crix351c

YOU ARE AN IDIOT...Your catalytic converter has nothing to do with your compression ratio......END OF STORY....Please stop talking if you dont know...

this is why most honda drivers get a bad rap...

zccr-xsi

ok so u are telling me more or less backpressure dont effect your c/r?just like what everyone eles tells me PROVe it.and btw i didnt say it had everything to do with c/r.all i was saying is changes slightly without no cat.next time read lil slower dip ****.

Targa250R

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vteckillenzc &raquo;</TD></TR><TR><TD CLASS="quote">ok so u are telling me more or less backpressure dont effect your c/r?just like what everyone eles tells me PROVe it.and btw i didnt say it had everything to do with c/r.all i was saying is changes slightly without no cat.next time read lil slower dip ****.</TD></TR></TABLE>
You're wrong. Whether or not there is catalytic convertor has no effect on the static compression ratio.

zccr-xsi

what bout overall c/r.cause i was told not useing a cat lowers c/r slightly.not enough to notice.when im talking bout overall c/r not c/r in each cyl.

Tyson

do you know what compression ratio is?

im curious to hear what you think it is.

zccr-xsi

my answer would have to be.the volume above the piston at bottom-dead-center divided by the volume above the piston at top-dead-center (TDC).
ok maybe i am wrong it might not effect it in anyway.i guess what i was told was b/s

Blue Hybrid

your thinking of back pressure, it has nothing to do with compression ratio

Tyson

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vteckillenzc &raquo;</TD></TR><TR><TD CLASS="quote">
ok maybe i am wrong it might not effect it in anyway.i guess what i was told was b/s</TD></TR></TABLE>

glad thats clear now...

zccr-xsi

ok then why do on some sites i seen they are quoting 2 diff c/r for the zc and the one with no cat has low c/r

9:3.1&lt;&lt;witout cat

9:5.1&lt;&lt;with cat

are they just blowing **** out there *** or what

NACvicSi

Anyways back on track. OP, nice number for a stock ZC.

zccr-xsi

damn man to see a stock zc dyno out at 102 hp thats kinda depressing.i thought it had more then that.i need to dyno mine now.

NACvicSi

Loss is between 15-17% thats what we said. Thats in tip top shape, I'm sure this one is loosing more because it's an older engine.

Tyson

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vteckillenzc &raquo;</TD></TR><TR><TD CLASS="quote">ok then why do on some sites i seen they are quoting 2 diff c/r for the zc and the one with no cat has low c/r
</TD></TR></TABLE>

on UK crx, they offered SOHC and DOHC engines. compression ratio on DOHC engine is 9.5:1, however they offered two SOHC engines with cat, and without for use with unleaded and leaded fuel respectively. the difference of compression ratio was 9.5:1 with cat, and 9.1:1 without cat.

seeing that the bore and stroke remained the same between unleaded and leaded fuel engines, then the pistons were different which leads to a different compression ratio. its not that having the cat or not changes the compression ratio, its how the engine was designed for use with or without a cat. removing the cat on an engine designed to utilize the cat doesnt change the compression ratio of the engine.

http://media.honda.co.uk/car/o...8.pdf

SINISTR

Wouldnt the Compression Ratio you're Refering to be also different because of different Gens of ZC motors?

Brown Top (~84-85) would have the lower C/R over the Blacktop ZC (~87-92) would have the 9.5/6:1?

If you measure the C/R of each cylinder - you're doing it without the exhaust even operation - motors turned off... so the CAT has nothing do do with the Comp Ratio. - its Backpressure that makes a diff.

CATS are designed to flow easy anyway - a NEW CATs flow will be equivalent to a HighFlow CATS flow... when you run the car for 10yrs its reducing the flow - increasing BackPressure.

zccr-xsi

i think i was confuseing back pressure for the cat

South Bay Surfer

102 whp? damn you got me scared to dyno my dohc zc. but i need to know the truth one day.

NACvicSi

Really. I want to dyno my new motor but I'm scared, if it's bad I might get pissed lol

South Bay Surfer

If my motor were to dyno that low I would give up on that motor.

zccr-xsi

damn thats still dont sound right.i wonder how much hp a b16 would lay to the wheels.what like 130?

Blue Hybrid

my stock b16 made 134 on a chassis dyno

South Bay Surfer

Im hoping for at least 110-115 whp with my dohc zc w/i,h,e, and testpipe. ****, my d15b w/i,h,e vafc, hi flo cat, fpr, pulleys cam gear--all untuned made a baseline of 115 whp. After it was tuned it made 123whp and 98lbs of torque.
Don't the dohc zc and d15b both make 130ps?
If my dohc zc puts up similar baseline numbers I'll be all smiles.

zccr-xsi

i dont even want to think what mine will put down.im already planing on ls/vtec now.im ashamed of my zc now.

SINISTR

Guys - Sorry - but do you even read 'complete' posts or just pick all the stuff you 'want to' hear and reply to that? - its becoming annoying.

Australian DYNOS read LoWER than most other Dynos. B16As on the day got about 120HP, worked B18Cs got 150HP.

This conversation has been going on for 3 pages now and you still come back telling me it TOO LOW for a ZC. Obviously US dynos are calibrated alot better than Australian Ones.. at the end of the day its not good to compare dynos anyway - its more a tuning tool.

With all of your 110/115WHP how quick do you guys go down the 1/4? cos thats a better indicator of the HP than a Dyno anyway. With 115whp you guys should Id assume get a mid 15 second pass in a street trim car...???

Pls don't take this the wrong way im only mucking around - but obviously when Japan made ZCs for the US market they gave you the better ones didn't they? so while in Australia we only get 100hp you guys get 115hp more! WOW.. im moving to US - maybe my D16A8 will make 130@wheels???

SINISTR

These are the dyno HP readouts that we got on the day - for you guys to compare.. You'll realise its all the cars reading LESS than what you guys think - simply because of the different Dyno calibrations...

owner car engine dyno 1 dyno 2

nsx c32a 225hp 237hp

eg8 zc (jdm) 97.3hp 99.9hp

eg9 d16a8 (jdm) 85.9hp 88.7hp

crx zc 95.8hp 98.3hp

crx d16a8 99.1hp 102.0hp

ek1 d16y 93.2hp 93.3hp

ek1 d16y 91.0hp 93.1hp

eg8 d16y1 85.9hp 89.9hp

eg5 d16y1 100.1hp 99.6hp

em1 d17a 99.9hp 100.7hp

ej8 d16y8 101.8hp 104.6hp

ef9 b16a 109.6hp 113.4hp

eg5 b16a 120.6hp 121.9hp

eg4 b16a2 130.6hp 132.5hp

ek4 b16a2 122.3hp 120.9hp

eg4 b16a 119.2hp 119.7hp

del sol b18c 141.7hp 145.2hp

ek4 b18c 146.2hp 147.0hp

da8 b18a 97.1hp 97.9hp

teg gsi b18b 103.3hp 104.1hp

ek4 b16a2 111.2hp 111.9hp

dc5r k20a 153.2hp 148.6hp

dc5r k20a 148.0hp 150.1hp

dc5r k20a 156.1hp 159.4hp

pulsar sr20de 115.3hp 117.7hp

prelude h22a 143.3hp 144.2hp

ef - 67.6hp 66.8hp

s2000 f20c 171.6hp 177.0hp

dc5r k20a 150.6hp 150.2hp

kantfadedisazn

just a question ur d16a8 is that the single cam jdm zc cuz that is wat i hav, as for low buget mods that make good power since u allready hav IHE take a d16y8 intake manifold and bolt that on its like the type r manifold for single cam, second add on the exospeed sr909 cam it makes really dam good power and only costs $200 the specs are 294 degrees 304 duration, another cheap mod is the racing crank pully from unorthadox u gain some power there, and last but not least an ecu from prospeed they know how to work their magic on sohc. thast wat ima going to do so hopefully that helps u out anyway