Turbos

I've never really dealt with aftermarket turbos but now I own one. Here's what I know:

1. My engine is a 2.0L DOHC Hyundai beta with forged 8.8:1 pistons. It might have cams. It might have crazy porting and ARP bolts, but I don't know. Factory redline is 6500 rpm, though I have no idea where the fuel cut is.

2. The turbo is a Garrett GT28. The hot side housing says ar .82. If that's the aspect ratio, that seems huge to me.

3. The waste gate opens at 1 bar.

4. The car doesn't achieve full boost until 5,000 rpm, even at high load.

Is this a workable setup? Am I really likely to have an aspect ratio of .82? I actually don't mind having a relatively NA car for putzing around, but full boost at 5k is the laggiest setup I've ever experienced, for certain.

That turbo might be a little too big for that engine. How open is your exhaust? The turbo itself is the only muffler your car needs. Strip off anything that might add back-pressure and throw it in the dumpster!

And since air can't get out of the engine unless it first gets in, be sure to get rid of restrictions on the intake side also.

How is fuel and spark handled? If it's a primitive setup you may be tuned to prevent engine death on boost but hurting your off boost performance (and delaying achieving said boost).

It's a full 3.5 inch stainless setup with a racing cat and a (nice) fart can. The intake is a big pod filter sitting on top of the factory CAI.

The cat might be fubared, but if it is, the top end sure isn't suffering!

In reply to MrJoshua: I have no idea, but I do know a guy with a dyno. I take that back, I know it's a hacked stock ECM.

That could mean a well adjusted setup with adequate control over fueling and spark or it could just mean they tricked a few sensors to think the engine is cold so it will run rich.

This Garret naming link may help decipher the specs of the turbo you have.

If its free turbo its probably a good match. Sounds like the gtir turbos thats a great budget upgrade for sr motors, a friend had one on a ca18 and it ran VERY well. We both thought the exhaust was a bit big,same .86, but once it was on we were shown its just right. Hit around 3500 pulled very strong to redline. I know apples to oranges but it was a smaller motor that still worked very well with the pressumed same turbo ,t28 with .86 ar exhaust. So id recon a guess a bigger motor would be even better

That is NOT a large turbine for the engine, but it is a large turbine HOUSING.

1500rpm of peak boost isn't fun. For the cost of a gt28 on the used market you could likely get a manifold and an Evo 16g, then swap in a billet wheel and have a nice fat power band (you'd need engine management and tuning to play nice with the changes made, and if decided that you wanted more top end a 20g billet wheel would be a simple rebuild away).

The cheapest way to get a properly sized turbine housing may be to buy a whole ebay turbo with the same turbine wheel and then sell the turbo again with your old housing on it on CL for $70.

OR sell the big housing to someone on the forums trying to max out their GT28.

I would be looking for issues in the rest of the system. That turbo/housing is a pretty good size for that motor. What kind of power is the car making? What is the fuel setup and intercooler, wastegate, setups look like? If you cheaped out, it might be hurting you now.

With the sr20s also 2.0 but with 7500 redline and a .62a/r ( at least some of them) maxxed out those t28 would clear 300whp and spool up much quicker

Figure out your power goals and match everything else up. 3.5 inch exhaust is dead weight but won't hurt power. On the intercooler tubing end extra lots of tube and big diameters will bump spool up times 1000s of rpm higher.

In reply to Vigo:

Keep in mind its a little turbo with a almost large exhaust housing. Nissan put this turbo (I believe its this one, otherwise a similar t28 with ar .86 exh) on a 2.0 liter as factory...pulsar gtir, sr20 powered

But if it were me and i didnt already have a turbo id get an evo 8 or 9 turbo and make a manifold for it, its funky looking but man is it an awesome turbo, spools quick and flows a ton

I actually don't know a lot of the answers. I bought the car with this stuff already installed. Literally all I've done is fix the front brakes.

I'll go over the system in more detail when finals are over.

Keep in mind its a little turbo with a almost large exhaust housing. Nissan put this turbo (I believe its this one, otherwise a similar t28 with ar .86 exh) on a 2.0 liter as factory...pulsar gtir, sr20 powered

Exactly, which means if you put a factory size turbine housing on it it will spool like a factory sized turbo.

Vigo,

How can I find the housing size?

Well you need to know what inlet flange and outlet flange you have to get something else that will be bolt on.

I THINK there is only one 'gt28' turbine wheel size so you won't have to worry about it being machined for stage 1/2/3 etc. I think.

disco potato

(I have no idea if that link is at all helpful, I am just amused by the name and this is the first time for a while that link has come up in my searches. )

MrJoshua wrote: disco potato (I have no idea if that link is at all helpful, I am just amused by the name and this is the first time for a while that link has come up in my searches. )

I knew the GT28R was called the Disco Potato but I never knew why.

A lot of those names/businesses are VERY familiar to this reader of Sport Compact Car in its heyday.

In reply to Vigo:

I guess im not getting you but the .8x was factory for that 2.0l i mentioned but you said earlier its way too large and needs something smaller. Excuse my simple mind.

Op: housing is more than likely a t2, measure bolt hole spacing and cross check google. Then take a visual of the turbine outlet to see what style it is to fit. Personally i wouldnt bother trying to find another turbo and would search to see whats causing that turbo to spool so late because as i mentioned, that basic turbo on a 200cc smaller motor was making positive pressure at 3,000rpms. Id check physical timing and then ignition timing and do you have a wideband on it? Knowing fuel ratios would be helpful too. You mentioned the cat might be clogged, check that too cause that would cause it to not build boost properly

3.5" exhaust is too big. Slow flow.

iceracer wrote: 3.5" exhaust is too big. Slow flow.

That doesn't generally matter for a turbo setup. Pre-turbo, flow velocity matters. Post-turbo, low backpressure will make more of a difference than anything.

Ayup, turbo is the only time when you can't go too big on an exhaust system, performance-wise.

chiodos wrote: In reply to Vigo: Keep in mind its a little turbo with a almost large exhaust housing. Nissan put this turbo (I believe its this one, otherwise a similar t28 with ar .86 exh) on a 2.0 liter as factory...pulsar gtir, sr20 powered But if it were me and i didnt already have a turbo id get an evo 8 or 9 turbo and make a manifold for it, its funky looking but man is it an awesome turbo, spools quick and flows a ton

It might be a s15 turbo, I think they had the larger housing and wheel. The gtir s had the smaller housings but I could be wrong

Let's see some photos that might help too

I'd honestly want a .63 hot side housing for that.....