This is the Build Thread for FR500S #32. Reply below.

Some updates on FR500S #32 returning to active duty.
- Very slim Cobra seat replaced with a wider Sparco and slider. The Cobra is now on the passenger side where there was none before. Having a slider makes it SO easy to get in and out of the car. I am used to seats that are bolted in place.
- Set of Apex 18x11, spacers for front, and a set of the new Bridgestone 295/35-18 RE-71RZ. The distributor said I got the first ones that size in the US. I know 315s would work but I like the wider wheel to tire ratio. At my not so skill level 20mm more will not make me faster.
- Of course a refresh of fluids, belts, etc. I’m not sure which brake pads are in there but they were new so they will work,

I got two days of HPDE at WGI, a day at Pocono, and another at Monticello. I love driving this car! It’s so easy, much more forgiving than my C7 Grand Sport that I have beeen driving for 10 years. I have never driven a live axle on a track before. Feels great. The car has all the original FR/Boss chassis goodies but came with the rear sway bar removed. After driving it for 4 days I have no wish to add a rear bar or pursue a watts link.

The rear of the car does like to hike upward on heavy braking. I adjusted the shocks as much as possible. I ordered a set of the BMR brackets to lower the rear control arms. We are removing all the coil over shocks and sending them to Sachs for rebuild. The suspension is well controlled now but they 18 years old so it’s time even though they have little actual use. I was happy to find that Sachs will still rebuild them for $400 each.

The rear poly window is discolored. We polished it and better but still very difficult to see who is behind you on the track. Since I spend at least as much time looking behind as ahead that visibility is important. Can I simply cut a sheet of polycarbonate or is the window molded to a curve so requires a made unit? Maybe I should put in a glass window? Can’t be much difference in weight?

The next project will be the engine. These cars were stock 4.6 3v with headers tuned to exactly 325hp at the crank. That’s not a lot going up the hills at WGI. I don’t want to do a Coyote swap and I don’t want a supercharger. Lots of discussion and video about how to get more out of a 4.6. I ordered the 500 level Comp Cams with valve springs. That is their hottest one that does not require porting the heads. I ordered the FRPP high rise manifold, FRPP throttle body, billet oil pump gear, under drive pulleys, and of course the fancy blue Ford Racing valve covers that are necessary for speed. With a proper dyno tune I think we should be about 350hp at the wheels or about 75 more than I have now. Should be enough for my entertainment.

The car came with the FRPP cold air tube and filter. I’m not sure if the larger FRPP throttle body will fit the inlet tube diameter. We will see when the parts are here.

I investigated having the heads ported by two of the well known shops. Between the head work, labor, and other required parts that would add about $7,000 to the job for another 25 or so hp. Not worth it for now.

Ordered a set of EBC SR-11 pads for the front. I use those in the Corvette with great results. Also very cost effective. EBC does not have the rear size in SR-11 but they have the RPX should be good for what little braking the rear does. Interesting the FR500 front Brembo caliper takes the same pad size I used to have on the Corvette when it had the GM Brembo 4 piston calipers. I later upgraded the Corvette to AP 6 piston.

Congrats on all the changes and I will admit I really liked a slider in my Boss 302S --- just makes it easier to get in and out.

Need advice on fuel pump and injectors. We are adding Comp Cams #500, valve springs and FRPP high rise manifold. Not porting the heads. Car already had headers from the original Ford build. Will be tuned. Based on what I read I am expecting about 350 WHP. Do I need to change the fuel pump or injectors to support that power? What I read says stock fuel system is ok without a blower.

Google says the FR500S came with Ford LU47 injectors (please verify). They should be good to N/A 550-600 on gasoline, or 450-500 on E85.

Awesome car! Looking forward to following the build. If you ever want a buddy for a track day let me know - I live about 40 minutes from you based on your profile location.

@Dave_W I haven’t seen that can you point me? The FR500S parts list is posted online multiple places. Everything I see engine and fuel system says stock Mustang GT.

Everything I can find online indicates the stock injectors are good at the horsepower levels I will run. Guess I will leave it there.

CarSalesman said:

I haven’t seen that can you point me?

Click to expand...

I simply did a Google search on "what fuel injectors were used for the ford fr500s" and the AI answer is "The Ford FR500S track-day car came equipped from the factory with 47 lb/hr fuel injectors. These high-impedance, multi-hole injectors were part of the Ford Racing catalog."

But if I look at the references it has for that answer, one is a sales video on the LU47 injector with no mention of the FR500S, one is an article on the FR500S that has no mention of any fuel injectors, there's an eBay ad and couple other pages. None specifically tie the LU47 to the FR500S.

When I ask Google "what fuel injectors were used by ford for the fr500s" it replies "The Ford Mustang FR500S race car utilized the factory standard 24 lb/hr fuel injectors." And the references are once again a random sales video, eBay listings, etc., with no specific FR500S reference.

So, I guess in the end, all we've learned is that AI hallucination is a real thing. If you ask a question that it has no real factual data about, it makes a guess. The bad thing about AI is that it is often very insistent that it's complete wild guess is absolute fact.

Sorry.