Forged Performance: 2011 STi Sedan MONSTER Build **check back often**
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From: Texas
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Are you gonna finish tuning after getting catback on there? I read this week in a magazine where a big turbo supra gained 103whp going from 3inch to 3.5inch catback. I thought catbacks where overpriced and didn't do much but I may get a catback for my car after seeing that.
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Former Vendor
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From: Marietta, GA
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Are you gonna finish tuning after getting catback on there? I read this week in a magazine where a big turbo supra gained 103whp going from 3inch to 3.5inch catback. I thought catbacks where overpriced and didn't do much but I may get a catback for my car after seeing that.
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Former Vendor
Joined: Jun 2010
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From: Marietta, GA
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Hi everyone,
I want to give you a brief street-based review of the GT Spec and Whiteline components now that I've had a chance to drive the car around town for about 350 miles. As a refresher, we've installed nearly the entire GT Spec and Whiteline catalog on our 2011 STi sedan, however, the shocks are still stock with just some drop in TEIN S-Tech springs. Obviously, the shocks leave something to be desired, but here are my impressions nonetheless.
Even on stock shocks, the car's chassis is transformed from washy and unstable to very firm and tight. Gone is the overall slop and play of the OEM bushings and arms. The car now tracks straight and true with very little input from the driver. Body roll has been reduced and staright line manners have not been sacrificed. It's also important to note there is ZERO increase in noise, harshness, rattles, or anything else of that nature. It's tight and quiet as a church mouse.
That said, we are really looking forward to installing the JRZ RS1 coilover's which are really the centerpiece of our suspension system. As a preview we just installed the first set of JRZ RS1's on the Forged Performance 370Z and the improvement is literally night and day compared to the TEIN Monoflex's that were on the car. The car changes directions like a go kart with no body roll whatsoever yet is extremely compliant in a straight line for daily driving purposes.
Once the JRZ RS1's are installed and dialed in, I'll be retesting the STi at Road Atlanta in March. I am really looking forward to what kinds of laptime improvements we see.
Now back to working on the exhaust...
Sharif
I want to give you a brief street-based review of the GT Spec and Whiteline components now that I've had a chance to drive the car around town for about 350 miles. As a refresher, we've installed nearly the entire GT Spec and Whiteline catalog on our 2011 STi sedan, however, the shocks are still stock with just some drop in TEIN S-Tech springs. Obviously, the shocks leave something to be desired, but here are my impressions nonetheless.
Even on stock shocks, the car's chassis is transformed from washy and unstable to very firm and tight. Gone is the overall slop and play of the OEM bushings and arms. The car now tracks straight and true with very little input from the driver. Body roll has been reduced and staright line manners have not been sacrificed. It's also important to note there is ZERO increase in noise, harshness, rattles, or anything else of that nature. It's tight and quiet as a church mouse.
That said, we are really looking forward to installing the JRZ RS1 coilover's which are really the centerpiece of our suspension system. As a preview we just installed the first set of JRZ RS1's on the Forged Performance 370Z and the improvement is literally night and day compared to the TEIN Monoflex's that were on the car. The car changes directions like a go kart with no body roll whatsoever yet is extremely compliant in a straight line for daily driving purposes.
Once the JRZ RS1's are installed and dialed in, I'll be retesting the STi at Road Atlanta in March. I am really looking forward to what kinds of laptime improvements we see.
Now back to working on the exhaust...
Sharif
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Former Vendor
Joined: Jun 2010
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From: Marietta, GA
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Careful! We will hold you to it.
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Former Vendor
Joined: Jun 2010
Posts: 1,354
From: Marietta, GA
Rep Power: 0
Ok, we just wrapped up our prototype 3inch exhaust. We are still making some changes to the system, but I want to share a quick teaser dyno. On the first pull, I realize just how much trq, spool, and power we were missing and the results are nothing short of spectacular. Boost level is the same on both runs, and I think we're one of the only shops to post boost curves. All in the interest of sharing as much as possible with the community.
The only change is we switched from the stock exhaust to our 3 inch exhaust. I did not adjust timing, but I did have to ADD additional fuel because the new exhaust naturally resulting in less backpressure and more efficiency from the engine.
400rpm earlier spool which shifted the power curve 400rpm to the left
50ft/lbs peak trq improvement and 21whp peak improvement.
But even more telling, is the 100lb/ft trq improvement in the midrange
That said, the car as it sits now is actually decent in the midrange and a lot of fun to drive around town. Certainly not a road racing turbo by any means but much more tolerable than I would have expected with this big PTE 6765. I've got a bit more tuning to do on pump, but so far these are the highest numbers I've produced from 20psi on a 100% stock engine STi on our dyno. It would be nice to hit the magic 400whp on pump. Good stuff.
Shortly after that, we'll do some before/after testing of the one-of-a-kind AMS Prototype Intake Manifold.
The only change is we switched from the stock exhaust to our 3 inch exhaust. I did not adjust timing, but I did have to ADD additional fuel because the new exhaust naturally resulting in less backpressure and more efficiency from the engine.
400rpm earlier spool which shifted the power curve 400rpm to the left
50ft/lbs peak trq improvement and 21whp peak improvement.
But even more telling, is the 100lb/ft trq improvement in the midrange
That said, the car as it sits now is actually decent in the midrange and a lot of fun to drive around town. Certainly not a road racing turbo by any means but much more tolerable than I would have expected with this big PTE 6765. I've got a bit more tuning to do on pump, but so far these are the highest numbers I've produced from 20psi on a 100% stock engine STi on our dyno. It would be nice to hit the magic 400whp on pump. Good stuff.
Shortly after that, we'll do some before/after testing of the one-of-a-kind AMS Prototype Intake Manifold.
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From: Texas
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Nice! So to be clear those gains are form switching form a stock catback to 3inch catback?
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Former Vendor
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From: Marietta, GA
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Yes, but keeping in mind,we also have the turbo kit, intercooler, and the rest of the power adders in that mix. But yes, the exhaust was the only "additional" change that generated this power improvement.
Registered User
Joined: Nov 2010
Posts: 81
From: Texas
Rep Power: 19
Ok, we just wrapped up our prototype 3inch exhaust. We are still making some changes to the system, but I want to share a quick teaser dyno. On the first pull, I realize just how much trq, spool, and power we were missing and the results are nothing short of spectacular. Boost level is the same on both runs, and I think we're one of the only shops to post boost curves. All in the interest of sharing as much as possible with the community.
The only change is we switched from the stock exhaust to our 3 inch exhaust. I did not adjust timing, but I did have to ADD additional fuel because the new exhaust naturally resulting in less backpressure and more efficiency from the engine.
400rpm earlier spool which shifted the power curve 400rpm to the left
50ft/lbs peak trq improvement and 21whp peak improvement.
But even more telling, is the 100lb/ft trq improvement in the midrange
That said, the car as it sits now is actually decent in the midrange and a lot of fun to drive around town. Certainly not a road racing turbo by any means but much more tolerable than I would have expected with this big PTE 6765. I've got a bit more tuning to do on pump, but so far these are the highest numbers I've produced from 20psi on a 100% stock engine STi on our dyno. It would be nice to hit the magic 400whp on pump. Good stuff.
Shortly after that, we'll do some before/after testing of the one-of-a-kind AMS Prototype Intake Manifold.
The only change is we switched from the stock exhaust to our 3 inch exhaust. I did not adjust timing, but I did have to ADD additional fuel because the new exhaust naturally resulting in less backpressure and more efficiency from the engine.
400rpm earlier spool which shifted the power curve 400rpm to the left
50ft/lbs peak trq improvement and 21whp peak improvement.
But even more telling, is the 100lb/ft trq improvement in the midrange
That said, the car as it sits now is actually decent in the midrange and a lot of fun to drive around town. Certainly not a road racing turbo by any means but much more tolerable than I would have expected with this big PTE 6765. I've got a bit more tuning to do on pump, but so far these are the highest numbers I've produced from 20psi on a 100% stock engine STi on our dyno. It would be nice to hit the magic 400whp on pump. Good stuff.
Shortly after that, we'll do some before/after testing of the one-of-a-kind AMS Prototype Intake Manifold.
Last edited by Rollracer; Feb 15, 2011 at 03:09 PM.