how much more power can be exspected?

rw98gt · Jun 22, 2008

ok, i know this has been asked a million times,i have a set of pi heads w/comp cams 270's and bee hive springs now i was thinking of getting the heads ported and polished. i waunt to keep it street worthy i would be interested in seeing what you think about how much more power that i might be able to gain from porting my heads. i'm also running a low boost supercharger 6 lbs. so please tell me what you think and also how much might this cost(the heads were just done over and have not been installed as of yet) i just hate to install them not ported as long as it's not to much $$$. thanks for your input.

COramprat · Jun 22, 2008

Each mod has an increasing effect on the next. I'm just guessing but a P&P would probably net around 10-15 HP.

rw98gt · Jun 22, 2008

wow that's it! i thought it would be a lot more than that. it would hardly be worth spending the $ for that little of a gain. if it were 50 hp i would probly do it but i won't bother if 15hp is all i'll get.

COramprat · Jun 23, 2008

rw98gt said:
wow that's it! i thought it would be a lot more than that. it would hardly be worth spending the $ for that little of a gain. if it were 50 hp i would probly do it but i won't bother if 15hp is all i'll get.

Like I said each mod increases it's effect as another is added. It could be more but generally a P&P gains about 10.

AntiRice98 · Jun 23, 2008

I did a CNC P&P job on my 98. I also put in comp cams 262's and BBK LT's. With the stock CAI I made 305rwhp and 328 rtq in 95 degree heat with 100% humidity. Now that I have a JLT I'm sitting somewhere around 320rwhp. The P&P job if done right will get you way more than 10-15hp.. My tuner was amazed that my car was putting out over 300 to the wheel, he said most of the PI swap stangs he tunes are around 260 rwhp range. With your cams, I would guesstimate you would make around the 270rwhp range without any work on the heads.

COramprat · Jun 23, 2008

AntiRice98 said:
I did a CNC P&P job on my 98. I also put in comp cams 262's and BBK LT's. With the stock CAI I made 305rwhp and 328 rtq in 95 degree heat with 100% humidity. Now that I have a JLT I'm sitting somewhere around 320rwhp. The P&P job if done right will get you way more than 10-15hp.. My tuner was amazed that my car was putting out over 300 to the wheel, he said most of the PI swap stangs he tunes are around 260 rwhp range. With your cams, I would guesstimate you would make around the 270rwhp range without any work on the heads.

Could be. Interesting to see if someone else had some good numbers. 305/328 is pretty stout. Most claims are for 10-12% increase so if you have 270HP you may gain 30 with a P&P but without before and after numbers to back it up it is hard to make that decision to go that route. I'm nt much on dyno numbers so generally I like to compare track times. Now granted if I were doing a headswap and the heads were already off the car I'd go ahead and have the P&P done anyway.

AntiRice98 · Jun 23, 2008

Before my swap I was running 8.9's in the 8th. Now my best so far is 8.32 and is getting lower. I used to have a large set of cams in the car before did the swap. It dynoed at 230rwhp..

mrvax · Jun 23, 2008

From a bunch of info I gathered over the years on SN, mostly about headswaps, I came to these conclusions about P&P jobs.
You have to know what you are doing, you could actually decrease flow if you don't do it right.
A 4.6L that is not supercharged will only see minor gains from a P&P job. Maybe 5rwhp.
4.6L's that are supercharged do see decent gains with P&P. It seems like if a good job was done, the more boost, the more the P&P job helps.

There are always exceptions to the rules but this is what I have gathered over the years from countless posts.

rw98gt · Jun 23, 2008

does anyone know how much$ roughly for p&p job??? ijust need a ball park so ican figure if it will b worth it to do. thanks for all the input. with all the modds listed below except the heds (not installe yet) my car dynoed on a dyno jet 235 hp 300 torque yea, that realy sucks. so do i just install the 11lb pulley r do the heads p&p & stay w/the 6lb pulley?

Winters98GT · Jun 23, 2008

your car dynoed at 235rwhp with a blower?

98COBRA281 · Jun 23, 2008

port them your self, its easy, heres a pics of my ported npi heads with pi gaskets i have been working on, your car dynoed a 235-300 with a 6lb blower , i dynoed 225-270 N/A

rw98gt · Jun 24, 2008

yea, i know no one seems to belive it. but my car is an aode and i am running the powerdyne p.o.s. supercharger w/only 6lbs. i am starting to wonder how much more i might gain w/the pi heads ,cams and intake still running 6lbs of boost. i think that i will just install the heads the way they are, i realy don't see the a big enough gain to support spending more $$ on 15 - 20 hp.

d98gt · Jun 24, 2008

Have you been to the track with the car? Those numbers aren't right if the engine is healthy AT ALL!

rw98gt · Jun 24, 2008

d98gt said:
Have you been to the track with the car? Those numbers aren't right if the engine is healthy AT ALL!

no i have never taken it to the track. the motor runns perfect,so i don't know why the #'s are so low. i just figured that it was the aode that was killing it. the motor only has 88k miles and runns smooth i'have never had any issues w/it.

how much more power can be exspected?

rw98gt

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COramprat

...I can take it. I think.

rw98gt

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COramprat

...I can take it. I think.

AntiRice98

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COramprat

...I can take it. I think.

AntiRice98

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mrvax

Stay thirsty my friends

rw98gt

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Winters98GT

Whoop...whoop-whoop-whoop-whoop...GANGNAM STYLE!!!

98COBRA281

rw98gt

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d98gt

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how much more power can be exspected?

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