My mechanic's thoughts on the Berk CBE & HFC

Shadax · 03-01-2012, 12:41 PM

Quote:

Originally Posted by erkthejerk73

maybe 4 cats = 4 O2 sensors?

Yeah I'm not sure on his confusion about 4 cats. He pointed to the piping in front of the cats (not the exhaust direction, the other side. Between the cat and the headers I guess?). So, almost as if he made it seem as if there was an additional cat in front of each one. If that makes sense.

Not sure what would compel him to think that.

Quote:

Originally Posted by m4a1mustang

Maybe there were two actual cats living just south of the manifolds. Ya never know.

Not gonna lie, i lol'd haha

SS_Firehawk · 03-01-2012, 02:40 PM

Everything between the headers and midpipe on these cars is a huge restriction on your exhaust. So anything that opens that up (HFC, LTH, or Y pipe) will see a large increase. The rest of the exhaust, get what you like

GaleForce · 03-01-2012, 03:08 PM

Quote:

Originally Posted by m4a1mustang

Maybe there were two actual cats living just south of the manifolds. Ya never know.

Come on meow, that's a little far fetched...

MaDMaXX · 03-01-2012, 03:12 PM

In for the lols

A lot of mechanics identify cats by looking for the heat shielding, if a factory exhaust has bracing or just heat shielding for the heck of it, they usually yell cat!!

Red__Zed · 03-01-2012, 03:28 PM

Quote:

Originally Posted by MaDMaXX

In for the lols

A lot of mechanics identify cats by looking for the heat shielding, if a factory exhaust has bracing or just heat shielding for the heck of it, they usually yell cat!!

Which helps us all out when it is time for an inspection

Shadax · 03-01-2012, 03:36 PM

Just picked up the car. He said everything went smooth, and it does sound really good.

Only thing is I can *definitely* hear air coming from where the cats are. At high RPMs on the road it's noticeable, and when I have the car stationary with the door open during revs. Should I be able to?

For example if I give it a nice rev up to 4k while in neutral, on the release I'll hear air from the front-middle of the under carriage.

I was a bit concerned at first, but I wasn't sure if it was because I'm not used to it, or something isn't right.

kielbasa16 · 03-01-2012, 03:43 PM

Quote:

Originally Posted by Shadax

Just picked up the car. He said everything went smooth, and it does sound really good.

Only thing is I can *definitely* hear air coming from where the cats are. At high RPMs on the road it's noticeable, and when I have the car stationary with the door open during revs. Should I be able to?

For example if I give it a nice rev up to 4k while in neutral, on the release I'll hear air from the front-middle of the under carriage.

I was a bit concerned at first, but I wasn't sure if it was because I'm not used to it, or something isn't right.

If its a hiss on deceleration, when you let go of the gas, then this is perfectly normal. Modifying any component of the 370Z exhaust has this effect, particularly the cats. If you hear it when revving up, when accelerating then you could have a leak.

Alchemy · 03-01-2012, 03:45 PM

Quote:

Originally Posted by Shadax

Just picked up the car. He said everything went smooth, and it does sound really good.

Only thing is I can *definitely* hear air coming from where the cats are. At high RPMs on the road it's noticeable, and when I have the car stationary with the door open during revs. Should I be able to?

For example if I give it a nice rev up to 4k while in neutral, on the release I'll hear air from the front-middle of the under carriage.

I was a bit concerned at first, but I wasn't sure if it was because I'm not used to it, or something isn't right.

You will hear a hissing sound at low RPM. TOTALLY NORMAL. My test pipes hiss like a mo-fo! Esp around 2k

Shadax · 03-01-2012, 03:52 PM

Quote:

Originally Posted by kielbasa16

If its a hiss on deceleration, when you let go of the gas, then this is perfectly normal. Modifying any component of the 370Z exhaust has this effect, particularly the cats. If you hear it when revving up, when accelerating then you could have a leak.

Huh. I think I actually do hear it when accelerating.

How can I absolutely determine if there's a leak and how is it typically rectified?

Thanks for this info!

Quote:

Originally Posted by Alchemy

You will hear a hissing sound at low RPM. TOTALLY NORMAL. My test pipes hiss like a mo-fo! Esp around 2k

Do you hear the hiss when accelerating too?

Alchemy · 03-01-2012, 03:55 PM

Quote:

Originally Posted by Shadax

Huh. I think I actually do hear it when accelerating.

How can I absolutely determine if there's a leak and how is it typically rectified?

Thanks for this info!

Do you hear the hiss when accelerating too?

No acceleration hiss

Urbanracer · 03-01-2012, 06:35 PM

Quote:

Originally Posted by GaleForce

4 cats? Really? Tell your "mechanic" to

Some of the older VQ35 engines used in the maxima had four cats, two pre-cats ahead of the normal cat that you'd normally see in an exhaust. I'm not sure why he would say that after having the car up on a lift though, it would be immediately evident that the pre-casts were not present on the 370z.

In my experience, most mechanics will try to convince you that aftermarket parts are a waste if they are not an enthusiast themselves. They are so used to seeing cobbled up stuff that they usually push people away from aftermarket parts. I wouldn't give the guy to much credit because he obviously doesn;t know much about the 370. You've made a good choice and will be very happy with the money that you spent.

Shadax · 03-01-2012, 07:05 PM

Quote:

Originally Posted by Urbanracer

Some of the older VQ35 engines used in the maxima had four cats, two pre-cats ahead of the normal cat that you'd normally see in an exhaust. I'm not sure why he would say that after having the car up on a lift though, it would be immediately evident that the pre-casts were not present on the 370z.

In my experience, most mechanics will try to convince you that aftermarket parts are a waste if they are not an enthusiast themselves. They are so used to seeing cobbled up stuff that they usually push people away from aftermarket parts. I wouldn't give the guy to much credit because he obviously doesn;t know much about the 370. You've made a good choice and will be very happy with the money that you spent.

That's reassuring, thanks! My only concern right now is the possible hissing\leak during acceleration. I don't always hear it, only if I really step on it and it's between like 3k and 5k before it's no longer audible.

I wish I had other Z owners to hang out with or check it out to see if it's just me not used to the sound or an actual problem

MaDMaXX · 03-01-2012, 07:49 PM

Vid of the sound or it doesn't sound cool

Also, it might help to hear the sound if possible.

Staples · 03-01-2012, 07:52 PM

Quote:

Originally Posted by MaDMaXX

Vid of the sound or it doesn't sound cool

Also, it might help to hear the sound if possible.

What he said ^

Shadax · 03-01-2012, 07:53 PM

One more thing. And I'm on mobile at the moment. But I revved the car just now and I can actually smell exhaust. Just throwing that out there ... Shouldn't be normal right...?

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I am here: http://tapatalk.com/map.php?syhl2o

03-01-2012, 02:40 PM	#17 (permalink)
SS_Firehawk Premium Member Join Date: Oct 2011 Location: Tampa Posts: 4,142 Drives: 13' Magma Red Nismo Rep Power: 7334	Everything between the headers and midpipe on these cars is a huge restriction on your exhaust. So anything that opens that up (HFC, LTH, or Y pipe) will see a large increase. The rest of the exhaust, get what you like __________________ Old Car:GTM TSC'd 550whp / 410lbft tq @ 11.88PSI New Car: Under Construction

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03-01-2012, 03:12 PM	#19 (permalink)
MaDMaXX Enthusiast Member Join Date: Jan 2012 Location: Oregon from England Posts: 292 Drives: 350z Rep Power: 13	In for the lols A lot of mechanics identify cats by looking for the heat shielding, if a factory exhaust has bracing or just heat shielding for the heck of it, they usually yell cat!!

03-01-2012, 03:36 PM	#21 (permalink)
Shadax Base Member Join Date: Mar 2011 Location: Camarillo, CA Posts: 64 Drives: 2010 370z 6MT Rep Power: 14	Just picked up the car. He said everything went smooth, and it does sound really good. Only thing is I can definitely hear air coming from where the cats are. At high RPMs on the road it's noticeable, and when I have the car stationary with the door open during revs. Should I be able to? For example if I give it a nice rev up to 4k while in neutral, on the release I'll hear air from the front-middle of the under carriage. I was a bit concerned at first, but I wasn't sure if it was because I'm not used to it, or something isn't right.

03-01-2012, 07:49 PM	#28 (permalink)
MaDMaXX Enthusiast Member Join Date: Jan 2012 Location: Oregon from England Posts: 292 Drives: 350z Rep Power: 13	Vid of the sound or it doesn't sound cool Also, it might help to hear the sound if possible.

03-01-2012, 07:53 PM	#30 (permalink)
Shadax Base Member Join Date: Mar 2011 Location: Camarillo, CA Posts: 64 Drives: 2010 370z 6MT Rep Power: 14	One more thing. And I'm on mobile at the moment. But I revved the car just now and I can actually smell exhaust. Just throwing that out there ... Shouldn't be normal right...? --- I am here: http://tapatalk.com/map.php?syhl2o