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S197 3V What to look out for in a '05–'06 GT for endurance racing?

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Hi all!

I've been racing autox and time attack for several years and feel it's time to get into wheel to wheel racing. I'm leaning towards the Lucky Dog endurance series as a "less expensive" way to get into it. The newest model year car they allow is 2006, and the most popular cars in the series are Miatas and E36/E46 BMWs. But, I'd like to do something a little different! I think a 2005 or 2006 manual transmission GT coupe would be great fun, and relatively inexpensive to work on with lots of aftermarket support. (And a really active forum!)

Most of the inexpensive used GTs I'm finding have well over 100K miles on them. That's OK as long as the body is straight, but I'd like to avoid engine or transmission failure—or major rebuilds right out of the gate. My initial work will be to put in the cage, fire suppression system, etc., and to upgrade the suspension and brakes. I'm hoping to put off any major driveline work until the second year.

So, in a 2005 or 2006 GT, what should I be wary of in a high mileage transmission and engine? Is there any preventative maintenance beyond what's in the normal maintenance schedule that I should do to get the most life out of them? Any other tips when shopping for an endurance racing car? Thanks!
 
1,161
2,116
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
Any other tips when shopping for an endurance racing car?
Make sure you draw up a mock budget of what it will cost to run a weekend of endurance races, then multiply it by some factor, probably 1.3 to 1.5 to see if it’s really something you want to commit to. @PaddyPrix and I went to the length of making the right buy on a Gen 3 Camaro with a really nice cage, 24 gallon cell and some other nice goodies. LS with EFI conversion and upgraded brakes is what the car needed to be a perfect enduro car. Ultimately we have both been consumed with our Mustangs, so we decided to let the Camaro go to a new home.

We started our search looking for the exact car you’re looking for. A stock 3v with 5 speed would be perfect. Most decent cars were $5k+, and by the time you add cage, fire suppression and safety gear, your pushing $10-12k pretty quickly. Now if you go decide to move forward, AND you’re looking for a couple co-drivers in the greater SoCal area, we’ve got you covered!!
 
Heh, even the beaters I'm seeing are around $8-10K, but maybe I need to troll some auction sites? Anyway, glad to know I'm not alone in thinking an early S197 manual GT would make a good endurance racer! Yeah, I have a budget worked out, and splitting it four ways makes it very easy to achieve. I figure on building it this year, doing some track days to shake it down, and then hit most of the California races next year.
 

PaddyPrix

If breakin' parts is cool, consider me Miles Davis
725
1,081
Exp. Type
Time Attack
Exp. Level
Under 3 Years
San Diego
Make sure you draw up a mock budget of what it will cost to run a weekend of endurance races, then multiply it by some factor, probably 1.3 to 1.5 to see if it’s really something you want to commit to. @PaddyPrix and I went to the length of making the right buy on a Gen 3 Camaro with a really nice cage, 24 gallon cell and some other nice goodies. LS with EFI conversion and upgraded brakes is what the car needed to be a perfect enduro car. Ultimately we have both been consumed with our Mustangs, so we decided to let the Camaro go to a new home.

We started our search looking for the exact car you’re looking for. A stock 3v with 5 speed would be perfect. Most decent cars were $5k+, and by the time you add cage, fire suppression and safety gear, your pushing $10-12k pretty quickly. Now if you go decide to move forward, AND you’re looking for a couple co-drivers in the greater SoCal area, we’ve got you covered!!
Other things that help with some of the math is to take a look at some of the results on tracks that you know. Like you mentioned, the winners tend to be e3x's and Miatas, and for good reason, they're cheap to run, good on consumables, and cheap to repair. We were hoping that with a 2800# 450-500hp car, we could literally coast to victory, coasting through some turns and killing it on the straights with an overall 7-8ths pace to beat teams that'd have to run 10/10ths for hours on end. 500hp would consume a decent amount of gas, and assuming that the MPG was as terrible as my car, we'd go through like $1200 of gas o_O

Willow Springs, winners ran 240 laps, best 1:35 -- https://speedhive.mylaps.com/Events/1853812
Chuckwalla, winners ran 219 laps, best 2:01 -- https://speedhive.mylaps.com/Sessions/6352087?user=MYLAPS-GA-293126e19c074357aa9f4b0c62a6ad27

but those times are certainly achievable with a lightened 05-06 GT without too much work, really. The only other thing to keep in mind might be the tire setup, as their recent partnership with Hankook has everybody running a Ventus RS4, which aren't terrible, but they might not be in an optimal size. $129 isn't bad at all for a 255/40/17 -- https://luckyhankook.com/products/rs4-tires?variant=39253923168464 -- but I guess depending on the track perhaps something like a 275 or 285 might be preferred, and with them only available in 18's just about doubles the tire price.

I got tired of trying to juggle 5 cars in my 2 spaces, but yeah, if you're looking for a spare hand or driver, there are a bunch of us around. I don't know if Bjorn's on TMO, but he's also running a S197 in WERC, and pulled a friggin' Ironman all on his own last time out.
 
Thanks, @PaddyPrix , for that! I'm hoping to run at the front of the B group, instead of the A group, in an attempt to keep the costs down—but with their dynamic classing based on qualifying lap times, who knows where we'll end up? I'm going to play it by ear with the wheel and tire sizes and see how we do on the OEM size tires. If I need more speed I can bump up to 18x11 wheels and run the 295/40R18 tires, or do something to the engine, but again I'm trying to avoid the A group to keep costs lower.

As far as what to look out for when buying a car, it seems like the big things are:
  • the horrible two-piece spark plugs that tend to break when removing them, and
  • the likely need to install a new timing kit
If I'm installing a new timing kit, I might as well replace all the cam followers and lash adjusters, too.

Cam phasers may also be close to their end of life, so I should probably budget for replacing both of those as well.

Any other known weak points?
 
98
143
Exp. Type
Autocross
Exp. Level
20+ Years
Olsburg, KS
I honestly haven't looked, but there is supposedly a one way clutch on the alternator. I've heard people say they go out relatively frequently, but at 55k miles it hasn't been an issue for me yet. For track time you might want to make sure you've got a non-clutched unit to reduce a potential failure point. I've been around 1 high mileage 3V 4.6 (in an '06 Explorer) and the only issues it ever had were coils and the original spark plugs. The mechanic had to extract 2 of them. Once the original two piece ones have been released they're not really a problem any more. Mid way through '08 they changed the heads and those were never an issue. The Explorer made it to 294k miles before the transmission gave out. Engine had never been touched other than coils and plugs. It was still going 7500 miles between oil changes with no oil usage.
 
6,360
8,181
the 05 series engine will get you a 3 valve, if you are really interested in doing this, I would contact Joe Aquilante at Phoenix Performance, because I think they have some race ready cars up there that would fit this bill. I would not be afraid of the 100K thing, these engines had no bad vices, I would install new FORD timing chains and tensioners, along with new valve springs.
Phoenix may have some customer cars that are ready to possibly upgrade as well.
 
98
143
Exp. Type
Autocross
Exp. Level
20+ Years
Olsburg, KS
Thanks for the tip on the alternator, @Steve68Cougar !

I wonder if I can put a set of '09+ heads on a 2005/2006 engine?
I'm pretty sure they're interchangeable. The change was done mid model year 2008 (sometime before they started making Bullitts) and the visible difference that's usually mentioned is the color of the coils. I think the newer ones are brown. One other thing that some don't know about is that the '08/'09 Bullitts and all production 2010 GT engines had a larger harmonic damper on the front of the engine and they had an increased rev limit of 6500rpm. If you're using an aftermarket damper then the point is moot, but something that made a small difference when stock.
 
One thing I wanted to note. The one way clutch on the alternator is there on manual cars only. It is intended to allow the alternator, which has a lot of inertia due to its mass, to free wheel when you clutch in to shift at the top of the rev range. If you remove the clutch pulley for a normal one, when you reengage the clutch and the RPMs drop your belt will now skid on the alternator pulley to slow it down to match engine RPM. You will prematurely wear your accessory belt out, particularly in an on track scenario where you are doing this many times over per lap.

As someone noted, the 05-09 alternators have a few common failure points. The clutched pulley is one of them due to its design. The common move, which is what I did, is to swap in a Denso alternator from the 2010 GT’s. Brand new units from Ford are only available in automatic trans style that does not have a clutched pulley. Since I track the car I wanted the clutched unit, I ended up buying a reman unit and it’s been flawless
 
Black coils are on the earlier heads with the 2-piece spark plugs. Brown coils signify the later heads.

I have earlier heads and did the spark plugs at 100k miles for the first time. I had the Lisle extraction tool ready to go just in case, but did not break any spark plugs. I replaced them with the updated design plugs that are supposedly stronger and installed them per the TSB with anti sieze on the ground shield. Put in another fresh plugs last week at 130k to prep for Laguna this weekend and this second set came out just fine as well. I was less concerned this go around since the updated plugs were in there and they had only seen 30k miles.

I wouldn’t let earlier vs later heads steer you in selecting a car. I’d look at mileage and condition primarily. These 3V engines are tanks. I boroscoped my cylinders for the first time when I did the plugs last week and all cylinders still had great cross hatching
 
6,360
8,181
One thing that has worked for me on those 2 and 3 valve heads is to carefully break loose the plug, maybe not even a 1/10th of a turn. Then load it up with PB blaster and go have lunch. When you come back you can work the plug, slowly, in and out a bit at a time (more blaster) and get them out without destroying the heads. I've been remarkably successful at this, I'm almost afraid to mention it as I have to pull plugs on my latest project and I'm sure they've been in there since it was built.
 
98
143
Exp. Type
Autocross
Exp. Level
20+ Years
Olsburg, KS
One thing I wanted to note. The one way clutch on the alternator is there on manual cars only. It is intended to allow the alternator, which has a lot of inertia due to its mass, to free wheel when you clutch in to shift at the top of the rev range. If you remove the clutch pulley for a normal one, when you reengage the clutch and the RPMs drop your belt will now skid on the alternator pulley to slow it down to match engine RPM. You will prematurely wear your accessory belt out, particularly in an on track scenario where you are doing this many times over per lap.

As someone noted, the 05-09 alternators have a few common failure points. The clutched pulley is one of them due to its design. The common move, which is what I did, is to swap in a Denso alternator from the 2010 GT’s. Brand new units from Ford are only available in automatic trans style that does not have a clutched pulley. Since I track the car I wanted the clutched unit, I ended up buying a reman unit and it’s been flawless
Thanks for the info on the alternator. I'll have to remember that when it comes time to replace my setup. Along the way I've heard of people just replacing with the non-clutched unit, but it makes sense that it would be hard on the belts during track situations.
 
@Steve68Cougar With track use, I lean towards reliability when possible. Ford designed the clutched pulleys on the manual cars for a specific reason. On the 3V alternators where the clutch pulley can fail prematurely, I can see the justification of swapping to the non-clutched pulley and checking the accessory belt more often for wear because there used to not be an alternative to address the bad pulley design. But the Denso alternator has a better clutch pulley design that addressed the issue, and also addresses the other common issue of the diodes in the alternator failing. It takes care of all of the weak points and let’s you keep the clutched pulley. Best solution all around, really.
 
One thing that has worked for me on those 2 and 3 valve heads is to carefully break loose the plug, maybe not even a 1/10th of a turn. Then load it up with PB blaster and go have lunch. When you come back you can work the plug, slowly, in and out a bit at a time (more blaster) and get them out without destroying the heads. I've been remarkably successful at this, I'm almost afraid to mention it as I have to pull plugs on my latest project and I'm sure they've been in there since it was built.
There seems to be lots of debate about this! Your method is pretty closely aligned with the Ford TSB. Others use an impact wrench and get them out successfully. I guess it's possible both methods will work?
 
@sobiloff Nah, I put the updated Motorcraft plugs in the engine that are not supposed to snap in half like the original design (still two piece though). Are the Champions a one-piece design?
The Champions are one piece. I guess when they first came out there were some problems with some of them dying early, but those complaints seem to have tapered off from what I can tell.
 

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