Got tuned at GST today
12-18-2013, 08:16 PM
#1
Registered User
Thread Starter
iTrader: (5)
Join Date: Jul 2004
Location: San Jose, CA
Posts: 4,300
Car Info: http://kiva.org/invitedby/brett4254
Got tuned at GST today
Had the 2004 STI tuned at GST today.
I'd like to first say that I'm happy with the results. The throttle response is much improved and the power comes on much more consistently now.
The results were a little disappointing from a peak power level. Mike is thinking the wastegate housing might be cracked... which would explain the HP hitting the wall at 5700 RPM Dyno chart here:
http://imageshack.us/photo/my-images/40/3bc8.jpg/
I'm deciding what I'm going to do
Another note, Mike did passes with my exhaust cutout both open and closed. It made zero difference in power output. I think this puts the debate on weather cat backs are just noisemakers to bed.
There's no way in hell any muffler flows better than an open cutout
I'd like to first say that I'm happy with the results. The throttle response is much improved and the power comes on much more consistently now.
The results were a little disappointing from a peak power level. Mike is thinking the wastegate housing might be cracked... which would explain the HP hitting the wall at 5700 RPM Dyno chart here:
http://imageshack.us/photo/my-images/40/3bc8.jpg/
I'm deciding what I'm going to do
Another note, Mike did passes with my exhaust cutout both open and closed. It made zero difference in power output. I think this puts the debate on weather cat backs are just noisemakers to bed.
There's no way in hell any muffler flows better than an open cutout
Last edited by Lowend; 12-18-2013 at 08:18 PM.
12-18-2013, 08:28 PM
#3
Registered User
iTrader: (11)
Join Date: Jan 2008
Location: Cheesesteakville
Posts: 6,833
Car Info: 05 wrx wagon, 90 celica alltrac, 66 mustang
Why didn't you post the pic in the thread? GOOD GOD ITS HUGE!
Nice looking curves! Do you have a "build thread" with all your mods listed? I need to quit being lazy and get my car done.
Nice looking curves! Do you have a "build thread" with all your mods listed? I need to quit being lazy and get my car done.
12-18-2013, 09:16 PM
#4
Registered User
iTrader: (10)
Join Date: May 2004
Location: Snatchin' your people up
Posts: 3,779
Car Info: Hilux Double Cab with a Dishka on top
I don't know if you can say definitively that catbacks don't make power. Wait until you fix your wastegate and do some dyno pulls then. You're probably not even hitting full boost right now based on your WHP numbers. For reference, a stock STi makes about 220-230whp on that dyno.
12-18-2013, 09:50 PM
#5
Registered User
iTrader: (14)
Join Date: May 2008
Location: Hayward, CA
Posts: 1,581
Car Info: amber lamps/fire engine/06 STi
I remember getting tuned by mike for a stage 2 wrx when I was young and naive and thought the dynograph would read 900whp. Boy was I disappointed haha. Ignore the numbers and appreciate the curve!
12-18-2013, 10:04 PM
#6
what kind of numbers were you talking about? Don't know if I wanna get a tune now anytime soon...... I'm like barely stage 1 about to go stage 2 or 2.5.
12-18-2013, 10:20 PM
#7
Registered User
iTrader: (5)
Join Date: Aug 2010
Location: Monterey, California
Posts: 4,961
Car Info: Miata and dirtbikes
I don't know if you can say definitively that catbacks don't make power. Wait until you fix your wastegate and do some dyno pulls then. You're probably not even hitting full boost right now based on your WHP numbers. For reference, a stock STi makes about 220-230whp on that dyno.
12-18-2013, 10:41 PM
#8
Registered User
iTrader: (2)
Join Date: May 2009
Location: SF Bay
Posts: 404
Car Info: 08 WRB/Gold STI. EQ Tuned, E85, 340whp 390wtq
I remember on my 08STI Mike got me 268whp & 285wtq, that was stock DP & AEM intake. Great tune.
With an OTS Cobb Stg1 tune (Base Run) & stock airbox it was 245whp & did fall off at ~5600rpm, you can see below the whp profile is similar to yours at the topend. Are you on the stock airbox?
With an OTS Cobb Stg1 tune (Base Run) & stock airbox it was 245whp & did fall off at ~5600rpm, you can see below the whp profile is similar to yours at the topend. Are you on the stock airbox?
12-19-2013, 05:38 AM
#9
Registered User
Join Date: Mar 2008
Location: San Leandro, CA
Posts: 3,856
Car Info: Forester XTi
Why would you have a cutout anyplace but right after the turbo? Kind of defeats the reason for having one if its anywhere but right after the turbo/headers(in a NA car).
12-19-2013, 08:38 AM
#10
Registered User
iTrader: (2)
Join Date: Nov 2009
Location: Dublin, CA
Posts: 369
Car Info: 02 WRX sedan
But the dyno posted later in the thread kinda verifies that. Picture is worth a bunch of words or something.
12-19-2013, 09:13 AM
#14
previously known as wrxBRAH
iTrader: (17)
Join Date: Sep 2010
Location: San Jose / Campbell
Posts: 3,383
Car Info: 2004 FXT
I thought it was well known that a muffler alone wouldn't give any extra power. I am curious though of actual numbers with a cutout on a catless DP. I've always heard things like 30hp+ but nothing to support that claim.
12-19-2013, 09:23 AM
#15
Registered User
Thread Starter
iTrader: (5)
Join Date: Jul 2004
Location: San Jose, CA
Posts: 4,300
Car Info: http://kiva.org/invitedby/brett4254
Mike indicated that stock STI's generally pull ~215WHP on his dyno. Which is in line with numbers I've seen elsewhere. Again - I'm happy with the results of his tuning; the throttle response and fatness of the powerband (what you should really care about) is much improved.
Ed - The car is a 2004 STI with just over 100K miles
Engine mods are minimal
Overbear - to be honest, I wanted a noisemaker. There are lots of issues that come up with a downpipe mounted cutout that I just didn't want to deal with.
A moment more on the catback HP issue.
My car even with the problem is pulling about 35WHP more than stock. With the cutout open there were no gains. The more power you make, the more CFM your exhaust system needs to move.
Being that a stock vehicle isn't making anywhere near the exhaust CFM demands that my car is, it stands to reason that a cat back which will flow less than an open cutout will show no increase on a stockish car.
As your horsepower levels increase - the the benefits of a larger exhaust will no doubt come into play. BUT I will also note that back in my Speed Merchant days, we regularly made over 400WHP on a catted single 3" exhaust with LSx powered Camaro's
Ed - The car is a 2004 STI with just over 100K miles
Engine mods are minimal
- Grimmspeed crank pulley (non-underdrive)
- AVO Catted Downpipe
- Cobb after MAF tube
- Airbox silencer eliminator
- 255lph fuel pump
Overbear - to be honest, I wanted a noisemaker. There are lots of issues that come up with a downpipe mounted cutout that I just didn't want to deal with.
A moment more on the catback HP issue.
My car even with the problem is pulling about 35WHP more than stock. With the cutout open there were no gains. The more power you make, the more CFM your exhaust system needs to move.
Being that a stock vehicle isn't making anywhere near the exhaust CFM demands that my car is, it stands to reason that a cat back which will flow less than an open cutout will show no increase on a stockish car.
As your horsepower levels increase - the the benefits of a larger exhaust will no doubt come into play. BUT I will also note that back in my Speed Merchant days, we regularly made over 400WHP on a catted single 3" exhaust with LSx powered Camaro's
Last edited by Lowend; 12-19-2013 at 11:35 AM.