I have a 1990 CRX Si with a JDM B18C swapped in.

I'm looking to run 8 psi (PR 1.54) of intercooled boost.

I don't want a tiny turbo that will rev up immediately and create
immense backpressure and all those goodies, but nor am I going for full-race (street car mainly)

my calculations show:
pressure ratio = 1.54
airflow = 24.46 lb/min at 7600 and 85 deg F

judging from this information, I concluded that I could use a t3/t04e
(in terms of flow maps, 50 or 54 trim seem to work well) to my
advantage. my other choices were gt28 or gt30, and the mitsu TD05H-18G seen on greddy kits.

I'm going for the T3/T04E-54 or 50. Does this sound like a reasonable choice?

In terms of airflow coupled with A/R ratios, how do I precisely calculate when maximum boost (8psi) will kick in?

Is there a way to see if backpressure and all will rise at the high rpm band - and to what degree?

finally, does 8psi sound reasonable with a 10.6 CR and stock internals? I was thinking of upgrading the pistons and conrods but I'm not sure I want to decrease the CR. if i did, however, how much low-rpm power would I lose?

I know thats a lot of qs but if you can answer them, i'd greatly appreciate it.
thanks

 

bump

 

t3/t04e .48 a/r

you choose the trim, probably the 54

edit: didnt read ur whole post, if you have the money go for the GT series

disco potato

 

don't feed phil!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtber &raquo;</TD></TR><TR><TD CLASS="quote">don't feed phil!</TD></TR></TABLE>

thats vito...

 

thanks for the response.
I have money, but are you sure about the GT being better? (my purposes = mid-high but not too high range power - mostly street car pump gas)

I know the basics of turbo flow, and i know how to read compressor maps, calculate densities, overall power blah blah blah,

I want to know:
mathematically how can I calculate what I want in terms of exducer/inducer bore (trim), wheel size, etc

I have found no resources on the above topics. I have read cover to cover corky bell and a. graham bell. They don't explain too much, surprisingly, about choosing turbines (specifically) and other things.

Any help/links to resources is super-appreciated.


Modified by b18-c-rx at 11:09 PM 11/30/2004

 

bump

 

I'd go with the 54 trim but make sure you're turbine is a .63, not .48. I've heard many complain that the .48 will drop off in the higher revs. If you're really not worried about quicker spool, why spend money on the gt? if money is not an issue, then why not get the gt? it really comes down to how much you want to spend...