J1A1H

Hi, i did a search but not much or anything relevent to what i was looking for came up, maybe i typed the wrong things... ANYWAY.

I was talking to a man at a garage today and talking about boosting my B16a engine. He then mentioned the compression and that if its very high.. i have to becareful how much i boost. People are saying with the average turbo like a T3, you can safly boost 7-8psi or even 10 with a gd tune.

Anyway my question is,

How and why does high compression effect how much you can boost it and what can be done to and engine in order to either bring the compression down or make the engine tolerate the extra boost.

Sorry but i am a new to turbos and want to have a full understanding before i purchase anything.

THANK YOU, and if this has been talked about, can you please point me in the right direction

THANKS

StreetEG

It has been talked about... maybe not specifically...but there are a bunch of boosted stock block b16s in the FI forum.

As for personal experience, it all depends on the tune...that being said, a buddy of mine has his boosted b16 running strong for about 8 months now on 12.5 psi. Not too shabby...puts down about 270 wheel on a t3t4 with other bolt ons....ya good tune=safer boost

94hatchling

can't answer your direct question and how and why the high compression of our b16s affects boost. well i could answer it, but my understanding of it isnt 100% complete and dont want to give false information.

but i do know, that a best friend ran 12lbs of boost on his stock b16a2, making 300hp with a t3 turbo, and a damn good tune. as stated above, great tune=reliable and safe boost.

J1A1H

Thank you for your help so far... so the people you know that have boosted their engines have done so on stock internals?

And can someone give me a rough explaination of why high compression means you cant run high boost..

THanks

deathplaza

turbos shoot compressed air into the combustion chamber, a b16's pistons are domed and make a small compression area. if you have a large combustion area you can fit more compressed air. thats as basic as i can put it.

J1A1H

oh right... So what can be done to reinforce the combustion area? is that where new aftermarket pistons come in etc...? what else can be fitted to reinforce this area?

THANKS i understand what your saying

Also whats the present compression ratio on the B16a blocks

THANKS

apexi_eg6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J1A1H &raquo;</TD></TR><TR><TD CLASS="quote">Hi, i did a search but not much or anything relevent to what i was looking for came up, maybe i typed the wrong things... ANYWAY.

I was talking to a man at a garage today and talking about boosting my B16a engine. He then mentioned the compression and that if its very high.. i have to becareful how much i boost. People are saying with the average turbo like a T3, you can safly boost 7-8psi or even 10 with a gd tune.

Anyway my question is,

How and why does high compression effect how much you can boost it and what can be done to and engine in order to either bring the compression down or make the engine tolerate the extra boost.

Sorry but i am a new to turbos and want to have a full understanding before i purchase anything.

THANK YOU, and if this has been talked about, can you please point me in the right direction

THANKS</TD></TR></TABLE>

A turbo basically increases the volumetric efficiency of an engine. Air is being introduced into the engine @ 14.7 psi (atmospheric pressue) so if you are boosting 7psi, you are more or less forcing more air at 50%. Anytime you compress air, you create heat. And excess heat can cause detonation. If you have an engine that's already running high compression in it naturally aspirated state, introducing any form of forced induction increases the likelyhood of detonation, i.e. the higher the engine's static compression ratio is, the higher the chances of detonation.

A buddy of mine runs a T3/T4 hybrid and ran 8psi for a while without problems. He was running bigger injectors, upgraded fuel pump and an FMU. A band aid solution really. He now runs a Hondata which made for much safer boost. But the jackass upped the boost to 13 pounds and his motor went to shiets.

It's not just boost levels and compression you have to worry about. Your fuel and ignition has to be able to keep up with the turbo as well. What about retarding spark timing under boost?

Honda engines have an open deck block so I'd start with that. Sleeve that shiet. then forged pistons with a dish or flat top. If you are going to run monster boost, rods as well. And of course fuel, ignition and engine managment upgrades to handle all of this.

typeoneeg6

depending on your tune and how good the gas is where you are you should be able to get away with 12 psi safely and reliably.b16's are alot stronger than most people think. on 1st gen b16's comp is 10.2:1 on 2nd gen its 10.4:1.