I most likely won't mod my engine for another 18k miles, but I am curious about which of the commonly-used mods (flashed ECU, uppipe, downpipe, exhaust, bigger turbo, etc.) add power at the 65-85 MPH level rather than the 0-to-60 level.

Specifically, I've always felt that my 2002 WRX is really lacking between 4th and 5th gear on the highway -- it feels like the engine does all of its "work" in 3rd gear (which car reviewers note is "tall") and then by the time I get to 4rth, the acceleration curve feels very, very flat, regardless of when the turbo spools up. If I ride it to 5500k and then shift to 5th (at which point I am going WAY too fast!) it feels like the power drops off a cliff.

The worst scenario, however, is when I am in 5th and am forced to drop down to 60 (and 2600 rpm), then suddenly speed up again. I have seen Honda minivans pull away from me in this situation, and I was WOT. If the tach drops below 2.7k in 4th or 5th gear, there goes all the power.

So, which mods help this high-gear power specifically? I assume anything that allows the turbo to spool up sooner (in the tach curve) and more quickly would be good; obviously ECU. What would be the LEAST number of components to upgrade to gain power past 65 MPH?

 

Well, simply put, 4th and 5th gear suck. They are basically overdrive.

The best place to get better top end is the exhaust. Start with that by replacing the stock uppie and downie with aftermarket ones like a helix or perrin. If you go catless they will also help out more.

Also, if you can afford it, get an sti 6 speed tranny

 

6sp transmission?

 

^STi 6 speed tranny

 

another vote for uppipe/downpipe. I recently added the helix up/down combo along with the HKS catback and it pulls very nicely through all the gears. All that needs to be done now is to make the boost more linear instead of full boost, then tapering off.

an MBC or reflash could'nt hurt. I'm probably going to send my ecu to Cobb next month.

 

This is the route I would like to go as well, and for some of the same reasons that meiler pointed out. I would like a bit more top end power and I am hoping the reflash will smooth out the boost through the gears. Which cobb reflash are you looking at?

 

There isn't much you can do to give you good power in 4th or 5th gear without doing some good mods to your engine. The mods suggested above will help, but they don't cure the problem.

Some say that the stock WRX gearing sucks..... but that depends on what mods you have..

The reason why 4th and 5th gear 'suck' on a stock wrx is that although the car is pretty potent at 227HP from the factory, it just is not anywhere near enough power to pull those gears with any authority.

If you changed to a bigger turbo with the associated mods, 4th and 5th actually become enjoyable gears to be in.. The stock turbo is just too small to keep up in 4th and 5th gears.. You can do all of the exhaust mods and ecu flashes that you want, but as long as the stock turbo is attached to the engine, you will still find your car.... top-end challenged..

 

sounds like you could use some driving technique
keep your rpms up, dont shift if you know your rpms will be under 4k after shifting
if you have to slow down on the hwy downshift

2600rpm is the LAST place you want to be.. I think the engine is making like 50hp at that speed

oh ya top-end mods: 3" exhaust and bigger wheels

 

I used to have a Talon with a large 57 trim turbo and that thing pulled like a motha in 5th not to mention 4th. I could get from 70 to 140 pretty quickly without shifting out of 5th.

 

Trust me, I'm familliar with downshifting to gain power I spent far too many years of my life driving underpowered NA cars to NOT downshift into four every time I need to pass. My point is exactly that, however -- why should I have to be at 4400 RPM on the highway to generate sufficient power? Heck, if I ride four all the way to 4800k I am going 20 MPH over the speed limit before I ever get to five! There has to be a way to coax more power out of the car below 3k RPM, and I am thankful for the suggestions.

I took the intake silencer out of my car, but I put it back in about a week later. Why? Between the intake "whoosh" and the turbo spinning up and the increased noise, my co-workers and wife thought I was beating the HELL out of my car when I was just driving around town! I can't wait until I have a high-flow uppipe and a Borla catback, they'll think the engine is going to melt every time I go on the freeway. They all drive cars that shift at 2800 RPM and idle at a few hundred....

When I reach 36k I think I'll do a "stage 1.5" -- high-flow cat uppipe, catback 3" exhaust, ECU flash (COBB) and a bigger bolt-on turbo -- maybe even Borla headers. I want to keep all the cats; I hate the noise and smell of a catless car, and I don't like the idea of putting out all that air pollution. I may upgrade the transmission bushings and internals (a friend of mine LOVES his carbon-fiber clutch) but the shift to a six-speed seems expensive and excessive. Then again, if my driving continues to be about 80% highway like it is now, that sixth gear might be a good investment...

 

Get a uppipie and a turboback exaust, with either a re-flashed ECU or a MBC and at 2700 RPM with will be at full boost with good pull. I noticed alot more power gain with a Vishnu re-flash.
never had to downshift in traffic to get back up to speed.

 

If you want to go fast topend look into a larger turbo and associated mods. That is the only way even with different gearing it wont be as fun

 

[QUOTE]Originally posted by dr3d1zzl3
If you want to go fast topend look into a larger turbo and associated mods. That is the only way even with different gearing it wont be as fun [/QUOTE

Bigger turbo wont help him out unless he wants to keep it over 90MPH Bigger turbo means more lag for the lower RPM

 

BS, unless you're talking Alex's turbo.

 

any low displacement engine you gotta keep the rpms up.. only way to have big power at low rpms is to get a 5.0l engine.

whats wrong with a lil more rpms? ever drive an old hotrod pushing 200+whp in the 2-3000 range? having your power band up in the 5-7000 range is much much nicer