Difference in 86 GT Engine vs others?

Heads and pistons.

Pistons are flat top pistons with no valve reliefs. It causes issues with P2V using heads that you could normally use on 87+ cars.

One exception to that are the TFS heads. They're a perfect match for the 86 flat tops and you'll get more compression out of them then you will from an 87+ bottom end. Since the valves don't use the stock 87+ reliefes anyway... it ends up being a bonus.

Footnote: Slowest? I don't think so. Cam-wise... I think we've got the best of the OEM Mustang cams. The heads are the only part on our blocks that really sucks.

but their still a roller block

The '86 engine was setup more towards real-world driving and not so much for the best qtr mile times. But, qtr mile times and max HP are what sell sports cars.

The '86 had the E6 high swirl heads. Much better at idle and low rpms than the E7s. The '86 had flat top pistons - dished pistons present problems with smog and detonation. The '86 had a 58mm TB vs the 60mm for 87+. The smaller TB meant better/faster throttle response. The '86 had a unique upper intake that was setup more for low-end and mid-range.

In *100% stock form*, the '86 had a faster 0-60 time than the 87+ Stangs. Again, better for real world driving.

One of the few things you can do to an '86 without hurting the low-end HP is to get a bigger exhaust and better X/h-pipe. Even headers push the HP/torque range up.

But, 5.0's have plenty of low-end grunt anyway. So, IMHO, mod away if you want. I decided that the Explorer intake, 65mm TB, FRPP/BBK headers (basically the same), Banssi (sp?) x-pipe, and exhaust where good mods that didn't kill too much of my low-end.

I'll add that unless you change the cam and heads, STAY WITH SD! Going to a MAF-based EEC does NOT buy you any HP!! It buys you better idle control and the ability to do custom tuning with a Tweecer RT. I run a MAF-based EEC with a GM-MAF (LMAF is best for people for with a chip/Tweecer), GM-MAF to Ford-MAF converter add-on electronics (a custom design), with a Tweecer-RT/Moates EEPROM set-up. But, I do it because I design control/response systems for a living and my Stang is my hobby. And, I go to/from MAF/SD, GM-MAF/LMAF/94-95-MAF, 5.0/Explorer intake A LOT! You're likely have a better chance at the lottery than guessing what my exact setup is on any given day.

IMHO, GET RID OF THOSE WORTHLESS POS '86 10" BRAKES ASAP!!!. The '86 GT is a DEATH-TRAP waiting to happen with those POS 10" brakes that are sized for a 2500 lb car with 100hp! At least upgrade to the 11" 87-93 brakes that are only semi-POS. Best is to go with an sn95 set-up. But, with rims, etc, that starts getting into much more money. Still, is YOUR life worth the ~$1000 for an sn95 setup?

stang&2Birds said:

The '86 engine was setup more towards real-world driving and not so much for the best qtr mile times. But, qtr mile times and max HP are what sell sports cars.

The '86 had the E6 high swirl heads. Much better at idle and low rpms than the E7s. The '86 had flat top pistons - dished pistons present problems with smog and detonation. The '86 had a 58mm TB vs the 60mm for 87+. The smaller TB meant better/faster throttle response. The '86 had a unique upper intake that was setup more for low-end and mid-range.

In *100% stock form*, the '86 had a faster 0-60 time than the 87+ Stangs. Again, better for real world driving.

One of the few things you can do to an '86 without hurting the low-end HP is to get a bigger exhaust and better X/h-pipe. Even headers push the HP/torque range up.

But, 5.0's have plenty of low-end grunt anyway. So, IMHO, mod away if you want. I decided that the Explorer intake, 65mm TB, FRPP/BBK headers (basically the same), Banssi (sp?) x-pipe, and exhaust where good mods that didn't kill too much of my low-end.

IMHO, GET RID OF THOSE WORTHLESS POS '86 10" BRAKES ASAP!!!. The '86 GT is a DEATH-TRAP waiting to happen with those POS 10" brakes that are sized for a 2500 lb car with 100hp! At least upgrade to the 11" 87-93 brakes that are only semi-POS. Best is to go with an sn95 set-up. But, with rims, etc, that starts getting into much more money. Still, is YOUR life worth the ~$1000 for an sn95 setup?

Click to expand...

Everything EXCEPT for the bolded statement I can 100% agree with, but my 86 was a droptop which may be the reason it was so slow

Strype said:

Everything EXCEPT for the bolded statement I can 100% agree with, but my 86 was a droptop which may be the reason it was so slow

Click to expand...

By droptop, do you mean modified roof, or vert? I would think that a lower roof would make the car even faster.

And, to be correct, you'd have to compare your '86 droptop to similar 87-93 droptops.

stang&2Birds said:

By droptop, do you mean modified roof, or vert? I would think that a lower roof would make the car even faster.

And, to be correct, you'd have to compare your '86 droptop to similar 87-93 droptops.

Click to expand...

True... so maybe it was faster

C_Heath said:

so an h/c/i would wake this thing up? and not have to mess with speed density?

Click to expand...

An SD system uses the engine vacuum to help determine load. So, do NOT mess with the cam! ANY cam change will effect how much vacuum there is for a given load. It is "possible" to do a cam change with SD, but to be SAFE, do NOT change the cam.

Besides, with trick flow heads, better intake, headers, exhaust, you'll be near the limit that the stock EEC can adjust for the change in HP (~13%). In fact, depending on your specific engine and components, you can max out the EEC trims even faster. For SD, you can add an adjustable FP (cough, cough HACK!) and bump the FP up by ~3 to 5 psi. You'd need to monitor the EEC codes before and after to see if the engine had an "O2 sensor error" and it then went away.

So, when you read the PURE BS by some people how some mods gave them 35+ more HP, but they still have a stock EEC without a chip or bigger injectors, you'll know they are FULL OF IT!

Before you do ANY mods, you MUST read the EEC codes to make sure you're not running too lean! Then, read the codes right after the mods, and then again after ~30 miles of driving to make sure you're not running lean. Run lean, and BYE BYE engine!