i need opinions and maybe even dyno charts if you have them, i want to build my motor and don't know what compression i should do. its a daily driver so i was thinking 9.8:1 would be fine, i want to be able to run more then 8 psi safely. at 7 psi with drag kit and stock internals w/ vafc i only made...


i know
drag kit
boost

 

You will be happier being able to run more boost with the lower compression on pump gas. 9.8:1 is all fine and dandy for people running mammoth turbos that will make 400-450 WHP at like 12-14 pounds of boost, but for a typical T3/TO4E guy 9:1 + more boost is the way to go.

 

Just run 9:1 pistons with a cometic gasket and that will give you about 8.8:1 compression. You will be happy.

 

I say 9:8:1 because with tuning capabilities and equipment these days you should safely be able to.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mchuang &raquo;</TD></TR><TR><TD CLASS="quote">I say 9:8:1 because with tuning capabilities and equipment these days you should safely be able to. </TD></TR></TABLE>

Who gives a **** if you can run 9.8:1 and boost when you can make more pump gas power with 9:1 and boost. I am running 7.8:1 compression on my B16, and after having driven this I can say that everyone's interpretation on honda-tech of the huge loss in power and throttle reponse and turbo spool is far far exaggerated.

 

Just a suggestion. Ditch that VAFC before you build your motor. A good friend of mine destroyed a perfectly good built block (JE, Eagle) because of the overadvanced timing that the VAFC creates. After putting in a fresh B18, with stock internals, and switching to a standalone fuel management he has made in excess of 300 hp and ran a 12.1.

 

If you run pump gas, 9-1 max. Spooling speed is tied to exhaust size, not c/r.

 

im ruing 9.8.1... loving the low end power...

 

I'm running 10.5.1 and I'm really loving it. IMP great for a daily driver.

 

I ran 11:1 cr on stock block for about a year and now I've dropped it to 9:1 with built block. From my own experience and not going by HT hear-say, I can honestly say that I can't really notice much loss in low end spool or power having dropped 2 cr points.

So I don't really think you will feal a great deal of difference between 9:1 and 9:8, so I'll go 9:1 at least you get the extra safety margin.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ibiza &raquo;</TD></TR><TR><TD CLASS="quote">Just a suggestion. Ditch that VAFC before you build your motor. A good friend of mine destroyed a perfectly good built block (JE, Eagle) because of the overadvanced timing that the VAFC creates. After putting in a fresh B18, with stock internals, and switching to a standalone fuel management he has made in excess of 300 hp and ran a 12.1.</TD></TR></TABLE>

yeah going with hondata s200

i want to be able to run between 10-15 psi but not lose too much low end power.

 

running 8.9:1 in my ls vtec, feels nice in low rpms, i dont think ull notice any difference


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by highboostb18c1 &raquo;</TD></TR><TR><TD CLASS="quote">
drag kit
</TD></TR></TABLE>

please dont say that
i made 296hp at 9psi with my drag kit
look at my signature at 20psi dropping to 18psi

 

9.8:1 c/r gsr block 60trim t3/t4 at 12psi...made 332whp i like the mild compression as long as you have a good tuner and a good fuel mangement i had a hondata s200......

 

I agree ditch the afc. I will be getting uberdata once I am built.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ek9turbo &raquo;</TD></TR><TR><TD CLASS="quote">running 8.9:1 in my ls vtec, feels nice in low rpms, i dont think ull notice any difference


please dont say that
i made 296hp at 9psi with my drag kit
look at my signature at 20psi dropping to 18psi</TD></TR></TABLE>

i'm not saying a drag kit is garbage, i just wish i listened to everyone and did a custom kit. i'm keeping the kit just getting a bigger turbo. t3/to4e 57 trim

 

while i'm on the topic, whats everyone opinion on cp pistons? with eagle rods? and who makes the best block gaurd?

 

 

&lt;&lt; daily driven for over 1 year. about 8.8:1 compression altho i know its lower. made 301 @ 9lbs with a basic T3/T4. stock sleeves. i run on 89 octane the majority of the time. i recently tried 87 octane altho i didn't go into boost often. i didn't hear nor feel any detonation.

at low rpms the car is fine. i chose low compression so that the Turbo does most of the work. i think its part of reason why my motor has lasted so long.

my next motor will have the same compression except that it will be sleeved.

 

Yea this high compressin bandwagon is the biggest joke on honda-tech it seems.

Peeps keep mentioning how you'll make more power blah blah blah with lest boost blah blah blah...

Driving back to back 9.1 and 10.2 b16s I couldn't feel any difference.

I think the only thing you can guarantee by running higher compression is to kill your motor faster. Even if the tune is majorly conservative you WILL be more susceptible to knock than someone running lower comp. Weird and unpredictable things happen all the time, like a bad tank of gas, faulty fuel pump...to name a few.

Taking that in consideration why would you not want your motor to run on the lowest octane as possible, instead of having to run c16 every time you get on it?

 

Hey ek9turbo... was this all on pump gas? nice freakin numbers dude!

 

normal street turbo motors i build are 9.5-10:1. i have run 10.8:1 up to 16lbs on pump gas (92 octane) i have a buddy who dropped his compression on his b16 to 9:1 and it barely gets his del sol to start rolling, granted 21psi on pump gas is cool, but torque is more the issue than horsepower. i have big opinions on high compression turbo motors(honda) because i trust the combustion chamber design of the honda engines..i've tried it and i like it. i will say that actual spool rpms don't change much with compression but i did lose about 70 ft lbs of torque lowering compression from 10.8 to 9.0. it just moves the horsepower higher in the rpm range

 

Im gonna go with a 9.5:1 cr when i rebuild. Its right in the middle! haha. hopefully ill make some good number with that.

 

alcohol and whatever compression you want