just sold my old engine and am building a new one, its going to be a nice simple B16a1 turbo, iv got a T4/T3 hybrid turbo, a steel crank and all my old tuning bits, iv now gotta decide what compression ratio to go for, i have a choice of these:
# 8.2:1
# 8.5:1
# 9.0:1
# 9.6:1
the lowest one would be good but i dunno if the 1600cc lump will spin the turbo up fast enuf, at such a low level, it will mainly be used for street use, but will be going to a few drag meets,

any advice would be very much appriciated,
olly

 

How much boost are you going to be running? How is it being tuned? What are your HP goals?

If it is being tuned really well, you could get away with 9.0:1 or even 9.6:1 with lower boost. If higher boost and pump gas, go with 8.5:1.

 

stick with the 9.6:1 and you'll be faster at lower boost, but more tuning is required to maintain safe a/f levels and higher octane fuel is a must, which is obvious with all turbo setups

 

im hoping for as much bhp as i can get really, its having an AEM ecu and is getting mapped at one of the uk's top tuners so it will be a good setup, id be hoping to run 1.0-1.3bar boost.
the head has been gas flowed its got spoon valves, spoon cams, spoon valve springs, spoon cam gears, its had a block brace fitted and a new oil pump, its got a big bore throotle body, and a 75bhp wet nos kit, pace front mount intercooler, co2 spray bar, apexi vafc2.........

 

What are the specs of the turbo?
9.6:1 gets my vote esp if your running a t3t4 and looking to make some decent power.

 

it has been proven already that compression has almost nothing to do with turbo spool. gearing and how fast you get up on the tach is what makes the turbo spool.

9:1 will be fine

 

I run ~9.5:1. Decent low end and great spool on the T3/T04E. You'd better get some super high flow injectors if you're going to go below 9:1...

 

what injectors do u recomend, iv got a hks pressure reg on it at the mo, but still running a std fuel pump...... dunno if there up to much on a 91civic vti? altho i dont think they released this model in the states, so some of u prob wont know

 

I make 389 whp at 20 psi and I am at 100% duty cycle on my RC 550's, B&M FPR modifier at 60psi static pressure, and 255 lph (low pressure) walbro fuel pump at 7000 RPMs. I'm upgrading to RC 670's this week and going to retune.

It all depends on how much power you want to make. If you're not going to push the limits of the fuel system and won't be pushing a crap load of boost then you don't need to run a really low CR. It's all about what your goals are.

 

i hoping to get around the 300bhp mark allong with my 75bhp-shot on top, iv just been looking at these on ebay:
http://cgi.ebay.com/ebaymotors/ws/eB...949802861&rd=1
which i presume they are the ones you have?
what sort of hp are they good for, and do you think they will be the correct choice for me???
im going for the 8.5:1 ratio pistons, but im worried about my stock fuel pump and it would be a hell of a job to replace due tho the sound system!!!!!!
Im also buying an AC fuel rail from the same ebay store

one last thing iv been looking at the typhoon inlet maifold, do you think id get much out of this with it now being forced induction, or dont you think it would be a worthwhile thing to buy

im really appricative f you advice, manythanx