Hoffbro's Scheisse-rot Turbo

[varg]

For the turbo to be the problem with excessively lazy response, it would have to be visibly damaged, such as a ground down turbine or compressor wheel, in the wrong turbine or compressor housing, or not rotating freely. I've never seen an undamaged turbo actually cause boost response problems unless it's just oversized, there's not much else that can go wrong with them. Leaking seals won't make them spool slowly and a leaking seal could be a drain issue, I don't remember what yours looks like but some turbos are more sensitive to it than others as I saw with my wagon vs my E30 when using the same drain flange. I don't know what size your turbine is but my turbonetics is also a 60 trim T3/T04E* and I make full boost quite a bit earlier, I can't remember how much earlier in 4th gear/during a sweep of a few hundred rpm/sec. But I also have an internal wastegate and terrible boost creep. I think your wastegate is causing the problem. Not sealing well, missing its seat, lifting prematurely because of a spring issue, etc. or there's an exhaust leak before the turbo. I think the power is a little low for 12psi, but not massively. If the engine is unmodified and made around 155whp NA, 272whp (1.75x155) is reasonable for 1.82atm manifold pressure. I'd check the wastegate for flow while not in boost to see if it's leaking.

*T04E compressor 60 trim - inducer: 58mm, exducer: 76mm, F1-57 turbine 65 trim - exducer: 57mm, inducer: 64.9mm

[Hoffbrohaus]

Bought a new oil drain fitting. Per varg suggestion the turbo was probably having problems draining oil. You can see a difference in the picture, new one on left, old one on right. Won't get me any performance gains but should help longevity and get rid of those high rpm puffs of smoke maybe.

[Dj Buttchug]

Take a peek at TurboSmart.com I just picked up a turbo oil regulator. I think you Varg and I have all been battling the same issue. (maybe) ?? Ive tried three different drains and restrictors and after my tuning session I still have a puff of smoke as well.

Worth a look at least. It regulates the oil pressure no higher than 40psi no matter the engine speed. The idea is without the pressure regulated you end up with too much volume in the turbo and oil gets past the turbo shaft into the compressor and turbine housings.

[Hoffbrohaus]

Take a peek at TurboSmart.com I just picked up a turbo oil regulator. I think you Varg and I have all been battling the same issue. (maybe) ?? Ive tried three different drains and restrictors and after my tuning session I still have a puff of smoke as well.

Worth a look at least. It regulates the oil pressure no higher than 40psi no matter the engine speed. The idea is without the pressure regulated you end up with too much volume in the turbo and oil gets past the turbo shaft into the compressor and turbine housings.

Yes I will add this to the list. Can't hurt anyway thanks! Just saving up for a tial wastegate hoping that will fix my lag issue.

I also want to get my exhaust manifold, exhaust turbine housing, and downpipe coated in Swaincoat's white lightning. It's getting hot in Phoenix already.

Some baseline numbers before the coating, after a little boosting...

[mikey.antonakakis]

Yes I will add this to the list. Can't hurt anyway thanks! Just saving up for a tial wastegate hoping that will fix my lag issue.

I also want to get my exhaust manifold, exhaust turbine housing, and downpipe coated in Swaincoat's white lightning. It's getting hot in Phoenix already.

Some baseline numbers before the coating, after a little boosting...

I used a turbo blanket for my giant VGT turbine - I can rest my hand (with a little discomfort) on the blanket after pulling into driveway (after a 500ft climb up the neighborhood over ~1.5 miles). I definitely wouldn't be able to do that with coating only. FWIW I did ceramic coat my exhaust manifold, using I believe the titanium satin coating from here: https://www.performancecoatings.com/exhaust-coating

this blanket is the one I'm using: https://www.amazon.com/gp/product/B00PFBE9CY

[Hoffbrohaus]

Chasing down a turbo lag demon that I can't figure out. Been bothering varg asking for advice so want to see what you guys think. First the numbers.

Both varg and I are running a t3t04e .63 ar 60 trim. His is internally wastegated, mine is externally wastegated. With my wastegate port blocked off completely (to eliminate that as a cause) here are the boost numbers

RPM.....varg..... me
2500.....3.7.....1.2
3000.....7.8.....2.4
3200.....10.8.....3.2
3400.....15.8.....5.2
3700................9.4
4000................15

I have pressure tested and smoke tested from turbo to throttle body, no leaks, holds pressure.

I have smoke tested exhaust side of turbo (cold) and found no leaks pre turbo.

The turbo itself I bought used but has no visable damage or shaft play. It spins freely by hand and is spinning fast at idle.

Before I buy a new turbo what else can I check? varg was thinking maybe the turbine housing was too big for the inducer? But the guy I bought it from said it was a .63 a/r and it looks like it's stamped on the exhaust housing.

[mikey.antonakakis]

Yeah should definitely spool better than that. How’s the engine run off boost?

[Hoffbrohaus]

Yeah should definitely spool better than that. How's the engine run off boost?

It feels fine off boost, sounds good, stable, and seems to pull as much as it used to before I reach positive pressure. I can run a compression test sometime this week.

[zwill23]

That exhaust flange to the turbo housing is looking a bit goofy, T4 exhaust to a T3 housing? There isn't flow being blocked into the exhaust housing is there?

[Dj Buttchug]

Where the turbo bolts to the manifold is there a smooth transition into the turbine exhaust housing there? Any overhanging metal or ridges inside the t4 flange that could be causing the exhaust to bounce around weird in there before it eventually makes it into the turbo?

[Hoffbrohaus]

That exhaust flange to the turbo housing is looking a bit goofy, T4 exhaust to a T3 housing? There isn't flow being blocked into the exhaust housing is there?

I'll pull the turbo tonight or tomorrow and get some pictures but it's the rsi manifold with t3 and t4 bolt holes. "Dual pattern turbo flange T4 & T3"

[Hoffbrohaus]

Compression check complete. At operating temp with all plugs pulled, 5 cranks.

Cyl...Psi
1...129
2...130
3...129
4...130
5...130
6...130

Doesnt look like anything is blocking the flow of the exhaust out of the header to the turbine. Here's some pics though in case you guys see something funny.

[Panici]

Looks like the outer edge of exhaust flow is hitting a "wall" on the smaller flange. Can't be helping the situation.
How much meat is there in that area?

Could you take off the sharp corner and smooth things out a little? Carbide Burr would be my weapon of choice.

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Not the same situation, but first enlarging (and then later smoothing) each produced measurable results on my Miata's wastegate. In that case I completely resolved my boost creep issues by increasing flow to the gate.

[Hoffbrohaus]

Looks like the outer edge of exhaust flow is hitting a "wall" on the smaller flange. Can't be helping the situation.
How much meat is there in that area?

Could you take off the sharp corner and smooth things out a little? Carbide Burr would be my weapon of choice.

------------

Wow that wastegate enlargement looks like a huge improvement. I've got up to 1cm on the sides and 5mm top and bottom edges. I could taper it with a carbide bit and my dremel. Might not do much but will be fun.

[Hoffbrohaus]

Not the cleanest but we'll see if it works!