A Return to the Blog - New Project Car!!!!

Sometimes a Great Notion – 1989 Fox Body Build

Introduction

Sometimes a Great Notion, truer words could not have been used to more accurately describe this project. To lightly scratch the surface, SGN is, without a doubt, the biggest exercise in good ideas leading to doing things the hard way for the sake of what should be a fun adventure! So what is it? Well it's a 1989 Mustang GT... but more than that, it's a 1989 Mustang GT with a Cobra IRS! Well that's not unique, that happens all the time... FINE, it's a 1989 Mustang GT with a Cobra IRS that will be powered by motor that only a three other Mustangs have had in them! What motor? The 6.2L Overhead Cam V8 out of the Raptor... well... ok, this isn't a full Raptor motor, it's the motor out of a 2013 Ford F250 which is a camshaft change away from the Raptor motor! Did I mention the plan is 18x13 wheels at all four corners and 335's onboard? Ohh, and the inspiration for this is the Deutsche Tourenwagen Masters Foxbody Mustang from the early 1990's, with some tweaks!

Choices, choices, choices...

Someone is probably thinking to themselves, why in the heck isn't he just building a 302 Windsor, or a 5.0L Coyote, or a 351 Windsor or Cleveland? Why not do something easy? Well... lets look at that for a minute.

Why not a pushrod V8? While rebuilding the 302 that was in this car would be extremely easy, I priced out the cost of building a 331 stroker using a factory block and to say the least, the cost of doing it the RIGHT way was expensive enough to pay for the 6.2L motor itself. Power options in the stroker range are somewhere in the mid 400's with valvetrain stability and motor balancing being extremely difficult to overcome without spending cubic dollars. It is possible to make a pushrod V8 that runs at 7,000 RPM all day long for lots of money, but stiff valvetrains, and the constant fear of breaking a valve, pushrod, lifter, cam, etc, were all present in my mind while weighing the options. Needless to say, I see a lot more "dead" pushrod 302's and 351's from autocrossing than any of the modular engine family or it's derivatives (which is what the 6.2L is).

Ok, so why not the coyote? The reasoning here is more petty than anything... I hate the way the coyote sounds and I really don't care for how "common" the swap has become. It sure would have been an easy button swap. For the cost of doing a Coyote swap, I can also do a 6.2L swap which is more unique. The Coyote is VERY capable of revving up high and so is the 6.2L. So really this boils down to sound and uniqueness. Lets talk about power then! It's no secret that a Coyote can build great power, with more than a few 500 RWHP N/A motors in existence. The thing with these motors is the torque curve, something which only displacement can handle effectively. To achieve those high HP numbers it involves relatively low torque relative to the HP number. With the high frequency of which RPM killing corners exist in SCCA autocross, having torque can be a good advantage in addition to the HP and the larger displacement 6.2L should have torque in spades at the low end!

The 6.2L Motor

Ford's 6.2L OHC Boss motor is quite often forgotten in the world of Ford's modern V8's. It's easy to understand why. It's biggest impact statement to the world was as the main powerplant of the 2010-2014 Ford F150 Raptor in which it made 411hp and 434lb*ft of torque. It can also be found as the gas V8 option in the F250 and F350 superduties making 385hp and 405lb*ft of torque. Not exactly earth shattering power numbers given the displacement advantage over the 5.0L coyote and I suspect this is because Ford wanted to keep some reserve in the motor for additional expansion. Those peak numbers don't tell the whole story... specifically that low end grunt thanks to the torque created by the added displacement.

Lets discuss the differences between this motor and the modular engine family that encompasses the Ford 4.6L, 5.0L Coyote, 5.2L Voodoo, 5.4L, 5.8L, and 6.8L V10 motor. The 6.2L motor is NOT a modular V8. The modular motors all had a common bore spacing to simplify machining. Many of the parts from one V8 transfer to another, but not all of the parts do. The 6.2L has a wider bore spacing but not a significantly larger overall platform. In fact, the 6.2L is barely wider than a Coyote but it is obviously longer thanks to the wider bore spacing. Other simularities to the Modular platform are the deep-skirt block with cross bolt mains, crankshaft driven oil pump, bellhousing bolt pattern and being an overhead cam motor. That's where the simularities end. One of the biggest change in the 6.2L is the head configuration. The 6.2L employs a rockershaft valvetrain arrangement due to the hemispherical combustion chamber and requires two spark plugs per cylinder. The advantage here is that camshafts can have more aggressive profiles with lower spring pressures and it retains valvestrain stability at a much higher RPM's than a pushrod V8.

So the biggest advantages are cubic inches, uniqueness, and a traditional V8 sound. All good things! About those cubic inches... just how much displacement can this motor support? With sleeving the block and custom cranks, this motor can support 460 cubic inches! Try that with a coyote!

We wont get anywhere near that ridiculous with this build. The initial build will probably be no more radical than just getting it in there to run, maybe oil pump gears, maybe cams (made by Livernois, the only people I know who do them), springs, and obviously the exhaust which is mandatory due to the swap being unique. I'm hoping for upper 400's in RWHP and RWTRQ thanks to the use of a Megasquirt MS3 Pro Ultimate ECU, E85 (a bit overkill for this low compression N/A motor) and the fact that the engine wont be pushing around a 6000lb F250.... The "Sometimes a Great Notion" idea is to sleeve this block, pay cubic dollars to obtain the custom crank, rods and pistons to get an 12:1 compression 427 cubic inch (7.0L) V8 using this motor. That motor should make somewhere in the neighborhood of 800 RWHP and RWTRQ which is overkill for autocross. That's kind of the "dream" if you will, reality will probably be more gradual. Livernois sells a stroker kit that gets you to about 400 cubic inches but only at 9.5:1 compression. I haven't called to inquire about that going to 11:1 or higher compression... Manley also produces an 11:1 compression piston and rod combination. No increase in displacement, but higher compression for more power! That said, options exist to go for a more "formal" approach... everything else will have to be custom... GO FIGURE!

The Car:
The car is a 1989 Mustang GT that I purchased from my co-driver. It was a vehicle he bought when he was in high school. It was involved in only one small accident with a deer that damaged the radiator support. Very little rust on this car, in fact the only issues with the body is some light surface rust on the lip inside the rear wheel well and a crease in the driver side C pillar. Nothing damning or unfixable. I found some rust in the driver side wheel well but again, nothing damning. The only other issue with the chassis side of things was the driver side seat had one of the forward bolts tearing out of the cross member it was in. No biggie, will get that fixed before carpet goes back in.

The car was purchased for a steal of a price with everything included but the drive train out of the vehicle. The stock 302 needed rebuilt after some machine work, the T5 needed a rebuild and then everything needed assembled. The "stock" 302 was anything but stock but as you already know, the whole notion of running a windsor in this foxbody was tossed as soon as I found the 6.2L for as cheap as I did with as few of miles as it had. The car also had an upgraded rear end with a locker, upgraded 28 spline axles, and drums... all tossed as well! So, the truth is, I bought the car for the straight chassis and sold everything I didn't need from the drivetrain, which was, well, everything!

Keeping Things in Suspense:
As stated, the car has a 2003 Cobra IRS under it (now) which I was able to find for a good price locally. This is nothing unusual as IRS swaps are common enough in fox bodies. In truth, nothing unique will be done to this IRS... I plan on swapping in a Torsen T2R as I have extensive experience autocrossing with this differential. I plan on doing the full Full Tilt Boogie Racing bushing kit, bumpsteer kit, bracing, etc, to keep the IRS happy. I'll also be replacing the cross axis joints in this IRS. Wheel bearings seem fine for now so we'll rock those until they give me an excuse to replace them.

So why not go with something more, err, well, easy, like the MM torque arm + PHB setup for a live axle? The truth is that I'm not overly keen on live axle setups. Even though homefield is the Lincoln Air Park, home of the SCCA Autocross Nationals, and it is relatively smooth, the IRS offers some distinct advantages as far as kinematics are concerned. Mostly, it's the ability to have dynamic alignment changes to help the car. A live axle with dynamic alignment changes beyond roll steer is either broken or about to be! :) In truth, I felt like there was an advantage to be had with the Cobra IRS and the setup basically bolts into a Foxbody with minimal headache. No reason not to take the leap!

Up front is a bit more complicated... actually the setup is easy... it's nothing more than the MM K-Member, MM forward offset SN95 length control arms, and coilovers. This was NOT my original plan, but the original plan has been "in development" for several years and has yet to materialize. The original plan was to put a Short Long Arm (SLA) front suspension on this car, and I will eventually do exactly that. Real life has a funny way of injecting itself into project cars! I need this car to be mobile enough to move it out of the way, or move it in it's entirety, if I leave my current job. This is a long, drama filled "adventure" that I'll spare you, suffice it to say, having the car able to move is almost as important to me as finishing it. I get project ADD at times and not having the car running and just sitting there means little will get done. If it at least moves, I'll be more motivated to work on it since I can experience the changes sooner...

This decision was weighed heavily against the option of waiting... I could have jumped into the Agent 47 or Griggs Racing SLA's and I'm sure they are fantastic bits of kit, but my experiences with both companies has been less than steller... not having huge chunks of money to throw down right when I called will do funny things with customer service it seems. The other company I planned on using has been excessively patient with my timeline for making certain decisions... that company is Cortex Racing. Filip and I had been talking about the SLA for a while and it has yet to appear... so... with that in mind, I needed an alternative. Leveraging friendships I made during my S197 years, in comes Josh Gladish at Ridetech! A set of Ridetech TQ3's are on order and being built as I type this. They will form the foundation of the suspension until I decide to get creative later on, or until Ridetech decides to release their SLA kit for the Foxbody! (Hint hint, Josh...)

We've Got, the Meats!
Lets talk wheels and tires for a minute. I guess to do that, I need to explain what the car is going to be used for right? Truth is, if I ever get this thing done, it'll be used for autocrossing, maybe some track days (I said that about my current 2015 Mustang GT/PP and it has yet to see one :P) and probably a bunch of street driving. Maybe some car shows, but not as a beauty queen! #MeantToBeDriven. So with autocross, and specifically the Classic American Muscle car class as the goal, that means we are going to be shoving some real tire under this car. With a 3250lb minimum weight for CAM-C (going to play with the big boys even though I don't have to), and everyone running on no less than 305's at all four corners, we are going to run at least that, if not wider. The real "want" is 335 wide tires on 18x13 CCW classics but as with everything in this build, the priorities are to get this thing moving under it's own power and then worry about other niceties like wheels that nearly cost as much as the coilovers I went with... sooooo.... with that said, I have a set of 18x10 SVE Drifts that'll get shod in 285 wide 200 TW extreme summer tires for next year until I can swing the cost for the big meats. That'll also minimize the body panel modifications somewhat.

Other Random Bits of Gray Matter

The only other "major" thing going on with this build is the extent to which weight is coming out of the car. With a 3250lb minimum weight, even with the Cobra IRS and overweight 6.2L motor up front, I want as much weight out of this car as possible so I can add it back in (in the form of ballast) where I want it, preferably over the rear wheels and as low as possible. That extra weight is primarily coming from things such as the 8 billion pounds of sound deadening in the car... cheese and rice, for how loud a Foxbody is in factory trim with all the sound deadening, I wasn't expecting there to be ANYTHING in this car as far as sound deadening... I was wrong... the sound deadening pads in a Foxbody are insanely heavy and horribly inefficient. I very well may end up doing some dynamat style product on the rear of the car for easy weight and to deaden sound some (not that I'm expecting a luxury car), but seriously! Also, out came the HVAC stuff. I may improvise a light weight setup in the future, but for now, it's out.

Ohh yeah... since so much of this car is changing, from ECU, to engine, to fuel system, etc... I figured it's probably best to just start from scratch on the wiring. The car had some bad grounding issues anyway per the previous owner so it's just convenient to remove all the wiring and start fresh. In comes Ron Francis Wiring to the rescue! The kit looks great, but I've only just started installing it.

Ohh yeah, the end goal of this car is to make it look like a more modern version of the DTM Foxbody. There will be a lot of body panel modification and aero done to the car to the limits of the CAM class rules (which is basically no real aero). I'll probably even go with the Black/Red paint scheme since that is what I like!

We Aren't in Kansas Anymore!
So where are we now? Well, we are sitting here, with a car with no interior, no wiring, no transmission, no front body work at all, and waiting on parts! Such a fun time waiting, and waiting, and waiting! It's like Christmas, except a month and change early! Where we ARE is, the engine is in the engine bay. I need to fabricate custom motor mounts for the setup to get it in there. The wiring has just begun and as such, not much is done. I'll be taking some time off here in a few weeks to really work on this car and get as much done as possible. 

Here is the car's current state!  Mostly gutted...

Stay tuned for more updates!