mygt500

Well that sucks!!!!!!!!!!!!! Knew I should have kept the 87!

FoxGT

If you're talking about pressure, unfortunately the most overlooked engine in this section will put the 5.0, 4.6, & 3.8 to shame. There are a few people on these forums that are running over 25psi on their 2.3 4 cylinders on stock block, stock rods, stock crank, & stock pistons. One guy on this forum has even ran 32psi on the stock components. I personally have ran one with 24psi on pump gas.
Nothing to worry about. Forged or hypereutectic pistons are both going to hold up to more power than the stock block will support. Some people have actually swapped to hypereutectics on their turbocharged engines over the stock forged. Which one you pick should depend on your goals, forged is not always the best answer.

mygt500

Thats good to know thanks.... wish they did not skimp on the S197's (another topic in another section). Damn rods....

Solitear

mmm kinda find it funny when someones wife forces a choice on u, ur ganna be driving the stang 90% time so i dont see why she has to force a body style(unless u plan to have her driving it)

JayRolla

Hey man, she already hates my Talon's body. So she wants somthing she will like also. And if she does like it, that makes it easier to spend 3k on a turbo kit. See what I mean.

Just to add im running 32psi on a stock DSM long block. No issues.

Hamutoff

ALL true but one thing missing so if same power is produced the fox will kick butt dont forget that the for coupe (4 banger) is the lighest mustang ever produced!


ALL 1985-1993 HO have forged slugs, yes you can boost hyper but lean condition will make them go bye bye instantly. No worry if hyper not that big of a deal to get pistons there are so many darn choices, also a given block out there could, many times, be stuffed with other stock forged pistons on a buged the blocks are so hard that even 100,000 miles on them if you had a 93 block and no $$ but just had to have forged you could remove the hyper 93 and get somebodys throw away (but still good) 85-93 pistons, professionally hone the cylinders (check them first my 1989 block was fine for exactly this) and pop in the forged pistons





Aaah that sucks!!! Hmm ya know I didnt like the fox when I was first exposed to it until I rode in one, then I liked them fine, but I didnt want one for myself until I realized that there were coupes/notchbacks/trunk cars and then fell deep into obsession!!

JayRolla

I have always wanted a fox body. I think I still may get one, even if she dont approve.

On the side note a lean condition will kill any piston. Its all in the tune. People always say a motor will go at around a certain power level, but its usually when someone runs too lean, or to much boost/timing/compression for a fuel and causing detonation.

Thats why I'm going to run this motor on e85.

What AFR's are usually seen in boosted mustangs? I have always ran a rich tune on any boosted 4 cylinder (10.5:1 - 11.5:1 afr).

FoxGT

85-86 didn't have valve reliefs, 93's weren't forged they were hypereutectic
Lean is more of a killer than knock; you can hear knocking, you cant hear lean. Rpm plays a very big role in when an engine will go aswell. Usually a 1000 rpm difference can mean around a 100-150hp difference in breaking point.

I've always tuned my & customers cars for around 12.1-12.3 at wot. For cruise rpm, tune will depend on whether or not they have emissions. Most cars I lean out as far as possible at cruise which is generally around 16.1-16.6:1

JayRolla

In my experience knock cant be heard unless a prope is installed on the block. If its real bad from say very low octane fuel than you could hear a ping. Also when running boost or nitrous if you run lean you will have knock no madder what. So running lean causes knock which is what kills the motor right?

That afr sounds real lean on pump gas running boost. Do the fox body mustangs have knock sensors that can be read through an EMS of some type? I will be running e85 which can run a little leaner. I may run 12.1-12.3 gas equivalent afr (9.765 is e85's stoich).

So watching the rpms is real important on a ford v8? Not to much of an issue on the 4g63 in the dsm's, I have accidently spun too 10000 rpms and it was still fine.

FoxGT

Whether or not you hear it may depend on your car &how much insulation there is from you & the engine. I've been able to hear it very clearly like an intermittent "shhh" sound on every car I've changed the ignition timing with or when they've jumped time.

Running lean causes the temperature in the combustion chamber to get hotter. At lower engine loads running lean isn't as big of a deal because there isn't enough air/fuel in the cylinders to produce a hot enough burn to do damage.

If you don't feel comfortable with running a car at 12.1 with boost then don't. The leaner you go the more power you're going to get (up to a point) but you're also going to be sacrificing engine durability the higher you go. Around 12:1 is where most tuners will tune the car safely, I've tuned for 12:1-12:3 on most turbo & supercharged cars, and around 13.4 - 13.6 on n/a.

Stoich is going to mean nothing to you unless you're trying to pass emissions. The a/f mixture is going to burn the best there, but it will not give the most power, nor will it get you the most fuel economy. Gasoline's I'm sure you have seen is around 14.7 at wot if you stay at 14.7, the cylinder temps are going to get very hot. At cruise you're going to produce the least amount of emissions there, but you're not going to be getting the best fuel economy. For fuel economy you want to lean the car out as much as possible before surging, when the car starts to surge back it off a few points. Most cars (gasoline) will start surging in the mid 16's:1 a/f. This is ONLY for fuel economy, do not go that lean at a heavy load. The newer cars tend to stay around 14.7 at cruise (due to harsher emissions), but you'll also notice that their fuel economy is rated fairly low. You can generally pick up 4-8mpg from the factory tune by going more lean. If you're going to take an emissions test I would go back & try to get as close to 14.7 as possible.