Hello FI masters. I was wondering if any one can tell me the real difference between these two turbos. Although I'm familiar with turbo concepts, I really don't have personal experience as I'm more of a all motor guy. Right now I want to have a fast response turbo for road racing application (just want to test the power/speed of turbo Honda's). Gas used can be 91 oct. or 100 oct, or even higher oct. Looking for 300 whp reliably. If that's is not enough, just going to up the boost later.

I've been studying fast turbo road race and/or time attack cars a little bit lately... But there hasn't been there much data for turbo Honda's on circuits. If any of you have personal experience, please share. Thank you.

 

The GT28RS will do. Just get the .82. If you get the GT2871R, then get the .63 exhaust housing.

 

yeah, the normal gt28rs will make 300hp no problem, just make sure to get the 86ar t3 turbine housing.

 

how about real world or dyno results showing the spool characteristics of these two turbo?!

 

I was just looking at the GT info last night. Garrett rates the gt28rs (gt2860rs) at 320whp, which people have acheived with a d16, amoung other motors. The GT2871R comes in 3 diff trims (I don't know which is more common), but all are rated at 400hp.

The gt2876r is rated at 350hp, so you might want to look into that. Its a smaller trim than the 71r, acheived with a smaller inducer but larger exducer. A larger inducer usually leads to higher flow, but the larger exducer leads to quicker spool & higher pressure ratios. The garrett 'superXX' comp wheels basicly are that trim wheel with a larger exducer. So the 76r may be what you want, 300whp fairly easy, more availible, but still responsive.

http://www.turbobygarrett.com/...t.htm

 

Just stick with the standard GT28RS, it will make plenty of power and will spool quite nicely.

 

WHat engine? Personally I have a gt2871r .64 this is the most common kind and love it.

 

jdm b16a stock 10.4 cr. i was thinking to keep the stock cr (to get good throttle response), and run low boost. we will be using neptune rtp for tuning. with some conservative timing, this should be fairly reliable. what do you guys think? this is to demonstrate the reliability (on 91. oct. pump) of properly setup and tuned turbo honda for road courses use.

if needed, 100 oct. or race gas can be used.

 

If all you want is 300whp you could even step down to a GT28R .64ar T25 it will squeeze out that much if you don't mind pushing it to the limit.

If you want a little more breathing room in it for more get a GT28RS .64ar T25.

Anything bigger (GT2871R, GT2876R) or larger turbine housings including .86ar T25, .63ar T3 (this is equal to .86ar T25), and especially .82AR T3 (this is equal to much bigger than .86ar T25, maybe equivelent to a 1.06ar T25?) are overkill for 300whp.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tsukuba07 &raquo;</TD></TR><TR><TD CLASS="quote">how about real world or dyno results showing the spool characteristics of these two turbo?!</TD></TR></TABLE>

Here is a dyno chart from the full-race website.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by full-race website &raquo;</TD></TR><TR><TD CLASS="quote">The following dyno plot illustrates the difference between a GT28RS (with a T3 housing) and a GT3037, both at 11psi. The GT28RS is represented with the solid lines while the GT3037 is represented by the dotted lines. Dyno testing performed by Evans Tuning on a honda 1.8L vtec motor with a full-race turbo kit.
</TD></TR></TABLE>

 

I have a few dynos here.

I just got the gt28rs AGAIN as my 2nd turbo. I LOVE IT SO MUCH i got it again. 1st time i had the t25 flanged gt28rs .86 housing on my d16z6 full boost at 3800. NOW gt28rs witht the t3 housing .82 on b18c. here a few dynos i have saved for my build. to compare. Thanks to Evans tuning for the dyno.

http://forums.evans-tuning.com...t28rs
http://forums.evans-tuning.com...t28rs
http://forums.evans-tuning.com...t28rs

Hope this helps.

Kevron

 

.82 T3 is a little on the big side, may want to try out the .63..

 

GT28RS is the turbo you're looking for I assume you'd want to run an external wastegate setup for easier boost control, so the T3 0.63 housing would be the way to go as Geoff stated earlier.

 

what's the max whp ppl have seen using GT28RS on c16 on high boost?!

Tony: can you post some graphs of your GT2871? you need to update your web site. last time i checked it was kind of jacked up. :-)

 

what's the max whp ppl have seen using GT28RS on c16 on high boost?!

you will not be able to max out 93 on an RS much less C16..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18CXr &raquo;</TD></TR><TR><TD CLASS="quote">what's the max whp ppl have seen using GT28RS on c16 on high boost?!

you will not be able to max out 93 on an RS much less C16..</TD></TR></TABLE>

Could you elaborate on why that is so? Because you won't need to run very high boost levels to max out the 28RS?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18CXr &raquo;</TD></TR><TR><TD CLASS="quote">what's the max whp ppl have seen using GT28RS on c16 on high boost?!

you will not be able to max out 93 on an RS much less C16..</TD></TR></TABLE>

what chu talking about yack? that doesn't make sense.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tsukuba07 &raquo;</TD></TR><TR><TD CLASS="quote">

what chu talking about yack? that doesn't make sense.</TD></TR></TABLE>

It means the GT28RS would not be able to push the airflow needed in order to max out the engine (at detonation limit) on pump gas even on a stock block Honda.

GT28RS is rated for 33 lbs/min, roughly 300-340 WHP on our Honda motors. You don't put C16 on a 340 WHP motor because premium gas could already do the job. On the GT28RS, "high boost" is around 20 psi, and most of the time, the turbo is already juiced out... That means no more air, doesn't make any more power, won't hold any more boost, zip, dried out, no meat left, done deal. What's the point of C16?


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tsukuba07 &raquo;</TD></TR><TR><TD CLASS="quote">what's the max whp ppl have seen using GT28RS on c16 on high boost?!

Tony: can you post some graphs of your GT2871? you need to update your web site. last time i checked it was kind of jacked up. :-)</TD></TR></TABLE>

Yeah, I didn't have time to organize my crap... give me some time, because I am supposed to get my own dyno soon so I can whip up all those cool comparisons. Maybe I can finally do a real comparison between ITR IM vs Bike ITB's vs Jenvey ITB's vs FullRace IM, etc...

 

i saw these graph's from SGT's b18c.com site:





if anyone else has b16a turbo dyno please share, anyone with GT2871 b16a dyno? i'm pretty much set on GT28RS...

 

My setup is w/ the Greddy TD05-18G. I have 9.9:1 CR in my B16A. Check my sig for power @ 12 psi.
You'll be fine at 10psi (stock MAP) with a GT setup. Just keep it conservative and you'll be good on 93 octane.

 

i have made 380hp with a gt28rs, sleeved 84mm b16 with an rlz head, stock cams, 22psi on 93 octane

 

The main problem I've had with a big HP turbo Honda on a road course is non-linear torque delivery. Take a low-CR B16 running 20+ PSI from a fast-spooling GT28RS:




You pick up 100 lb/ft of torque in less than 500 RPM, which on a road course translates to a trip through the weeds if you push it too hard in the corners. What I see a lot of guys with this setup doing is the same thing I used to do, go deep and slow into corners so I can take a straight line out, as opposed to a faster momentum line that would have me tracking out while accelerating, and potentially losing control. So I'd lose time in the corners, but make it up between them, not the best situation, and not the best line through a course.


Now take a 2L high-CR motor running less boost from a bigger turbo (think it was a GT3071R):



Notice the even torque delivery, less power, slower at a drag strip, but faster on a road course.

If I did it again, then I'd go with a bigger turbo and lower boost, or at least a 2-stage boost controller that would let me only make high boost in the straights.

 

found another one



Car: Del Sol

Engine: Bone Stock b16a, gsr cams, BDL cam gears

Mods: Inline pro manifold, t3/t4oe 57 trim .63a/r, tial 38mm wg, 3" dp, 3" exhaust, no cat, long dumptube, custom 2.5" charge piping, pwr 20x8x3 ic, RC 550cc injectors, walboro 255lph pump, stock ignition, avcr boost controller, neptune

Tuning at 9.5psi on 93octane:

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KevronsEG &raquo;</TD></TR><TR><TD CLASS="quote">I have a few dynos here.

I just got the gt28rs AGAIN as my 2nd turbo. I LOVE IT SO MUCH i got it again. 1st time i had the t25 flanged gt28rs .86 housing on my d16z6 full boost at 3800. NOW gt28rs witht the t3 housing .82 on b18c. here a few dynos i have saved for my build. to compare. Thanks to Evans tuning for the dyno.

http://forums.evans-tuning.com...t28rs
http://forums.evans-tuning.com...t28rs
http://forums.evans-tuning.com...t28rs

Hope this helps.

Kevron </TD></TR></TABLE>

thank you so much for sharing!

 

that's interesting... so at lower boost gt28rs produces smooth torque curve but with high boost it has crazy torque gains in small rpm range? how about boost response when down shifting?!