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Old 10-16-2019, 02:00 PM   #1
JayBob
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Default Turbo pairing with 272 cams?

Alright, I have an 04 STI with an IAG stage 2 block with a quasi-built heads (GSC valves, springs, retainers, etc) and GSC S2 cams. I’ll be running a 38mm EWG and Grimmspeed TMIC and I’m looking for a new stock location turbo.

My power goal is high 300’s and quick spool with a streetable power band for daily driving.

Anyone have any suggestions? I was looking at the Blouch Dom 1.5xtr with a 8cm hot side. The gentleman at Blouch said that 272 cams were pretty aggressive and he wouldn’t have went with them but recommended a 20g or the 1.5 to kinda counteract the cam profile. Any insight or knowledge?
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Old 10-16-2019, 03:40 PM   #2
rtv900
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Quote:
Originally Posted by JayBob View Post
The gentleman at Blouch said that 272 cams were pretty aggressive and he wouldn’t have went with them but
^he said that because your goals are a good streetable powerband and daily driver, which is the opposite of the goal of someone who gets 272 cams, which are very high rpm cams that will perform poorly on the street.

So to make it work you have to do a double wammy and get a bigger turbo, which will give you an even worse power band for a daily.

Cams aren't that expensive man, you aught to sell them and get new ones.
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Old 10-16-2019, 04:03 PM   #3
subydude
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272's are fine for the street....288's are "very high rpm" cams. I consider 260-272 fine for street stuff and 280's up more of a "you know you're going to live above 4,500 all the time" cams.

280's are where things get lumpy so definitely a big loss of DD there.

272's will move the powerband about 400-500 rpm right, so you want to size your turbo around a BW 7163 or Garrett G25-660. Those are better versions of a 20G and 1.5 XTR.

I will say smaller cams help spool quicker, but to hit high 300's on pump gas means a turbo roughly the size you're looking at anyway, and those cams will help you get there. You will likely not see full boost until 4k though, so for DD that means more puttering around and a downshift to "mean it".
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Old 10-16-2019, 04:28 PM   #4
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what fuel injectors ?
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Old 10-16-2019, 04:40 PM   #5
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what fuel injectors ?


1050’s
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Old 10-16-2019, 04:45 PM   #6
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I would go dom 2.5 or 3.0 with the larger hotside options and probably make over 400 on a much better overall package with components that compliment each other rather that get into a bar brawl every time the key is turned
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Old 10-16-2019, 05:02 PM   #7
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Quote:
Originally Posted by motorbykemike View Post
I would go dom 2.5 or 3.0 with the larger hotside options and probably make over 400 on a much better overall package with components that compliment each other rather that get into a bar brawl every time the key is turned


I was thinking about the 2.5 initially before I realized my cams would hinder my quick spool goals.
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Old 10-16-2019, 05:21 PM   #8
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Quote:
Originally Posted by motorbykemike View Post
I would go dom 2.5 or 3.0 with the larger hotside options and probably make over 400 on a much better overall package with components that compliment each other rather that get into a bar brawl every time the key is turned


What about a 2.5 with the 8cm hot side? Would that lower the rpm range? Also, I assume you mean everything would be counteracting by “bar brawl”?
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Old 10-16-2019, 06:18 PM   #9
motorbykemike
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Quote:
Originally Posted by JayBob View Post

What about a 2.5 with the 8cm hot side?

the smaller hot sides restricts the top end flow too much on an already restricted stock location style housing to make it worth my while = yes but who cares

Would that lower the rpm range?

sure but only by a couple hundred rpm at best but it will loose more than that up top = 2.5 has a mountain in the middle and top end kinda sucks so just let it breathe and do so safer and cooler with less drive pressure

Also, I assume you mean everything would be bounteracting by "bar brawl"?

yes = a well balanced package designed to have all components working together as a team is way better than a few really cool parts that don't any day


cliff notes , the cams you have are great , send em to the playground with kidz that they will be friends with


don't try to bandaid one part with another that is not paired well , the end result is most often everything sucks
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Old 10-16-2019, 08:16 PM   #10
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Quote:
Originally Posted by motorbykemike View Post
don't try to bandaid one part with another that is not paired well , the end result is most often everything sucks
right
cams are cheap
put the right cams on
you have the wrong cams and want to do a 'work around' on that fundamental issue
doesn't make much sense
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Old 10-17-2019, 02:06 PM   #11
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for a stock location turbo and mid to high 300's a 1.5xtr will work well but the low end will still be cam limited though. If you want to keep the cams go with a 2.5xtr and accept that life begins above 4k or swap to a different cam set and go 1.5xtr.

Alternately, the spoolinator GTX3071 kits are pretty sick looking.
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Old 10-17-2019, 11:49 PM   #12
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I have a 2.1 with tomei pon cams and a gtx3067 spoolinator and dont get into my power band til 4000 even with avcs... might be a little different with a 2.5 but I don't think much
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Old 11-01-2019, 07:42 AM   #13
Dwbarrett7
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Default BC272 Cams with Dom1.5xtr

In a 2017 STI I’m running a closed deck 2mm long rod motor with a gsc valve train, bc272 cams, and the heads have also been ported (headgames). This motor is accompanied with a Dom 1.5xtr 10cm 3” inlet running on E85. I had the build assembled and tuned by BrenTuning and it made a healthy 511whp/436wtq on E67 @7400RPMS and 461whp/395wtq on 93. When I received the phone call about how much power it made I was in disbelief. After driving the car for 2 months and extensive “testing” I’ve determined it makes all of the power. I’m very impressed and I think these cams are a great fit for this turbo! PS this car bone stock baselined at 250whp/248wtq. Best of luck
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Old 11-06-2019, 03:35 PM   #14
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nevermind already posted
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