DYNO Predictions - GT25R - Martin @ XAT

[ka24det-power]

So I am having my car ROM tuned by Martin at XAT on the 10th. Just wanted to see what people think I will put down to the wheel. Lets see if anyone can hit it on the head, I will include as much detail as I can on my setup.

Motor and Relevant Upgrades:
Blacktop S13 SR20DET - 169 average compression at operating tempature
3" Turbo back Exhaust, no cat
GReddy Intake Manifold
Greddy IC Pipes
24x11x3 FMIC, bar and plate
Nismo Termostat
Brand New GT25R Turbo (small AR .62 .63 wich ever one it is)
600cc Injectors
Walbro Fuel Pump
UR Crank Pulley
Z32 MAF

Wheels:
18x9.5 in the rear 28lbs each

I will be running as much boost as I can safely. Like 12.1 AF Ratio :squintd: .

[ka24det-power]

I am hoping for 330rwhp. Well see, I might have to get the HKS 264 cams to make it past 320.

[TheSnail]

What psi???? Your turbo is the .64 ....

[Jeff240sx]

So I am having my car ROM tuned by Martin at XAT on the 10th. Just wanted to see what people think I will put down to the wheel. Lets see if anyone can hit it on the head, I will include as much detail as I can on my setup.

Motor and Relevant Upgrades:
Blacktop S13 SR20DET - 169 average compression at operating tempature
3" Turbo back Exhaust, no cat
GReddy Intake Manifold
Greddy IC Pipes
24x11x3 FMIC, bar and fin
Nismo Termostat
Brand New GT25R Turbo (small AR .62 .63 wich ever one it is)
600cc Injectors
Walbro Fuel Pump
UR Crank Pulley

Wheels:
18x9.5 in the rear 28lbs each

I will be running as much boost as I can safely. Like 12.1 AF Ratio :squintd: .

Where are you from? Give me the time and I can drive to XAT and meet with you for the dyno.
Next up - you'll be stressing that turbo at 330hp. And you're mixing up intercooler terminology. But at 3", I'd guess it's the bar and plate, not tube and fin.
-Jeff

[TheSnail]

But Jeff, Bar and fin is the new hybrid lol. And with a .62 exh gt25r he is sure to never dyno it. Or maybe he will, I just never knew it existed.

[Jeff240sx]

But Jeff, Bar and fin is the new hybrid lol. And with a .62 exh gt25r he is sure to never dyno it. Or maybe he will, I just never knew it existed.

Those turbos are too small for me to have ever cared about. I don't know of it's (in?)existance.
-Jeff

[ka24det-power]

Ok,.. nit pickers... I looked it up this time it is a .64 AR. :D

I live in Cape Coral (its near Naples/Ft. Myers).

I was also thinking about the GT2871R. I still have the option of going with the .86 AR or 2871 due to the fact that I am having them put the turbo on that morning. I will be getting there at about 10am Friday the 10th.

My boy Pete has a Garret GT32 that is putting down 396 @ 19.5PSI. It pulls like a champ but the spool time sucks ass.

I want something that pulls right off the line, its a daily driver. Martin said that the small AR GT25R will max out at about 350hp with HKS cams and 750cc injectors.

[ka24det-power]

I am not sure what PSI, I am going to have them push it until fuel runs out or the turbo runs out of breath. I am guessing 14-16 PSI.

[TheSnail]

With a .86, my friend put down 323 at 17psi. The .64 would be at 19-20psi. Go with the .86 and an engine management if you want to do some damage.

[ka24det-power]

What RPM was he at MAX boost? I talked to a guy the other day who was running an internaly gated GT25R .86 and he wouldnt see 18 PSI until just under 5k rpm.

[TheSnail]

I would have to ask him, but most of my friends seem to be obsessed with a variant of the turbonetics 60-1 so I would check into that before you buy a turbo, search (SilviaDrftr) 440rwhp 60-1 stage 3 , I myself like the gt25r .86, But I will decide later, for now I will stick to a s15 t28 for the mean time.

[wootwoot]

gt2871r .86 on sees full boost 3800-4200 from what I have seen. The .64 sees it around 3200-3500

[Jeff240sx]

gt2871 is a good turbo. Comparing choices.. your s13 has t25. An s15 turbo would be a better, and far cheaper, option over the gt25r. That'd just be a waste of money.
-Jeff

[ka24det-power]

Humm,... according to my research this is what I have found, in order of power and spool:

Turbo - Max Power Output - Price
Stock T25 - 250hp - Free
S15 T28 - 300hp - $800
GT25R .64 - 350hp - $800
GT2871R .86 - 380hp - $1200
GT25R .86 - 450hp - $1000

None of this is set in stone this is just what I have read / been told.

Matt @ Enjuku posted last night 330 (on FA). If he is right then I would say the small gt25R would be a better bet as far as price of a NEW turbo.

Also here is a post from Scott A (Enthalpy) " explaination: the wheels are equal in efficiency...in fact the 48 trim 76.1mm T04S compressor wheel in the GT25R is actually a bit more efficient (1-2%). HOWEVER. for a 350whp applicaiton the 56trim 71mm GT35 compressor wheel is a better match for several reasons. the speed lines of the NS111 turbine wheel mathces the speed line of the 71mm compressor alot better than the that of the 76.1mm compressor. this results in less losses and better spool performance. however i dont think this turbo is really good for much over 360hp by lookign at the comrpessor map. it statrts to fall below 70% efficeincy after 35-37 lb/minute flow. so if you are looking for 315-350whp. this is your boy. if you are lookign for more....try the GT25R.

as for exhasut housings. i have seen 360whp go through the smaller turbine housing (.64A/R) on a GT25R. it will be a bit tougher on teh GT2871R because of teh compressor loosing efficeincy around this flow level but i think it is still possible wiht the proper setup. cams, intake manifold, and a nice exhasut manifold. "


I dont think anyone has ever gotten 360 out of the S15 T28. Don't take this as me being argumenative. I am just trying to compair all the facts from repuatable sources. As you know there is a ton of crap on boards people guessing and all that. I condsider you, Scott, Matt and Martin to be great sources of information.

[TheSnail]

You left out the gt25's wasted gated price .64-$1000-1150, .86 $1150

[mjjstang]

gt2871r .64 900$ should be decent. I just hope it doesnt feel too stock.

[chlatboy]

i say you will get 300hp. Just dont overdo it cuz you will get no HP once ur engine blows

[Jeff240sx]

Well hey, if Scott says it's good to xxxhp, it is. He's tuned more sr20dets than I've ever seen.
-Jeff