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Old 02-28-2005, 09:50 AM   #1
Darryl
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Default Best way to increase low-end grunt?

hi gang,
For low end grunt there comes to mind no fix except more displacement. Having said that, and possibly showing my ignorance, what can one do to increase low end-lower rpm torque in the 2.0 ej20?
I have the old Club Spec kit (minus the Unichip), and the Cobb Stage2 reflash for 93-octane. One thing I have done that seems to work well with the reflash is to tighten the tension on the wastegate actuator. This allows the turbo to spool faster, making boost avaialble a bit earlier than before. I suspect this makes things work "normally" now. Drivability seems much improved. I'm seeing 5-6 lbs of boost in closed loop 1st gear pull-off before it drops off. I think the Cobb reflash allows higher than stock boost in 1st gear during wot.
Anyway, what are some ways to get that V-8 grunt? IIRC, headers are good for top end work. I still have the stock up pipe on, and not gutted.
thanks,
Darryl
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Old 02-28-2005, 10:20 AM   #2
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First thing is replace your stock uppipe with either an aftermarket one or a gutted stock uppipe...

Second would be items like intercooler hoses, pulleys, turbo inlet hoses...

Beyond that you get into things like reducing rotational mass (i.e. lighter wheels) or going with a lighter aftermarket flywheel to help the engine rev a little quicker...

Or a twinscroll turbo setup...

Just a few thoughts...

Peter
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Old 02-28-2005, 10:22 AM   #3
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Quote:
Originally Posted by Darryl
Anyway, what are some ways to get that V-8 grunt? IIRC, headers are good for top end work. I still have the stock up pipe on, and not gutted.
thanks,
Darryl
There is no way to get V8 grunt in the low end, besides getting a V8. An aftermarker uppipe and IC hoses will help alot, but there is no replacement for displacement.
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Old 02-28-2005, 10:45 AM   #4
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You heard him, buy something with a smallblock...It's just not in your cars nature. You can get spool-up a couple hundred rpms lower, but you're never going to get a low rpm "hit" or any of that grunt with a 2.0 liter...especially not a low compression turbocharged one...

Just be happy you're off boost gas milage is better...

John

Quote:
Originally Posted by mbiker97
There is no way to get V8 grunt in the low end, besides getting a V8. An aftermarker uppipe and IC hoses will help alot, but there is no replacement for displacement.
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Old 02-28-2005, 10:52 AM   #5
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I could be wrong about this, and don't know from experience, but I have heard that there are some differences when you compare the US and JDM stock ecu. People have said that the JDM stock ecu delivers more boost at lower rpms than the US one. Appearently the US one is trying to reduce emissions in the lower RPM range. So, it stands to reason that you could get a little more low-end torque with more boost in that range. And, it sounds like thats what you've tried to do with the wastegate changes.
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Old 02-28-2005, 12:08 PM   #6
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deleted. did not read closely enough.

Last edited by ptaaty; 02-28-2005 at 06:17 PM.
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Old 02-28-2005, 12:13 PM   #7
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You seriously need to invest in an aftermarket up pipe, and I/C hoses. Maybe even a better flowing TMIC. Or a spray of nitrous from 1,000rmp-3,000rpm. JUst a 75shot.
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Old 02-28-2005, 12:13 PM   #8
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AP - AccessPORT......research it....
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Old 02-28-2005, 12:13 PM   #9
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Cleaning up the airflow will help. (Inlet hose, Y pipe, Up pipe, TGV delete...) However, the only thing that will really bump low end on a 2.0 is a quick shot of NOS. This can cause a lot of other issues, but it will speed up spool considerably.
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Old 02-28-2005, 01:23 PM   #10
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BOV. . .

The up pipe and IC hoses are probably the most feasible without getting drastic. 2WD conversion will eliminate much of your drivetrain loss. . . if you want to go crazy with it. But as it's been said, no 2.0 is gonna give lotsa grunt, it's just not in the cards.

Can't you stroke this engines a bit? I know that a stroker V8 is awesome for grunt. Not sure how subies respond to that, or if there's room.

What about a supercharger to replace your turbo? They spin tires very well.
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Old 02-28-2005, 01:32 PM   #11
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Slap in a 2.5L shortblock.

use a proper turbo with a good Electronic boost controler.
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Old 02-28-2005, 02:06 PM   #12
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Just a thought --

Would going 1 cat (highflow) in the downpipe for Cobb stage 2 yield more low end throttle response? -- versus catless of course.
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Old 02-28-2005, 02:09 PM   #13
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Quote:
Originally Posted by bryan_johnson
I could be wrong about this, and don't know from experience, but I have heard that there are some differences when you compare the US and JDM stock ecu. People have said that the JDM stock ecu delivers more boost at lower rpms than the US one. Appearently the US one is trying to reduce emissions in the lower RPM range. So, it stands to reason that you could get a little more low-end torque with more boost in that range. And, it sounds like thats what you've tried to do with the wastegate changes.
I believe the JDM's allow for full boost at partial throttle, whereas the USDM's require full throttle too acheive full boost. Don't hold me to that cause I may be mistaken, but that's what I've read.

Of course, that doesn't help your low end grunt issue...which you shouldn't consider an issue cause it's just the car's nature. In spirited driving, just keep it in the 3-5k rpm range, where it really comes alive. The car was built for that.
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Old 02-28-2005, 02:11 PM   #14
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Add AVCS.
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Old 02-28-2005, 02:20 PM   #15
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ebeck just inspired a new thought here...

jdm v8 swap...

Not exactly the most cost effective route
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Old 02-28-2005, 02:50 PM   #16
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I would suggest a 2.5 block with a small turbo and pistons to raise the compression.

A JDM version 8 motor is not going to have more low end than a stock turbo WRX.
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Old 02-28-2005, 02:58 PM   #17
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up pipe
Port the exh housing on your turbo
Port your FACTORY EXH MANIFOLDS
GM boost control solenoid or Perrin's
Free flowing TMIC like a hyperflow core
Lightened pullies
catless turboback
GOOD custom tune, this means either take the car to cobb, or go to engine management that you can get it tuned on a dyno.

I have heard of cars with the above setup making 245+ft/lbs at the wheels by 4krpm
Thats pretty much small block V8 grunt. I drove a car like that, there was NO, and I mean NO lag. Instant power when you hit the gas. It made 14PSI by roughly 2500RPM and was peaked at 17PSI by 3000rpm. It almost made positive manifold pressure off idle.
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Old 02-28-2005, 02:59 PM   #18
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Quote:
Originally Posted by Capt Crunch

A JDM version 8 motor is not going to have more low end than a stock turbo WRX.

The hell it wont. (as long as AVCS is working)
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Old 02-28-2005, 03:57 PM   #19
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Quote:
Originally Posted by StealthfishWRX
AP - AccessPORT......research it....
Thats not going to help him much, he already has a cobb stage 2 reflash...
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Old 02-28-2005, 04:03 PM   #20
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Quote:
Originally Posted by Happy_Days
Just a thought --

Would going 1 cat (highflow) in the downpipe for Cobb stage 2 yield more low end throttle response? -- versus catless of course.
Nope.
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Old 02-28-2005, 04:54 PM   #21
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Quote:
Originally Posted by Davenow
up pipe
Port the exh housing on your turbo
Port your FACTORY EXH MANIFOLDS
GM boost control solenoid or Perrin's
Free flowing TMIC like a hyperflow core
Lightened pullies
catless turboback
GOOD custom tune, this means either take the car to cobb, or go to engine management that you can get it tuned on a dyno.

I have heard of cars with the above setup making 245+ft/lbs at the wheels by 4krpm
Thats pretty much small block V8 grunt. I drove a car like that, there was NO, and I mean NO lag. Instant power when you hit the gas. It made 14PSI by roughly 2500RPM and was peaked at 17PSI by 3000rpm. It almost made positive manifold pressure off idle.
^^^If you want low end....listen to Dave....'cuz he knows.... ......and I know someone that had almost the same setup and it ROCKED
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Old 02-28-2005, 06:24 PM   #22
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Stock makes peak torque at about 4K and makes about 160# of torque at that point. I have make 140# more at the same rpm with a "laggy" turbo. I also make 100whp more at that same rpm point than my USDM VF34 did. I often wonder if those with JDM motors even have thier AVCS running. AVCS can actually be not functional and get no CEL. I have heard 3 people recently with JDM motors state that AVCS does not make a difference in low end. Strange. It is SIGNIFICANT. Here is a guys take on it after I took him for a ride. http://forums.nasioc.com/forums/show...ight=light+JDM

It is not that expensive to do a swap. Check it out... http://forums.nasioc.com/forums/show...ight=stage+jdm

For a 300-350whp car, on pump fuel, a JDM 2.0 is REAL hard to beat. A real 300-350whp. Not the "my USDM, VF34 makes 320whp."
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Old 02-28-2005, 07:25 PM   #23
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Quote:
Originally Posted by Darryl
One thing I have done that seems to work well with the reflash is to tighten the tension on the wastegate actuator. This allows the turbo to spool faster, making boost avaialble a bit earlier than before.
Does Cobb recommend this? Something tells me their reflash was not meant to work with something like that..
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Old 03-01-2005, 03:14 AM   #24
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Low end grunt is just displacement and in the STI's case the gearing helps as well. On a 2.0L your better gaining it back in the mid/top end of the power band, it is much easier to accomplish. Its almost like asking a v8 to rev to 7-8000rpms, not many do, and to do so takes a great amount of work. Work with what you have and what seems to work. It'll save you alot of money in the long run.
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Old 03-01-2005, 08:19 AM   #25
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thanks for the replies, guys,
I hear a familiar thread in this "thread": no replacement for displacement. Good enough for me. Oh, with the old Club_Spec kit still on the car I have sopme of the (APS) items mentioned: APS intercooler Y_hose, APS bov, APS CAI, APS TBE. One day I may do the up pipe mod too. I donn't think porting the exhaust is in my future, though.
As for Cobb recommending the wastegate tightening, I thought he did not oppse doing it to a degree. Are all wastegate actuators created (set) equal? I think not. Not all 2002 WRXs dyno the same either. So tightening the wastegate yields, imho, a very individual results. It works great for my car so far. The reflash seems to have no problem controlling boost, and there are no wild boost spikes into the nether regions of destruction. Plus, I watch the boost, and am not seeing any cause for concern insofar as boosting beyond the stock turbo's safe operating range, nor abnormally high boost in open or closed loop operation. Remember, the Cobb reflash let's the car make a bit more boost in the lower two gears.
hhmmmmmmm very intersting thoughts here.
thanks guys,
Darryl
PS about that wastegate adjustment, I have no ptfb going on.

Last edited by Darryl; 03-01-2005 at 09:03 AM.
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