Worth Upgrading To 15g?

[jschaefer7406]

For what you want, the best combo would be your current 13T with a 6cm angled housing. Let's make sure you have a 7 cm angled first. Can you get the numbers stamped on the turbine (exhaust) housing? (not the turbo ID plate)

Yes, all TD04HL 6/7 interchange.

And yes, sounds like the ETS has something to do here...

Hello again,

With the turbo on the car, what is the easiest way to tell what turbine housing I have? I have no access to a lift @ the moment. With the heat shield removed, can it be viewed from above (maybe with a mirror)? Any sample photos of what I'm looking for?

Thanks,

Joe

[TryingBe]

Wastegate set to 3 psi.

I would add more pre-load to the wastegate, setting it at 3 psi may cause it open prematurely. Easy test.

If you want to use that 15G, swap the 13T turbine housing onto the 15G and bolt that 15G on and you're done.

Unless you bought the turbo from Japan or Europe, you have 7 cm angle housing. Only people that have a 6cm angle housing is when they bought the turbo aftermarket.

[flaco]

Hello again,

With the turbo on the car, what is the easiest way to tell what turbine housing I have? I have no access to a lift @ the moment. With the heat shield removed, can it be viewed from above (maybe with a mirror)? Any sample photos of what I'm looking for?

These numbers: (NOT the 780)

Ive never tried to get the numbers off an installed turbo, but I suppose a flashlight and a mirror will do the trick?

[jschaefer7406]

Hello again eveyone,

Okay, not to sound stupid or anything, as I know how a turbo works and all (not too familiar with the in-depth AR numbers, trim, etc). Do have a few more questions though. If people say that a 19T without a tune can provide too much low RPM boost and bend connecting rods, then how would a 15G have too much lag? If a huge 19T (well, huge for a TD04 ) can provide low RPM boost, why wouldn't a smaller 15G be able to provide more low RPM boost than the 13T on the car now? Make sense? I've been told that the 13T was chosen for the AWD cars due to the limited lag and early spool. But the "smaller the turbo, the earler the boost" theroy contradicts the above. Insight?

Thanks,

Joe

P.S. - I have had a few turbo cars over the years, all others were red blocks with the Garrett T3's. They boosted plenty early in the RPM range, even with their huge size...

[Big Will]

Joe, I could be wrong, but I think that putting that 15G on and just re-using your old angled exhaust housing will provide a bit more power on your car but will drive quite similarly. It should just shift where you feel the turbo kick in a bit higher in the rpm range. I think this is a fine intermediate step while you save up for a tune to take advantage of the bigger turbo. It's not such a dramatic difference like a 19T would be so I don't believe there's any danger to rods etc. If the boost comes on too strong just back off the wastegate a little bit.

For reference, I have my wastegate set at ~4 PSI. Just slightly above the factory spec.

[flaco]

Okay, not to sound stupid or anything, as I know how a turbo works and all (not too familiar with the in-depth AR numbers, trim, etc). Do have a few more questions though. If people say that a 19T without a tune can provide too much low RPM boost and bend connecting rods, then how would a 15G have too much lag? If a huge 19T (well, huge for a TD04 ) can provide low RPM boost, why wouldn't a smaller 15G be able to provide more low RPM boost than the 13T on the car now? Make sense? I've been told that the 13T was chosen for the AWD cars due to the limited lag and early spool. But the "smaller the turbo, the earler the boost" theroy contradicts the above. Insight?

P.S. - I have had a few turbo cars over the years, all others were red blocks with the Garrett T3's. They boosted plenty early in the RPM range, even with their huge size...

Almost everyone in here talks about the compressor side of the turbo, ie 13/15/16/18/19T. Funny thing is, all these turbos use the SAME turbine (exhaust) wheel, ie a TD04HL (for 5 cyl blocks).

Thermodynamics 101 tells you that the amount of work extracted from the exhaust gases by the turbine (and nothing else!) is what drives the compressor wheel.

In order for ANY turbine (power plants, jet engines, etc) to extract useful power from the stream, the inlet of the turbine must be choked. Choking is good, in the sense that without it you will not be able to extract a useful amount of power from the stream. Since all TD04HL turbos use the same turbine wheel, there is little to be done about the wheel itself. However, you have different turbine housings (conical, straight, angled, 6 and 7 cm) that will dictate how and where in the powerband the flow will choke (hence, how much power you extract, and when).

AFAIK most 19T's came from japan, and they had a 6cm housing installed. What does this tells you? A 6cm housing will choke any flow earlier than a 7. Hence most 19T's produced boost at low rpms, and choked the engine at high rpms. You get more power from higher boost, even tho the engine exhaust is 'more choked' than before.

The T3 garrets in the B230FT had a small turbine/housing, hence early boost.

That took a while to type! (I wonder if this post is worth a free VS membership lol)....

The tighten-your-wastegate suggestion is pretty good as well!

[Dave 54]

7cm housing, = lag?

This is where the full 3" exhaust comes in to play, free flow=less lag.

[jschaefer7406]

Hello again,

Just checked he numbers on my turbine housing and this is what I came up with. Not sure if the angled housing numbers are a different arrangement, but I found nothing in the sequence of "115-89...". I have:

6-189-13302

Does the 6 indicate a 6cm housing? Any other way to tell (besides measuring it, which is out of the question at this point)? Is this the right set of numbers (only set I saw on the hot side)?

Thanks,

Joe

[flaco]

Yep, sounds like a 6cm angled to me.

Try adjusting your WG (tighter), and make sure you dont have any leaks on the BOV or hoses. If not, Id say your ETM is playing a big factor here.

You can always try diff combinations, but to me you already have the 'least lag' turbo.

[jschaefer7406]

Flaco,

Thanks for the reply. I know the actual spool time on the 15G is quick, as I love it in the wife's car. Will the 15G come on harder is the question (especially with this 6cm angled turbine). As you said, it must be partially the ETS system only using using as much throttle as needed, thus limiting the turbo. Unless the bearings are tired in the 13T. Seemed to spin freely last I had the fresh air hose off. Should a good turbo continue to spin once released, or only while you're turning the shaft? I assume the latter (unless it's a ball bearing unit, as I know the TD04 is not). As I said, once the pedal is pressed, the boost is instant. I just want it with less pedal (which may only be a fantasy with ETS, not sure). Anyway, other than a kit, the 15G is practically free, so I might as well do it. I can only see it being better. Is the concensus to rsplit the compressor housing and cartridge while the turbine and manifold are still in the car, or remove the whole lump? I normally remove it all, but some lately have said it's super easy to leave the hot side installed. Thoughts?

Thanks,

Joe

[steve s]

that's weird.. maybe it's ur awd that's making things feel porky and sluggish. last comparison i had with a s70 glt fwd, the 13g turbo felt like it came on a lot stronger and faster, i'd say ~1000 to ~3000 rpm and then loses steam. where as the 15g took forever (relative to the 13g) and came on after ~2500 and goes up farther to maybe 5000ish?

[jschaefer7406]

that's weird.. maybe it's ur awd that's making things feel porky and sluggish. last comparison i had with a s70 glt fwd, the 13g turbo felt like it came on a lot stronger and faster, i'd say ~1000 to ~3000 rpm and then loses steam. where as the 15g took forever (relative to the 13g) and came on after ~2500 and goes up farther to maybe 5000ish?

Steve,

This is going to sound strange, but the car does not feel sluggish by any means. It's just that if I snap the throttle in town, it still doesn't use the turbo. If I floor it, it's right there instantly at 5-6 psi. Again, this may sound weird, but if I don't look at the gauge and just drive, the car feels quick. I'd just like to see more turbo boost without the heavy throttle (like I'm used to with the others I've had). As for actual lag, the 13T boosts instantly when you step on it hard, so no complaints about spool time. I'm just looking for something to boost easier (without having to step on it as hard). Make any sense?

Thanks,

Joe

P.S. - As I said earlier, it may just be the electronic throttle limiting how far the throttle is opened (only giving enough to satisfy the request). I'm leaning toward that scenario, but figure the 15G with my smaller angled turbine housing can't hurt (as it's practically free)...

[jschaefer7406]

AFAIK most 19T's came from japan, and they had a 6cm housing installed. What does this tells you? A 6cm housing will choke any flow earlier than a 7. Hence most 19T's produced boost at low rpms, and choked the engine at high rpms. You get more power from higher boost, even tho the engine exhaust is 'more choked' than before.

Flaco,

Does this mean that a larger turbo can provide strong boost at lower RPM's with the right turbine (ie, the one I believe to have)? If so, wouldn't the upgrade to a 15G with the 6cm angled housing provide more lower RPM boost than the 13T? If it were all about the 6cm housing, then the 13T would be bending rods. In short, shouldn't the 15G be more powerful at lower RPM's than the 13T (since the 19T can prove lethal)? I don't mean to talk this thing to death, just trying to understand why the huge 19T will produce enough boost @ low RPM to do damage but some are saying that the smaller 15G will only be useful for shifting the power band upward. Thoughts?

Thanks again,

Joe

[dongle]

From what I've gathered the 19t is credited with being better at demolishing rods over the stock turbo b/c people seem to be more concerned with spending their money on a big turbo rather than getting a decent tune.

Could just be coincidence though.

[jschaefer7406]

From what I've gathered the 19t is credited with being better at demolishing rods over the stock turbo b/c people seem to be more concerned with spending their money on a big turbo rather than getting a decent tune.

Could just be coincidence though.

Hello,

Not sure if that was aimed at me, but whatever . I cannot afford a tune at this point, nor am I sure I want one. I am not after 20 psi boost, just a little stronger boost progression. In any case, my point was that some are saying that the 15G will make no difference without a tune. But if a 19T can make enough bottom end difference to bend connecting rods, why can't a 15G provide something a little more? A 15G is quite a CFM jump from a 13T, no?

Thanks,

Joe