I was searching up on the hogan downpipe (with HF cat) and didn't find what I was looking for.

Tax time is here and I want to look in to a downpipe, I have a Magnaflow cat-back already....Will the hogan downpipe lose any power? and also will it throw any codes?

And If I don't go with the Downpipe, I seen that my Car has a U bend, If I delete that will it make a difference?

Thanks

 

This info is easily searchable.

Yes it can throw codes so plan on getting a tuner. Power loss, well you might lose a bit of torque but will gain HP so its a good mod for us as we have plenty of torque available. I was very happy with mine when I had it.

 

Thanks, I dont want a tuner yet, so I might just go with the ubend delete pipe.

 

What specific part of our stock downpipe has the U-bend? Maybe I'm out of it but when I look at my stock downpipe I don't see it.

 

After the cat before the join to the catback.

 

not enough of a bend on our cars to even worry about it... at least not on my monte it isn't.. had to really look for it to even see it...

had 2 exhaust guys tell me it wouldn't gain or do anything for me cuz it was so miniscule, and to just leave it...

 

The ole 3800 ubend was terrible ours isnt too bad at all.

 

Ya the 3800 powered cars U bend was horrible. THe down pipe on our cars is where we get our power.

 

The biggest restriction on the stock down pipe is the inlet. Right after the flange it shrinks internally to about 2 to 2 1/4 inches. To me it doesn't make sense to have a high flowing cat back system with such a restrictive exhaust further up, unless it's just for sound.

 

so the stock downpipe is bad.....I have to look into an new downpipe.....I have a friend here that just bought a G8 GT and bought the HP tuner, he said he can tune my car....(he works at GM here)

 

Yes he can, you are golden, just make sure he has enough credits.

 

credit are like $50 a piece right

 

Okay I might get the downpipe after all, I hope its worth it......my magnaflow cat back is sagging (the center pipe) so I have to take it in the shop, and I can get them to install the downpipe.....should I leave the resonator on? i dont want the exhaust to be raspy.

Thanks for the info

 

With the Magnaflow I would keep the resonator.

 

Thanks im looking into the downpipe, the wbody store has one as well.

 

WBody Store buys them from Hogan. WBody store is a good company and I would recommend them. I know the owner Mike and he is a great guy, fantastic customer service and a hell of a good drinking buddy!

 

well I got paid today, I didn't buy the downpipe total was going to be 430.00can from 335.95us, so I ordered smokes LED tail lights and GXP 3rd brake light sticker, total was 362.00can and tomorrow I will be ordering the Airaid TBS....one of these months I will be getting the downpipe....BTW the car is still in the snowbank....I would like to thank fastLS4 and sittingmongoose for there help in the PM's.

 

Hey WilliamGT, I would not worry about the cat unless you are going to do some serious mods.
Here is a quote straight from GM:

With its front-drive layout, the LS4’s exhaust manifolds are joined by a crossover pipe, with a single, high capacity underbody catalytic converter.

 

Yeah the DP to the cat is of more concern than the cat itself.

 

so your saying that our cat is high flow as it is?

I was looking at this down pipe from hogan DP5S, just get an exhaust shop to weld the stock cat on it.

http://www.hoganperformance.com/DP5S.htm