pr3 or p30?

I just received my pr3 pistons which were suppose to be p30 pistons. My question is…is there really a difference besides one being jdm? Also will the pr3 pistons go in my b17 without modifications like the p30 pistons?

:search:
they are different, but fitment is the same. You wont get as high if compression with the pr3 's.

Thank you. How high of compression we talking? Anywhere near 11:1 with pr3 pistons? Is the different compression between the two noticeable? Reason I ask is I wanna know if its worth the hassle of returning and getting p30 pistons

you should return them, seems like you paid for jdm but got usdm pistons. emagine buying jdm 1pc headlights and getting the 3pc in the mail. the difference is JDM is what you ordered or you would of not bothered to order it in the first place.

just my thoughts.

Damn. Ok I’m on it. Thanks guys

you know, i’m selling a set of p30’s for 100$ shipping not included
the rods are still in, but i could press them out to lower shipping costs
lemme know

here is a link that helps you calculate the compression of pistons, head gasket and other parts on a motor.

you can compare the difference of the pr3 vs p30 and what compression they make.

http://www.ff-squad.com/technet/cr-calculator.htm

Yeah I did the compression calculator and the pr3 pistons will make the b17a1 10.77-1 while the p30 pistons make the b17a1 10.99-1. Is this differene really noticeable or a big difference in power?

just add a 2 layer headgasket

pr3’s were in the first gen b16a’s aswell as the A2/A3 blocks so I wouldnt call them JDM

Ok cause some of the members on the board make it seem like its gonna be a big difference if i don’t go Jdm. But if the compression calculator is accurate enough i don’t see why i should go through the headache and wait for .2x of more compression. Thanks again peeps, this is what makes are forum shine over the others…Team work and respect. BTW taking the Teggy(Luceal) down the 1/8th mile track wed before i install the pistons to see what she does, just broke in the Xtd stage three 6 puck as well. wish us luck. :rockon:

It’s not a big difference, it just depends on what you want. Will you be able to feel the difference? Probably not. Is there a difference, yes. The difference will be greater the more the motor is built. If you did a pretty intense build with the intention of making maximum power then yeah, of course you’ll want that extra 2 points. Actually, you’d probably want more.

The question you keep asking does not have a solid answer. We can’t decide which piston you should run, that’s up to you.

The fact of the matter, like the OP said, is that they sent you the wrong part. You can use it if you’d like, but personally I’d want the part I ordered, or some sort of refund, or something. Plus, the P30’s are harder to find, the pr3’s are all over the place…

And like the other person said, this isn’t a JDM vs USDM thing. It’s pr3 vs p30.

^^ Wisely spoken^^ Well if i wanted to go all out I do have some Pct(CTR) pistons staring at me, but that isn’t the case. I just wanted a compression around 11-1 and wise member on here(Colin) said the p30s are a very good choice for the b17a1. I was more worried about the pr3 pistons not snapping right on to the rods if anything. But i guess ill just run with the pr3 pistons for now. Thanks a lot again guys. :rockon:

The pr3’s will fit your rods exactly like the p30’s. The only difference between the pistons is the dome, which results in higher compression with the p30’s…

^^Hey chief, how is your motor running with the p30 pistons? Is it a lot better than the p61 pistons? I bet that bad boy is running strong.:rockon:

I never ran the motor with the stock configuration, bought a totalled gsr from a friend and rebuilt the motor before swapping it into my car. Its in it’s second rebuild now and second chassis with me. Still less than 300 miles on it but it feels good, hopefully I’ll be getting it tuned and finished breaking in by early summer.

The low compression is the biggest drawback to the b17 compared to other vtecpower motors, so IMO its the most important place to start when building one.

there isnt a noticible diffrence from 10.7:1 and 10.9:1. high compression just enables you to run higher octane fuel now lets say u went from 10.7:1 to 11.7:1 then you might of seen a 3-5 hp gain if you ran higher octane fuel. just remember the higher compression you go the higher octane fuel you will need to run the pr3 will be just fine no real diffrence from the p30. another way you can look at it is the obd0 and obd1 b16 there is a 10 bhp diffrence yet the obd1 b16 has a better intake manifold and better fuel and timing maps in the ecu the 10 hp comes from the better tune and intake manifold not the compression diffrence

ok cool, I just had the hype running through my head that the JDM p30 pistons are that much better. Really i just want to wake the b17 up a little bit. thanks for all the help. BTW she did a 9.6 in the 1/8 mile with alot of weight in car and spinning, and the ls transmission doesnt help lol. But hopefully after the pistons and tune she will do better. We shall see next week. Thanks again

Quick question. After installing the new p30 pistons and rings should I use the 30w non detergent oil for 1st 100 miles and then change? Also which ngk plugs should I use?

use a std dino oil like castrol or something 10w30. NO PENZOIL. no synthetic. i’d run it for 500 miles, change it to another dose of the same, and drive it another 500 miles, change it again to what you want to run permanently, and enjoy. you CAN, if you want, run a break in oil, but it’s not absolutely necessary.

use the std plugs made for your car. iirc ngk bke11e ersumshit.

Ok cool, so ill run standard castrol gtx 10w30. With the compression being higher will it be safe to push the car without a tune? I know a tune will only help the car, but until I do tune will it be ok? Thanks for the help