Hi everyone!
I'm really not sure if this truly belongs here or in the muscle car section, but the car is a tube chassis so here goes. This is my '69 Mercury Cougar that I've had since I was 15. Several years as a street car, but more as a partially assembled track build of constant scope creep. This car has been my education and a constant challenge to myself to do better. I can't wait to keep learning, and she's not done teaching me things. Not by a long shot. .

If I could do it all over again, would parts of it be different? Yes, and I may touch on some of those items if appropriate. Would some stay exactly the same? Also, yes. I have evolved with the car over more years than I'd care to admit. Skills and workmanship has improved, knowledge has expanded, and compromises have been made due to my own development over the coarse of such a long project.

Here's a few pictures of the car as it was.
Mild 351W, 4-speed, 3.89 gears, TCP front CO conversion w/manual rack, leaf rear, Vintage Venom front and rear disc brakes using New Edge/SN95 mustang PBR 2-piston calipers in front. The car drove alright. Right around the time all that up there was done, I bought an '04 Cobra. All of a sudden my fun driver did EVERYTHING BETTER than my toy car. Un...acceptable.





Here's the car today. Never done - I will be redoing the flares, paying attention to making it one color eventually, maybe try my hand at some composites for the heavy body parts...on and on, better and better. I've had the car on track a couple times with a setback or two but I'm about ready for some more track time!

EFI Yates SBF 2004 season Busch series engine, Jerico 4-speed, front geometry by RSRT, RSRT decoupled 3-link, AP brakes, 18x13 wheels front and rear. Other than the roof and about 18" of front frame rail, every other component has been modified in some way.

Actually the rear bumper is untouched...hmm...









I'm going to try my best to cover as much of the build as I can. Still trying to figure out where to start. The beginning of the track only build, or in the waaaay beginning? Like I said above, there was a lot of this, then that, or maybe this... Car almost driving again, then I was just like, "But if i just...". The car isn't built to any set of rules other than safety items. Feel free to comment or ask questions!

Before you comment on the roll angle in the track photo, Ron, I have the front ARB set to max stiff for the next outing as we discussed. Had to make a shady transaction for my media guy at work to take another pic from the same angle haha!

No negatives from me. I think the roll angle is about 1.6°, so it's pulling more lateral G's than I thought it would. That's good. We just need to stiffen the bar & see what else it needs to stay balanced. Might need more rear spring rate.

I'd like you to show how you built your muscle car body into a tube chassis, including what you did for clips, cage, suspensions, steering, brakes, etc.

The year was 2013 and the scope creep was about to come off the rails. Current build status - Griggs Racing front suspension installed with SN95 spindles, aiming for a ride height of 5-5.5" under the factory frame rail, front aprons cut out, firewall modified for a cleaner (HA!) install of a 4.6DOHC and T56, 1-3/4x.120 wall  DOM roll cage from Auto Weld Chassis, and 03/04 Cobra IRS out back. The motor wasn't built but I had 2000 Cobra R heads, a Teksid block, forged crank, and an email chain with Precision Turbo aiming for around 750whp.





The car had a nice pair of subframe connectors that fit inside the front frame rails already, but I always thought of them as a bandaid. Its time to build a frame! Out with the floor and in with a rear cross member and 2x3 frame rails using the factory front rails as a starting point. Here's that first "I woulda, coulda, and shoulda". Shortly down the road I integrated a perimeter frame as well that ties into the front cage landings, but I have learned that straight rail cars are hard on drivers in the event of a crash. Something to think about. Back to carnage!

I didnt have the space (or honestly the experience) to build a frame table so I kept the whole car level with wooden blocks and sheet metal shims. The car was checked every time I started working on it. Concrete moves with weather. Wooden blocks swell with weather. When it was time to set the car up for the first time the frame was out of level by less that 1/16" at one corner. I'm not upset with this.

At that time, I was cruising the internet looking at suspensions and what not I never stumbled upon large projects like I was undertaking so I designed things as the made sense to me. I was learning, developing skills, and the only word was, GO!









At this point there was a change in thought...first of many. I thought that I could get better weight distribution by doing a rear mounted transmission. Out with the cobra IRS! I bought some C5/6 rear suspension bits and started measuring.





You can see a little bit of evolution at the qtr panels. I welded 1x1 with jacking bolts to support the car and more easily level things.

At this point there was a shift. I sold my '04 Cobra in effort to fund the Cougar build. Picked up a really nice Foxbody that needed and engine rebuilt as a new daily. Somewhere along the way I decided to start cruising SVTPerformance forums hunting for a cheap set of aluminum heads for a little bit of a performance boost and stumbled across an engine that I had to have.





Refreshed 9:1 Yates engine from a Busch series NASCAR. Last tech dates on the C3 heads was May of '05. All of a sudden the T56 seemed unrealistic. I was concerned with shifting over 7500RPM. The new plan was a Jerico 4-speed and a torque arm/watts link SRA setup from Griggs Racing. I purchased some universal rear frame rails and got to work.





As you saw in my last post the rear floor was cut out. This created an issue. I already had a cage in the car that connected to the coilover mounts for the IRS and a similar story up front with the cage landings.






This was my solution at the front. I had made mounting boxes tying the floor and rocker panel together for the cage to land on so I could removed them for welding out the top of the cage. They turned into a nice point to bring the frame in and also integrate a 2x2 perimeter frame. I also took a triangulating tube to the front of the car from the cage landing.





Lets get back to the rear of the car for a little bit. My Griggs TA/Watts setup had arrived and I was keen on getting it worked into the car. The next photo shows a lot.



This is where a degree of precision gets put into the build that I previously didn't think about. I was no longer working off of factory frame rails like the front of the car. The first thing I did was make a centerline of the car - you can see the strings in the picture. I picked three points on the car. In front of the front k-member, behind where the rear axle was going to land, and halfway between on the frame I had built. Using plumb bobs I made 6 marks on the floor making it possible to get a centerline of the car. Its a lot of up and down. Check the alignment on the marks, move the string, retape. A chalk mark can also be used but I was regularly moving the car around my 2-car garage, so I got really good at making a centerline. Off of that centerline I made two right angle triangles behind the car. This wasn't an axle CL but it created a perpendicular line that I was able to get a perfect axle CL from, measuring forward. You can see the axle CL string on the floor in the picture. EVERYTHING gets measured from these lines. Upper shock mount cross member, watts mounts, front TA mount, the axle location itself, control arm mounts. You can also see the shims under the jack stands for the axle simulating ride height.







Here's Rev 1 rear suspensions ready to go. Figured out an ok way to tie the rear cage down tubes back into the frame and if you look at the front lower control arm mounts (I'm sorry I don't have more pictures of), I made a box and then used spacers to give me the ability to move the front of the lower control arm up and down for rear steer and AS adjustment. Slotted brackets would have been better, but that was a suggestion from GR. The rod ends are mounted horizontally which is fine but dirty and grime will rest on top of the race and loosen the rod end sooner. If you're going to use them in this direction so Seals-it dust covers are a good idea. BTW, the coilovers were free units I just used to mock the whole thing up.

Also around that time I noticed I had a problem where my driveshaft and rear crossmember were going to occupy the same space. I braced the rear cross member, cut, and tacked in a hoop. The hoop gets properly installed later.

Did you keep the dynamat in the final build?

No dynamat left un-removed 
The firewall goes away pretty soon, and all the dynamat with it

Quote from: Ryan Kennedy on Feb 09, 2026, 11:22 PMNo dynamat left un-removed 
The firewall goes away pretty soon, and all the dynamat with it

I was wondering why you kept the Dynamat. That stuff is heavy. Glad to hear it's coming out when you re-firewall the car.

Couple pics of fuel cell cage that I made. This was for a 15 gallon cell which I made my own aluminum can. Always had more time than money, so I made things that some would buy. I chose an ATL saver cell for up front cost reasons but there are long term cost reasons as well. So, hard cells vs soft cells. They each have their advantages and disadvantages. Hard cell is less resistant to crushing but more resistant to piercing. Hard cell doesn't expire...that one is the big reason I chose it. For the best in safety, shape options - both off the shelf and custom, and internal configuration (they'll internally configure your bank account too), the soft cell is the best. There is one other item I liked about the hard cell, though, an aluminum can is able to be used vs steel on the soft cell. I was trying to be weight conscious. For those making your own can ----> READ THE MANUFACTURER DIMENSIONS! The can is to be 2 or 3% larger than the cell. The cell will grow once fuel is introduced. I, did not. Its ok, because I ended up changing to a larger cell before tuning/tracking the car first, but not before I ran out of fuel idle testing with 2 gallons still in the cell. The cell expanded and pushed the floor (and surge tank) upwards since there was no room to expand. Fuel cell cage is 1x1 .083 wall square.










We'll circle back around to fuel system later.

Right around this time, I stumbled upon Ron Sutton Race Technology. Our first conversation and business had to do with transmission gear ratios. I mentioned earlier that I had concern about a T56 and shifting at high RPM. There are solutions for this and I looked into them. Talked to a couple people about face plating, looked into a true dog ring conversion, etc. The most promising, or really what I could afford was faceplating a gearset. ZR1 ratios were recommended which are just super common to come by so I decided on a 4-speed Jerico instead. This gave me the ability to choose my gear ratios as well as replace parts instead of entire gearsets. If this was today, I would go with GForce's T101a if staying with a 4-speed. Reason - spares available new. The old school Jerico is all I could afford at the time. We'll see how long it lasts! I digress.

Good bye cruel firewall.

While waiting for the transmission to be built, I discussed some frame things with Ron. As mentioned before, I didn't have any experience in frame design or tools to bend tubing, so it was "that seems like a good idea". The cage kit was supposed to come with a traditional bay bar but idk what happened. It came with some tubes that were too short so they got re-purposed. I ran a tube from the dash bar location to the shock tower. Ron didn't ask that I start over, but did make some suggestions. This is what I came up with. I did alright for a first timer. Sorry for the grainy pics - old.


Cut and capped the removed area from the top of the factory subframe and ran tube down. Would have gone to the base of the a-pillar but driver leg and pedal interference would have been a problem at the time.






Now the fun starts!

At this point the motor is set in the car about 8" back from factory but not mounted, and I hadn't decided to change any suspension geometry, though I was toying with the idea of having Ron make me a pair of spindles. The Tilton bellhousing has mounts integrated to be its own midplate. The bellhousing was an older front mount starter design using a 153 tooth flywheel, while the newer models are typically a rear mount starter that require different...well, everything. For anyone thinking of the rear mount stuff, its great but you need to make sure and consider floor/firewall clearance when setting the motor back.


Due to the motor being dry sump and having a decently shallow pan, the lowest point of the driveline is the bellhousing. TIlton does flatten the bottom to allow things to be a little lower. I put the bottom of the bell flush with the frame rails for several reasons - easy mock up/support of the motor and transmission, keeps the motor from being the lowest thing on the car, and makes application of a flat bottom easy in the future. 






Repurposed bay bars! Haha! The bent tubes sent that weren't long enough to be a bay bar worked out as motor mount tubes. Mounting plates are 3/8" aluminum that later had another ear added to the back of the frame side to put them in double shear. It has always bothered me the single shear at the bellhousing but I've seen so many of this style bellhousing mounted in that way. Its also important to use a quality high performance fastener in this application.

AN hardware or shear bolts are a good choice. Measuring them can be a bit of a pain, but they're sold in incremental lengths and different thickness washers are intended to be used as spacers to make up for small differences as they have a very short threaded portion. They also incorporate jet nuts, which are a great low profile nut but remember, they get torqued to a much lower spec than typical hardware and incorporate mechanical locking. I don't use them in as many places as I should but that's been ramping up recently. 

Time for something up front. I was looking for something other than a typical front plate due to the stack up of all the accessories, and I needed a brace to tie the front shock towers together so I decided to make a combination piece to serve both purposes.


Brace mount!







Doing this only required one change to the accessory drive. The third picture you can see the mounting ear for the power steering pump. there was a spacer there that needed to be shortened. The motor came out of the car several times after this during the build and the brace mount usually gets left on the engine.

I moved around this time, so the back drop is going to change.

Back to work. Little more brace suggested by Ron.


The front tubes land on top of the factory frame rail where I intended to run the ARB...starting to think a little more like a load path.  Sadly, its time to go to work - boo. But its Friday - yay!

Aaaand we're back. First off, here's a picture or two of the rear crossmember. Last time it was shown, there was a loop above the driveshaft just tacked in, and that's about it. At this point I was still planning on running the car at 5" ride height under the rails. After working with Ron and lowering the ride height to 4", a straight crossmember with a relief cut on top and a loop could have been run, but some bracing, and angle cut 2x3 tube finished the crossmember off nicely.




Ok, so this is where things started going a little bit oops. Not full oops, just some oops. Exhaust and floors.

I was under the impression that I was going to be able to keep the mufflers under the car and selected the smallest OD round muffler I could find in 3.5", which was borla XR1. Here's what I came up with. Long story short - after lowering the car the muffler location was completely unrealistic, but...the exhaust shaped how the floor was made which was the second oops. So lets do this! I knew I wanted an X pipe but due to the location of the transmission and the torque arm crossmember there wasn't going to be a whole lot of room. The X pipe would need to start rotating the exhaust downwards to clear the crossmember so I make one from two 90* bends that were cut in half and clocked.

It would be interesting to see what someone who has real world data has to say about the X. What I'd seen of exhausts made by the NASCAR teams running X pipes, the two pipes making up the X should just kiss. Not merge, not cross, kiss. We're equalizing pulses and encouraging scavenging, not crashing the pulses into each other or taking two 3.5" tubes and cutting the cross section in half at the merge. That's where my mind was at least. Since then the car made great power, I must have not missed it by that much  . First exhaust I'd made and more to come. The headers were used C3 Tri-Y's that just so happened to be flush with the bottom of the frame rails. Can't turn down some fitment luck when it smiles at you.









Now comes the floor, driveshaft tunnel, and a step backwards. I wanted to keep as flat a floor as possible with the overall design, so the frame rails were always meant to be on the inside of the car. I had it in my head I could weld down the frame rails slowly and it wouldn't distort. And then I learned about fighting physics and how physics doesn't lose. Someone out there could probably take what I'd done and fix it but I couldn't. Here's some pictures of my first run at it.










I dropped the floor roughly 1" from the bottom of the pinch to meet the frame rail locations. The tunnel was a universal unit that I cut up and made work. It turned out alright but lead me to a part of the build where I would 100% change how I did it - the firewall.

Oh the firewall. I pieced and pied and welded it all together. I didn't care a whole lot about small amounts of distortion since I had accepted there was going to be some and I knew there would be a lot of things mount and covering it.






A total nightmare welding it all.


If I were to go back and do it differently, there would be a square/rectangle perimeter with bracing to the tunnel offering flat surfaces to either spot weld or bolt the firewall in place. No more outside corner welds, no more fillet welds worrying about heat, just a clean firewall and some seam sealer in key locations. Also would have likely fabricated a square tunnel with a tube skeleton out to the frame and firewall tubing. Again, everything could unbolt or be cleanly spot welded in place.

Speaking of bolting sheet metal into place...

Bolt in sheet metal? If you read my last post I made an open ended comment about losing to physics. Yes, there are ways to shrink and stretch metal with tooling as well as with heat after welding has done its thing, but I definitely wasn't there in my knowledge and skill. The plan to weld the sheet metal floors to the frame rails was complete and the outcome left a lot to be desired. I tried several different bandaids trying to get the oil canning and warping to subside but in the end I cut the floors out but I left a 1" flange around the perimeter to use for a bolt in sheet steel floor.




Best thing ever. Still happy that I ended up with bolt in floors. There was a lot of build left to go and the floors were intentionally thin and flat. I would have destroyed them working on the car, and I still removed them for servicing certain items on the car.






You were lookin at my welds weren't you...yeah. I know. I was learning so much and getting a lot of experience. I switched over to TIG pretty much 100% around this time. Keep learning, keep doing, keep pushing to get better. Moving on. So what about floors for the people? The collectors opening up to 3.5" next to a 3" tall tube was an issue with putting a flat floor for the driver so I did a raised false floor on both sides and spot welded (eh? learning...) into place. You'll also see pedals in these pictures.






Pedals are a 600 series Tilton overhung crossbar pedal setup and a used racing take off throttle pedal. Throttle pedal is super smooth but there's definitely more on that later getting it to work with my throttle body. Here's another opportunity to talk about planning with your build. Pedals, masters, ABS. ABS has never been in the budget for me and at the time Tilton had limited offerings for master cylinders that would hold up to ABS use. They have better offerings, now, but the price tag is still high for the ABS masters which do require a different pedal box...kinda. Why kinda...because the bracket that makes the 800 series pedals an 800 series, bolts onto a 600 series pedal box. At least on the overhung setups. I believe they've upgraded the crossbar to a trunion style on the 800 series now which does add some definite value.

So which pedals to choose? This is something I've come to have a decent amount of experience with having worked with all the different setups tilton has to offer - firewall, overhung, and floor mount. Each one has its pros and cons. I welcome anyone to weigh in on my opinions of each pedal box style.

Start with firewall - I have least experience with this one and I feel it has the most difficult Cons to overcome.
Pros - Near factory mounting height which makes reservoir mounting fairly easy. Serviceability to the master cylinders is typically easiest of the three options.
Cons - Heat...all of it. Masters right above the headers, lines are in the engine bay for at least some portion even if going into the car immediately. The firewall has to be where the masters are, requiring possible sheetmetal work with no real advantage.

Overhung
Pros -  No mounting location limitations (mostly - see cons). Depending on dash configuration, good serviceability. No preheating of master cylinders and brake lines. They just look cool if you like bending hardline 
Cons - Mounting location versus reservoir height. Later on you'll see what I had to do to get my reservoir high enough to work with the setup. If not planned properly it can be a very challenging problem to solve. If you have a full dash, serviceability is worse.

Floor mount-
Pros - Mounting and planning can be generally easier and does not require a significant structure high in the car to mount to (consider floor reinforcement) . Adjustability is an available option with cables to allow the pedal box to move - this is huge for racing with multiple drivers. Generally good heat management. Virtually unlimited reservoir mounting options.

Cons - Serviceability is a literal pain. If you have a cage, embrace your inner pretzel and probably remove the seat. Packaging, if there isn't room, you must make room in a challenging location. New floor height can sometimes cause seat position to need changing. Rocks and debris are now a much larger concern. Rocks get in places that can either stop brake operation or hinder pedal return causing other issues.

Really cool build Ryan. Not every day you see a tube chassis track killer with a 69 Cougar body. 

Thank you for sharing all the build story & photos. 

What's next for you & your toy?

There's always a small laundry list of things I want to do and try, but right now - retuning on E85 with a flex sensor to run pump E just to try and get the cost of operation down a little bit and then seat time!

In the spirit of jumping around, I moved onto rear closeout panels now that the dry sump tank was mounted - outlet around 1" higher than the level of the pump. Believe it or not, it was already looking like real estate was going to be an issue in the rear of the car. Sometime around here I acquired a manual bead roller and decided to get to work. I wanted the closeouts be removable for service and also to look good so I went after the painstaking task of filling the gaps between the main hoop tubes vs covering them up. Here's a couple complete pictures. The package tray area received similar treatment but without the effort for easy removal. Other than completely redoing the rear suspension later on, I haven't had any other reason to remove the package tray area closeouts.





Next on the list was removing the rocker tubes I had installed and bending up some actual door bars. The rest of the cage was already built using 1-3/4 x .120 wall tubing. Little did I know the car was going to come in under 3000lbs without me in it, making a .095 cage legal - who knew. Door bars are a personal choice. NASCAR bars are still my preference to date having bent up and installed over a dozen custom cages. An X brace is all that is required on the driver side per NASA and SCCA, but....and this is a big but IMO, ease of entry and exit. We all get in and out of our caged cars differently, but a flat NASCAR bar that doesn't make you slide to the middle of the door bar when you sit on it EVERY TIME you get in and out of your car is sooooo nice. Just my .02









Quick touch on gussets since I don't have a ton of pictures. Tube gussets for the halo to main hoop and a-pillar tubes to halo. The cage kit I bought didn't use a continuous A-pillar tube from the floor to to top of the main hoop, which is how I do them now, but it does make a gusset that much more important. They're hard to see in the picture but the gussets double has a grip when getting in and out of the car. If space allows I'll put the windshield tube gussets in front like this for that reason





Going to end it there for today. Cooling system stuff coming up!

Really nice roll cage Ryan.  I prefer the NASCAR bars too ... if the Driver wants to live in a left side impact.