more hp with pi head swap than just stock pi's
- Thread starter crazystang05
- Start date
hognutz
New Member
you get a bit more compression I can't remeber if it is a .5 or 1 point. so yes it is true to a certain extent. it kind of hurts you if you supercharge the car though.
hognutz
New Member
hognutz
New Member
you get a bit more compression I can't remeber if it is a .5 or 1 point. so yes it is true to a certain extent. it kind of hurts you if you supercharge the car though.
Blev
New Member
tripple post 
The PI headswap is for 96 - 98 engines. So we don't have stock "pi's" we have NON-PI heads. PI = Performance Imporved.
The PI headswap is for 96 - 98 engines. So we don't have stock "pi's" we have NON-PI heads. PI = Performance Imporved.
70stangcoupe
Founding Member
hotmustang331
Active Member
What I have heard is that they get around 285 HP after the swap...I guess the chamber CC is smaller, raising the compression over our cars...also wouldnt doubt if you have to run 93 octain.
Parkway performance claims 60+ hp gain... but ill find out soon, just finished the swap. the compression ratio will also rise to 10:1 - 10:5.
The Ford Racing catalog says it will bump your compression ratio to 10:1 from 9:1 (I think). This is because the non PI motors have flat top pistons where the 99+ motors have dished pistons. Like others have said, boost is not recommended with this increased compression. I've heard that nitrous loves compression, though.. so I'll let someone more knowledgable than I comment on that.
when i took apart my heads i seen that the pistons are dished, but i thinks its the 92-98's with 11cc and 99+ have 17cc, and nitrous is the best choice, you can run a s/c but @ very low pounds of boost.
Blev
New Member
We only wish those numbers could be reached. The average HP after a swap that I have seen was between 245 and 260. You also have to factor in other mods as well. The swap with non ported PI heads will give you about 40 - 50 more HP. These are actual numbers from Dyno sheets that have been posted. You may have a factory freak push a few more ponies but nothing close to 285. Once again you also have to factor in other mods such as cams, headers TA and of course a good tune.hotmustang331 said:
PG98GT
Founding Member
I ended up with 249 hp three pull average at the rear wheels after the headswap. Mine prefers 93 octane gas too. The hp/tq didn't really come alive until after the chip was custom burned with all the bolt-ons and other "tweaks" done to it. It's worth the money, especially if you take the time and do it yourself. It's not that difficult, just time consuming.
Don't forget that the PI swap consists of more than just the PI heads. Without the PI intake to accompany them, you'll still fall short of stock '99-up GT numbers.
CanadaStang
New Member
Did you get the head swap kit from Parkway? Thats where I bought mine, I'm going to start the swap on Monday, when I get off work. Nice kit!! Looks very complete, all Ford parts, even the sparkplugs.tomustang said:
big o car 4.6
Founding Member
CanadaStang
New Member
I payed $1200.00 for the Parkway Ford kit, [includes free shipping], new off ebay. The Buy-it-now price was $1320.00big o car 4.6 said:
Similar threads
