machine4321

im goint to be running my f20b this year on low boost (i hope to get up to 8psi safely but we will see)

my question is am i goign to end up with the same overall power if say,

11:1 on 6 psi
or 10:1 runnign 10psi.

i hate lag (im coming from itbs) so im tempted to rung the 11:1 but i keep hearing about higher comp not helping spool at all witch completly boggles my mind .

with the higher comp will it not have more power below the said spool time .

.all i can afford this year is a HG and that would be it for lowering comp.

let me know what you guys think

Blaze45

This topic has been beat dead literally a million times. Do a quick search and youll find a lot of results.

have fun!

Blaze

ahobbs

i 2nd that but your last staement was "all I can afford" that's what u need to stick to.

machine4321

i know its been covered before but i have a hard time with this search lol . no really i never find what i want

thanks

beerbongskickass

Lag is way overrated. Your going to be on pump gas, so go with 9:1 like everybody else. It's much safer. I see no benifits of going with higher compression. The low end power and spool time isn't that much different. I would much rather have a safer motor than a little more horsepower.

tokesGTR

The difference between 10:1 and 11:1 would be made up with by like a pound of boost, not 4.

machine4321

ahh ok , makes a bit more sense then .

i guess i should grab a HG then to be on the safe side , and yes ill be running pump gas

GaRn

10:1 is nice, but I would be inclined to go for 11:1 and boost..

I'm like you, I like better torque/etc...

If its a street car and you are only pushin lower boost levels like you mentioned, then go for it.. lower end torque is nice on the street.

You will have more torque before the spool up, and you will spool up faster, if measurable, but still faster.. whoever told you that does not have any common sense lol..

tuning will be reaaaallllly important, so have several gauges to monitor the car..

slowteg550

no, go for lower compression. Everyone who has a boosted car will tell you that "lower boost" is bullshit. You'll drive it for 3 months and it'll feel slow so you'll want to turn up the boost. If you go ahead and put low compression pistons in it now then you'll be set, if not you'll be rebuilding or stuck w/ the dreaded LOW BOOST... we all know that sucks ***.

my crx is rhd

high comp is good w/ a nitrous setup...but forget about that motor anyway...that motor is junk....if your have the option to rebuild and change compression, than i am guessing you'll have the cash to buy a jdm f22b which is the same as the h23...very tourquey motor...slap 10lbs through one of them, you should be very satisfied... with that setup. they'll do well over 300hp...

hotimportcrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slowteg550 &raquo;</TD></TR><TR><TD CLASS="quote">no, go for lower compression. Everyone who has a boosted car will tell you that "lower boost" is bullshit. You'll drive it for 3 months and it'll feel slow so you'll want to turn up the boost. If you go ahead and put low compression pistons in it now then you'll be set, if not you'll be rebuilding or stuck w/ the dreaded LOW BOOST... we all know that sucks ***.</TD></TR></TABLE>


You will up the boost. Turst me. Go lower compression because its better for boost...and the whole theory about higher compression = less lag is completely false....before i bought my 9:1 compression pistons i researched it alot..and can tell you its false...anyonewho says higher compression will eliminate lag needs to research...lately alot of people think this and there is alot of people have be mistaken!

sc4dr

low comp. higher psi

machine4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by my crx is rhd &raquo;</TD></TR><TR><TD CLASS="quote">high comp is good w/ a nitrous setup...but forget about that motor anyway...that motor is junk....if your have the option to rebuild and change compression, than i am guessing you'll have the cash to buy a jdm f22b which is the same as the h23...very tourquey motor...slap 10lbs through one of them, you should be very satisfied... with that setup. they'll do well over 300hp...</TD></TR></TABLE>

dont down on the motor , your thinking of the f20 sohc
this id a dohc vtec 200hp . basicly destroked h22 with some goodies from the factory

machine4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hotimportcrx &raquo;</TD></TR><TR><TD CLASS="quote">


You will up the boost. Turst me. Go lower compression because its better for boost...and the whole theory about higher compression = less lag is completely false....before i bought my 9:1 compression pistons i researched it alot..and can tell you its false...anyonewho says higher compression will eliminate lag needs to research...lately alot of people think this and there is alot of people have be mistaken!</TD></TR></TABLE>

yea i hear what your saying .
to me it just seemed liek the way it sould be (in theory) i would think more comp = more combustion = more heat = more energy to spint the turbine , id love to find the threads where its talked about .

i need you guys to keep in mind that this is only till i can get more money to buy pistons . i do want to have about 400 whp in the end , but that wont happen this year (i dont think )

my crx is rhd

if your setup correctly, you wont have to worry about lag,....gearing, turbo size, powerband(rpm) etc....just get quality components in the first place. the only concern with that is that a setup thats best for a 10psi level, might not be best when you turn it up into the upper teens or low 20's....i'm sure u and everyone knows that..but keep that in mind....also power isnt everything....ive been beaten by 200-250 hp all motor cars...and i'm around 450 to 500 given the tune i'm running at the time.

GaRn

Regardless if you go with 10:1 or 11:1 you will be able to achieve your goal, and since its a street car, I still say go with the higher compression..

Of course higher compression will decrease spool time, I never said it would ELIMINATE lag, use your brain.

lower compression isn't necessarily "better" for boost, although it typically allows you to run more timing when you start packin on the boost alot..

Example, there are plenty of stock compression s2000's running around with turbo kits, making damn good hp at that..

Don't go by what some of these lemmings say, that just follow whatever they may hear or read from who knows who/what all they do is relay what they hear.

Tune it well and you will be fine, oh and a alch injection setup would be nice as well..

slowteg550

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GaRn &raquo;</TD></TR><TR><TD CLASS="quote">Regardless if you go with 10:1 or 11:1 you will be able to achieve your goal, and since its a street car, I still say go with the higher compression..

Of course higher compression will decrease spool time, I never said it would ELIMINATE lag, use your brain.

lower compression isn't necessarily "better" for boost, although it typically allows you to run more timing when you start packin on the boost alot..

Example, there are plenty of stock compression s2000's running around with turbo kits, making damn good hp at that..

Don't go by what some of these lemmings say, that just follow whatever they may hear or read from who knows who/what all they do is relay what they hear.

Tune it well and you will be fine, oh and a alch injection setup would be nice as well..</TD></TR></TABLE>

Hey Fucktard, we're not dealing with an S2K,that's a shitty example. It's not just "following the norm" to run low compression pistons, it is just the right thing to do. Why run 11.1's at X psi reaching the danger zone, when you can run 9.1's at X+3 (or so) psi and achieve the same power, while still leaving room to up the boost more?

machine4321

actually the f20b was the r&d motor for the f20c. all there research was done on the f20b (jgtc all motor accords were 300ps). so they are pretty simalar.

but back on track , ive decided to boost the 11:1 since there isnt much point in cracking open a perfectly good motor just to put a headgasket in it , and then have to take it out when i get pistons.

if i blow it up then ill have to speed things up .but hopefully by then ill have the money saved up .

thakns for the help guys

Tony the Tiger

Higher compression will not improve spool time. Think how EGT's change with compression ratio, and you'd soon realize that lower compression would mostly yield higher EGT's instead.

Watching that boost gauge needle fly up doesn't mean much at all though. I am sure we've all seen the boost gauges installed on factory turbo VW's or Audi's jump around all day, but the engine feels laggy and not responsive at all.

If you want a fast street car with a nice powerband and good response, you should go with higher compression, something along 10.0:1 or 10.5:1 depending on the fuel you are running. Lower compression will definitely kill throttle response, and it would make the car feel like a dog. Lag is when the car doesn't really move all that quick and you'd have to wait for the power just to pass traffic. If you have great off-boost power and good throttle response, then really, you don't feel much lag at all because the car already accelerates nicely without the boost. Also in partial boost regions or during onset boost, higher compression does indeed make more power and torque. We'd all know that at ie: 2-3 PSI, the higher compression engine will make more power and that would decrease turbo lag quite noticeably.

This is coming from a guy who just went from 11.5:1 CR down to 10.5:1 CR on the exact same turbo, same everything with the exception of tuning (I had to up the timing + others after lowering CR.

And this is probably the 10th time I've posted this, so I am being nice for the last time

machine4321

thanks tony , and i though you were in T.O when i watched the vids, couldnt get a look at the plate .

love the itbs+boost, if i had a proper set i would do the same .

id love to get a ride in your car , it looked fun as hell in the vids

so you were runnign 11.5:1 for a while ?

my crx is rhd

sometimes lag isnt a terrible thing for a street car....me crx goes nuts when the boost kicks in....and sometimes it'll do it when i dont want it to....with a slightly laggy turbo, i feel you have a little more control over when you see power....but on the other hand, it sucks when you want it to be there, and you cant find it....like when your doin 65mph...on I-95 and a Z06 fly's by....and your ride out 5th waitin on the boost.....f*ck that Z06.....lol

GaRn

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slowteg550 &raquo;</TD></TR><TR><TD CLASS="quote">Hey Fucktard, we're not dealing with an S2K,that's a shitty example. It's not just "following the norm" to run low compression pistons, it is just the right thing to do. Why run 11.1's at X psi reaching the danger zone, when you can run 9.1's at X+3 (or so) psi and achieve the same power, while still leaving room to up the boost more? </TD></TR></TABLE>

How about you post without the attitude? Replying like that just makes you look bad..

beerbongskickass

It doesn't look bad at all because he's right...

It's safer to go with lower compression, plain and simple. Especially when it's a daily driver on pump gas.

Lag is way overrated anyways, it won't even matter when your racing because your rpms will never drop low enough to where lag will be an issue. Were all at a disadvantage having a FWD car with dinky tires, a lot of low end power will just make it harder to drive. Hondas are all top end...

GaRn

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beerbongskickass &raquo;</TD></TR><TR><TD CLASS="quote">It doesn't look bad at all because he's right...

It's safer to go with lower compression, plain and simple. Especially when it's a daily driver on pump gas.

Lag is way overrated anyways, it won't even matter when your racing because your rpms will never drop low enough to where lag will be an issue. Were all at a disadvantage having a FWD car with dinky tires, a lot of low end power will just make it harder to drive. Hondas are all top end...</TD></TR></TABLE>

What is he right about? He didn't have anything to say that disagreed with what I said..

Lag is overrated? I would say thats personal preference. I think saying things are "overrated" is overrated. I don't think we are talking about compression and "lag" for the sake of racing, but daily driving. I hate having a sluggish car below boost, it feels mushy, with horrible throttle input that just doesn't feel good, but thats my opinion. I have driven several DSM's and at their low compression(1g 7.8:1 i think) they feel like slugs until you start spooling.. Lol at the FWD/power point.. Its not like going with higher compression is going to give you 500 lb ft of torque, just makes for a nicer/more enjoyable car. Any four cylinder is all top end. Also, yea lower compression is safer when it comes to pushin tons of pressure, so yea it is pretty plain and simple, but like I said, I'm pretty sure we are talking about a STREET car, he is not gonna be runnin 25 psi daily..

The point is, with high compression you will be able to make all the power you will want(and safely at that, just tune conservatively its not hard), no problem with that.. If you were building a drag car and dont care about driveability then go with your 8.5:1 compression and huge snail that spools at 5,500 rpms..

my crx is rhd

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beerbongskickass &raquo;</TD></TR><TR><TD CLASS="quote">It doesn't look bad at all because he's right...

It's safer to go with lower compression, plain and simple. Especially when it's a daily driver on pump gas.

Lag is way overrated anyways, it won't even matter when your racing because your rpms will never drop low enough to where lag will be an issue. Were all at a disadvantage having a FWD car with dinky tires, a lot of low end power will just make it harder to drive. Hondas are all top end...</TD></TR></TABLE> i agree with that....lag isnt there if your setup correctly....i guess you can say what some people call lag, could be considered before your powerband....so rather than make power from 2500- 7000 maybe its 4000-9000rpm's.....if you think about it