Does bad exhaust job=low boost??

[lamboiah]

I just got a 3" in/4" out megan exhaust installed. The installer really messed things up though!! He cut the main tube to the stock exhaust and capped it, then welded a 2 1/4 or 2 1/2" tube from the 3" megan to the bypass tube. My 9th grade knowledge of physics suggests to me that this severely affects my flow. My problem is that my boost still reads the same boost on primary and secondary but the car just doesn't have the same go as before.

[*]Is the boost loss totally due to the exhaust job

[*]What should I do when it is rectified?

[*]do 3" bends from the megan then reduce to 2.5"? or,

[*]do the reduction at the megan then do the bends in 2.5" tubing

[Joker]

2.5" is optimal from my readings, from Turbo slowly "opening" to 3" near end but not what you described

but OMG look at that hack job - did you ask for cheep or quick job perhaps?

[lamboiah]

No actually I asked him to tell me what I needed to get it done. I expected him to give me a list of bends and sizes but he said he could get it done. Didn't expect this at all. I'm sourcing the bends and will have it redone.

[Guest DVNT]

 JoKer said:

2.5" is optimal from my readings, from Turbo slowly "opening" to 3" near end but not what you described

but OMG look at that hack job - did you ask for cheep or quick job perhaps?

+1 on the hack job dude thats bad ask for your money back...no seriously ;D

[DRFVDR]

I would actually suggest asking for your money back and going somewhere else

the guy dont know sh*t,cant weld,does not have correct tools and is a tool

U do not gas cut exhausts

[lamboiah]

Yeah I agree with you guys about the refund. I'm definitely going after that!

Can any one suggest how to get from the 2.5" tubing before the diff-back to the 3" muffler?

[DRFVDR]

just run 2.5 over the axle then use a 2.5 to 3 reducer to the muffler

[Glen]

That is disgusting. Even worse than the time I took mine to Pitstop. Refund and then never go back there!

[lamboiah]

Does anyone think that my boost could be affected by the setup?

[Glen]

Does it run a seperate pipe from each turbo?

[lamboiah]

No it's the stock JDM setup. The stock tubing splits just before the oem muffler. The welder's job just capped one of the tubes instead of removing it.

Can this adversely affect boost pressure?

[Glen]

Have you, or have you not lost boost pressure? Your first post says both.

Either way there will be a reduction in flow of exhaust gas. Get it replaced with 2.5" up to the first flange, or even beter, all the way to the turbo's.

[Guest keltik]

Personally i cant see it making a huge difference to boost pressure. But that IS a totally ****ty job. Id be demanding my money back!

It wouldve taken an extra 5 mins to bend a piece of piping to suit instead of that crap

Oh and who did it? So we can add them to the list of shame

[Guest jedi warrior]

oooh i see whats happening.,....!!!!!!!!!!!

EPIC FAIL:

here is why...

this is an example... and not sure on terms but my understanding of it is:

for example with exhaust manifolds if you have over lap of the manifold and it creates a slight blockage of the exhaust gasses there is some kind of blow back and doesnt create a proper vacuum which is why the manifold/ extractor system should not allow gases to flow back into the engine by "stepping" it out and having the gases hit the block and not back into the engine...

i could imagine this is what is happening here where gases are being forced iinto the top pipe and recirculating disrupting airflow.. in a similar way to what i described above

IMO u would of been better to find a muffler that has a single pipe and weld that inplace of the double pipe. what a stupid muppet that did that. rah dont ya just wana go there and point and laugh at that poor excuse for a exhaust job.

if someone could confirm my theory that would be great. if not i am happy to be flamed.

LOLi

[lamboiah]

I believe you're on the right track. The problem is not with my turbos as they are boosting as usually according to the boost gauge. The car is just not going when the secondary should kick in. I think there's too much back-pressure with this setup.

[Guest keltik]

wait just a minute, the stock exhaust system is set up like this with a butterfly closing off one of those pipes, therefore it seems impossible that this exhaust job would be any worse than stock.

Yes its crappy welding

No its not ideal gas flow

But its not so bad as to cause that major a problem in my opinion. More likely the welding fecked with your ECU which now needs a reset

[lamboiah]

Yes I considered that the stock does the same thing, but only at low rpms and/or partially throttle. When you're at high rpms or floor the pedal the butterfly opens up and there's a definite difference in sound and performance as the valve opened.

When I got the car back the clocks were all unset so I know the battery terminal was disconnected. I just don't know when...