Pi intake swap numbers?

[98bluevert]

Ok i was wounder what the swap numbers are under the curve for a npi intake to a pi intake. i know its like 17 peak rwhp. but does anyone have a dyno graph or just numbers all the way through the curve for the difference?

Also what about those adapter plates i have read about. peak to peak its only a couple of ponies but again what about under the curve? Does the mismatch mess anything up through the powerband?

 

[COramprat]

I don't have my graph loaded but from all indications it helps from the mid to top range of the curve. I installed mine with some homemade adapter plates a guy designed so the professional plates would be a tick better I guess.

The real result was the 3 tenths and 4 MPH I gained at the track with the PI intake.

 

[TGJ]

Actually the gain was 17 RWHP, 31 RWHP at the peak difference.

 

[LI98GTStang]

This is a comparison chart of the pre and post PI intake swap on my stang and also the addition of an FRPP catback. Red color is the NPI intake and the blue is with the PI intake. You can see it definately changed the torque curve considerably (peak is down, but makes more in the upper ranges) and allowed engine to keep making hp over 4.2k rpm all the way to 5k rpm.

Note that I don't have the adapter plates or tune as of yet. I probably won't go back in and put the plates on, but will be getting a tune eventually.

 

[Dusstbuster]

This is a comparison chart of the pre and post PI intake swap on my stang and also the addition of an FRPP catback. Red color is the NPI intake and the blue is with the PI intake. You can see it definately changed the torque curve considerably (peak is down, but makes more in the upper ranges) and allowed engine to keep making hp over 4.2k rpm all the way to 5k rpm.

Note that I don't have the adapter plates or tune as of yet. I probably won't go back in and put the plates on, but will be getting a tune eventually.

How...just...how....??!?!?!?


I hate my car, and you...

 

[LI98GTStang]

How...just...how....??!?!?!?


I hate my car, and you...

We do have very similiar mods . My guess, that the difference can be explained by being that they were measured on different dynos, pulleys, 5sp vs. Auto and a little more agressive stock chip on my '98. Do you have 1/4 mile times? Either way, the PI intake is well worth the time and money.

 

[Dusstbuster]

We do have very similiar mods . My guess, that the difference can be explained by being that they were measured on different dynos, pulleys, 5sp vs. Auto and a little more agressive stock chip on my '98. Do you have 1/4 mile times? Either way, the PI intake is well worth the time and money.

Mine was on a Dynojet chassis dynamometer model 248c tuned by Andy at Dynotuneusa.com. The biggest difference I see is the 5spd vs auto and I guess pulleys, otherwise my car is chipped so the tune shouldn't matter I wouldn't think. Either way yes, PI swap stuff is WELL worth it.

No 1/4 mile times yet, I have never been to the track but will be this summer, so my times will suck more than likely

 

[98bluevert]

i know its worth it (so are the cams)but do the adapter plates make a difference under the curve. smooth anything out maybe more power under the curve because of it, or are they just a waste of money. so should i just use PI gaskets and rtv around the coolant passage.

 

[Dusstbuster]

I'd say they probably aren't worth the $100 most places charge for them. If you can find some for fairly cheap then get them, otherwise I think they're too expensive for minimal gains.

 

[screamin gt]

I've got one on ebay for $10 right now. took off my 99

if you use it on a 96-98 don't you need to swap the heads too? or is that the adapter plates your talking about?

 

[Dusstbuster]

I've got one on ebay for $10 right now. took off my 99

if you use it on a 96-98 don't you need to swap the heads too? or is that the adapter plates your talking about?

No, you don't need PI heads nor do you really need adapter plates. The adapter plates allow a smoother flow of air but you still see significant gains over NPI cams/manifold/head vs PI manifold/cams & NPI heads.

The big reason full PI swaps net 10-20 more HP than just PI Cams/Manifold is the bump in compression. It flows slightly better, but nothing overly spectacular. The one nice thing about PI heads is the wider variety of more aggressive cams you can choose from though.