# Help me pick a turbo!



## Hispanic Panic (Sep 9, 2004)

From looking at dyno's of ka's on ka-t.org with a t3/t04e it seems that the t3/t4 turbo produces a better powerband (which is what i want). But they didn't have any dyno's for any gt series turbo. The thing i don't understand is the different trim's and a/r's avaliable for that one turbo. Also for some gt series i have picked for my car, i don't understand what Inlet size does and why it matters. So here's some turbo's i've picked out. Gimmie some feedback

t3/t04e with a/r and trim large enough to max out at 450hp

GT3071R Housing, .63 ar??? .82 ar???? 2.06 ar?????
http://www.atpturbo.com/Merchant2/m...tegory_Code=GRT


GT3071R-WG The compressor inlet is 2.75. WTF does that mean. What is different about this turbo and the other GT3071R besides the housing its put in.
http://www.atpturbo.com/Merchant2/m...tegory_Code=GRT

Gt2871R - The housing is .86 ar, isn't that bad for spool? Would spool up time be affected if i got the 56 compressor trim over the 48 trim? what is different between the two compressor trims.http://www.atpturbo.com/Merchant2/m...tegory_Code=GRT

GT3071R-WG This is the same as the other one but the ar and trim is smaller. Would this turbo spool earlier than the other one? Would it be able to max out around the same amount? 
http://www.atpturbo.com/Merchant2/m...tegory_Code=GRT

GT2540R Is this turbo a GT25R turbine with a gt40R compressor? Will this turbo see boost the earliest upon all other turbo's mentioned, and at the same time max out around the other larger gt turbo's? .64 ar? .86 ar?? What the hell does the inlet and outlet sizing mean.
http://www.atpturbo.com/Merchant2/m...tegory_Code=GRT



i want the EARLIEST spool possible on a turbo and compressor combination that maxes out anywhere between 400-450 hp. Can anyone tell me which of these would be the best to do that job And what sizing should i get on that specific turbo ( ar sizing and trim sizing). Also, if i use that turbo and i'm pushing 15 lbs, about when could i see full boost on my KA24DE, and when would i be able to start seeing boost with that turbo.

Sorry, i know its allot but i want the best. Oh, and my car is an s14 with a KA24DE.


----------



## chimmike (Oct 17, 2002)

the GT2540R is going to be laggy because of the HUGE compressor on small wheel.......its a 400hp turbo.

The GT series will always be better than the old school t3/t4s because of the much newer technology used.

the GT ball bearings will OWN a t3/t4 in terms of response and spool.

2871R won't get you 400-450hp. I'd say the GT3076R from atpturbo will do what you want.


----------



## Hispanic Panic (Sep 9, 2004)

well people say that the gt series isn't exactly bought for its early spool, as much as its bought for its efficient compressors. I've heard of people buying a gt series turbo (around the same size as a previous turbo) and spooling only 300 rpm's quicker. This being on a rwd sr20det. The website does say every single one of those turbo's maxes out from 400-450 hp tho. 

If i did get a gt2540R, when would i be able to see boost compared to a GT2871R?? Which would get me to full boost sooner? Compare the better of those two to a GT3071R-WG. How far behind will the gt3071R-wg be?

Also, would you be able to answer my previous question's about the trim's and a/r options on these different turbo's?


----------



## chimmike (Oct 17, 2002)

the 2540R just isn't as good an option. It isn't matched as well in terms of compressor vs turbine. I'd avoid it.

the GT series you're looking at will ALL spool faster than an equivalent T3/t4.

2871R definitely will NOT make any 400-450hp. 3071R is good, 3076R is best suite for that imo....If not a straight GT30R.


----------



## Hispanic Panic (Sep 9, 2004)

if i do get a gt3076R-WG, when do you think i'd be able to see 15 lbs of boost on a ka24de?

http://www.atpturbo.com/Merchant2/m...OD&Product_Code=GRT-TBO-033&Category_Code=GRT


----------



## chimmike (Oct 17, 2002)

It depends on the flow of that turbo. I'd hold it around 7psi and dyno it, see what numbers are made, then go from there. Don't base it off boost, base it off whp.

remember the KA24 can't handle insane power like the SR20 for long...the crank just doesn't like it.


----------



## Hispanic Panic (Sep 9, 2004)

chimmike said:


> It depends on the flow of that turbo. I'd hold it around 7psi and dyno it, see what numbers are made, then go from there. Don't base it off boost, base it off whp.
> 
> remember the KA24 can't handle insane power like the SR20 for long...the crank just doesn't like it.




I don't know if you know anything about ka24de's at all, but the crank definately won't go out first. In fact it won't go out at all. The rwd sr20det can only withstand 100 more reliable hp than a ka24de, both on stock internals.

I'm basing my turbo off boost because thats what it does. IT creates boost. And i want a turbo to create boost as early as possible. whp has nothing to do with boost. Thats why you see engines making 400 whp at 25 lbs of boost, and engines making 25 less hp on only 15 lbs of boost. An obvious conclusion would be that tuning means more to power than boost.

I want something with early boost because it will mean i can make more power earlier.

So all my questions remain unanswered and it seems there is only 1 person on this board who knows anything about what i'm talking about.


----------



## javierb14 (Jul 9, 2002)

fwiw, we have seen GT2871Rs with external wgs support 400whp on honda motors


----------



## TURBOKONGEN (Sep 13, 2004)

The GT2871R recently made 457hp(not whp) @1.7bar(25psi) on a Audi RS2 2.2tq in Finland. This was on regular street petrol .
I was amazed myself with this amount of hp .
I am not sure what turbine housing they were using , but I think it was the .86ar version .

I am currently building a ca18det with Pauter rods, JE pistons , Tomei 260/270 cams, ported 60mm throttle body, ported cylinder head(flowed on Superflow 110/120),Big FMIC, 550cc injectors, z32 maf , lightened flywheel,ss ex. manifold etc etc , and I am wondering about using either the GT2871R or the GT3071R . I am currently runing a GT28RS .86ar at 1.4-1.5 bar boost and do not really want very much more lag than now , but I probably will have to accept a bit more lag with the GT2871R .86aror the GT3071R .86ar .


----------



## MyFirstNissanIsApath (Feb 14, 2005)

javierb14 said:


> fwiw, we have seen GT2871Rs with external wgs support 400whp on honda motors


I ran 600+ hp on an internally gated PTE turbo on a DSM motor... 65lb a min.. 

The 3076R with a .64 AR turbine housing will spool pretty quick given it's size when a 2.4 is blowing thru that tighter turbine housing and high efficiency exhaust wheel. That is a 52lb min compressor. ~520 hp 

I have seen 3500 spool points on DSM 4G64's (2.4) with bigger turbos.. like 60-1's with larger turbine housing A/Rs.. 

Check these guys out... 








http://linux.forcedperformance.net/...CTGY&Store_Code=FP&Category_Code=Nissan-Turbo

Their 3076 is AKA a 3052 

If you want an internal gate or something different just ask them.. Send the specs and goals in an Email.. they will get you the right turbo..


----------



## javierb14 (Jul 9, 2002)

the 2871R is a great turbo for a _quick_ street car. we recently installed on a bone stock (head gaskets and studs) GSR motor (1.8L) in a civic hatch. we ran the 0.82 AR 5 bolt T3 turbine housing with an external gate. in any gear, 3500-4000rpm and above, 25% throttle would yield full boost (10-11psi). this turbo has great response


----------

