Exhaust leak causing slow spool?

[dsmcoder]

I have a 1g dsm with 16g turbo and 2g exhaust manifold and 2.5" cat bypassing downpipe with the rest of the exhaust stock. I have an ets street intercooler kit and I'm running speed density and all supporting fuel mods.

I'm not building full boost which is 20psi until 5000rpm. I've read that I should be building that at least by 3500rpm and probably sooner with me since I have a cyclone intake. In link it shows that I'm only building two psi by 3500rpm. I have an automatic transmission and I'm using first gear for the tests.

I seafoamed my car to see if I have any leaks and I noticed that it's leaking the worst at back part of the gasket that connects the turbo to the manifold. It's also leaking a small amount at the o2 sensor and in it looks like it's leaking a little bit in that area I marked red in the pic on the turbo.

Now would these leaks cause my turbo to build full boost this late? These leaks are not huge either

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[dsmcoder]

I actually have a ported 2g manifold and ported o2 housing installed. The hot side of the turbo is not ported should I port it?

I was thinking that I can remove my stock catback exhaust and just run a downpipe temporarily to see if that helps my spool, that way it will tell me if my stock exhaust is causing slow spool or something else.

 

[T is for TURBO]

However YOUR specific problem is the stock catback. You have this "huge" downpipe which is like a storm drain to water, then put a McD's straw at the end of it and expect to run off all your rain, or in this case, build any boost.

I'm not saying you're wrong by any means, but he's only building 2psi by 3500 on a 16g. He has a 2.5in DP which is only 1/4" bigger than the stock piping. It seems to me that there is something more to this than the remaining stock pipe. Though, it should be a pretty easy test... Drop the remaining stock exhaust and take it for a ride.

 

[dsmcoder]

I'm not saying you're wrong by any means, but he's only building 2psi by 3500 on a 16g. He has a 2.5in DP which is only 1/4" bigger than the stock piping. It seems to me that there is something more to this than the remaining stock pipe. Though, it should be a pretty easy test... Drop the remaining stock exhaust and take it for a ride.

It is 2.5" from the part that connects to the o2 housing but is 3" on the other end. It's an apexi n1 downpipe.

 

[T is for TURBO]

It is 2.5" from the part that connects to the o2 housing but is 3" on the other end. It's an apexi n1 downpipe.

I see. Well, drop the remianing stock pipe and see what happens!

 

[dsmcoder]

Will do ASAP, I'm just waiting for a couple exhaust gaskets to come in.

 

[Mr PopUps]

I was referring to porting only the exhaust runners and it's correlation with exhaust gas velocity (as stated in my post). The OP is asking specifically about the late spool up of his turbo. In this context, porting the runners might make the spool up worse. But since I have no data for or against doing this I started it off by saying "Theoretically."

Thanks for providing the 1/4 mile results though. I have no doubt that porting post-turbine (if properly done) gives gains. Both theory and real world results support this.

On a side note, I herniated a disc at L5-S1 a few years back. That pain was worse than what I had with multiple broken bones. So I can definitely understand what you mean when you say that you weren't able to work.

Oh, sorry didnt see that you said runners, yes in cases it can hurt, but if you look closely you can see where the stock gasket hits the ex-man, the head is almost the same size so hitting the ex-man runners causes more choking.

S5-L1 is what i did, but mine pinches my sciatic nerve and sometimes so hard that i about fall to the ground when its flared up. The weekend it happened i seriously thought i pulled a hamstring or something cause the pain was in my lower butt cheek/upper back thigh. It wasnt till i got an MRI that they figured out what was wrong.

I actually have a ported 2g manifold and ported o2 housing installed. The hot side of the turbo is not ported should I port it?

I was thinking that I can remove my stock catback exhaust and just run a downpipe temporarily to see if that helps my spool, that way it will tell me if my stock exhaust is causing slow spool or something else.

Yes, you should get it ported and the O2 at the same time.

I'm not saying you're wrong by any means, but he's only building 2psi by 3500 on a 16g. He has a 2.5in DP which is only 1/4" bigger than the stock piping. It seems to me that there is something more to this than the remaining stock pipe. Though, it should be a pretty easy test... Drop the remaining stock exhaust and take it for a ride.

Yea, there is no way to fit a 3" dp onto the O2 housing, so theres a small part thats 2.5" to allow it to fit. Some places did the 2.5" all the way to the flex section then 3" after.