APS monster exhaust
08-08-2005 | 07:09 PM
#22
A monster exhaust doenst have mufflers like this one here 
We will have this system available with HKS Carbon Ti's as well as with straight pipes next month.A straight pipe system will run you about $100 and the Carbon Ti system will be about $1600-1700.We might offer some other muffler options for less money as well.
We will have this system available with HKS Carbon Ti's as well as with straight pipes next month.A straight pipe system will run you about $100 and the Carbon Ti system will be about $1600-1700.We might offer some other muffler options for less money as well.
08-09-2005 | 05:42 AM
#28
for turbo applications, the larger the diameter, the better. In fact, if you could run with no exhaust at all, it would be optimal.
Unlike NA (for low end torque etc), backpressure does not help turbo applications so the least amount of backpressure you have, the faster the spoolup on your turbos will be and you will make more power for longer in your rev range. That's also why some people are seeing 10+psi on their stock APS maps when they put in test pipes... less backpressure, more boost, more power.
Of course, you'd need to be careful about reducing backpressure too much and overboosting, so everytime you reduce backpressure, the ideal is to retune.
Unlike NA (for low end torque etc), backpressure does not help turbo applications so the least amount of backpressure you have, the faster the spoolup on your turbos will be and you will make more power for longer in your rev range. That's also why some people are seeing 10+psi on their stock APS maps when they put in test pipes... less backpressure, more boost, more power.
Of course, you'd need to be careful about reducing backpressure too much and overboosting, so everytime you reduce backpressure, the ideal is to retune.
Last edited by mojo powered; 08-09-2005 at 05:45 AM.
08-09-2005 | 06:09 AM
#29
Originally Posted by mojo powered
for turbo applications, the larger the diameter, the better. In fact, if you could run with no exhaust at all, it would be optimal.
Unlike NA (for low end torque etc), backpressure does not help turbo applications so the least amount of backpressure you have, the faster the spoolup on your turbos will be and you will make more power for longer in your rev range. That's also why some people are seeing 10+psi on their stock APS maps when they put in test pipes... less backpressure, more boost, more power.
Of course, you'd need to be careful about reducing backpressure too much and overboosting, so everytime you reduce backpressure, the ideal is to retune.
Unlike NA (for low end torque etc), backpressure does not help turbo applications so the least amount of backpressure you have, the faster the spoolup on your turbos will be and you will make more power for longer in your rev range. That's also why some people are seeing 10+psi on their stock APS maps when they put in test pipes... less backpressure, more boost, more power.
Of course, you'd need to be careful about reducing backpressure too much and overboosting, so everytime you reduce backpressure, the ideal is to retune.
08-09-2005 | 06:24 AM
#30
yes I am sure.. but I also want to make something else clear.. it's not just about diameter when we're talking about reducing the backpressure, it's also about the bends of the exhaust.
A 2.5" twin exhaust that has better bends than a larger diameter twin exhaust with less smooth bends might result in higher performance.
The ultimate is the largest exhaust with the smoothest bends no matter if you have single or twin turbo. After a certain diameter though, the gains will be minimal and eventually hit zero. But you will not lose horsepower by going larger and larger, you just won't make more power after a while and you will make your car louder and louder for no gains. So you'd have to figure out the largest diameter with most gains without going overboard since you are also making the car louder by reducing backpressure by going larger diameter and smoother bends.
That's why good quality performance exhaust are mandrel bent, which preserves the diameter size around the bends without kinking the tubing.
Please keep in mind that everything I said above is valid for single or twin turbo applications ONLY, not NA obviously.
If you're interested to learn more, here is a great article by Cobb Tuning, I hope it will help. http://www.cobbtuning.com/tech/exhaustdesign/index.html
A 2.5" twin exhaust that has better bends than a larger diameter twin exhaust with less smooth bends might result in higher performance.
The ultimate is the largest exhaust with the smoothest bends no matter if you have single or twin turbo. After a certain diameter though, the gains will be minimal and eventually hit zero. But you will not lose horsepower by going larger and larger, you just won't make more power after a while and you will make your car louder and louder for no gains. So you'd have to figure out the largest diameter with most gains without going overboard since you are also making the car louder by reducing backpressure by going larger diameter and smoother bends.
That's why good quality performance exhaust are mandrel bent, which preserves the diameter size around the bends without kinking the tubing.
Please keep in mind that everything I said above is valid for single or twin turbo applications ONLY, not NA obviously.
If you're interested to learn more, here is a great article by Cobb Tuning, I hope it will help. http://www.cobbtuning.com/tech/exhaustdesign/index.html
08-09-2005 | 06:27 AM
#31
Originally Posted by D@ActiveTuning
Are you sure that's right? I don't think you'd want a 5" exhaust for example on a twin turbo. For a single turbo you may want something crazy like that...but on twins, I thought after a certain points, there are losses? I'm basing this also on a Supra buddy, and what he's done to his car.
09-06-2005 | 04:26 PM
#36
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From: vancouver, wa
09-09-2005 | 07:20 AM
#37
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Joined: Jan 2004
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From: ATL-What U Know About That???
Originally Posted by D@ActiveTuning
Are you sure that's right? I don't think you'd want a 5" exhaust for example on a twin turbo. For a single turbo you may want something crazy like that...but on twins, I thought after a certain points, there are losses? I'm basing this also on a Supra buddy, and what he's done to his car.
Think of the exhaust spinning the turbine as you would you blowing a pin wheel. Put any form of restriction behind the pin wheel and it slows down forcing you to blow harder to maintain its speed. Same principle behind a turbo and exhaust tubing. Put a restrictive exhaust on and the turbine slows and diminishes the turbos performance. The only problems with larger exhausts are fitment and clearance issues.
09-09-2005 | 08:21 AM
#39
Originally Posted by meatbag
The less restrictive the better. For any turbo. I think on some setups you can gain low end torque with backpressure but its at the sacrifice of spool time and overal power.
Both of you are mostly correct.
The idea is to have an exhuast system that creates zero back pressure, or as close to this as possible. Even on a turbo system, high back pressure will create massive trq down low, at the expense of heat, and power up top...not ideal...and boiderline dangerous.An exhuast system that is complete open may not be ideal, as an exhuast system can help with exhuast gase scavenging, and can help draw the exhuast gases out of the combustion chamber. And a small amount of back pressure can increase low end trq. It is a very fine line.
That said...true dual 2.5 inch is generally optimal for about 10psi, and anything above that, I would be looking at a 3 inch true dual.
09-09-2005 | 10:44 AM
#40
Sharif is the voice of reason(as usual) lol. I'd rather make up for the low end losses with higher duration cams. My car can overheat easily right now at 12psi with the borla td and test pipes. My torque number is higher than my hp number because of this.
Originally Posted by Sharif@Forged
An exhuast system that is complete open may not be ideal, as an exhuast system can help with exhuast gase scavenging, and can help draw the exhuast gases out of the combustion chamber. And a small amount of back pressure can increase low end trq. It is a very fine line.
That said...true dual 2.5 inch is generally optimal for about 10psi, and anything above that, I would be looking at a 3 inch true dual.
That said...true dual 2.5 inch is generally optimal for about 10psi, and anything above that, I would be looking at a 3 inch true dual.