A friend and I were debting what the maximum Compression ratio would could use 8psi of boost in say a b18c1 with good tuning and only uning pump gas... Just a debt between friends

 

I'm running 11:1 compression at 10 lbs of boost on 94 octane pump gas. The tune is conservative:

11.5:1 Air/Fuel at the leanest

18 degrees total timing at 10 lbs of boost and 7,500 rpm on up.

 

hmm interesting... but we only have 91 octane here in az

 

stock ITRs run 10 lbs all day. So that should give you an indication.

 

So the stock ITR with 10.6:1 C/R can handle 10lbs or boost with tuning... Forgive me but I'm not very knowledgable on boost, but 11:1 could handle 8psi on 91 octane, and still make good power without having to retard the timing a ton?

 

is this supercharger intercooled? that will make a big difference in the outcome.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 &raquo;</TD></TR><TR><TD CLASS="quote">is this supercharger intercooled? that will make a big difference in the outcome.</TD></TR></TABLE>Sure intercooled(or after cooled) either way

 

if it's intercooled, then i'd say 8psi on a b18c1 is no problem, as long as it is tuned properly.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 &raquo;</TD></TR><TR><TD CLASS="quote">if it's intercooled, then i'd say 8psi on a b18c1 is no problem, as long as it is tuned properly.</TD></TR></TABLE> So 8psi on a b18c1 block with 11:1 Compression would b fine, if it was tuned and had an intercooler?

 

you'll be fine, i've tuned a 11.5 cr b18c1 motor on 93 octane with 10 psi unintercooled. Just can't go to crazy with the timing. You might not make much more power than a 10.5 motor with the same setup and boost because of the limiting pump gas, but now you always have the option to tune on race gas as well and really make the power difference. Not a honda, but i've also seen a 13.5 cr chevy small block with a blower dyno. He was on a race gas/93 octane mix.

 

what do you recommend as far as tuning for like fuel and ignition?
This is what I got right now:
11.1 compression, TD04, intercooler, timing at 0, external coil, stock pump, b16 injectors, B&m fpr, 91 octane(highest in my area)

 

Hmm i recommend you get some sort of tuning device hondata, uberdata, aem ems, or if money is tight, atleast a afc with bigger injectors or a basic fmu setup. As of right now it seems your injectors would be to small to make any decent power, and i am assuming your just retarding the distributor as far as ignition goes. For what you have now, you could raise fuel pressure and keep the distributor retarded but it would run with only a fraction of its potential compared to control from better engine management. I would be cautious of boosting with the fuel and timing setup that you have now. Just take it easy for now and save up for some fuel and ignition upgrades and hit the dyno

 

jesus all this talk about boost is making this die hard N/A guy start to think hmmm (opens wallet)

 

i feel the same way

 

Thanks bxsi,
You are right, Im short in money, so I'll just raise my FP for now and take it easy until I can afford a fmu.
Do I need to gapp my BCPR6-11 plugs to like 0.032? Right now Im running stock gap.