NumberB

i have a b18c3 with stock internals and gonna be running a log. anyone running one of these or can give any input if these are good for street? gonna be tuning with crome and also unsure how big injectors to get, 440 or 550?. i am looking to street performance. i know the gt28rs spools faster but is the gt3071r to big for street?reason im leaning toward the 3071r.my downpipe is going to be 3inch and i am unsure if i can get a flange to fit the exhaust side of the gt28rs. probably going to be running 7-10 psi until i can get my block sleeved. any input would be helpful thanks.

TheShodan

iTrader: (14)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by milb16a &raquo;</TD></TR><TR><TD CLASS="quote">i have a b18c3 with stock internals and gonna be running a log. anyone running one of these or can give any input if these are good for street? gonna be tuning with crome and also unsure how big injectors to get, 440 or 550?. i am looking to street performance. i know the gt28rs spools faster but is the gt3071r to big for street?reason im leaning toward the 3071r.my downpipe is going to be 3inch and i am unsure if i can get a flange to fit the exhaust side of the gt28rs. probably going to be running 7-10 psi until i can get my block sleeved. any input would be helpful thanks.</TD></TR></TABLE>


This really all depends upon the power that you're looking to gain from the car, and not just "quick spool'.

RANT: I know this is of no fault of your own, but I'm rather annoyed at the fact that many on this forum look at "quick spool" as the only benefit or characteristic of the GT series line (especially the smaller ones, i.e. GT28RS, GT2871, GT3071, GT3076, GT42R, etc) when looking at it efficiency, and not the efficient powerband as a whole. Its understandable that no one wants a giant laggy turbo for street use or the occasional *** whoop, but people need to either ask the turbo pros or do some additional research about what turbo works best for them, and not just a "I want a quick spooler, what do I get?"

Ok, off the rant.... The GT28RS/GT3071 is a very nice solution to a decent power problem, but you must understand that you can't look at PSI pressure to determine the turbo chosen. It is based upon power rating, and CFM of air volume. What kind of hp are you looking for? Do you understand about Internal wastegates? Yes they can be converted to external, but do you know the sweet spot in terms of efficiency for each of these designs? If not, it's o.k., just tell us what the purpose of the car is, how responsive do you want it, and if you want more power later.... that would be the best help.

GT3071 turbos are very efficient for the B18C1, but there are some that are just as efficient without having to worry about a ball-bearing CHRA..

NumberB

well i guess i misused the quick spool concept but i was just looking into something with good response over high end for about 300hp . i honestly dont know how much cfms i will be pumping out and am not really great at reading compressor/turbine maps. will be getting the external wastegate turbos. just looking for reponse on the street. just cant stand huge turbo lag

NumberB

i figured my cfm at redline to be 27cfm/1.58pr at 7psi and 30.8cfm/1.78pr at 10 psi? can anyone chime in if this sounds about right for a gsr? i did the calculations myself so i am not sure if these are close? also i figured that 440 injectors would max out at about 300 hp? 300hp*.60/4=45lb/hr*454/60/.75= 454 cc/min? which would be on a fairly conservative tune? just need some validations these are in the right ball park? also anyone know where i can get a gt2871r compressor map?


Modified by milb16a at 5:00 AM 6/9/2005

TheShodan

iTrader: (14)

Well, you're close but no cigar. It's about 34lb/min at 7psi and 39psi @ 10 psi. You didn't include your max rpms.

I'm not going to get into the calculations, because there are a lot of other factors you're missing, But this is why I design turbos. There's more to it than the map. PM me, so I can get you the best solution

rmcdaniels

I currently run a GT3071R, before that I ran a GT28RS. Personally if I was only aiming for around 300WHP I'd get a GT28RS, it responds to throttle input more quickly than my GT3071R does and can push enough air to make well over 300WHP. Spool time will be primarily dependent on your tune, so invest in a good tuner if you aren't one.

NumberB

i did those for 8100 rpms. i decided on a gt2871r t3 5 bolt housing 63 a/r. i wonder where my numbers went wrong. also since my compressor math was slightly off, was wondering if my injector calcs were off too? thinking of going with 550's. hopefully crome will allow the injectors to chill at idle and not run rich all the time.

JDogg

550's will make about 350-370hp

if you only want 300hp, get the ATP 0.83a/r T3/GT28rs and run