replace the body mounts that are beat up.

On the back side of the transverse bar at the very front of the car there is a dent/crease. This appears to be from being hooked to be towed and is localized to one spot. I will patch over this across the width of the car.

The worst of the damage is the left front corner. The outigger bar is dented, the body mounts are tweaked, and the pickup point for the lower control arm looks like it has been broken and poorly repaired. After looking closely it also looks like the crossmember located at the rear pickup point of the front lower control arm is twisted up on the left side and about 5 degrees out of level.  The car has obviously had an impact or failure on this corner of the car.  The odd thing is I dont see any immediately recognizable damage to the body or clamshell at this corner. My best guess is a hard impact with a really bad pothole or road debris. Either that or the body has been replace (doubtful). Any other possibilities im missing?

To address this im going to cut out and replace the dented section of round outrigger, sister and reinforce the pickup points, and cut out the entire crossmember and replace once I have my engine positioned.  I spent about 4 hours with levels, calipers, straight edges, and tape measures and it appears the frame is generally straight and level. That section of frame may be twisted a bit but the shoddy weld repair seemed to have miraculously ended up with the pickup point in the approximatly correct location.

Fun!

About your drivetrain plans - a six-speed from an NC Miata should bolt to a four cylinder Ecoboost. There's a five speed as well but it's uncommon. 

 You are at the correct address. There are at least 3 other 2500M owners currently on this forum and several others of us who have worked on them since they were new cars. "TVRScott" is doing the conversion you are contemplating. When you cut the tubes open that you are already planning, pay close attention to the corrosion on the inside of the tubes. You need to clean all the undercoat off too. My betting instincts and TVR knowledge says the body has been off. I saw a corrosion induced suspension arm failure on a Vixen 2500 when the car was less than 10 years old, and I had visually inspected it within 2 months. That tube looked perfect on the outside. I am following your build, I Have worked on TVRs here in the US since my favorite, the Vixen 1600 was new, and felt from the beginning that the TR lump was too heavy.  Good luck with it!

Found this in a box today, indicates it's been nearly 30 years since the car was taken apart to paint and not reassembled. Could be a good part of the reason for the lack of rust damage. Explains the thoroughly '90s color too.

Welcome, great to see another build get started! I am nearly on the other side of the tunnel with my '74 M and it's been great driving the finished product around.

No hate on the engine swap coming from here. In addition to the one being built that TurnerX19 mentioned I am acquaintances with the seller of this car: https://bringatrailer.com/listing/1974-tvr-2500m-29/#comments-anchor. I can always put you in touch if it would help. I also know of one more nearby me with a turbo Cosworth-Ford 4cyl.

I may have missed it, where are you located if you are ok with sharing?

ViperT4 said:

Welcome, great to see another build get started! I am nearly on the other side of the tunnel with my '74 M and it's been great driving the finished product around.

No hate on the engine swap coming from here. In addition to the one being built that TurnerX19 mentioned I am acquaintances with the seller of this car: https://bringatrailer.com/listing/1974-tvr-2500m-29/#comments-anchor. I can always put you in touch if it would help. I also know of one more nearby me with a turbo Cosworth-Ford 4cyl.

I may have missed it, where are you located if you are ok with sharing?

Hi yeah I saw that unit, after I purchased mine. I cant say unfortunately, so far pretty happy with where I landed 

Im in Maryland, south of Baltimore north of DC

I was able to get the frame completely dissembled and clear of every bit and bob. I'll drop it off at the sandblaster tomorrow morning. They told me around 2 weeks turn around.

I was also able to get the interior completely cleared out. The burlap padding was a complete pita, the tools I ended up using were a house type paint scraper and a die grinder with mesh type pad. You'll see a battery charger in the passenger footwell as I tested the wipers and blower motor, both seem like with cleaning and lube will be serviceable.

And on to something NEW. I ordered a Super 8.8 differential out of an S550 mustang. I know the Triumph and TVR folks love the Nissan diff, but the good ones seem to have already been scavenged. The S550 diff comes in aluminum or iron housing, all come with a limited slip, and a wide range of ratios. They're also well supported by the aftermarket including some absolutely ridiculous ratios. The one I grabbed is a 3.55:1 with an aluminum housing.

I've actually never held one of these in my hands, but the measurements I've seen show it should be a good fit.

The hardest part will be the CVs, but if I can get it mounted up I have a path forward I'll share 

I'm one of the TVR folks, and I think the only reason the Nissan diff became a popular option is because Richard Good started marketing a complete kit based around it. He did the engineering and everybody started copying it. Absolved them of design.