Exhaust Q's!

1. Does anyone here have SLP or Dynomax cat-back exhaust, and do you like either of them? Which is better to get?
2. Does the dynomax catback delete the stock resinator? I cant tell from the picture on PFYC.com
3. What Does the stock resinator do, and does it restrict exhaust flow?
4. What kind of horsepower gains can i expect with just a intake and catback exhaust, pcm, & U-Bend Delete?
Thanks for your help!

1. No
2. I believe it does
3. The resonator takes the sound and resonates it through a chamber, making the exhaust note considerably quieter. It does restrict flow, if only slightly.
4. You can expect APROXIMATELY 30hp, depending on other mods. UBend is good for like 10-15, PCM is another 10-15 with no mods, and catback isnt really a hp increase, because the stock one is good to like 300whp.

Hello,

1. I can't help you with that one.
2. Catback Exhaust does not delete the U-bend. Catback Exhaust is designed to bolt to the flange just after the U-bend.
3. I agree with Evolution, and would like to add that the resonator is primarily designed to reduce cabin noise. Slightly restrictive, but, IIRC you can see through it, so restriction is minimal.
4. I'm guessing 20-30HP

Later now,
Clint

Ditto.Chico

Let us know what happens with you choice.

Basically what i got from your answers is that stock exhaust is pretty much fine for flow. Do you think cat-back exhaust is mainly for sound, maybe a lil better flow? Thanks for all of your answers

Here is Trasher's study of exhaust.
http://thrashercharged.com/tech_htm/exhaust.shtm

In my opinion and based on this study, it does help hp but not by much. Heavy modded cars would benefit more. However, it is primarly for sound.

thanks tasty bake that link was interesting. so a cat-back will typically gain about 5-7hp, and up to 10hp at the most. I read somewhere on hear that replacing the U-Bend will add another 10hp is that true??? if it is, that would mean that u-bend adds 10hg of backpressure???

For stock to mild mods go with a set of muffs. Best bang for the buck. On Ebay you can grap a pair of flowmasters for about 100.

So should i just keep the stock exhaust and upgrade mufflers, and u-bend delete?

What are your mod plans for the motor? That's the biggest question. That will decide what you should do with the exhaust.

Agree with Herc. Think about what extent your mod plans are for the GP.

Definately, get the U-Bend delete. It will give you around 4-8 hp gain. If you're thinking about getting muffs, you also think about getting 2.5" pipes. Going further, you can think about getting a 3" downpipe with/out a hi-flow cat.

Post up if you have further questions.

I deleted my cat, u-bend and res. with one 2 1/2" straight pipe with a 02 sensor bung for after the cat. I lost approx 2MPG and gained approx 10-15 hp to the wheels. This was when the car was completely stock.

I bet the loss of MPGs is because you can't keep your foot out of the happy pedal.

You should have gained some MPG.
Agree with Herc, ease up the happy pedal.

Just can't help it...

Why not just do the whole thing while you are there?

It will probably be cheaper to do it all at once.