bronx

Does anyone know what compression ratio these pistons would make in a jdm gsr motor???? 94-96 motor

also, what cr would usdm sir pistons make in the same motor???


thanks

zeeman

iTrader: (1)

well the pr3 (usdm b16) would be about 11.3:1 and with p30's (jdm b16) it would be about 11.5:1 and with the pct's (ctr) it would be about 12.3:1.
This is an approximation, there are many other variables when determining static compression.

bronx

Bumping the compression with OEM pistons seems to be popular in Hondatuning magazine

If I decide to do some work on my motor in near future,
I might pick up JDM B16a pistons and put them together with stock rods, and balanced crank,
plus get better valvetrain and cams.....

the setup should be enough for 195WHP
with the right fuel system upgrade and some tuning...

zeeman

iTrader: (1)

depending on which cams you choose i'd say 195whp is realistic. Don't forget tuning. Tuning is important, especially with high compression and big cams.
I would personally run some Rocket M22 or BC3+ cams and valvetrain. I couldn't see needing anything more than some DSM (blue top) 440's, which is nice because you can grab some of them with a resistor box for pretty cheap.
I would use the pct's if i were you and an even bigger cam, but then you will need to worry about clearance. If you really want to use b16 pistons use the p30's.

bronx

yeah, p30s sound good enough...i wanna keep it a daily driver
get the skunk2 valve springs and retainers, plus itr valves,
did you mean that i should get new dsm 440's injectors or used ones? plus id probably wanna upgrade the fuel pump to walbro 255lph

i was planning on using buddy club spec 3 cams and adj gears...

and get it tuned at splitfire.....he chipped the p72 for me a few weeks back

bronx

yeah, p30s sound good enough...i wanna keep it a daily driver
get the skunk2 valve springs and retainers, plus itr valves,
did you mean that i should get new dsm 440's injectors or used ones? plus id probably wanna upgrade the fuel pump to walbro 255lph

i was planning on using buddy club spec 3 cams and adj gears...

and get it tuned at splitfire.....he chipped the p72 for me a few weeks back

LEITNER

i hate the name "buddyclub" reminds me of "hello kitty" its just real weak like it should be an anime cartoon. "on this episode of buddyclub misty and brian fall in love". im done now.

i would definitly use the pct's but im not all into the jap sh*t for cams. i would go with a set of endyn bumpstix and his valve train. i know it first hand and the quality is second to none and they kick a**. i would get a set of rc injectoers 310cc. i hope your head is ported cause you wont be getting the power you could if its stock, there is alot more involved than opening the valves more and holding them open longer.

zeeman

iTrader: (1)

rc injectors are good if you don't want to run a resistor box b/c you can just order saturated injectors. But don't u think you would max out 310's even on his setup? IMO when choosing an injector you should always pick more than you need. You shouldn't be running your injectors maxed out (which is really only 80% duty cycle).
I totally forgot about headwork. A big cam and high compression are just part of the equation when trying to make lots of power (like steve said). Start with all of the bolt on's, because you want to be able flow the best you can. And headwork is a must! A good port job and valve job will go a long way and will get that head flowing nicely and really get the most out of some nice cams and high compression.
What good is a high lift long duration cam if your engine can't get the air in and out?
You really like the Endyn stuff eh steve?

8.5K

STD size PCT's in an 18c will yeild 12.92/1 c.r. with oem headgasket and unmilled p72 head. some people are in love with compression, which is funny. because, very little timing can be run with high compression. to be honest, compression is completely overrated. its a way for people with less than stellar set-ups to yeild more power. unless its a race motor. but, at the end of the day...a good setup and with less compression and more timing will yeild very close to, if not better numbers and a broader powerband....as motor with those c.r. #'s (12.8+/1) need big cams that have narrow powerbands. and, the lower c.r. motor will live a much longer life. i've personally never liked the Buddy Club name, but, they make the power time after time. there are very few cams out there that produce power like BC3+'s & BC 4's. its a fact. i have no comment about endyne. i have no experience with there products. but, 99% of the people on here are not serious, hardcore enthusiasts anyway. they are just internet surfers. with that being said, i would not reccommend more than a CTR cam and moderate compression. for the simple fact the they don't know what goes into this type of ****. like $1+/L gas prices, more than regular maintenance, high quality oils and fluids, $12.50/per pop spark plugs, regular inspection of your valvetrain (if you run big cams and rev to or above 9K) etc. this motor **** is not for kids. therefore, i usually reccommend mild over wild. and, BRONX, there is no need for ITR valves in your set-up. trust me. i'm not going to get into it, but, they are not needed...at all.

DefconDave

This is a nice combo 218whp 159 torque SAE corrected
B16 head B20 bottom

Walbro 255

ported head

Buddy Club Stage 3 or 3+ (you might wanna go with valve springs, Buddy Club says you don't need them, I've seen problems with valve float and contact)

440 RC's (just to know your getting new injectors, you don't wanna have to deal with old injecotors and getting them flow tested, then looking for and buying a resistor pack)

zeeman

iTrader: (1)

Its strange how different CR calculators give different #'s.
I agree 100% with you 8.5K (as i always seem to).
Most people don't know what goes into building/maintaining a high performance engine. I guess thats why i see the same few people responding to these types of questions.
Sure someone can go to a machinist and have them build an engine, but do they really know what goes into maintaining it? Or even what to look out for? Like what detonation sounds like or how to tell if something isn't right.
I agree with what you are saying about compression not being so important, on its own. But as a part of the equation it is important, but its not the only thing to consider. But like you said for the average "internet surfer" mild compression and CTR/ITR cams should be more than enough. Especially if you are the kind of person that takes your car to speedy for oil changes....meaning the kind of person who leaves maintaining their car to someone else.
Like 8.5K said this stuff isn't for kids or for someone with shallow pockets.

8.5K

its so true...there's only a handful of people that respond to this ****. as for c.r., trust me its overrated. its different with a 16 because it lacks displacement. but, when i regularly see low compression b20vtec's (9.2-9.8/1 c.r.) make close to 200whp with bolt ons and ITR cams tells the masses alot. displacement owns. all that high compression does is limit your options. trust me people its overrated. Z...did you ever see Backdrafts 81.25mm lsvtec dyno? he made 217whp with 11.3/1c.r and S2S2's. its all about the set up. i keep telling people...if you are building a race car and need to extract every last pony, then you have to ride the edge of the limit. in regards to compression. but, flip, man....i've seen too many mild compression 1.8L motors (10.0-11.3/1 c.r.) make in excess of 200whp. anyway, we will see what happens. i'm trying to make 200whp on an oem 18c1 shortblock. stock bore, less than 11-1 c.r. and 8600 rev-limiter. we will see what happens, but, i'm not worried at all. my set up is near perfect.

zeeman

iTrader: (1)

very very true. I've seen and experienced a very low compression b20vtec EF haul a$$
I would rather have a little lower CR with more timing than high CR and stock timing. Like you said you can make as much, if not more power with a little more timing.
It makes me excited to hurry up and finish my new build. And i know you'll get what your looking for outta your 18c build up.

DefconDave

Hmmm you guys make a good point. However, I believe in maximum power gains. If your gonna do it, you gotta do it right!!
I do not consider it my job to hold back for people, unless I am asked. When it really comes down to it, all I care is about is what's in the rear view. LOL just breaking stones guy's

Disclaimer: If you are the type of person who uses sh1ty gas and oil, do not listen to DEFCON DAVE

^^^^

zeeman

iTrader: (1)

^^^^haha. But there's more than just gas and oil.

zeeman

iTrader: (1)

Its true, because when tuning a car you don't extract power from tuning the fuel as much as the ignition timing. You just basically get the air fuel ratio flat and steady as a platform to start pulling timing. Thats where the power is made, through tuning the timing. That is unless your ARF is all over the place and in desperate need of adjustments. In which case you will prolly see some decent gains from gettin the AFR flat.

DefconDave

THERE IS NO REPLACEMENT FOR DISPLACEMENT

LEITNER

compression is over rated? narrow power bands? you have just made the stupidest statements i have ever read by someone who apparently has some knowledge. i will leave it at that.

i have had enough arguing with internet idiots who dont have a clue. geez.

LEITNER

where is this narrow?

zeeman

iTrader: (1)

wow that engine really likes it lean around 6k.
Is this the 2L b18c?