Horsepower with Warranty

[Kirby]

Dalite,
I'm thinking the same thing , since I have the BTG duals myself, and my "seat of the pants" dyno would agree with Larry's findings.

I would dearly love to see not only what 20 more horses on top would do, but the 1st gear boost and broader range duty cycle would make it feel like 40.
Too bad, I live in southern CA, they have smog only shops that don't allow ANY funny business.

[Ian-PT-GT]

Here I go again with old school.

I was taught that: One mod by itself won't make a big diference but if you combine it with other items, the performance increase will be biger. for example: If you increase boost, remove intake restrictions and increase fuel flow, where would the bottleneck be? In the exhaust. Once installed, you will se a big improvement.

On the othe hand, If you just install the exhaust and don't do anything else to the engine, your HP increase will be very low.

$0.02

Ian

[SteelBlueGT]

I agree with old school too. Because when "old schol" dont work it becomes "no school". There is a lot of truth in what you say! However, every once in a while one mod does make a big difference. I put on an X pipe on my 87 Mustang 5.0 and it alone made a big difference of course I then immediately added headers and even through the factory cat backs and stock intake that combo rocked!

[Ian-PT-GT]

The trick is "Combination"!

You cannot place something by itself and hope to get 20 Horses. The Mustangs and Most V8 are by default "detuned" to meet legal standards, any mod would liberate hidden horses. 4 Cylinder cars are almost maxed out from the factory to keep up with the increased horsepower minimums. A bolt on item by itself doesn't guarantee instant satisfaction.

I was reading an article in "Sport Compact Car" about an exhaust for a Mini cooper. The exhaust actually reduced horsepower by 3 with the "Performance" mufflers the kit came with. With them removed, the car improved but the noise was unbearable. But because it is a low restriction and it was a Titanium kit, later mods would work better and horsepower gains will be more noticeable.

Again, $0.02

Ian

[jramosGT]

I had read that post about gaining 20 hp with an exhaust upgrade. That might happen if one were to replace the catalytics as well as the OE muffler. No way it could happen otherwise.

The rotary engine is well-noted for being more responsive then a piston engine to intake and exhaust changes. A cat-back on a rotary gives a 5 hp increase to the wheels. Replacing the the pre-cat and main-cat with a downpipe and midpipe, respectively, adds 20-25 hp to that.

Given that the GT OE muffler is already somewhat free-flowing, I doubt if even 5 hp would be gained by installing a cat-back only. IMO.

[COP TZER]

i essentially have twin straight pipes run on my GT, but with a cat (damn emissions), as well as an intake...all that's left to do is a matching down pipe then we'll see some serious gains. Simply doing any one of the three with out the others will not yield much of a gain as they work together... Keep in mind also, that to do future mods on a turbo engine these three are the basis from which to build your platform

[dsm_mike]

"to do future mods on a turbo engine these three are the basis from which to build your platform"

Exactly. While doing these mods may provide a decent amount of power, on a turbo engine these mods are not done necesarily to increase power, but to support the power from added boost. Slapping a boost controller on a stock car may seem like a cheap and quick way to increase performance noticably, but the gains would be much higher once the engine can breath properly.

Also, these mods make the car more effiecient. If you drive normally, you should see some increases in fuel economy. This is kind of hard to do though, since the car is much more fun with them, its kinda hard to stay off of the boost. Also, your mileage may vary.
Just my $.02

[Kirby]

I have a BTG dual exhaust. It may not give me the 20 hp that the poster boy got, but it did SIGNIFICANTLY change the performance of my car.
The OE exhaustwas NOT mendrel bent, I would guess the tube was squeezed down to at least a 2' dia at the bends. The bends themselves were more severe, one being a complete 90 degree bend.

The BTG exhaust has fewer changes in direction and is "smooth as a babys but" for flow.

Changing a baffled muftler for straight through resonators released a lot of backpressure.

My around town mileage increased by at least 5mpg, I don't know why, but a tank goes much further now.
I pull several hills regularly... this too improved substantially.
I love the exhaust note, not too loud, but pleasant. My wife says that the car purrs like a cat now.

I sincerely hope that if the stage I upgrade is EVER released to the unwashed masses, that it has as much effect on my PT.

[OVcruzn]

Lotsa inf on the BTG system...anyone put on the Scottsdale duals or any other for that matter? Looking at getting duals put on this month. Also, anyone make an aftermarket (gutted?) cat? Thanks for the info.

[dsm_mike]

Nobody sells gutted cats. You could gut your own cat and get a mil eliminator if you dont have to worry about emissions testing. You could also get a test pipe, or if you want to be a tree hugger about it[], you might be able to find a high flow cat, dont know if anybody has made one yet though.