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Old 05-11-2009, 01:29 AM   #1
banannersz
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Default How to increase more HP on a 2.5i.

Hey fellas/ladies. i was wondering how to increase more horsepower on a 06 2.5i. without putting a turbo in it. more of like the easy basic things you can do to increase horse power. help me out
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Old 05-11-2009, 01:39 AM   #2
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Gee I don't think this question has been asked before...


Short answer: You can't do much.

Long answer: Search. Start here: http://forums.nasioc.com/forums/show...ht=white+paper
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Old 05-11-2009, 01:54 AM   #3
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i have a weapon-r intake, perrin light weight crank pulley, borla header, random tech cat, and a stromung catback. these are the "bolt-ons." with these, u should be around 200HP at the engine. other than this u need head work, cams and an ECU to get the most out of the car before turboing it.

that all depends on ur budget. i strongly recommend the stromung exhaust. it sounds sick.
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Old 05-11-2009, 02:17 AM   #4
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lw flywheel was my favorite bolt on as far as engine goes. but if you really want to get the most out of your car do suspension work
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Old 05-11-2009, 02:24 AM   #5
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Increasing horsepower? Cams and headwork or give up.

Increasing the usable torque over most of the rev range? Start searching for threads by me.
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Old 05-11-2009, 10:59 AM   #6
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Quote:
Originally Posted by PA-Outback2000 View Post
i have a weapon-r intake, perrin light weight crank pulley, borla header, random tech cat, and a stromung catback. these are the "bolt-ons." with these, u should be around 200HP at the engine. other than this u need head work, cams and an ECU to get the most out of the car before turboing it.

that all depends on ur budget. i strongly recommend the stromung exhaust. it sounds sick.
That is a horribly generous estimate. Consider yourself lucky if you see even a 10-15hp increase at the crank.

The biggest butt dyno increase of any simple bolt on would be the OBX equal length headers. You don't have to bother with replacing your stock cats if you don't feel like spending money on it, according to williaty.
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Old 05-11-2009, 11:04 AM   #7
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we dynod both the obx and the borla on my car, and the results came out the same.
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Old 05-11-2009, 11:22 AM   #8
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Everything we learned on the N/A 2.5 doesn't neccessarily tranfer over to the 2.5i. The heads have bigger ports. The exhaust has bigger ports. The AVLS works different than previous designs. Dyno runs produced surprising numbers when runs with stock and aftermarket components were done. There were not any noticable increases between stock air box and after market intakes. No difference between EL and UEL headers either.

The biggest gains will be found with a combination of heads, cams and EM. Nothing else really makes a difference with these engines. None of this really qualifies as bolt-ons though.

See www.rallitek.com for more information regarding these upgrades as they are the authorized distributor for the AP.
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Old 05-11-2009, 11:24 AM   #9
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Quote:
Originally Posted by PA-Outback2000 View Post
i have a weapon-r intake, perrin light weight crank pulley, borla header, random tech cat, and a stromung catback. these are the "bolt-ons." with these, u should be around 200HP at the engine. other than this u need head work, cams and an ECU to get the most out of the car before turboing it.

that all depends on ur budget. i strongly recommend the stromung exhaust. it sounds sick.
Very generous... You will not hit 200chp without cams on a pre-AVLS 2.5. We are no longer comparing apples to apples when you compare the pre-AVLS motor with the AVLS motor.
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Old 05-11-2009, 02:28 PM   #10
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Quote:
Originally Posted by olsen726 View Post
we dynod both the obx and the borla on my car, and the results came out the same.
Then you did it wrong.

I dynoed both on my car and there were big gains with the OBX.


EDIT: Just noticed you have a 2.5i and I have a 2.5RS. Perhaps there's a difference with the newer cars as Qman says.
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Old 05-11-2009, 02:37 PM   #11
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these are my dyno graphs.







i have heard all the things "wrong" with them like varying temps and not a "true" baseline dyno, but WHP/WTRQ gains are what they are. i gained 25WHP and 18WTRQ overall, with a gain of 35WTRQ at 3500rpm. the car performs great.

the 1st one, RED, was the baseline with just an intake and pulley. the 2nd, BLUE, added the CBE and gained 13WHP and 8WTRQ. the 3rd, GREEN, added the high flow cat and header for 12WHP and 10WTRQ. with the header alone, i gained 18WTRQ at 3500rpm on this graph.

having the baseline with the intake may add 5WHP or so to the total and should bring me to around 195+HP at the crank. 1WHP gained is more than 1HP gained at the crank, not 1:1. this is solid proof of what the gains can be, granted each car reacts differently to the mods.

Last edited by PA-Outback2000; 05-11-2009 at 02:43 PM.
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Old 05-11-2009, 02:41 PM   #12
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Though you apparently don't want to hear it, your temperature changes are more than big enough to put some of those "changes" deep into question.
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Old 05-11-2009, 02:54 PM   #13
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this is an N/A and temps don't have that much effect like a turbo car. i may be off by 5HP or so. these are still gains. numbers aren't that important, but i still had gains. the car goes better than stock and i am happy.
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Old 05-11-2009, 02:55 PM   #14
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I thought the same thing you did when I started all this.

Then I actually started doing logging and dyno runs at different temperatures. These cars are a hell of a lot more sensitive to temperature than anyone gives them credit for.
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Old 05-11-2009, 02:58 PM   #15
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the car is also an automatic.
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Old 05-11-2009, 04:27 PM   #16
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Quote:
Originally Posted by Qman View Post
Everything we learned on the N/A 2.5 doesn't neccessarily tranfer over to the 2.5i...There were not any noticable increases between stock air box and after market intakes.
Do you have data for these conclusions?

There is difference on mine with SRI, big difference. Others have reported the same:

http://forums.nasioc.com/forums/show....php?t=1156560

Where is the link/data for the no difference between the EL and UEL headers?
Please elaborate/attach some data.
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Old 05-11-2009, 04:47 PM   #17
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I'm running an injen sri and an injen ses catback at the moment for bolt on hp mods. they run well but there's alot of fussing i had to do to get the full catback to work well. in the end i gustimate that it gained around 12-15 hp. it isnt much but thats all you're going to muster with thoes kinds of mods because the motor still run between .5-17.5psi...the flow is just better. the most cost effective "speed" mod would be a short shifter and bushings, that should shave some time off the 0-60 with shorter and more precise shifts. light weight pulleys and wheels are good too, reducing rotating mass will free up more lost hp at faster speeds. i woudn't recomend a lighter flywheel ( i tried it and hated it) because it's very hard to start from a dead stop (let alone launch off a start line). reground cams and valve work is another great place to gain some more power. if you want MORE power...wait untill a good supercharger comes on the market, it would make for the ultimate "sleeper." I"ve heard good things (and some bad things too) with the AVO turbo but in my opinion, a 10.1:1 compresion ratio and turbo surge is a bad mix.
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Old 05-11-2009, 05:51 PM   #18
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no offense or anything but i bet you didn't gain much of anything with that short ram and cbe
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Old 05-11-2009, 06:39 PM   #19
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Quote:
Originally Posted by olsen726 View Post
we dynod both the obx and the borla on my car, and the results came out the same.

Im guessing you didn't tune.
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Old 05-11-2009, 09:42 PM   #20
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Quote:
Originally Posted by olsen726 View Post
no offense or anything but i bet you didn't gain much of anything with that short ram and cbe
nothing to write home about. i have the rest of the pipeing to go cold air but not too comfortable doing it beeing in new england and all (i had to occurances driving at night where i suddenly found myself driving through a "river" in a rain storm). the cbe did help balance things out though...the intake cost me some low end torque due to the deletion of the air box at the throttle body and the cbe hepled gain most of it back. there definately is more power than the stock setup. i knew from thoes alone i wouldn't see serioius gains. however, having a better entrance and exit from the engine for gas flow will help allow maximum performance of any more in-depth engine modification i may do in the future.
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Old 05-11-2009, 11:05 PM   #21
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Quote:
Originally Posted by Jerry Xu View Post
Do you have data for these conclusions?

There is difference on mine with SRI, big difference. Others have reported the same:

http://forums.nasioc.com/forums/show....php?t=1156560

Where is the link/data for the no difference between the EL and UEL headers?
Please elaborate/attach some data.
Data is available. I do not possess it. It is part of the Rallitek tune on Olsen's car. Gains but not significant to impress Sean Sexton(Rallitek). I will try to see the dyno plots but I believe the same has been posted by Olsen already.
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Old 09-19-2014, 06:45 PM   #22
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gonna revive an old thread here, whats the last updated power you got out of this setup?
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Old 09-22-2014, 06:34 PM   #23
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Quote:
Originally Posted by williaty View Post
I thought the same thing you did when I started all this.

Then I actually started doing logging and dyno runs at different temperatures. These cars are a hell of a lot more sensitive to temperature than anyone gives them credit for.
-35C redline FTW
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