Does anyone else have input on the 2.5" dp to 3"catback idea?

 

My hack job of a downpipe is 2.5" and I just got stuff today to build a 3" one. Hopefully that cuts down my spool time (I know ARM I'm not fully tuned yet) but still

 

I was told 3" should cut spool by a few hundred rpm

 

Was that a few hundred rpm for 3" dp or 2.5 dp with 3" catback

 

3" dp instead of 2.5

 

ended up putting my stock tune back on my cobalt last night. back to being an extra slow dd

 

nick what are you spooling that 5862 at?

 

Open dp ftw

 

I see MBC controlled 19 psi at about 4300rpm in 2nd gear

 

How about 3rd

 

anyone have input on my my poll i posted?

 

what are you looking for from the car?

 

Around 4k I believe maybe a little lower. I decided to get a 3"made.
So I'll have a catless dp 2.5, the 3"catback will start right at the subframe. I'll have to figure out my space issue for the dp when I have someone make a 3" dp. There's just no room by the trans mount.
The added backpressure should help with a little torque and then the 3" catback will compensate for the heavier, cooler air coming thru, almost like an open system after the dp

 

Honestly I'm not completely sure. I'm always paying so much attention to everything else going on haha.

I'm about to make a 3" downpipe and decided I'm done with the corsa catback because it will hold me back being 2.5" or smaller. I am going to be catless, to some muffler or resonator then to a turn down. I've ran open dp before and I know I can't handle that noise for daily driving. So im wondering if you guys would recommend a resonator or a muffler and what brand?

 

If you worried about noise I think that would still be too loud. Why not just get a 3" catback?

 

picked up the last of my parts. just need to get cracking on it

 

time for the millionth question!
anyone even have any weird lag in first if you boost too much? Set at 20 psi, exaclt what im tuned at, the car doesnt like it if you mash it in 1st gear once the waste gate opens. it will even lag a little in 2nd when you shift.

another way to say it is if i wanted to, and i dont!, i could not sit there and burnout in 1st full boost. the car seems to hit a little bit if a wall?? but this doesnt appear in 2nd, 3rd, or any other gear.

any ideas on this? map sensor maxing out maybe?

 

oh and btw, the 3" subframe back i ran made an awesome difference spools a little sooner and makes great sound compared to the 2.5".

 

I was trying to take the easy way out. I think I am going to end up doing that

 

I have a vibrant 3" that uses both a muffler and resonator. Never had an issue with it when the car was running. Fits like a champ, and it's 3" all the back, even at the part that bends at the rear axel.

 

Vaughn, you got a link? I'm assuming that you're wondering about switching to turbo?

 

It's official, ordered a magnaflow muffler. So if anyone is running one on their turbo lsj let me know what you think. Can't wait to have a 3" exhaust

 

a buddy of mine has that exhaust, and he's quite pleased with it. Very deep sounding, and not very loud during normal driving.

 

It'll be all custom built by me with just that muffler welded in. Should be a lot louder than the corsa

 

nah, mainly because of the turbo. He's had that exhaust since he was sc'd. Once he went turbo, it was pretty quiet.