Nissan 370Z Forum - View Single Post - Fast Intentions resonated HFC's installed

Jessobear · 12-16-2010, 02:15 PM

Just installed a set of Fast Intentions resonated HFC's this morning. Quality of the parts was really nice and Tony was great to work with. I had previously installed a Nismo OEM CBE and at idle and slight revving (no load), there was only a very small increase in sound. Unfortunately it started snowing in the middle of the install and just getting the car home was a nightmare, so I couldn't get a really full review of these compared to the stock parts. I will say that at regular cruising speeds of under 3000 rpm, these are really seamless. You basically can't tell there's anything different, so they make for a good daily driver mod.

Here are some pros and cons of these. Other than one thing, which I'll expand on below, the cons are really more of small suggestions.

Pros:

- Extremely good fitment with nice welds and flat flanges.
- Excellent packaging.
- Detailed instructions come included.
- Great customer service.
- Very little sound increase at idle and cruising speeds.

Suggestions:

- I did not need to remove the steering rack to do the install. A proper swivel socket and a LONG extension was all that was needed to get the upper outboard bolt loose.
- The instructions say to reuse the copper 3-bolt gasket between the manifold and the catalytic converter. My car did not have a gasket there at all. I'm not sure if this is a difference between '09 and '10?
- OEM copper crush washer should have been included with the hardware.

Cons:

- The way that the HFC seals to the manifold.

The stock design for this is very good and I can't understand why it wasn't duplicated? Basically, the stock piece has a small bit of vertical pipe that sticks up above the flange. Around that is a conical copper crush gasket. The inside of the manifold has a reverse cone and the pipe extension/crush gasket fits nicely inside of that. Not only does that align things properly, it makes for a very good seal.

The Fast Intentions part simply has a flat flange and attempts to seal the whole works with high temp silicone. This is not a great solution. The high temp silicone is rated only to go intermittently to 650F, a temperature that we know exhaust manifolds will exceed.

Having missed the part about needing new crush gaskets, I was forced to reuse them. We basically used the high temp silicone to stick them in place before bolting up the HFC's. Everything seems to be sealing for now, but I'd be a lot more confident if I weren't depending on silicone to prevent an exhaust leak.

I don't want to dwell on that complaint because overall I'm extremely happy with these. If I were in the market for an exhaust, I would definitely look to Fast Intentions. I just feel that honest feedback is good and if it can lead to an improved product, all the better.

Once I get some decent weather, I'll get some videos of the setup in action.

12-16-2010, 02:15 PM	#1 (permalink)
Jessobear Base Member Join Date: Oct 2010 Location: Washington, DC Posts: 201 Drives: '10 370Z Tour/Sp M6 Rep Power: 15	Fast Intentions resonated HFC's installed Just installed a set of Fast Intentions resonated HFC's this morning. Quality of the parts was really nice and Tony was great to work with. I had previously installed a Nismo OEM CBE and at idle and slight revving (no load), there was only a very small increase in sound. Unfortunately it started snowing in the middle of the install and just getting the car home was a nightmare, so I couldn't get a really full review of these compared to the stock parts. I will say that at regular cruising speeds of under 3000 rpm, these are really seamless. You basically can't tell there's anything different, so they make for a good daily driver mod. Here are some pros and cons of these. Other than one thing, which I'll expand on below, the cons are really more of small suggestions. Pros: - Extremely good fitment with nice welds and flat flanges. - Excellent packaging. - Detailed instructions come included. - Great customer service. - Very little sound increase at idle and cruising speeds. Suggestions: - I did not need to remove the steering rack to do the install. A proper swivel socket and a LONG extension was all that was needed to get the upper outboard bolt loose. - The instructions say to reuse the copper 3-bolt gasket between the manifold and the catalytic converter. My car did not have a gasket there at all. I'm not sure if this is a difference between '09 and '10? - OEM copper crush washer should have been included with the hardware. Cons: - The way that the HFC seals to the manifold. The stock design for this is very good and I can't understand why it wasn't duplicated? Basically, the stock piece has a small bit of vertical pipe that sticks up above the flange. Around that is a conical copper crush gasket. The inside of the manifold has a reverse cone and the pipe extension/crush gasket fits nicely inside of that. Not only does that align things properly, it makes for a very good seal. The Fast Intentions part simply has a flat flange and attempts to seal the whole works with high temp silicone. This is not a great solution. The high temp silicone is rated only to go intermittently to 650F, a temperature that we know exhaust manifolds will exceed. Having missed the part about needing new crush gaskets, I was forced to reuse them. We basically used the high temp silicone to stick them in place before bolting up the HFC's. Everything seems to be sealing for now, but I'd be a lot more confident if I weren't depending on silicone to prevent an exhaust leak. I don't want to dwell on that complaint because overall I'm extremely happy with these. If I were in the market for an exhaust, I would definitely look to Fast Intentions. I just feel that honest feedback is good and if it can lead to an improved product, all the better. Once I get some decent weather, I'll get some videos of the setup in action.