20G wheel in a TD05 housing

JusMX141 · Feb 9, 2012

pj91gsx said:
Actually that was Ryan that did his own turbo, but I tell people about what the 20g flows and his is a great example. His consists of an antisurge 20g compressor cover, with a 7 cm turbine housing. The turbine wheel is clipped and flowing 52 lb per minute around 24-26 psi.

I'd like to see logs of said 52 lb/min 20G.

The 20G compressor map ends at 45 lb/min. A TD05H turbine is honestly too small for a 20G compressor to reach it's peak 45 lb/min of flow in a 7cm housing, even if it were clipped as much as 25*. It's virtually impossible to push such a compressor that far beyond it's map with an undersized turbine. An additional 2-3 lb/min is possible with ridiculously high boost levels and high-flowing turbines, but not with boost in the mid 20's. Something is very wrong with the calibration allowing it to register 10 lb/min or so higher than what it actually is.

Further proof of this is the anti-surge cover, which tends to hurt peak airflow instead of helping it. The cover works by allowing a small amount of air to bypass the compressor inducer, like this explanation from another forum:

A ported shroud compressor cover is used to broaden the width of a compressor map. As mentioned before it does cause a small penalty in compressor efficiency. At low flow/high pressure situations (where you typically would surge) some of the air is allowed to escape through the ports. Realistically the surge line for the compressor wheel/cover combination stays the same.

So there you have it- LESS compressor efficiency...not more. A surge cover broadens the width of the map by moving the surge line, but does nothing to increase peak airflow production.

Here's a thread where even 50 lb/min from a Green at 24psi is inflated by improper calibration:

http://www.dsmtuners.com/forums/tur...-school-fp-green-pushing-50lbs-min-24psi.html

^ ...and that's a T04E50 compressor with a TD06H turbine- a completely different realm of airflow than the TD05H 20G.

Edit:

pj91gsx said:
My point was that a 20g capable of flow numbers of the 68hta. (unported, unclipped, 68hta 47lb per minute). Given the fact that Ryans is clipped, it has a little bit of an advantage, vs being able to compare just compressor wheels.

It should also be noted that the 47 lb/min flow rate from the 68HTA was achieved prior to the turbo ever being offered in the DSM platform. It was done with an 8cm turbine housing on a 2.5 liter Subaru application....better-flowing compressor cover, more turbine flow, higher engine displacement than a DSM 68HTA.

While I believe it's possible for a 20G to have nearly the same peak flow as a 68HTA, the 68HTA will stomp the 20G in terms of efficiency across the board.

DSMTyson · Feb 9, 2012

JusMX141 said:
It should also be noted that the 47 lb/min flow rate from the 68HTA was achieved prior to the turbo ever being offered in the DSM platform. It was done with an 8cm turbine housing on a 2.5 liter Subaru application....better-flowing compressor cover, more turbine flow, higher engine displacement than a DSM 68HTA.

While I believe it's possible for a 20G to have nearly the same peak flow as a 68HTA, the 68HTA will stomp the 20G in terms of efficiency across the board.

I saw a log on the ECMLink forums from a guy asking for advice, and he was running a FP 68HTA at like 28-30psi and peak airflow was somewhere between 47 and 48 lbs/min. I'm pretty sure it was on a 2.0L too. So the same airflow can be acheived on a DSM. Of course, assuming that he had his airflow calibrated correctly at the high RPM range of the map.

Yes, the 68HTA is more efficient across the board from the design of that billet compressor wheel. But at the end of the day the 68HTA is now 3 times the price(Yikes..) of one of these bastard 20Gs and doesn't flow that much more than the one. But if you feel like spending nearly $1200 on a turbo that peaks out at 47-49 lbs/min. Go for it.

JusMX141 · Feb 9, 2012

DSMTyson said:
I saw a log on the ECMLink forums from a guy asking for advice, and he was running a FP 68HTA at like 28-30psi and peak airflow was somewhere between 47 and 48 lbs/min. I'm pretty sure it was on a 2.0L too. So the same airflow can be acheived on a DSM. Of course, assuming that he had his airflow calibrated correctly at the high RPM range of the map.

Correct- assuming. Seems like airflow logs and dyno charts are easily inflated these days....I like timeslips better; they don't lie.

The 68HTA will always have a slight airflow advantage by design. It spools quicker, meaning it will generate more airflow sooner than a cast 20G. It also has a smaller hub area at the center of the wheel, meaning the blades themselves are deeper and can draw in a greater volume of air. The wheel itself is wider than a 20G as well, greatly improving the surface area of the compressor blades.

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DSMTyson said:
But at the end of the day the 68HTA is now 3 times the price(Yikes..) of one of these bastard 20Gs and doesn't flow that much more than the one.

What vendor is selling new Bastard 20G's for $400?

DSMTyson said:
But if you feel like spending nearly $1200 on a turbo that peaks out at 47-49 lbs/min. Go for it.

Could be worse- you could spend $1000 on an Evo III 16G and get 40-42 peak.

DSMTyson · Feb 9, 2012

Seems like airflow logs and dyno charts are easily inflated these days....I like timeslips better; they don't lie.

I'd have to agree with you on that LOL

.

The 68HTA will always have a slight airflow advantage by design. It spools quicker, meaning it will generate more airflow sooner than a cast 20G. It also has a smaller hub area at the center of the wheel, meaning the blades themselves are deeper and can draw in a greater volume of air. The wheel itself is wider than a 20G as well, greatly improving the surface area of the compressor blades.

Yeah this is true. Its got a hub area even smaller than the ebay wheels? Wow, thats pretty awesome. If only I could buy a 68HTA wheel from FP at a decent price, or at all.

What vendor is selling new Bastard 20G's for $400?

PM'd

JusMX141 · Feb 9, 2012

DSMTyson said:
Yeah this is true. Its got a hub area even smaller than the ebay wheels? Wow, thats pretty awesome. If only I could buy a 68HTA wheel from FP at a decent price, or at all.

Than the eBay billet wheels? Probably not- but the 68HTA compressor is in a category of it's own as far as R&D...it's not modeled after anything. It has one additional major and minor blade than a MHI 20G wheel. It's inducer is smaller than a 20G but larger than an 18G.

Sirnixalot · Feb 9, 2012

No idea if this is relevant.

I got a 20G wheel and housing from Nickel_sport on ebay and am pleased with it thus far, keeping in mind i am running an Evo X turbo on my Evo 3 (same shit save for the 12cm^2 twin scroll turbine housing and possibly A/R of the compressor housing?).

I would really like to try one of the billet wheels at some point (once the price drops LOL

). I have also seen some supposedly "revised" cast wheels with smaller hubs on ebay as well.

Either way it is a great setup for what i do with the car so i am happy, especially if i can crack 400whp and as much wtq as i can make on virtual dyno.

DSMTyson · Feb 9, 2012

Sirnixalot said:
Either way it is a great setup for what i do with the car so i am happy, especially if i can crack 400whp and as much wtq as i can make on virtual dyno.

That amount of power shouldn't be a problem with a healthy motor and that twin scroll turbine housing design.

DECODER22 · Nov 23, 2012

JusMX141 said:
I'd like to see logs of said 52 lb/min 20G.

The 20G compressor map ends at 45 lb/min. A TD05H turbine is honestly too small for a 20G compressor to reach it's peak 45 lb/min of flow in a 7cm housing, even if it were clipped as much as 25*. It's virtually impossible to push such a compressor that far beyond it's map with an undersized turbine. An additional 2-3 lb/min is possible with ridiculously high boost levels and high-flowing turbines, but not with boost in the mid 20's. Something is very wrong with the calibration allowing it to register 10 lb/min or so higher than what it actually is.

Further proof of this is the anti-surge cover, which tends to hurt peak airflow instead of helping it. The cover works by allowing a small amount of air to bypass the compressor inducer, like this explanation from another forum:

So there you have it- LESS compressor efficiency...not more. A surge cover broadens the width of the map by moving the surge line, but does nothing to increase peak airflow production.

Here's a thread where even 50 lb/min from a Green at 24psi is inflated by improper calibration:

http://www.dsmtuners.com/forums/tur...-school-fp-green-pushing-50lbs-min-24psi.html

^ ...and that's a T04E50 compressor with a TD06H turbine- a completely different realm of airflow than the TD05H 20G.

Edit:

It should also be noted that the 47 lb/min flow rate from the 68HTA was achieved prior to the turbo ever being offered in the DSM platform. It was done with an 8cm turbine housing on a 2.5 liter Subaru application....better-flowing compressor cover, more turbine flow, higher engine displacement than a DSM 68HTA.

While I believe it's possible for a 20G to have nearly the same peak flow as a 68HTA, the 68HTA will stomp the 20G in terms of efficiency across the board.

i wish i could get 52 LOL

most i have ever seen is 47.6 and a average of 40-45 with boost levels anywhere from 22psi to 30 psi

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20G wheel in a TD05 housing

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