testes1010's '05 LGT Mod thread.

[testes1010]

Did one pull this morning to just over 6k rpm. I'm still hitting 100%IDC but that much better than 111% previously. Oh, and notice the 3.75 g/rev:eek:, its amazing what 22psi of boost will do. Can't wait to get the WBo2 hooked up this afternoon, dial in the AFRs and do a few road dyno pulls.

 

There was nothing else changed between the two graphs tune-wise other than the Injector scalar increased and the tip-in. LearningView is after 50 miles or so driving on the same map. Depending on what the WOT AFRs are doing I may need to reduce the injector scalar just a bit.

[Spec B]

Damn...I am now starting to lean back toward wanting a Vf39 or Vf43 turbo.

[testes1010]

Damn...I am now starting to lean back toward wanting a Vf39 or Vf43 turbo.

 

I've always liked the VF39, 43, 48 turbo ever since the first time I tuned a STi. In capable hands they perform very very well. I'm NOT saying its the best turbo out there but considering you can pickup the 39, 43, 48s relatively inexpensive used, there's a lot of bang for the buck and the VF52 is same just not as 'cost' effective.

 

The only turbo that I would be willing to upgrade to at this point is a TD05H-20G-8cm^2 but I'd absolutely need larger injectors.

[LittleBlueGT]

You wouldn't consider an hta68?

[testes1010]

You wouldn't consider an hta68?

 

No 8cm^2 option and no TD06 compressor cover makes it undesirable for me.

[LittleBlueGT]

No 8cm^2 option and no TD06 compressor cover makes it undesirable for me.

 

You do realize the hta comp wheel is more efficient, thus requiring less exhaust energy to spin it (to the same flow as a comparable non-hta wheel). Therefore a smaller turbine housing isn't exactly the hinderance that you may seem to think it is, more gasses go through the WG (all things being equal) vs a non-hta comp wheel.

[testes1010]

You do realize the hta comp wheel is more efficient, thus requiring less exhaust energy to spin it (to the same flow as a comparable non-hta wheel). Therefore a smaller turbine housing isn't exactly the hinderance that you may seem to think it is, more gasses go through the WG (all things being equal) vs a non-hta comp wheel.

 

I understand the efficiencies. I would just prefer a 8cm^2 exhaust housing to better accommodate a 2.5L engine on a IWG to minimize any boost taper at redline. If I were to run EWG, the 7cm^2 would be more than adequate for my goals. I would say the same on the TD05H-20G-8cm^2, if it were EWG a 7cm^2 would be ok.

[LittleBlueGT]

I understand the efficiencies. I would just prefer a 8cm^2 exhaust housing to better accommodate a 2.5L engine on a IWG to minimize any boost taper at redline. If I were to run EWG, the 7cm^2 would be more than adequate for my goals. I would say the same on the TD05H-20G-8cm^2, if it were EWG a 7cm^2 would be ok.

 

At first I suspect you understand, but then I am not sure.

 

An 8 cm housing "accomodating" a 2.5 liter engine is just a rule of thumb based off of how much exhaust energy is required to spin a given comp wheel. (exaggerating here) If we could get a super super efficient comp wheel that only needed 10 lbs/min exhaust flow to spin a 47 lb comp wheel up to speed, then a 5 cm housing would probably do, and a 7 or 8 cm housing would induce too much lag, and not make any more whp at all.

 

In reality I believe it goes something like this:

 

44 lbs wheel requires 22 lbs through turbine to flow to full potential

new 47 lb hta wheel requires 21 lbs through turbine to flow to full potential.

 

Just guesses, and an 8 cm turbine may indeed help out the hta68, but it may not.

[testes1010]

An 8 cm housing "accomodating" a 2.5 liter engine is just a rule of thumb based off of how much exhaust energy is required to spin a given comp wheel.

 

I have no first hand experience with newer billet wheels so its one of things that I can't judge until I've seen first hand.

 

As we all know, many of the past's 'rule of thumbs' in the Subaru community have been a joke. Years and years went by everyone recommending a TD06 wheel on a 20G for a 2.5L, where its been proven time and time again the TD05H makes as much power as the TD06(at least on pump gas) and spool much much faster making the power band broader/better than the TD06.

 

Even a TD06-20G is a bit 'lopsided', I can't believe these turbo companies are still selling TD06-18G and a few have had TD06-16G in the past. People do not understand how 'big' the TD06 turbine actually is. Its the same turbine Greddy puts on the T67 which is a TD06H-25G, larger capacity-wise than a Garrett GT30R.

 

As far as the 8cm^2 for me its more so a personal preference based on experience of the TD05H-20G depending on whether its IWG or EWG. The TD05H-20G-7cm^2 on a 2.5L spools as quick if not quicker than a VF39, 43, etc(sub-3100rpm) and holds ~18psi to redline on a 7cm^2. The 8cm^2 should hold a bit more to redline at the cost of ~100-200rpm of lag, maybe.

 

(exaggerating here) If we could get a super super efficient comp wheel that only needed 10 lbs/min exhaust flow to spin a 47 lb comp wheel up to speed, then a 5 cm housing would probably do, and a 7 or 8 cm housing would induce too much lag, and not make any more whp at all.

 

Obviously, ^ an exaggeration to prove a point, but there will be a point in the size of the housing becomes a restriction in the VE of the engine and the wg can't divert the exhaust gases quick enough that the turbine reaches a extremely high pressure ratio, regardless of how efficient the compressor is. Exaggerated of course.

 

I understand efficiencies, better than most for sure. Thats one of the reason I never recommend a Tial 44mm EWG for any bolt on turbo and 95% of the rotated ones. I'm sure you understand, but I wonder how many people know why I don't recommend them???

[Ryandigi]

Wow...you both just blew my mind. I need to learn more about turbos.

 

Could the tdo5 7cm^2 make 340-350whp on pump gas at sea level or should I be looking at the td06. I mean 100-200 rpm lag aint that bad at all in my opinion. now 500+ rpm lag would suck.

 

You guys recommend any books to read to understand all this (efficiencies etc...), or is it just straight up learned as you worked on different cars? Once I am out of school...in 4 years ughh...then I will have some more money for my car hobbies, oh well

 

 

P.S. left you feedback for the AEM LBGT, thanks again!

[Bolksey85]

The only turbo that I would be willing to upgrade to at this point is a TD05H-20G-8cm^2 but I'd absolutely need larger injectors.

Is that the same unit you had on your WRX?

[testes1010]

Could the tdo5 7cm^2 make 340-350whp on pump gas at sea level or should I be looking at the td06. I mean 100-200 rpm lag aint that bad at all in my opinion. now 500+ rpm lag would suck.

 

The TD05H will make as much power on pump gas(non-E85) as the TD06; the TD05H will have a broader powerband/more power under the curve, making higher average power.

 

You should be able to pretty easily hit 340-350whp on 93 octane with a TD05H-20G-7cm^2 at sea level. I would port the hell out of the turbine housing and wg to prevent any boost creep.

 

Attached you'll see a graph of a 3rd gear pull on a TD05H-20G-7cm^2 with a APS DR525 FMIC with EWG, talk about pinning you back in the seat at 3200rpm.

 

As for reading on turbos and engines, majority of my reading has been on the internet and experience from tuning(obviously more reading, researching goes on there too).

[testes1010]

Is that the same unit you had on your WRX?

 

I had a TD05H-20G-7cm^2.

[snow05gtRI]

have you seen the BNR turbo thread? he's making 16/18/20g turbos that work with the stock housings so we can continue to use the stock TMIC location. i thought i saw him saying that the exhaust was a bit bigger than the 7cm^2, but dunno if its all the way up to the 8cm^2....not that i know exactly what that means anyway

[testes1010]

have you seen the BNR turbo thread?

 

Yup. Many of the IHI housings(VF52, & VF39, 43, 48, etc) are larger than 7cm^2. I believe the VF40 & 46 are smaller than a P18, but I can't confirm it.

 

These are all calculated, please forgive any misinformation.

P18 = 18 / 25.4 = 0.708 A/R

P20 = 20 / 25.4 = 0.787 A/R

P25 = 25 / 25.4 = 0.984 A/R

^ The VF39, 43, 48, 52 have a P18, a P18 falls between 9 & 10cm^2, say 9.5cm^2.

 

6 cm2 = 0.41 A/R

7 cm2 = 0.49 A/R

8 cm2 = 0.57 A/R

9 cm2 = 0.65 A/R

10 cm2 = 0.73 A/R

11 cm2 = 0.81 A/R

12 cm2 = 0.89 A/R

[robinlsb]

Did you add a roll center kit yet??? Ya gonna need it with all that HP;)

[LittleBlueGT]

Yup. Many of the IHI housings(VF52, & VF39, 43, 48, etc) are larger than 7cm^2. I believe the VF40 & 46 are smaller than a P18, but I can't confirm it.

 

These are all calculated, please forgive any misinformation.

^ The VF39, 43, 48, 52 have a P18, a P18 falls between 9 & 10cm^2, say 9.5cm^2.

 

I am not disagreeing, because I have never looked into it, but:

 

You are saying that a VF39 has almost a 10cm hotside? Really?

 

FWIW Blouch has new 10cm hotsides with their new billet wheels, (billet = hta AFAIK). Time for new turbos of the month! In all seriousness there is small efficiencies gained here, how much I don't know, but some.

 

If the VF39 has a 9.5 cm hotside, then I do not imagine that a 10cm hotside is going to be much of a spool penalty for a 49-59 lb/min turbo.

[testes1010]

You are saying that a VF39 has almost a 10cm hotside? Really?

 

If the VF39 has a 9.5 cm hotside, then I do not imagine that a 10cm hotside is going to be much of a spool penalty for a 49-59 lb/min turbo.

 

I cannot 'back' the numbers they are only calculated and collected on NASIOC multiple places.

 

But for the sake of argument, we can all agree that a VF39/43/48 will full spool properly tuned around 3100rpm(+/-100rpm) on a 2.5L. Lets say it does have a 9.5cm^2 housing.

 

 

vf39

6 blade compressor height=.922

inducer=1.831

exducer= 2.365

 

11 blade turbine height=.911

inducer= 2.079

exducer= 1.885

tdo5-18g

6 blade compressor height=.865

inducer= 1.927

exducer= 2.692

 

12 blade turbine height= .794

inducer= 2.207

exducer= 1.893

From what I've read in the past, IHI wheels are heavier than MHI wheels & we can all agree that most the IHI turbo are somewhat inefficient when compared to modern wheels.

 

So based on the dimensions above, how does a VF39-9.5cm^2 and a TD05H-18G-7cm^2(since the comp are similar size as well) compare?

 

MHO & experience, A TD05H-18G-7cm^2 'should' spool up a bit faster than a VF39, but not much. The VF39 will hold as much boost to redline if not more than the 18G-7cm^2.

[LittleBlueGT]

FWIW my hta68 (not done tuning yet) spools about 200 rpm faster then my friends 09 WRX (but he doesn't have ELH, inlet, TGV, EWG, all of which make very little difference IMO cept ELH), same gas temp, elevation.

 

It also can flow a lot more air, many say it is very comparable to a 20g in flow, but I have yet to verify that.

[NSFW]

6 cm2 = 0.41 A/R

7 cm2 = 0.49 A/R

8 cm2 = 0.57 A/R

9 cm2 = 0.65 A/R

10 cm2 = 0.73 A/R

11 cm2 = 0.81 A/R

12 cm2 = 0.89 A/R

 

Do the TD05 and TD06 have the same "R" ?

[testes1010]

I would think most Subaru bolt on turbos should have roughly the same 'R', maybe some variation but not alot. It would be the 'A' that would vary between models. Some of the 'custom' turbine housing like ATP or other maybe a bit different R's.

 

The cm^2 measurements for the metric turbos refers to the 'A'.

 

http://www.turbominivan.com/tech/arratio.jpg

 

The TD06 and TD05 refer to the turbine wheel itself, not the housing.

[NSFW]

I don't see why R needs to be similar for all stock-location turbos, it seems possible to angle the flow a little bit from the top of the up-pipe to where the flow meets the wheel.

 

I also don't how two different sized turbine wheels can be fit into the same housing. Look at this picture for example (ignoring the divider), how can you change the wheel size without changing the housing as well?

 

http://www.turbobygarrett.com/turbobygarrett/images/tech_center/tech_102/divided_turbine_housing.gif

[testes1010]

I don't see why R needs to be similar for all stock-location turbos, it seems possible to angle the flow a little bit from the top of the up-pipe to where the flow meets the wheel.

 

I'm only going by what I've read on the A/Rs. On the Subaru fitment turbo there would have to be a significant change in the shape of the turbine housing in order have a larger R. Just after the turbine inlet flange the housing would have to belly out quite a bit, which some do, but majority of the OEM turbos are very similar on the shape of the housing. So I am assuming the OEM turbos have the same R, maybe a bad assumption, but an assumption none the less.

 

Never stated the TD05 and TD06 used the same turbine housing. KAMAK's website shows different part numbers for the turbine housing on the TD05H & TD06H turbines. I would imagine the differences is exactly where your image shows around the inducer/exducer area of the turbine. Both would share the same A/R(ratio) since both are 8cm^2(kamak's list).

[Spec B]

Testes...how do your IDCs look after the pump install?

 

*EDIT - NM, just say the chart. Can you post your ROM?

[testes1010]

Can you post your ROM?

 

It can be found here

 

note: map is setup for +10psi fuel pressure & non-stock MAF curve.