S13 KA24DE: S15 stock GT28R T2 Turbo vs Garrett T3/T4E

[supra33202]

1) S15 GT28R setup:

S15 stock GT28R T2 Turbo (http://www.thenismoshop.com/ikorb.php?f ... id=341)N60 MAFS15 SILVIA 480CC INJECTORSSSAutoChrome T25/T28Turbo Manifold (http://stores.ebay.com/SSAutoChrome-Sto ... 145912)HKS SSQV BOVEbay FMICEbay 3" exhaust systemNistune

2) Garrett T3/T4E setup:

Garrett T3/T4E, 50Trim Compressor, StageII Turbine (T3 5 bolt .48 A/R) (http://www.aptuning.net/ProductDetails. ... rtID=1)N60 MAFS15 SILVIA 480CC INJECTORSJGS KA24DE Turbo Kit Starter Package with wastegate (5-bolt down pipe) (http://www.jgstools.com/turbo/ka24et.ht ... 69878)Ebay FMICHKS SSQV BOVEbay 3" exhaust systemNistune

I want to have a 250-300 WHP S13 KA24DET drift car. Since I will not rebuild the engine, I think I will run 10psi boost.

Pros for GT28R setup:No need to get custom hot pipe; can use T25/T28 components.Less lag; higher torque in low RPMBall bearing - spool faster, last longer (how fast and how long?)

Cons for GT28R setup:Less HP in high RPM (choking for KA24DE?)Ball bearing - need water coolant lines

Pros for T3/T4E setup:Capable for high HP output (400+HP?)non-Ball bearing - no need for water coolant line

Cons for T3/T4E setup:Need to get custom hot pipeNeed to wield the dump pipe to downpipe if noise is the concernNeed to get external wastegate

Do you prefer the GT28R setup or T3/T4E setup? Feel free to discuss the pros and cons.

Thanks!

[silverkaturbo]

I've always thought the S15 GT28R seems like its a way overpriced unit when you could have a T3/T4 produce more power at a fraction of the cost even though it may take a half a second longer to spool. However, if someone was just looking for a simple bolt on upgrade for a current T2 flanged setup it might be worth the simplicity and ease of installation; hence my running a S14 GT28R instead of a t3/t4 after I mangled my t25(super sweet deal on price was also a large determining factor though). But any T2 bottom mount complete setup seems like its usually an easier "bolt together" affair so unless you are really really REALLY against any of the very minor custom work you listed for a t3/t4, the GT28R might be the better choice, but thats just me...

[bruinbear714]

T2 turbos are generally easier (and cheaper) to bottom mount than T3/T4 turbos.

Every top mount setup I've seen have issues with the brake master cylinder reservoir melting or the fluid boiling.

[biggie]

Top mount can be protected from BMC.

Bottom mount does remove the BMC problem completely, but only smaller turbos fit.

To me the top mount is easier to work on.

[lrb_2000]

Plus topmount looks way more badass. Bottom mount you can't even see the little turbo.. lol.

[sunnys14]

Bottom mount does remove the BMC problem completely, but only smaller turbos fit..

I ran a GT3076R bottom mount, that's pretty small?

[silverkaturbo]

I ran a GT3076R bottom mount, that's pretty small?

Yea dude, those can only dish out what 500hp? Pshh, im sure it cant be all THAT big.

[supra33202]

Let's say I want 280whp. How much psi do I need to run to achieve that if I used the T2 setup and how much psi for T3 setup?

Thanks!

[WDRacing]

I ran a GT3076R bottom mount, that's pretty small?

The exhaust housing is to small. Tell everyone how restrictive it is at 12 psi...

Yea dude, those can only dish out what 500hp? Pshh, im sure it cant be all THAT big.

You won't make 500 or even close with that turbo unless you run 2 external wastegates. The T2 flange IS to small for the KA. The opening just DOES NOT flow as much as is required for a 2.4 liter 4 banger.

It would be a great turbo for 280whp though, which is what the OP wants.

To much opinion and not enough fact in this thread.

Top mounts only have issues if you use a POS ebay mani. You only have break issues if you fail at heat wrapping etc. Bottom mount T2 flanged manifolds themselves have very small runners that merge into a T2 flanged collector. Those to things lead to a combo that becomes very restrictive at higher rpms and or any boost over 8 psi.

We've had members blowing out gaskets because there is so much back pressure INSIDE the manifold. That means you're also getting exhaust gas reversion. Reversion is when the exhaust flows back into the combustion chamber displacing incoming air/fuel with hot burnt gases. So you lose power because you're not losing air and fuel and you're combustion temps also rise drastically.

Those are facts guys. Yes people use the T2 flanged turbo's all the time. But they ARE restrictions compared to even the .48AR T3.

If you used a T2 flanged turbo on a better manifold with a bigger external wastegate you wouldn't have the restriction problem. But everyone uses the same ebay bottom mount because it's cheap. Cheap doesn't = good.

WD

[Chris28]

If you're still thinking about going with the bottom mount setup, look into a Pulsar GTi-R turbo. It's the same as an s15 t28 but it's journal bearing.

[DrifterProdigy85]

Top mounts are definitly easier to work on. Buy a heat blanket for the turbine housing. Never will have an issue with the master cylinder. I did a 67mm Top Mount setup with my SR20 and never had any issues for the 2 years i had it.

Have you ever had a water leak on a bottom mount setup? You gotta pull the entire manifold and all out. With a top mount you can get to the turbo lines while the turbo is just sitting there. Much much easier to maintain.

[hannibal]

Let's say I want 280whp. How much psi do I need to run to achieve that if I used the T2 setup and how much psi for T3 setup?Thanks!

Not really sure on the T28. The T3/T4 can make 280-300whp on 10-12psi.

[WDRacing]

With a set of cams and a T3/TO4E with one of the older JWT tunes the KA put down 350 at 10 psi. I don't have all the details, that was from one of our OG members about 4-5 years ago.

You simply can't beat the T3/TO4 for the bang/buck comparison.