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Old 02-02-2013, 04:37 AM   #1
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Default Power Potential of Turbo vs. Motor... Uh, maybe not the best title

So I may be subject to being put on blast for this as I haven't researched, but I may also be a little buzzed...

When a motor is built it is assumed that higher boost may be used, but why? I am comparing the puny 2554 output at 15psi to say a 2560 at 12psi, and I am not sure (in my current state) why, if a 1.6 can handle a 2560 at 12psi relative to power output of the motor why it couldn't take a 2554 at 15psi; or could it?

In any discussion I have seen about selecting the right turbo for a built motor, it seems to be stated that the big power guys say ditch the 2860 'cuz the motor can handle high psi of a bigger more powerful turbo and the track guys go with the 2860 only for heat.

can I has mor booosht? Really probably not going to do it either way, just curious to be spoon fed. please and thank you.
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Old 02-02-2013, 05:02 AM   #2
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Old 02-02-2013, 09:18 AM   #3
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lolwut?
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Old 02-02-2013, 09:18 AM   #4
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I think I get you. Think of a straw vs tube. 15 psi out of a straw wouldn't be too much but out of a 3" tube would be a considerable amount of force. Now the rods bend at the same torque figures, about 225ish for stock, so 15psi out of a 2554, or 8psi out of one of the larger turbos.

However, I can't tell you why, but I seem to remember there being a reason why the same power with less pressure in a bigger turbo is better, even after ignoring head room and compressor efficiency maps. Someone better than I will have to comment.

Edit: wait, does it have something to do with p=v*t or whatever? Cause more pressure with the same volume would equal more heat.
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Old 02-02-2013, 09:19 AM   #5
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to limit all the low end torque and impress your friends with the shitty boost threshold?
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Old 02-02-2013, 10:20 AM   #6
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:NewOrleansWest:
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Old 02-02-2013, 02:01 PM   #7
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More boost equals higher intake temps. That's why it's better to run a big turbo at low boost than I small turbo at high boost.
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Old 02-02-2013, 06:54 PM   #8
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Higher intake temps = less timing advance = less torque.
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Old 02-02-2013, 06:57 PM   #9
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id rather have a 2554 making 225hp than a 2560 doing the same.
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Old 02-02-2013, 07:15 PM   #10
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Quote:
Originally Posted by Braineack View Post
id rather have a 2554 making 225hp than a 2560 doing the same.
Right. Me too, but that's going to be higher than 12psi right?

Last edited by hankclaussen; 02-02-2013 at 07:41 PM.
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Old 02-02-2013, 07:19 PM   #11
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Quote:
Originally Posted by thirdgen View Post
More boost equals higher intake temps. That's why it's better to run a big turbo at low boost than I small turbo at high boost.
Plus you have the option to up the boost when you get tired of what you currently have without having to swap out the turbo.
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Old 02-02-2013, 07:37 PM   #12
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Originally Posted by gearhead_318 View Post
Plus you have the option to up the boost when you get tired of what you currently have without having to swap out the turbo.
but laaaaaaaaag?
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Old 02-02-2013, 08:01 PM   #13
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Quote:
Originally Posted by Braineack View Post
id rather have a 2554 making 225hp than a 2560 doing the same.
OMFG you little turbo crybaby ------s never shut up about this ****. Try vagina, seriously. I want a turbo that won't make target boost earlier than 3500rpm. That way I can get a larger turbine housing to make real torque.

I am a turboless ------.
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Old 02-02-2013, 08:48 PM   #14
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I liked when my sr20 made 225whp @ 12psi, I'd love a 3076 that makes 225 at like 8 psi. I just feel that I'd be wasting a turbo unless I use it to it's max.
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Old 02-02-2013, 08:50 PM   #15
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to aim for 225 on a 3076 is stupid. might as well buy a honda with boltons
I was at 300 and often felt I was wasting the turbos potential
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Old 02-02-2013, 09:08 PM   #16
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IMO, you first get a power goal, then you figure out the smallest turbo that will meet that power goal without having to seriously over stress the turbo. IE if you want to make 230 wheel, you can squeeze that out of a td04-13t, but you'll have to run right up to or maybe past the edge of the compressor map.
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Old 02-02-2013, 09:16 PM   #17
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Quote:
Originally Posted by 18psi View Post
to aim for 225 on a 3076 is stupid. might as well buy a honda with boltons
I was at 300 and often felt I was wasting the turbos potential
Exactly. Since my goal is 240whp, I'm just gonna max out my sr20 and not feel bad.
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Old 02-03-2013, 02:03 AM   #18
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With the current drought in proper street tires I'm starting to wonder if it's worth even going above 300whp.

OP, ****, just read the stickies and get a ride in a turbo car.
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Old 02-03-2013, 02:08 AM   #19
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OP is assuming that there's a boost limit on our engines.

OP needs to never think this again.
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Old 02-03-2013, 03:28 AM   #20
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Pressure build heat. Heat is stress. Little turbos spool fast and blow hot air at the top. Big turbos blow hurricane status at a lower pressure with cool air but take a bit longer to get there. It's all a balance.

EFRs blow unicorn farts that spool instantly with air from the arctic. Compressor map gives me wood but makes my wallet hurt. Maybe next season...
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