yellowturbo

When I build my project 2 winters ago I wasnt able to afford a ball bearing turbo so I got a SC50 .63ar, not a bad turbo... I did some good numbers with it but im tired to use it on the street. At the begining I was sure that I would have use my car for drag more often that I really do... and now I tryed my car for road racing and I really like that. The lag on my SC50 .63ar is not that bad but im sure that I could get a better power curve with a turbo that spool faster and it would be funnier for me that use my car on the street 99% of the time than running a turbo that could push +400whp...

I spoke with some guys on the board via PM and most of them gived me the same choice. Now I just want to be sure.

Here is what I need...

-a turbo that will push 300whp or more @ 15 psi and have a good spoolin time.

-T3 turbine that will fit my old SST manifold and be 5 bolts flanged to fit my DP...

-better spoolin time than my SC50 .63ar

- keep running my EXTERNAL WG !!!

its just that the choice is not clear between the 2 turbo ??

Give me your idea....

yellowturbo

Its for a fully build D16Z6 sorry !

JDogg

go w/the 2871.. the d wont rev enough to choke that turbine too bad in the top so you can use the bigger compressor.

get the "t3 drop in" 0.86a/r

yellowturbo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">go w/the 2871.. the d wont rev enough to choke that turbine too bad in the top so you can use the bigger compressor.

get the "t3 drop in" 0.86a/r</TD></TR></TABLE>

are you sure that you would go with a .86ar ? I dont know if it would affect my spool time... I could also get it with a .63ar, ATP offer this ar too.

My rev limiter is set at 8200.

Now my SC50 beging to push hard after 5000rpm but begin to build boost between 4000-4500rpm... I would like to get better than this....

Maveric

Just go down to a .48 a/r on your current turbo...you will gain about 500-800 rpm's in spool time

JDogg

anything smaller on the gt28rs turbine will choke up really bad on the top.. i cant say for the sc50, but overall spool time isnt the point of the 28rs .. its the throttle responce

yellowturbo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Maveric &raquo;</TD></TR><TR><TD CLASS="quote">Just go down to a .48 a/r on your current turbo...you will gain about 500-800 rpm's in spool time</TD></TR></TABLE>

yeah but the .48ar wont give me 300whp at 15psi. I also want a ball bearing turbo that will take more abuse than a regular thrust bearing.

This option was a good idea but not what I really want.

a1320addict

iTrader: (1)

i think the gt28rs and gt2871 are both prime canidates...check out some dyno plots on jeff's site, http://www.boosted-hybrid.com of the 28rs .82 ar "t3 drop in"...it does look like a great street turbo...i think the 2871 gives you room to grow a bit...but its really about what you want with the car.

i mean...for a road racing application...you pretty much just want instantaneous throttle response...which is exactly what the 28rs would give you. the 2871r i think would pull harder up top naturally.

if you need some real world advice...contact TheShodan....he has a lot of knowledge on the gt series from garrett.

good luck

JDogg

the 2871 wont pull harder up top.. they both have the same turbine, which is what limits those 2 turbos

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">the 2871 wont pull harder up top.. they both have the same turbine, which is what limits those 2 turbos</TD></TR></TABLE>

Here are two dyno plots from evans-tuning of a GT28RS and GT2871R on a GSR. I would say the extra 40 +/- WHP from 6.5K-8.2K RPM's would make it pull harder up top, hehehe. But the GT28RS has a torque curve which peaks earlier, so some people might like that better. I think there was a thread on here comparing the 28RS and 2871R, but I couldn't find it. Either Tony the Tiger or Tony1 posted it I cant remember.

GT28RS

GT2871R

JDogg

those 2 engines have so many different parts, there is no way you can compare the 2

the 2871 will have more in the mid range once the boost comes in, but up top they will make the same power, the limitation is the turbine

im not at all impressed with the 2871r... that dyno you posted was with a gsr motor... i have done b16's with the 3071r that spooled just as fast and made more power/tq at the same boost level. the 71mm compressor is too big for the 28rs turbine... imo 3071&gt;2871.. especially on a b-series

AndyFloyd

Ummm no. The 71mm compressor on the GT2871R flows a lot more air. Yes they share the same turbine wheel but that turbine wheel is NOT maxed out at 350whp ( about the most youll see from a GT28RS ). The RS wheel is only good for about 34lb/min and the 2871 compressor wheel can flow around 50lb/min ( Its the same compressor as the 3071R ). It has been proved with that dyno chart so if I was you I would change my mind.

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">those 2 engines have so many different parts, there is no way you can compare the 2</TD></TR></TABLE>

close enough, hehehe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">the 2871 will have more in the mid range once the boost comes in, but up top they will make the same power, the limitation is the turbine

im not at all impressed with the 2871r... that dyno you posted was with a gsr motor... i have done b16's with the 3071r that spooled just as fast and made more power/tq at the same boost level. the 71mm compressor is too big for the 28rs turbine... imo 3071&gt;2871.. especially on a b-series</TD></TR></TABLE>

Is the GT2871 sort of like the GT2540R where the small turbine is mated up to a really big compressor? I heard that the 2540R is better suited for people wanting to run really high boost or that want to run them in a TT setup. Is the 2871R the same way? the turbine being jus a little too small for the large compressor? I found the thread with the 28RS and 2871R and it was Tony the Tige that posted it. He also felt that the 71mm compressor was not a good match for the turbine.

https://honda-tech.com/zerothread?id=1276407

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AndyFloyd &raquo;</TD></TR><TR><TD CLASS="quote">Ummm no. The 71mm compressor on the GT2871R flows a lot more air. Yes they share the same turbine wheel but that turbine wheel is NOT maxed out at 350whp ( about the most youll see from a GT28RS ). The RS wheel is only good for about 34lb/min and the 2871 compressor wheel can flow around 50lb/min ( Its the same compressor as the 3071R ). It has been proved with that dyno chart so if I was you I would change my mind.</TD></TR></TABLE>

I think in a way he is right, in that link in my previous post and in a thread about the GT2540R people have said that matching a small turbine to a large compressor is not the ideal setup for a small 4 banger.

EDIT: also check out the link and see what blundar has to say about the 2871R.

AndyFloyd

Yeah I mean the turbine is going to be the limit eventually......however the GT28rs doesnt max out the ns111 turbine because the RS compressor can only pump 34 lb/min before its just tired and cant flow any more air. The 71mm compressor on the 2871 has the ability to flow 51 lb/min...now im not sure if the turbine can support that flow ( I personally dont think it would ) but the fact is that the turbine is not the limit for the gt28RS...its clearly the compressor that limits that particular turbo. Now on a 2540R yes the turbine is a huge limiting factor and I think that the 40 compressor is too large for the small turbine but people with sr20's still see mid 400's with that turbo because even though the turbine is overworked the compressor is so efficent and can pump so much air that somehow it reaches mid 400's. I think mid 400's is the maximum that the GT28 53mm NS111 turbine wheel will support and I wouldnt necessarily push it that high but it can make that power.

AndyFloyd

To answer the original posters question I think for his needs the GT28RS would be the better turbo. The GT2871R will spool about 500rpm slower and yes it will provide more topend power but at 15psi the D16 is not nearing the flow limit of the GT28RS yet so you wont see huge gains on the topend since the engine doesnt need as much flow as a B18 or B16 does.

JDogg

at high rpms the turbine does indede choke up.. i have tested this on several different setups. its just too small to support high rpms.

Drew Peacock

Speak to any of the nissan guys the 2871R is a MUCH better turbo, retarded comparing them imo. Flows considerably more then the RS <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">at high rpms the turbine does indede choke up.. i have tested this on several different setups. its just too small to support high rpms.</TD></TR></TABLE>

JDogg

the 2871r is good for nissan guys because they dont need to rev, thus they are not limited by the turbine.. same reason they all use gt2540's and the like

SOHCmaster

What about a t3/t4 50trim 48hot side ? Cheap and gets the job done from what I hear...

mochasi

yeah i got pretty much the same needs.. which one is best!!

yellowturbo

thanks for all your reply.

Well from what I can see from your experience I will probably choose the GT2871R... I dont want to fall with a too small turbo... The GT28RS may not push as hard on the top. My rev limiter is set at 8200rpm.

The only thing that im not really sure is the ar choice for the turbine, JDogg tell me that the .63ar that can be choose for the turbine would choke my engine compare to the .82...

Or I could go with the GT28RS .82ar ??

Damn....

yellowturbo

I dont know if this list could help you out to choose the good one....

D16Z6 Benson sleeved block ( no head gasket problems eheh )
CP pistons
Zex 59300 cam
PLX M300 WB
AEM EMS
MSD igniton SCI +coil
Crower springs + retainer
Cometic MLS HG
Eagle rods
PWR radiator with a slim fan.
B&M oil cooler mounted right behing the intercooler with the thermostat that came with the kit.
Edelbrock IM
SC50 .63AR
Ceramic coated Lovefab SST manifold
Wrapped 3 inch DP
JDM ZC DOHC 3,4 and 5th gear
etc...

village_idiot

gt2871r

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yellowturbo &raquo;</TD></TR><TR><TD CLASS="quote">
Well from what I can see from your experience I will probably choose the GT2871R... I dont want to fall with a too small turbo... The GT28RS may not push as hard on the top. My rev limiter is set at 8200rpm.</TD></TR></TABLE>

What about the GT3071R? JDogg said that the 3071R spools just as fast, but has more HP and TQ.