I know i see a lot of old post abiut the p8r head b18 combo but they are really old. I dont wana get flamed for bumping old post.
I have a b18b1 with a p8r head and at fist i was iffy but i seen threads that said it could be done but no detail into performance or dyno or compression test.
So i wana hear from those that have done it. I want to boost my set up soon and want to see if anyone ran cams or spray or boost on this set up.

 

Will it be safe to boost if i have 150 psi on all cylinders. My motor does not burn oil and it feels strong. I will just get arp head studs.

 

I would love to dyno it as it feels like it pulls really nice between 3-6k range. Just running on a street tune for now but without any real mods i really want to just build a boost kit and tune for like 250hp. Im using a stock b18 hg.81mm I heard people using the 84mm hg

 

Put this thread in the Forced Induction forum. they will have a lot more help to give.

 

built this about 4yrs ago for a close friend of mine in his daily driver Integra. had a cheapo Ebay header, cusotm 2.5" exhaust i made him and stock RSX Type S muffler, I used PR3 pistons which I had laying around, LS block and the CRV head...butt dyno was beyond belief for an LS motor...threw it on the dyno and it pulled 163whp...no tuning as there was nothing really to tune just wanted to check a/f with stock PR4 ecu...

The CRV head flows alot more than the LS head...this flow more than offsets the lower compression from the bigger head chamber in the CRV head...the correct way to do it is to use the 84mm headgasket.

 

163hp WHEEL??? No cams or anything? On an ls??? I dont know about that, 143 maybe, but a stock ls normally dynos 110-120whp, or around 140hp crank.

Even the p8r headed b20s dynos around 140-150hp crank stock

 

yeah 163whp...PR3 pistons...they're from the B16A and have a dome - compression is higher than stock PR4 pistons LS pistons
mods...header, exhaust, intake...i think it was stock LS ecu but maybe I did chip it, i just cant remember what i did since it was a good 4 years ago. And if i did chip i def didn't go alot higher with the timing maps since his goal was daily driving.

 

Yeah I know what the pr3 pistons are out of but thats still only around 10-11:1 compression. The nonvtec cams are weak so you can see why im skeptical considering most gsrs dyno around 140-150whp in stock form. To put down 160whp means its sitting at like 190hp crank (vs 180hp crank for a gsr)

 

My built B20 P8R with 68mm ported intake/TB,port match, in/ex ports cleaned up, Nice set of crane cams, ITR rep pistons @ 11.2CR, Toda rep header with 3" exhaust Dyno'd at 166/142
So im saying that dyno that was used was set rather high..typical for shops to set them higher to make their customers happy. I just dont see a 1.8 making that much

The chambers in the P8R are 47mm which would drop your CR a few points..

IDK, Im hitting the bullshit button.


Heres my sheet:

 

I checked it out and the comp would be something like 10.6 or 10.9.

I could see 150-160 crank considering they were rated in the mid 140s crank and someone dynoed a few and were reporting that honda underrated the power, but never 160 whp

 

lol the bullshit button...sounds funny.

anyway, that was 4 years ago and I just remember the 163 number...was on a dynojet 248C. i have no reason to make this stuff up...especialyl considering the setups I work on these days...
sometimes the simple things is overlooked when tweaking these motors and not everyone knows how to extract full potential out of these motors...which is something that i've been doing for years.

 

Well now that you mention a dynojet it seems a bit more plausible. Those read pretty high vs a mustang dyno (iirc the numbers I quoted for the vtec and nonvtec were off a mustang dyno)

 

^^
They all can read whatever the shop wants them to read. Everyone has their own favorite dyno.

 

I know the p8r lowers compression how can I calculate comp ratio? I want to know what my comp ratio would be using pr3 pistons with the p8r head. And why is the 84 mm the correct gasket to use I used the stock because I figured it would seal the cylinder better.

 

http://www.zealautowerks.com/bseries.html


P8R has 47cc chambers, milling about 15-20 should bring it down to 45 area..

 

now i figure i should know the answer to this, but i thought you couldnt put a p8r head on a 1.8 block because the combustion chamber was that much larger.

is using the b20 hg the way around that?
if so, are there problems with hg sealing ?


with that stock pr4 ecu it must have been running like almost 14:1 afr. i know from my personal low compression b20 w/p8r that it was too lean on stock ecu without additional fuel pressure. cant imagine how bad it would be with another 2 points of compression

 

Yea arent you supposed to use the HG for the head?

 

I've done a couple high compression B18bs for stock car guys, both made 160whp with stock heads and PR3 pistons. Adjust the valves too tight to pass tech and away you go....lol

 

Maybe I should change head gaskets to see if there is a difference but my car runs good with the 81mm head gasket.