My First Boosted Motor

[bafbrian]

Been comtimplating this for a while and have done a few weeks of research decided to go the forced induction route.

Now here is what I am wondering. If want to turbo the motor, but I don't want to run ungodly amounts of boost through it to achieve my goal (25 or greater psi) of 400-450whp. After doing some research, I am, still undecided as to what compression ratio to run. I know that I can a run a higher compression ratio and utilize less boost to achieve decent number or a low compression and high boost and possibly achieve the same results.

I was looking at a compression ratio somewhere between 8.5:1 to 9.9:1 ( lets just say under 10.0:1 ).

Here is what I got when I bought the first motor(*) and what I have bought(**):

JDM B18C block **
Darton Sleeves bored to 84mm (Closed deck) *
JE Pistons 84mm ( 8.5:1 ) *
Manley Rods *
ARP Rod bolts *
Type R crank ( micropolished ) *
and some new ACL bearings when all it assembled.

So you know, the pistons will either be 84mm or 84.5mm pistons when it is rebuilt.

So, what compression ratio would you all recommend for this build. I have a few thousand for this build and also, this would a be a daily driver (boost will be turned down depending on how high it is).

[T34me]

If your looking at running some higher boost around 15-20, you definitely want to keep your compression under around 9.4 maybe 9.6 for reliability. I know your going with forged everything, but youll be streaching head bolts left and right if your running 20psi and a 10-1 compression. Just my two cents.

[THEONE]

low boost good tune = lots of fun!!! keep it simple

[Frög]

BOOST FTMFW!

[B18c1Turboed]

9.7 is what we all run!!!

Its perfect for street and racing!!

[bafbrian]

Ok, I appreciate the responses, but I am looking for some explanations behind why you are running your desired CR.

[japan4racing]

i have no experience with built motors so my opinion really does not matter. but it seems to me that as long as you keep it in the low to mid nines and get a good tune you can make all the power you are looking for and not have any probs. many ppl make 400+ on 9.0:1 motors. what turbo are you running? what kinda fuel set-up are you running? there are alot of details that need to be known however you cant go wrong with the norm..stick to 9.0:1 - 9.5:1 and get a good tune. you will like the results.

[SL33P3R]

I was running 9:1 on mine

[SPOOLIN]

with a good turbo you can make near 500 on right at 20 psi, say around 480, like a t67(which is the largest turbo i would do for a daily street car) I wouldnt do the darton sleeves, maybe something more along the lines of golden eagle, aebs, or benson. Compression isnt as big of a deal really these days as long as you dont do something like 11.5:1. your gsr crank will work perfectly fine, no need to search and buy a type r crank, tons of people use LS cranks, all of the honda OEM cranks in a b series will hold more horsepower than you can throw at it.

[bafbrian]

with a good turbo you can make near 500 on right at 20 psi, say around 480, like a t67(which is the largest turbo i would do for a daily street car) I wouldnt do the darton sleeves, maybe something more along the lines of golden eagle, aebs, or benson. Compression isnt as big of a deal really these days as long as you dont do something like 11.5:1. your gsr crank will work perfectly fine, no need to search and buy a type r crank, tons of people use LS cranks, all of the honda OEM cranks in a b series will hold more horsepower than you can throw at it.

Ok, this is what I am talking about.

The reason for running the darton sleeves is that this is what I have, however, I have considered selling these and getting some golden eagle sleeves that are open deck cuz that would a lot less to put in a block.

As for the Type R crank, that is also what I got, actually two of them cuz I got two motors, both disassembled.

As for the CR, I was thinking like 9.0:1 to 9.3:1 and do about 20psi max.

I know there are a lot of variable that are a factor for tuning and achieving the desired results, I just haven't gotten that far. I am only on the motor build part of this project. Heck, I might just make a thread to show the progress when I get some more money.

[dowhatido]

boost is a very beautiful thing, that can fuk u hard if ur not on top of ur game, i would run 8.5-9.5, prob closer to 9flat, but upgrade ur waste gate and put a bigger spring it, we took the 5lb out of a 45mm (??? may have been 35mm, cant remember) and put a 9lb spring (this was in a delsol with b18c1 all stock internals) but it was a big fukn diff, i was very shocked........look into the other aspecs on the turbo subject dont just limit urself to boost, but at the same time boost is great