IHI RHb5 - too small for b18a1?
 

would this turbo be sufficient enough to make a difference? it's pretty small, my friend has one on his crx.. and he's boosting about 12psi out of it, but he's on a sohc motor.. i've seen around that it can really spool up quick anywhere from 2500 - 3000 till redline..
but then was wondering if going to a dohc if it would overkill the turbo..
i've got the turbo already, and was just wondering if i should go ahead with the work to make an adapter plate for it or, if i should find another turbo..

thanks.

Re:IHI RHb5 - too small for b18a1?
 

Find another turbo. Thats my opinion lets see if anyone chimes in with somthin else :P

Re:IHI RHb5 - too small for b18a1?
 

just find another turbo. if your already boosted why want a smaller turbo? if your turbo is smaller than that. then go ahead and change it. for an Ls id go with a good sized t3 such as a .60 compressor and a .48 exhaust. seems to be good for b series motors but what do i know. i just figured small exhaust for quick spooling big compressor for top end.

Re:IHI RHb5 - too small for b18a1?
 

im not currently boosted yet.. that's why i wanted to start off with a small turbo to get a feel for it basically.. but if it is too small to make a difference, then i was just trying to find out so i wouldnt waste my time on this one..

Re:IHI RHb5 - too small for b18a1?
 

get a bigger one and lower the boost to get "use to it" youll have it turned all the way up in a week.

Re:IHI RHb5 - too small for b18a1?
 

I wouldnt go that small on a b series id start with a .42 .48 t3 then if your not happy with that You can just up the size of the t3 to a super 60 or t3/4 and not have to change anything else major.

Re:IHI RHb5 - too small for b18a1?
 

.60/.63 for a b series... yes, its true, the turbine determines the spool characteristics, but it also determines the powerband. a smaller turbine will spool faster but will run out of steam up top.

Re:IHI RHb5 - too small for b18a1?
 

I will tell you what if the d series spools it like candy the b will be way to much for it. It won't be able to flow enough air up top cuz your engine is bigger. I doubt it will even hold 10 psi all the way. Just do it right he first time you build it. Doing work over sucks.

Re:IHI RHb5 - too small for b18a1?
 

do a google for "compressor map ihi rbb5"
compare that to you engine's estimated output and see if it's efficient or not... my guess is NO.

Re:IHI RHb5 - too small for b18a1?
 

http://list.miata.net/miata/1997-09/2595.html
here's what i found on the ihi RHb5.. it's on a miata 1.8L dohc.. anyone know how they are compared to a honda LS motor?
looks like this guy gives the turbo a thumbs up.. but then what i see on his writeup is that it spooled up to 12psi @ about near 5k.. and LS motors rev until 7k.. so would that affect anything?