For anyone wondering about max HP from GT25R

[PSI240SX]

Finally re-tuned my car after installing the Topspeed (Greddy copy) intake manifold. Here is the before and after graphs:
Before:
http://216.118.105.123/jay/361.jpg
And After:
http://216.118.105.123/jay/Silviaswap/dyno%20copy.jpg

Notice the addition of the intake manifold helps the power band pull all the way to redline. It was a noticeable difference. The torque curve is flat as can be too, and making 40 more lb/ft at redline then previously. The car felt really nice afterwards. This was done at 1.33 bar or 19.55psi on pump (93) octane.
That is the most power you will likely squeeze out of this turbo on pump gas with stock compression. Well, maybe a little more with a full standalone system.

Mods: GT25R .86 exhaust, SS (greddy copy) o2 housing, 3"dp, testpipe, N1, SS autochrome exhaust manifold, Tomei 740cc injectors, Walbro, Greddy VSPL, Topspeed intake manifold, Fidanza flywheel, HKS 264 Step 1 cams, and of course a Secret Services dyno tuned ECU.
Latest picture of car: http://216.118.105.123/jay/Silviaswap/Silvia.jpg

Although I just put on a VIS carbon fiber hood :)

[zero.counter]

wow! I love your car...

[lbcklik1486]

Damn, I remember when you first got the car and now already you have all this!

[andrave]

nice charts, thats probably about as much as you would want out of a street car! what is the size/offset of those wheels? looks good!

[lbcklik1486]

Just curious, what turbo did the Secret Services 180sx have in that vid where it pegs the speedo at 140. Man that car halled serious balls.

[HiPSI]

damn that thing has to scream :)

[PSI240SX]

18x8 and 18x9 +29 rear, not sure on the front offset. And I am not sure what turbo scott is running but its huge! And he was GPS verified to go 186mph 7800rpms in 5th!

[lbcklik1486]

18x8 and 18x9 +29 rear, not sure on the front offset. And I am not sure what turbo scott is running but its huge! And he was GPS verified to go 186mph 7800rpms in 5th!
:eek::eek: Dear god thats a nasty bitch. How much did it cost you for the turbo?

[PSI240SX]

$1030 for just the turbo.

[DuffMan]

So I read this thread, and yet I am still wondering about the max HP of a GT25R.

[PSI240SX]

check the dyno graph..... 387rwhp on pump gas with stock compression. Thought I made that painfully obvious.

[DRFT]

didnt you sell that car? or the seller fell through?

[DuffMan]

so you belive the turbo cant move any more than that?

[PSI240SX]

DRFT-Car didnt sell.

Duffman- with my current setup, No. There isn't much left to do that I have not done, maybe cam gears, or larger cams, valve springs, retainers, but most people considering buying one of these turbo's is looking for a relatively basic setup, due to the ease of installation i.e. using stock manifold and downpipe system. If I run race gas, and turn up the boost, I may squeeze 415 or so out of it, but that should be about it. The turbine is what holds this turbo back, and the fact that it uses an internal wastegate. Care to shed some light on this subject? Maybe you know something I don't? Speak your peace man, stop beating around the bush.

[PSI240SX]

By the way, I am very happy with the turbo, hell I am within 24rwhp of my old KA-T powered car which was running 30psi and running on 110 octane.

[Brolewigi]

Nice numbers, great looking car. Those numbers are very impressive, those mods are not that much to get almost 400whp. Keep going!

[Var]

By the way, I am very happy with the turbo, hell I am within 24rwhp of my old KA-T powered car which was running 30psi and running on 110 octane.


would you care to share what you had on the KA-T? im looking to go that route. What turbo were you running on that motor?

[HiPSI]

so you belive the turbo cant move any more than that?


on pump gas with a T25 turbine housing.... those are about as good as it gets.

and PSI240sx, how was the turnaround on the secret services ECU? they don't take 6 months like JWT does do they?

[GlacierFreeze]

On Tamparacing.com they were debating on JWT vs. SS ECU and came to the conclusion that SS is the best choice if you're local. You get an actual dyno tuned ecu and it can be done 24-48 hrs. I think they only do local though.

Look I'm nice, linky:
http://www.tamparacing.com/forums/showthread.php?threadid=131911&perpage=20&pagenumber=1

[dnbwithweed]

that chet is tight!nice ride!:bigok:

[nightwalker]

very nice. Wow, I'm shocked by the results versus what you said you had with the KA-T. 30psi, versus almost 20, and making close to the same rwhp? Care to share your mods on the old KA-T? Just like to compare the two, mods and money spent. I clicked your link, it doesn't work.

[DuffMan]

Well, maybe if you tried running more psi and gained hardly any power, I would say the turbo is maxed out. Maybe the turbo has more potential and maybe it doesn't I don't really know, but the title and what you posted don't really match up.

I'm just curious what that turbo can run. I have no idea myself.

[SR20DETpwr]

Love the numbers and the car. I've been looking at turbos that would suit my goal for 350-400whp, and this post has got me looking at the GT25 turbo. Do you think 550cc injectors would be good enough to still get that kind of power out of the turbo - just wandering because I think the 550's are rated for up to 500hp.

[PSI240SX]

westboroughpimp and nightwalker- I had a built KA-T with Arias 8.5:1 pistons and carillo rods, Custom short runner intake manifold, revhard exhaust manny, tial wastegate, custom piping and FMIC, 3"dp, N1, 72 lb per hour injectors with custom rail and a JWT ecu, T3/T04E 60 trim .70 a/r compressor, Stage 3 turbine with a .63 a/r Running 30psi it made 412rwhp and 412rwtq and ran [email protected] 118 and it broke on that pass, I coasted through the traps. I never had the car tuned... just plug and play with the ecu. Stock headgasket, stock headbolts, and stock cams

HiPSI- Yeah they are great but you really need to be local. That way he can customize and tune it on your car on the dyno.

Duffman- I cant run any more psi without using race gas, and since most people choosing this turbo will be using it for street use, I say my statement stands. This is a good example of what you can expect to make at the highest boost level on pump gas with this turbo. Back to my first point, someone looking for maximum horsepower levels for say drag racing or dyno queens would choose a different turbo setup all together. Wait til more people start installing this turbo on their cars, I guarantee you will only see a + or - of about 4% on pump gas, with all supporting mods.

SR20DETpwr-550's will be at 99% duty cycle and about 409rwhp. Seen it first hand. I would be safe and go with 740's.

[element240]

very impressive! :drool:

and i had a question about the fuel injectors..
if someone were go to w/ 770 injectors on a turbo'd sr20det, would it cause the car to run rich?

[fliprayzin240sx]

wow times like these makes me wish i got extra money to rebuild my block and go KA-T

[PSI240SX]

element240- not if the car is tuned properly for them.

[bri96se]

I have a question about the dyno graph. I see that the graph starts at 3500 rpm. Does this mean that the car doesn't make any hp until you hit 3500 rpm? And when driving around town does it take off like a rocket when you hit this point?

[kandyflip445]

I have a question about the dyno graph. I see that the graph starts at 3500 rpm. Does this mean that the car doesn't make any hp until you hit 3500 rpm? And when driving around town does it take off like a rocket when you hit this point?

:rofl::rofl::rofl:

[bri96se]

:Ownedd: Don't everybody laugh at once now.

[gsracer]

for those of you who care, the info about the greddy intake manifold is something i have been looking for a while. I took the time to plot the differencec in powerbands side by side between stock manfiold and greddy so you can have a subjective difference.

Psi 240sx how do you like the ssautochrome turbo manifold, i heard the are prone to cracking what are your thoughts???

[gsracer]

for those of you who care, the info about the greddy intake manifold is something i have been looking for a while. I took the time to plot the differencec in powerbands side by side between stock manfiold and greddy so you can have a subjective difference.

Psi 240sx how do you like the ssautochrome turbo manifold, i heard the are prone to cracking what are your thoughts???


here it is couldnt figure it out, :bash: the blue is the greddy the red is stock....

[Siizzzoooo]

VERY NICE! After seeing what that turbo can do, i definately want to do it this summer!

[PSI240SX]

I have been running the SS Autochrome manifold for like 4-5 months now at 360+hp and no cracks. I love it.

[Pudula]

This post really pumps me up...Im dropping my s14 sr in my '98 this coming weekend and running the same setup, but a gt2871r turbo, which is essentially the same but spools ~200rpm later and can run higher hp numbers. Everything is the same, not including the intake manifold, which will go in soon thereafter. Thanks for the Info!

Ryan

[Racer X]

This may seem like a stupid question but turbo is it. I know it says gt25r but who was it build by? all of the gt25r turbo i see say they will max out around 250hp. so thiss seems way off. Unless different companies call gt25r different turbos. this one of the gt series lists that ive seen. http://www.atpturbo.com/root/turboinfo/gtlineup/gtlineup.htm

[PSI240SX]

This may seem like a stupid question but turbo is it. I know it says gt25r but who was it build by? all of the gt25r turbo i see say they will max out around 250hp. so thiss seems way off. Unless different companies call gt25r different turbos. this one of the gt series lists that ive seen. http://www.atpturbo.com/root/turboinfo/gtlineup/gtlineup.htm

http://store.yahoo.com/cheapturbo/gargt86ar.html
that is the turbo that I have.