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pl0x

Help me get more Powaaaa

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Posted (edited)

Plox: 280kW ATW @ 28PSI  -  492 NM Torque 

Model: 92 RS Legacy BC5

Displacement: 2.0l

Mods: gtx3071 gen 1 with mamba twin scroll 0.82 AR housing/ 880cc Side Feeds / bl/bp ts headers with twist adapter / 3Inch with 2 x coby & muffler / 550x230x65 FMIC / vipec i88 / post IC 50/50 water/meth injection / 272 Franklin reground cams / adjustable cam gears

Fuel: BP 98

 

dyno_compare_gt3076_vs_gtx3071.jpg

 

Top line is 28psi with water meth

Middle is 24ish psi no water meth

Dashed lines are old single scroll gt3076 0.63 housing 23psi no water meth

 

Couldn't pull any more than 280kw, torque drops off significantly, next to no top end gain adding boost and timing. Injectors weren't the limiting factor (yet), appears there is a airflow restriction.

Pressure testing results (on high boost):

Exhaust port egbp 40psi

pre turbo but post wastegate egbp 35psi

post turbo egbp 5psi

turbo outlet/pre intercooler 34psi

final boost/manifold pressure 28psi

 

Back to back core vs no core @ 40% open loop wastegate duty test showed 22psi with core 26psi without (so ~4psi of intake pressure drop is the IC, this added 20 degrees of IAT even with WM and made the car run mid 10 afr rather than the normal mid 11, and seemed to bring the boost threshold 200rpm earlier)

 

I've been "internet" advised IC is to thin and causing a restriction. Any opinions on this?

I have a suspicion the cams aren't what they should be, are a bad grind, or are dialed in wrong.

Any opinions on what could be the restriction or tests to suggest?

 

Edited by pl0x
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Made a new topic for this to save the Dyno getting too clogged up. 

 

Have you got some pics of your setup? Don’t think i’ve seen any on here before.

Like the sound of the Legacy TS twist adaptor, does it use single/twin wastegates on the adaptor, or piped up elsewhere?

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Yea, fair point, I had thought of splitting it out but dyno thread gets more action xD.

 

Single 38mm wastegate just before the up pipe. I did consider twin or larger wastegate but knew i was going to be running high boost and gambled it wouldn't have boost creep, which it doesn't.

 

I've only really got photos in the build, none of it completed:

36844821_2276483492369685_16434253627234

36843207_2276483135703054_32682232718955

36347801_2260056677345700_88227023460614

 

Intercooler is coming off this weekend to test the psi drop across a different core so can get a photo of the IC set up then. It's by no means pretty, but it works (same with the whole car really)

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4 hours ago, pl0x said:

 

 

I've been "internet" advised IC is to thin and causing a restriction. Any opinions on this?

I have a suspicion the cams aren't what they should be, are a bad grind, or are dialed in wrong.

Any opinions on what could be the restriction or tests to suggest?

 

 

What brand IC is it? Think my Fenix one is the same size (cant remember thickness) but havnt had any issues with mine my temps are sweet

Your turbo rear is a 0.72 yeah? thats smaller than my 0.86 (i think) but you made more power than me so something is happening good yeah?

Im still not 100% on my head setup as I never got them dialed in, in hindsight I probably would have gone to a v7 sti type head setup - shortie too 

I was thinking after the tune id get 270kW at 30psi, was very surprised to hear 270 came from only 23psi

David said thats nearly all the puff the garret has, everything else was ok except my wastegate duty was maxed out

 

What numbers were you expecting from the gtx twinny?

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It's one of the ITL cores, and it seems to cools great. IATs are better than the old (same size unknown brand) core.

The persons who said the IC was to thin - his theory was that the flow area was to small and is causing a restriction, and said he and mates had run into similar power restrictions which turned out to be the thin IC core.

 

Yea 0.72 TS is smaller than 0.86 SS, although I believe TS and SS housing sizes aren't directly comparable. The 0.72 TS housing probably more similar to a 0.63 SS housing.

 

I'm thinking the similar around heads, some avcs heads (either single or twin) could help bring the boost on earlier as well as flow. I'm considering bp/bl heads and adding sti or aftermarket cams, and some decent springs. But I need to test another IC core first, and then pull the heads off for a look and measure up the current cams.

 

I was hoping for better spool going TS and at least 300kw. I wouldn't care about the power figure if it had a punchy early-mid range, but at the moment is fairly laggy as well as torque tapping off. Thankfully with the 6sp once you are in the power it stays there.

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38 minutes ago, pl0x said:

It's one of the ITL cores, and it seems to cools great. IATs are better than the old (same size unknown brand) core.

The persons who said the IC was to thin - his theory was that the flow area was to small and is causing a restriction, and said he and mates had run into similar power restrictions which turned out to be the thin IC core.

 

Yea 0.72 TS is smaller than 0.86 SS, although I believe TS and SS housing sizes aren't directly comparable. The 0.72 TS housing probably more similar to a 0.63 SS housing.

 

I'm thinking the similar around heads, some avcs heads (either single or twin) could help bring the boost on earlier as well as flow. I'm considering bp/bl heads and adding sti or aftermarket cams, and some decent springs. But I need to test another IC core first, and then pull the heads off for a look and measure up the current cams.

 

I was hoping for better spool going TS and at least 300kw. I wouldn't care about the power figure if it had a punchy early-mid range, but at the moment is fairly laggy as well as torque tapping off. Thankfully with the 6sp once you are in the power it stays there.

 

 

Are you in AK? i think the BC5 guys are long overdue for a meet up, keen as to see a 6speed conversion in the flesh also :) 

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I put money on the fact the 272 Cams if from Franklin are not what they say they are if regrinds. probably stock lift.  I got rid of mine as they were called very mild as I had them checked by kelford, mine supposed to be 276 but weren't and basically lift was left stock. 

 

How much porting on ur heads? I don't understand why everyone praises v3 heads, I've seen them next to other heads v6 etc and there is no difference in port size, I don't get it. Late model  Legacy heads 2004 ish are far bigger ports from factory and when ported more flow a lot more than v3 ever would. I would have thought u hit a higher number than that, one thing that worries me though is that no tuning shop I have used would go above 25 psi on 98 fuel as its too much of a risk. 

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From the Waikato area. Will head up to night wars or similar at some stage.

 

Interesting... I think you could be on the money with the cams, it doesn't really have cam lump at idle.

Nil porting as far as I am aware. These are just the heads that the long block was built with, I assumed they would make the power with supporting mods.

 

I do have a bl/bp engine lined up, but its seized so unsure of condition of the heads (fingers crossed they are ok).

I'm not concerned with the high boost on 98, its what I asked for and that is with water/meth.

 

 

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Need bigger rear turbo housing I say. Subaru's do not like back pressure 

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17 minutes ago, gotasuby said:

Need bigger rear turbo housing I say. Subaru's do not like back pressure 

I only have 0.63 turbo housing on my car and got decent power, but I agree would be a lot easier to make power with 0.82 housing just have to way up the lag aspect. 

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2 hours ago, gotasuby said:

Need bigger rear turbo housing I say. Subaru's do not like back pressure 

You think based on those back pressure readings it would be an exhaust housing restriction?

I was thinking along the lines that with the turbo producing 34psi, that pre turbine egbp of 35psi is pretty good considering.

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@Username i think the tuners not going over 25 psi thing is due to factory 2 bar map sensors. Cant run any higher unless you get a bigger map sensor

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17 hours ago, Niran said:

@Username i think the tuners not going over 25 psi thing is due to factory 2 bar map sensors. Cant run any higher unless you get a bigger map sensor

Good call on normal cars but mine has a 5 bar upgrade and aftermarket ecu, I was always told it's not safe above 25psi  on 98. You are on water/meth which may give a bit of security,  I don't know much about water meth setups. 

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any reason you don't have ethanol? It's like the answer to every problem haha :D 

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13 hours ago, Username said:

Good call on normal cars but mine has a 5 bar upgrade and aftermarket ecu, I was always told it's not safe above 25psi  on 98. You are on water/meth which may give a bit of security,  I don't know much about water meth setups. 

Water/meth is said to have similar effects to ethanol, more det resistant and cooler IATs, so adds some safety. Although there are more risks with W/M than ethanol (in the event of blockages/leaks)

 

11 hours ago, slystiguy said:

any reason you don't have ethanol? It's like the answer to every problem haha :D 

To hard basket, mainly the fuel system upgrade required and nowhere local for me to get it. My solution was water meth and more boost.

If i need to upgrade my injectors I'll be getting some that are ethanol compatible.

 

The target is "only" 300kw with a decent torque curve so shouldn't need it.

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Totally unrelated but where did you get the flange for the twisted adaptor from? Need one for my own silly plans.

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In checking my ebay history, I noticed that turbine housing is 0.82 not 0.72, so slightly larger than originally stated. Have changed the original post.

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What model is the water/meth setup you’re running? Is it controlled externally with just a failsafe back to the Link or does it see a lot more info than just that? 

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It's a bit of a mixture of parts. Devils own pump and nozzles, pro meth pwm solenoid controlled by the link, rest of the tank, lines fittings from ali/ebay etc.

Fail safe is a bit average but is hooked into the link (pressure sensor only, which isn't as good as a flow sensor imo, but it seems you can't get reliable flow meters for methanol).

I've got knock control set up in the link as a second fail safe

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Planning to grab @Niran’s AEM setup and figured I should find the best way to get it running with a Link.

 

So have you got yours mapped to the Link to just start the pump x many sec/rpm earlier than the solenoid opening and the duty mapped against boost in the Link?

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I don't know what solenoid (if any) that set up comes with but would recommend a pro meth solenoid. They can be control directly by the link and is low enough current to not require a SSR or external pwm control.

Pump starts at 4psi or so, solenoid progressively opens mapped on injector duty (from memory the ideal mix of 50/50 water meth to fuel is 15-20%). much the same as doing it map vs revs.

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Not completely sure how the AEM one is setup.

Think it must have an internal solenoid in the pump to dictate how much is bypassed, or the pump just continually ramps up?

I know the pump is designed to always run at a lower duty then ramps up when required, with a check valve in the nozzle to prevent it dripping. The wiring allows for a solenoid to be installed but that’ll be a simple open/closed one that doesn't control the flow. 

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I Believe all the pumps are pretty much the same thing with minor brand specific difference but could be wrong, I've only seen the devils own one.

I thought the pumps have an internal bypass valve at a certain pressure.

You can run the pumps off PWM using a SSR to make it progressive. Not sure how else the AEM set up would control it.

I'd rather a solenoid than a check valve

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