As some of you may know I started the process of fitting a Coyote into my Pantera several months ago. As these projects typically go the project has snowballed into something a bit more extensive. Peter Havlik lives close by and visits on occasion and reccommended that I start a post detailing what I have begun so here goes. For those who are wondering why Coyote swap posts are in the chassis systems section that will soon become clear. In the process of fitting the motor in the position and configurationI wanted I came across many roadblocks. The first of these was the width of the frame rails. As with my last motor I will be running a dry sump system on the Coyote. The width of the oil pan filled the frame rails and left insufficient room for fittings. The next roadblock was also due to frame rail width. I could not lower the motor enough as the bellhousing even when heavily trimmed woud not allow the engine to sit any lower in the car. The third roadblock was insufficient space between the balancer and the lower firewall for a dry sump mandrel. I had already cut out the upper firewall for clearance. While slowly tackling each of these issues I noticed that the passenger frame rail was bent. At this point I made a decision. I was going to widen the frame rails. This would give me more space for the motor. I then decided that I was going to also move the lower firewall crossmember forward several inches and rebuild the firewall incorporating my roll cage as the new firewall. The project had begun and out came the sawzall. Might want to sit down for this one.



Keep in mind that I did brace and support all rear metal to prevent flex and bend while cutting. Really spacious in there now. Years ago I had installed the Hall Pantera chassis stiffening kit part of which involves installing 2x4 box steel tubing inside the rocker panels. The roll cage main hoop is welded to this. It makes for the beginnings of a very stiff chassis. The main firewall crossmember is made from 2x6 box tubing with an 1/8" wall thickness. It is a bit more weight than I was hoping for but it was also all I could get in any sort of a decent time frame. I can always add some lightening holes later if I feel the need. It has a 6' height so I can Pick up the full height of the rear frame rails, have it low enough to have the option of flat bottoming the car, and still have enough meat left to engage the 2x4 tubes in the rocker panels. The frame rails are made from a combination of 2x2 and 2x3 box tubing in a .093 wall thickness. The 2x3 tube has been cut lengthwise at an angle and welded to the 2x2 tube to mimic the angle of the stock rails. This has the added benefit of an extra stiffening rail within the tube. The frame rails have also been tabbed through the firewall crossmember on the vertical sides to add rigidity to the crossmsmber.

The same treatment was applied to the frame rail diagonals and I was able to use the off cuts from the main rails repurposed for this.
The frame rail layout is very similar to the stock setup and is very stiff once welded together.

Once the main frame rail assembly was welded together (tig everything as I dont have a mig) I fit it into the car. This was the most critical step. This would ulimately determine how straight the car was. As we all know these cars are not exactly perfect dimensionally in the sheet metal department. I wanted at the very least for the frame to be spot on. I borrowed a laser level from a friend for this purpose. everything was aligned on level to within 1/8 of an inch from the front frame to the center to the rear and tacked into place. At this point I tacked some temporary bracing in place to hold the frame in position while I completed the rest of the work.

With the transaxle further forward the next clearance issue was the axle passthrough in the stock inner fenders. Might as well chop all that out too. At this point it was clear that I would be building a hybrid space frame/unibody car. I continued to add frame bracing for suspension pickups and triangulation.


There will be much more going on as I continue but this is where I am at the moment. I am still hoping to have the car back on the road by the middle to end of summer but I have a ways to go.

Original Post
Blaine's fabrication (and insanity) skills are second to none. I know that, when this project is done, it will have been done correctly with much improved chassis rigidity and suspension geometry over the original. This will all be necessary to fit and use the Coyote, which Blaine will no doubt modify to ensure he has the highest useable rwhp of any Pantera in the world.

I can't wait.
Blaine,

Awesome work!!

If you keep cutting out the sheet metal and add a few more struts you'll effectively end up with the rear chassis from the Pantera Si model from the 90's. So you might check out some pics of those cars to get some ideas.

Also, I like your plan to "rebuild the firewall incorporating (your) roll cage. This should add considerably to the chassis stiffness. For reference, here's the way it was done on my race Pantera:



Fitting a dry sump between the frame rails even with a pushrod Ford engine can be challenging. But I imagine it's even more difficult for the Coyote engine.

Looks like you've made a great start!

Dave
Thanks for the comments guys. I certainly won't be going that far Dave but I will be adding some struts from the front of the main hoop forward a bit to reinforce the area where the rear frame ties in
I will do some digging to see if I can find some info on the SI stuff. That could help get some ideas flowing.
Hi Dave:

Please post the VIN of your 90Si or PM me with it for the registry. I am sure any information or additional photos of your Si and your race car that you would care to post here would be of great interest to many of us.

So as to not hijack this thread, I suggest starting a new topic under the "Specific Car Photo Forum" section.

- Peter
Simon, Peter,

As noted by Joules, this is chassis 9628. I owned this with a "partner" in the UK and eventually sold it. Both transactions were what you'd euphemistically call "learning experiences", but that's a longer story!

Blaine,

FYI, note that this "race" chassis actually added only a few extra bars for support at the rear (e.g. the down-bars from the main hoop). It also had some pieces cut away from the stock chassis to make the engine/gearbox fit. So that's a good testament to the fact that the layout was fundamentally sound to building a stiff platform. Your layout looks just as good.

Glad this was helpful. I have many other pics of the chassis including those from the 1997 logbook, and as I recall there are more details about the Si chassis in various PI magazine back-issues.

Look forward to seeing more pics of your project as you progress!

Dave

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