The LS Fox Concept Car

yldouright

Member
Jul 15, 2018
37
5
18
Brooklyn
Okay, I've had this idea bouncing around in my head for years and until recently didn't really believe in it but then I read a thread by a mechanic with art in his soul. I contacted said artist and told him I wanted to make a soup to nuts thread describing how to have an LS Fox outrun anything in its class for piddly money on a road track and still be useful to haul groceries. I was happy to say this artist didn't ridicule me or lecture me on the subversive nature of a Ford/GM union, he basically said, 'Go for it'! Let's begin:

Everything starts with a plan and all plans have parameters and contingencies for when plans don't work but before we even get to that we need to describe the end goal. When we do, we find we can eliminate lots of work and expense. That's a good thing when your opening statement uses the term "piddly money". So what's our goal? We want a car that won't wake our neighbors and interrupt polite conversations as we drive by them on the street so we can rule out cams and headers. Ideally, we can keep the stock exhaust but that's a later decision on our list. We can also rule out independent rear suspension because it fails our bang for the buck ethos. This post will be updated periodically and additional list items will appear/disappear as we add them. I should mention that nothing in this guide aims to help you get your body and interior sorted out but there are plenty of other resources for that.

1. We want this car to be fast around a track and for that, we need to stiffen the Fox. The most effective way to do this is with sub-frame connectors. For those that don't know what these are, they are basically two long metal structures that tie the front and back halves of the Fox uni-body. Without these, any further suspension upgrades will be made mostly useless by the flexing body. The budget for these is anywhere from $0 if you can bend metal and spot weld to ~$300 for a pro to put them in. So let's make the entry below:

2. If you've done the first step then we need to discuss what comes next. We can't really do anything more with the handling because the drive train will be changing and that interrelates with the wheels/brakes/routing etc. so what do? Start shopping! You guys can help by identifying the junkyard donors for our longitudinal mount LS engines and transmissions. As you include them below, I'll update the lists. The list for transmissions will be subdivided for auto or manual and iron or aluminum for engines. We can start thinking about our wheels and tires. I like the look of the Fox without flared fenders and since we're likely to put reversible track bars on the rear we need to plan our selection to account for an additional 0.25" axle float side to side. This looks like a maximum 235/45-17 on 8" wheels with a 36mm offset if we want to eliminate any rub driving normally. Personally, I think 225/50-16's on 7" wheels is a more conservative choice and with the right rubber, sufficient for 400hp on a 3200lb car but it may limit our brake/rotor choices. I'm willing to hear otherwise, remember, this is a discussion :)

3. I'm looking to get around ~425whp in this project so the tranny question was put to the forum in another thread. Thanks to @FastDriver and his links, I am satisfied that a T5WC will serve this project. The costs and inconvenience of an upgrade didn't outweigh the competency of what is normally found in a fox. This relieved many headaches of shifter positioning and cosmetics but may introduce others, we'll find out as we move along. Entry made below:

4. In shopping for an engine to make the power I had two routes to take, NA or charged air. I preferred the NA route but ultimately ended up going with an LC9 which produces ~300whp with 9.6:1 compression, has variable valve timing, active fuel management and flex fuel. Adding just 8lbs. of boost should achieve my goal and the price of the engine tipped the balance in favor of adding a turbo. Along with the engine came the computer, its connections and radiator but one of the changes required will be a conversion from electronic to cable throttle control. That process is explained pretty well here. I'll be sure to post problems with this guide if I run into any. Now comes the challenge of planning the fit. Engine weight looks to be about 430lbs, nice! Entry made below:

5. The cross member and mount of the engine offers a weight saving opportunity I would like to take advantage of. Please provide your recommendations for this crucial swap in decision. The factors I'm mainly interested in are the consequences to the existing quasi-Macpherson front Ford uses and its suitability for future steering front suspension upgrades.

6. Some of you may have noticed that we don’t have a car yet J We know it’s going to be a Fox but which one? I currently have four choices, 2 GTs, one LX Lima hatch with a manual and an SVO. Two of these have the 7.5” axles in the rear. The aim is to get the platform down under $1,000 net after part out sales and assuming another $2,000 of upgrades not including the engine to bring those costs to $3,000 total. The 7.5 housing should fit the same 28s axle shafts and saves ~40 lbs and that’s also why I might like the 7.5” rear. Also discussed was the desire for a torsen differential. It would be helpful to know in advance exactly how the axles above would mate with a T2 differential if one can even fit in a 7.5” pumpkin housing. I’ll put it to you guys, which way would you go?

1. sub-frame connectors (a video explaining everything you're likely to encounter is in this link).
2. wheels and tires - under discussion.
3. the T5WC will gear the car
4. the engine will be an LC9 to start the project.
5. K-member - under discussion.
6. the car - under discussion
I chose my engine so now I'm looking for T2/T2-R potential donors so submit your candidates below and I'll update the list here.
 
Last edited:
  • Sponsors (?)


Oh yea, your going to get along with a few members here :rolleyes:
I just read an article about the lq4 (6.0L) truck engine, stock block, iron heads, stock manifolds and a LS6 cam got 430hp and 435lb-ft at around 4800 rpms through the stock intake, so there you go! Cheap easy horse power. A bit heavy though.
 
I don’t think 225 wide tires are enough for 400 hp. If you are changing the rear suspension, will you be able to eliminate the quad shocks? That would give you a little more clearance to the inside with proper wheel selection.


This isn't a "cheap" swap, really. There is a lot of ancillary parts that you need to contend with - especially the fuel system if you are keeping it fuel injected. You will need specific headers for your exhaust, too, so keep that in mind. You are making it sound as if you want a street cruiser, so I wouldn't recommend a carburetor in that instance. Also, I am assuming you want to keep A/C?
 
@91TwilightGT
I suspect the junkers will have most of the ancillaries we'll need but you probably know better. Can you provide a short list of stuff that'll create headaches? I think the tire choice depends on the compound and the running profile. Racing tires in that size are very sticky and more importantly nicely predictable. A 7" wheel will generally roll better too but that decision may be outweighed by having more brake options. I think the pan hard bar will allow you to lose the upper control arms and there may be more gains there but we have to sort out the engine/transmission first so if we do choose a wheel now, it should be a conservative one. Maybe 7.5" wide is a good compromise with 235/45-17's. The quad shocks are definitely a headache but so is the rear shock mount angle. How big do you think we can go relying only on a beefy lower and track bar? Remember that we don't want to lose normal drive quality or muscle up our fenders :)

@General karthief
I know, I've felt the chill wind of the admin :)
Yeah, the LQ4 adds about 160lbs. and may require some hump cutting for the shifter, not ideal. Sometimes, what you save on, you lose trying to make it work. I'll include them and where to get them in the maybe donor list.
 
Last edited:
Okay, I've had this idea bouncing around in my head for years and until recently didn't really believe in it but then I read a thread by a mechanic with art in his soul. I contacted said artist and told him I wanted to make a soups to nuts thread describing how to have an LS Fox outrun anything in its class for piddly money on a road track and still be useful to haul groceries. I was happy to say this artist didn't ridicule me or lecture me on the subversive nature of a Ford/GM union, he basically said, 'Go for it'! Let's begin:

Everything starts with a plan and all plans have parameters and contingencies for when plans don't work but before we even get to that we need to describe the end goal. When we do, we find we can eliminate lots of work and expense. That's a good thing when your opening statement uses the term "piddly money". So what's our goal? We want a car that won't wake our neighbors and interrupt polite conversations as we drive by them on the street so we can rule out cams and headers. Ideally, we can keep the stock exhaust but that's a later decision on our list. We can also rule out independent rear suspension because it fails our bang for the buck ethos ethos. This post will be updated periodically and additional list items will appear as we add them. I should mention that nothing in this guide aims to help you get your body and interior sorted out but there are plenty of other resources for that.

1. We want this car to be fast around a track and for that, we need to stiffen the Fox. The most effective way to do this is with sub-frame connectors. For those that don't know what these are, they are basically two long metal structures that tie the front and back halves of the Fox uni-body. Without these, any further suspension upgrades will be made mostly useless by the flexing body. The budget for these is anywhere from $0 if you can bend metal and spot weld to ~$300 for a pro to put them in. So let's make the entry:

2. If you've done the first step then we need to discuss what comes next. We can't really do anything more with the handling because the drive train will be changing and that interrelates with the wheels/brakes/routing etc. so what do? Start shopping! You guys can help by identifying the junkyard donors for our longitudinal mount LS engines and transmissions. As you include them below, I'll update the lists. The list for transmissions will be subdivided for auto or manual and iron or aluminum for engines . We can start thinking about our wheels and tires. I like the look of the Fox without flared fenders and since we're likely to put reversible track bars on the rear we need to plan our selection to account for an additional 0.25" axle float side to side. This looks like a maximum 235/45-17 on 8" wheels with a 36mm offset if we want to eliminate any rub driving normally. Personally, I think 225/50-16's on 7" wheels is a more conservative choice and with the right rubber, sufficient for 400hp on a 3200lb but it may limit our brake/rotor choices. I'm willing to hear otherwise, remember, this is a discussion :)


1. sub-frame connectors (a video explaining everything you're likely to encounter is in this link).


As I stated above, I will be updating the list above with your entries and suggestions.

Your budget seems off $0-$300...if metal, a welder, cutting tools, measuring tools, time to R&D,....oops I cut twice measured once, wait my frame is not perfectly straight d’oh.....was zero there wouldn’t be a market for these.

Personally unless these are welded through the floor type, can’t beat MM for price or even Steeda. No point of reinventing the wheel on this.

Second
It appears you want something like this:
853EA61F-1791-4B77-AF97-DCCFBB0B395E.jpeg
 
FastDriver said:
You're thinking of a torque arm.
Yes, in combination with the PHB. Thanks for highlighting the comment so I could fill in the missing item. I know the T5WC is sub-par for the end result but I'm going with it anyway. Like @96pushrod said in the other thread, "if it breaks, it breaks". I'm currently sorting out connecting a (Torsen) T2-R differential to the 7.5 rear, any guidance?
 
Last edited:
I didn't give you bad advice, though maybe not as much as you may have needed. I guess you didn't appreciate my comments on reinforcing torque boxes, clarifying that a Torque Arm is not a lower control arm, that the PHB DOES NOT allow the removal of upper control arms, or that there is a difference between spherical and poly bushings.

In your insinuation that I should have looked more closely in order to know what is needed, you are unaware that I have 2 street fox-bodies, one with "race" LCAs and both with coil-overs.

Since you brought them up, and have talked about tracking the car, I figured you knew why you wanted the race LCA's in the first place. I also didn't realize that it wasn't blatantly obvious to you from a glance at the pictures showing spring perches on every LCA except the race arms:

1532598548896.png


I'm not writing the instruction manual for you, man. I'm just giving advice on things you might not be thinking about. An answer to a question here, unless otherwise stated, is not meant to be an exhaustive list of everything you could possibly need to know or do. And, there are always some assumptions in natural conversation.

Also, feel free to ask more specific questions than "What all do I need?" Um... Steering wheel... fenders... ejection seat... lol
 
Last edited:
  • Like
Reactions: 1 user
@FastDriver
Why so touchy? I guess you didn't see the smiley at the end of that comment. A sense of humor goes a long way preventing unnecessary tension and overreaction. I didn't add the additional detail to shame you but you have to admit that anyone buying those LCAs on your unqualified endorsement would have found themselves with a 'surprise' additional coilover purchase if they weren't as familiar as you were with what goes on back there. It's stuff like that can break and delay projects indefinitely. Of all the participants in my threads, your posts have been among the most helpful and I don't think I've made a secret of that. Yes, I'm not humble but I'm not disrespectful. There will be other inexperienced readers that will come to this thread and get misled by posts like that one so I felt a need to point it out. My respect for people in general guides me to make sure what's posted in my threads exposes what's true and that brings us to the next point:

The Windsor spec of 411lbs. seems dubious when the same reference lists a motor half its size from the same maker as heavier. The Lima there weighs ~420lbs. dressed and it was designed much later than the Windsor. Isn't it reasonable to assume that advances in design would increase cavitation volume and not add additional weight? Then add the fact that the Windsor is physically larger (significantly so according to CarMichael Angelo) than an LC9 which I personally weighed on a freight scale as 431lbs. and maybe you'll begin to understand my estimate of the Ford 5.0. All these considerations are in addition to the fact that getting the power for this project with a Ford heartbeat would be far more expensive than with the route being taken here. That's why this blasphemous thread exists. I concede the weight difference is not 150lbs but it isn't "insignificant" either. Anyway, the point is now moot, I'm committed to the engine I got and the discussion up top is currently on wheel selection and on whether an aftermarket cross member is going to hold the LC9 or live with stock support.
 
Last edited:
@FastDriver
Why so touchy? I guess you didn't see the smiley at the end of that comment.
1. Your sense of humor comes across as self-gratifying in how much better your research apparently is, and accusational toward me, i.e. "bad advice." 2. A requirement for humor to work is that it be funny. 3. You reaffirmed that it was not just humor in your follow-up post when you referred to my comments as an "unqualified endorsement."

It makes no sense to imply that a complete moron might come by and assume from my comment that "race" LCAs are a direct replacement.

4. It's late and I probably took your post too harshly. I immediately began editing my initial response, but you were apparently already replying. Thought I was alone in here at 3am PST.

The Windsor spec of 411lbs. seems dubious when the same reference lists a motor half its size from the same maker as heavier. The Lima there weighs ~420lbs.

You're just speculating about the weights now. You posted the link with the data. It seems pretty well confirmed across the net, too. 411 lbs is a fair estimate for the 302 Windsor, it seems. I don't know what a Lima is, but I don't see a reason to doubt the data on the 302. Why do you trust the Lima motor data more? And with the Lima in the same state of "dress", maybe it would be 80+ lbs lighter.
 
Last edited:
It's true, I'm speculating but the speculation is reasonable. The Lima is the the 4cyl. Pinto engine from the 70's, it's also the engine that was in the Merkur XR4, the Turbocoupe and the SVO. The Merkur guys confirm the Lima is no lightweight but provide no solid numbers on weight. I have another gaff to report. My engine is not an LQ9, it is in fact an LC9 so disregard any references I've made to the LQ9 in my posts, sorry for any confusion this caused.
 
Last edited:
@General karthief
I've conceded that my estimate of the Windsor weight difference vs. the LC9 I'm using is too high. Ceteris paribus that would indicate a 580lb. Windsor which does sound high but I'd need some significant proof to believe it would be lighter than the 430lbs. I've measured for what I got. You're up to date now. Next is a cost benefit analysis of a "K-member" upgrade to cradle the fit. If any of you reading got these in your fox, I'm eager to hear your results. How much came off the nose? Did you notice handling improvements, NVH degradation, etc?