S15 Turbo upgrade GT28R GT2860R

[Clawhammer]

Ian and I talked about this the other night but I thought I'd start a technical discussion and get this tagged for searchers as well. Maybe even get some numbers out of this.

My T25 is on it's last leg, smoking lots at idle.

Ever since my SR swap my future plan was to get an S15 turbo, 550cc injectors, a z32 maf, and an over the counter tune of some sort. I actually just found out the guy I bought my z32 ebrake cables from (local) works for RS Enthalpy.

Well there is a guy selling a very low mileage 28R with no shaft play at all for $425.

I'm very poor right now. What boost can I safely run the 28R at before things start to get too lean or my maf can't compensate? Just until I have the money to follow through.

Also, I didn't want to jack the other guy's thread but I plan on getting the Greddy suction kit for this.

http://www.240sxmotoring.com/grairinsukit.html



Multiple reasons. My current setup sucks. Filter sucks. No where to hook up my PCV or recirc my BOV which are two things I really want to fix. So this seems like the perfect thing for me. Only problem is I'm not gonna be running a z maf yet so how big of a deal could it be to hook up my sr maf? I'm sure it's no biggie and probably sounds like a stupid question. I'm not retarded, obviously if I had all the stuff in front of me it'd be a no brainer; I'm just trying to get a feel for things.

[supreamS14]

With out bigger maf/injectors and a tune I wouldn't run more than 10psi. 7 would be safer. I ran 14 it spiked to 16 and melted a piston. I have heard of people running 16psi on a gt28r for 2 years and not have any problem. But not every one has the same luck(mee). Get tuned before cranking the boost. Also, I hit 18psi a couple times and it sounds amazing!

[Kalypso]

^ thats sounds right to me,

keep it really low, the gt28 has a bigger compressor housing and it pushes more air.

12psi on a gt28R

is more than

12psi on a t25

[Clawhammer]

I was thinking 7-10 actually. What is the stock actuator set to?

[inkslingers13]

i think its at 8psi, id turn it down to 6-7psi just to run on the safe side till you can get 500s and a n62 maf. just my take on it.

[Clawhammer]

He's dropping the 28R off tomorrow. I was hoping it was at 7 or 8 psi so I could just bolt it on and not have to worry.

[wzntha]

.

[S14toRPS13]

My nephew's been running 14 psi daily and even as high as 16 psi with a S15 turbo on his stock redtop for about 5 years now. Maybe he's just been lucky.

[inkslingers13]

My nephew's been running 14 psi daily and even as high as 16 psi with a S15 turbo on his stock redtop for about 5 years now. Maybe he's just been lucky.

dam...

[Kalypso]

[Neil]

i think its at 8psi, id turn it down to 6-7psi just to run on the safe side till you can get 500s and a n62 maf. just my take on it.

I'm not certain what the spring rate is in the S15 Spec-R turbo's actuator, but the one that it comes with isn't adjustable, so unless you get a different actuator or get clever then you can't gimp open the wastegate to make it run less boost. It's probably 12psi if the Spec-R is supposed to have 260 brake hp from the factory. Whatever it is, it's not going to be more than that. While it's a little close to being in the 'red' on the safety meter, it won't toast anything if you don't flog it all over town.

My 2871 came with an adjustable actuator and because it flows more cfm than a T25 did I was scared to run it at any more than 10lbs with the stock injectors. I never had a wideband to see if it was actually okay, but i never had a problem, and it was as fast as my t25 was at 14psi. Now i've got 555cc injectors and run the 2871 at 14psi. on my old ****ty tune i was making 280hp to the wheels as 12psi, so I'm sure im over 300 at this point.

P.S. that greddy kit is badass. It's a little pricy and I don't really like the air filter but if you can swing it then it's definitely a great alternative to fabricating your own custom intake. which i had to do. about a month before i realized that greddy made such a kit.
Modified by Neil at 3:02 AM 8/30/2008

[Clawhammer]

[Neil]

Awww <3

[mistamacadamian]

i dont see a issue with saving and dishing out some more money to make sure you dont cause damage to your motor. if you go with the s15 spec r set up as you stated you'll be trapping 110. as i did before my friend blew my head up.

[Kalypso]

that greddy suction is expensive, that money is better spent on fuel injectors

[Clawhammer]

The issue isn't saving or dishing out money. I'm one that's all for doing things the right way. The issue is my T25 that is causing me to blow blue smoke every time I'm at a traffic light. I need a fix but I'm not gonna buy another T25 when my goal is to upgrade.

I'm not retarded, I'm not gonna kill the motor running crazy boost. That's why I'm looking for what's safe...until I finish saving the money for the rest of the setup.

[Kalypso]

the turbo can work, but that 300$ suction cup could be a waste of money.use the stock one!

my .02¢

[wzntha]

.

[newdude1]

Jw but what suction kit does everyone recommend using?

[Kalypso]

I want a mitsubishi 20g turbo they're underated and well built.

Jw but what suction kit does everyone recommend using?

the stock one with a K&N cone filter.

[Clawhammer]

Even if I were to find stock S15 intake I'd still have to worry about modifying the compressor inlet an outlets to fit my S13 stuff. The guy I got the turbo off of said that the stock S15 inlet pipe went too high and would hit the mani.

Speaking of which, all my searching says those are the only two things that need modifying otherwise this turbo is a direct bolt on affair.

To confirm with someone who has done this, do I just unplug my water and oil lines and plug them straight into the new turbo? Can it really be that simple?

Oh and I'm getting all 4 new turbo gaskets when I do this and I notice everywhere I look that there is a turbine outlet (5 bolt) gasket for S13 and then for S14/S15. Why is there a different gasket? This would lead me to believe that my S13 outlet wouldn't bolt right up.

[boro drift]

Circuit Sports makes everything you need to bolt that baby on. The oil and water lines are braided stainless with AN fittings, and inlet and outlet adapter plates that bolt the S13 inlet/outlet pipes on. I bought all this stuff from FRsport.com and I had my turbo installed in about 2.5-3 hours. Another thing they sent me was the S15 oil drain pipe and hose. The most important thing is you have to restrict the oil feed for the bb turbo and the Circuit Sports kit has a restriction fitting. Sorry to make you read so much!

[Emperor_Tha]

Jw but what suction kit does everyone recommend using?

Greddy super suction z32 for the s13 it comes with the turbo inlet and outlet piping

[Neil]

The S13 suction kit wouldn't work because it only replaces the rubber accordion. Since the T25 and GT28R compressor inlet flanges are clocked differently, he would still need to modify the inlet elbow from his T25. The S15 intake kit eliminates that need.

I've never heard of the oem S15 compressor inlet pipe hitting the exhaust manifold, stock or aftermarket. From what I understood the manifolds have been the same casting since the first SR20DET's in the early 90's. I can understand it not fitting when trying to install it on a T25 turbo, but that should be obvious to anyone trying for the same reasons a T25 inlet wont work on the GT28R.

There are those flange kits that essentially realign things to allow you to use the original T25 compressor inlet and outlet pipes on the GT28R. They're about $100. They're probably the cheapest way out, but they don't solve the recirculation problem.

I do like the Greddy kit, I just wish you could buy only the intake pipes, because foam filters are bogus and you can easily use the stock T25 compressor outlet pipe if you cut the first bend off of your hot pipe and connect the two with a 45° coupler.

My intake setup consists of this thing, one each of 45° and 90° 3" couplers, a section of an aftermarket intake pipe for a car I no longer own and a generic Z32 maf adapter with a K&N filter. After trying a couple different things and paying too much to get a recirculation fitting welded onto my piping, I ended up spending almost as much as the GReddy kit costs. GReddy released the kit a few weeks later and I would have liked to get it, but I don't mind because I like that I made my own intake and that it fits so well.

The Greddy kit looks like it would have better clearance around the A/C line, if that's a concern fo you.. the low pressure fitting is in very close proximity to my 3" piping, where the greddy kit reduces to 2" in that area.

If you have the cash, I say go for the Greddy kit. It just completely eliminates the chance of doing anything potentially half-assed. Since it's meant for Z32, The air filter it comes with won't work with your SR maf, and you'll need a reducer from 3" to whatever size your maf is. I bought all my couplers from http://www.siliconeintakes.com, they've got a large selection and are well priced. Technically not the best quality but I see no signs of deterioration after a year of being inches from the exhaust manifold.

As for the oil/coolant lines, you CAN use the T25 lines, the fittings are the same, but the center section of the turbo is clocked differently and the compressor housing is fatter so you'll need to bend them a bunch to fit and not be rubbing anything or preloaded.

One thing that I highly suggest you purchase is the oem S15 oil drain tube. you can bend the T25 one and use a longer piece of rubber hose, but speaking from experience you will probably warp the flange and make it leak a good amount of oil.
Modified by Neil at 12:28 PM 9/1/2008

[Clawhammer]

Damn, thanks for the response Neil.

I've decided to purchase the following for my install on this; I like to do things the right way the first time.

-A whole new gasket kit for the turbo (compressor inlet and outlet, turbo to manifold, and turbine outlet).-The Greddy intake kit-Circuit Sports SS braided lines w/ oil restrictor-Circuit Sports Oil Catch Tank

Now when you suggest the drain tube are you talking about the metal or the rubber part? If you're talking about the metal it came with my turbo (you can see it next to my mouth in the pic above). Otherwise you're talking about this:

http://www.frsport.com/Nissan-....html

And I just can't see paying 25 bucks for a couple inches of rubber hose...unless you guys have a real good reason why that's better than anything I could get from work (Lowe's).

[boro drift]

Sounds like a good plan to me. The Greddy kit is awsome! If you already have the metal part of the oil return, just use the rubber hose off your T25.

[wzntha]

.

[Neil]

If you already have the metal part of the oil return, just use the rubber hose off your T25.

what he said. i didnt notice it in the pic but yep that's it.

i think he's talking about the metal part. instead of bending it like he suggested, i just cut mine shorter because it was hitting something(can't remember, it was too long ago, lol). after cutting it shorter, i just went to kragens and bought a longer rubber hose for like a buck something.

Mine wasn't hitting the steering shaft, but when I tried a longer rubber hose It would kink and I wasn't comfortable with that. I never thought to try shortening the drain pipe to reduce the angle the hose had to make..

[supreamS14]

Don't get a hose that will kink! A kinked oil drain= Blown turbo seals! It happened to my first GT28R! I bought a oil drain for the GT28RS and used a thick high temp hose. Then I used wire tie and wrapped it around the hose so it wont kink!

[burntricer]

im running a 2860r and ive boosted to 15 no prob.