Stillen dual catback and spacer installed with dynos
Stillen dual catback and spacer installed with dynos
I took some time today to have my Stillen exhaust and spacer installed at Altered Atmosphere.
First impressions:
1) The Stillen is not loud for an aftermarket exhaust. It is louder than stock, but not annoying. I won't comment on which sound I like better; the stock was unique with its raspiness, the Stillen is more of a typical, nice, deep base sounding exhaust.
2) I couldn't discern any additional noise from the Z tube and spacer.
The maximum power increase I made was +11hp. However, if you look at the dynos, they are getting higher with successive runs. I did not drive the car at all after the install, it went right into the dyno.
In the dyno, the green line is my base from 2 weeks ago and the blue line is my first run today, and the red line is my last run today. In between these there were 1 or 2 runs that the dyno failed to graph, so the red line is about the 4th dyno today.
What you see is power and torque increases pretty much across the board. Stock, the power curve became flat at about 5600rpm whereas with the mods it keeps going up the whole way. It turns out that my car is 400prm off--he let off the gas when my car said 6500 rpm, but it turns out this was only 6100 rpm so I really still had an additional 400rpm to potentially make even more power.
On the street, the car feels much stronger than these numbers would suggest. The car is pulling really hard now, especially up high.
One memorable moment was when I was running WOT in first, for the first time ever I broke traction at around 4000rpm after having good traction to begin with. My guess is that the car is making more than the dyno-stated 11hp gain. Next time I go back after a few weeks I will dyno again and see if things have changed.
I decided not to put on my UR pulley set, so if anyone wants to purchase these from me with belts, never used, send a PM.
My next mods are the JWT clutch and flywheel and lastly an ECU reflash to add some fuel up high where I was running really lean between 3600-4600.
Just FYI--my max power and torque uncorrected were 248hp and 239 torque.
JZ
First impressions:
1) The Stillen is not loud for an aftermarket exhaust. It is louder than stock, but not annoying. I won't comment on which sound I like better; the stock was unique with its raspiness, the Stillen is more of a typical, nice, deep base sounding exhaust.
2) I couldn't discern any additional noise from the Z tube and spacer.
The maximum power increase I made was +11hp. However, if you look at the dynos, they are getting higher with successive runs. I did not drive the car at all after the install, it went right into the dyno.
In the dyno, the green line is my base from 2 weeks ago and the blue line is my first run today, and the red line is my last run today. In between these there were 1 or 2 runs that the dyno failed to graph, so the red line is about the 4th dyno today.
What you see is power and torque increases pretty much across the board. Stock, the power curve became flat at about 5600rpm whereas with the mods it keeps going up the whole way. It turns out that my car is 400prm off--he let off the gas when my car said 6500 rpm, but it turns out this was only 6100 rpm so I really still had an additional 400rpm to potentially make even more power.
On the street, the car feels much stronger than these numbers would suggest. The car is pulling really hard now, especially up high.
One memorable moment was when I was running WOT in first, for the first time ever I broke traction at around 4000rpm after having good traction to begin with. My guess is that the car is making more than the dyno-stated 11hp gain. Next time I go back after a few weeks I will dyno again and see if things have changed.
I decided not to put on my UR pulley set, so if anyone wants to purchase these from me with belts, never used, send a PM.
My next mods are the JWT clutch and flywheel and lastly an ECU reflash to add some fuel up high where I was running really lean between 3600-4600.
Just FYI--my max power and torque uncorrected were 248hp and 239 torque.
JZ
Last edited by JZ39; Mar 16, 2006 at 06:36 PM.
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Originally Posted by G35_TX
Nice, wish you had the break down per RPM for the stock and modded. Because per looking at the graph around 3500-4500 you gained around 15 hp and 15 tq. 
the stillen exhaust/spacer/ztube combo is so tempting, esp after seeing this dyno...
Originally Posted by JZ39
First impressions:
1) The Stillen is not loud for an aftermarket exhaust. It is louder than stock, but not annoying. I won't comment on which sound I like better; the stock was unique with its raspiness, the Stillen is more of a typical, nice, deep base sounding exhaust.
1) The Stillen is not loud for an aftermarket exhaust. It is louder than stock, but not annoying. I won't comment on which sound I like better; the stock was unique with its raspiness, the Stillen is more of a typical, nice, deep base sounding exhaust.
Last edited by RebelinRI; Mar 17, 2006 at 03:03 AM.
The pulley install was 200$ and all of the guys at this shop (that specializes in Zs BTW) have said that performance-wise the pulleys really aren't worth i on the Z/G.
I think the money will be better spent on having them tune my car once the clutch and flywheel is in and I have a few miles in with these mods. They said that almost everyone's NA car that they have tuned has picked up a max of 14-16 hp in parts of the power band. It helps having these guys locally.
Then, I'll lower the car and be largely done with the performance mods--unless the header itch comes.
Thanks for the replies.
JZ
I think the money will be better spent on having them tune my car once the clutch and flywheel is in and I have a few miles in with these mods. They said that almost everyone's NA car that they have tuned has picked up a max of 14-16 hp in parts of the power band. It helps having these guys locally.
Then, I'll lower the car and be largely done with the performance mods--unless the header itch comes.
Thanks for the replies.
JZ
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