Nope, not smelling it in the cabin, its when I get out of the car

Ill ask Tony and post up

 

I find it hard to believe you did much research on test pipes if you had no idea that replacing your cats with them would result in a fuel smell. When gasoline explodes and the untreated byproducts are released, it's gonna stink. Leaning it out won't help either. I have test pipes and after my tune my AFR is right where it should be and I still get plenty of fuel odor.

Only way to eliminate the smell is to hold your nose or redox the fumes with a cat.

 

what HFCs would you suggest?

 

I don't really suggest HFCs to anyone. I went with test pipes because HFCs can be nearly as loud as TPs and still have some of that fuel smell, so I felt like I might as well just remove the restriction altogether if I'm going to have drawbacks either way. Plus HFCs have a greater chance of cracking and needing replacement due to the additonal welds (compared to unresonated TPs). So my real recommendation to anyone is always Berk unresonated TPs, MD ART pipes, or keep the stock cats if you don't want to deal with loudness/smell/rasp. If I had to pick a HFC though, I guess I'd say Berk HFCs as I am impressed with the quality of Berk products.

 

I called Tony and asked him his recommendation about which HFC to get with my current setup and my current situation. He said that MD stopped making HFCs due to low demand, but what he would do is get a magnaflow or flowmaster HFC and weld it into the midpipes. Which is exactly what Rubidium said in Page 2. I do not have a bandsaw nor a welder, so paying for shoptime it is. He even said that since the HFC was so far away from my engine, it wouldnt impact a supercharger later either.

This leads into the next question is what cat-back HFC to get. Whatever HFC I get, I plan on getting ceramic if theres an option, so improved efficiency at the at most 1 HP loss. I've found 3 options, are there others? Is there really a big difference between them all?

Cat-back options:



Vibrant HFC: $400 per

 

Talked with Tony, and he said don't buy any HFCs over 7" as the TDX2 mid pipes each curve after that legnth. This negates the Magnaflow and Flowmaster above, but the Vibrant is 7 inches.

Are there any 7" long weldable HFCs for 3" pipes that don't cost $400 each?

Edit: These Flowmaster 223s are 10.5 inches, but there looks to be a ton of room that we can remove at either or both ends. Would this be a viable solution? Is this Flowmaster 223 a good product?

 

Ok, I called Flowmaster and they said that as long as I cut the 3" straight pipe sections (front and back), I should be good. Total HFC cat length is 10.5". If I can remove 2 inches per side that is 6" of actual product.

Next step: Go under car and measure how much pipe length I have before it bends.

 

See, I knew you'd find a solution!

 

yep yep you did help out thank you sir. The cats will be here Thursday, Moore's Automative of Fairfax Va said they would install them for a cost of $165. Not bad since I dont have a saw or welder.

 

How did the project turn out? I have the same TP/exhaust setup as you do. Any fuel smell or sound difference after the HFC's were installed?

 

My install date is this Thursday, Oct 8th. I'll let you know how it goes.

 

True. It reeked like hell when I first got it and then I couldn't smell it at all.

 

what would constitute an exhaust leak? Improper fitting between manifold and ART? Between ART and Exhaust? I used the properly supplied gaskets and everything lines up tightly. Besides, if there was a leak, it would be underneath the car, so why would I smell it in the cabin?

 

because various holes, cracks, seams

 

So, I just spoke with Paul at Moores Automotive, and he said don't even bother installing those flowmaster cats. He said, despite what Tony at Motordyne said, the cats down there won't do much because it only gets to be 500F after the muffler, while the test pipes get to be 1000F and thats what the cats need to work. Not only that, but after a while, the cats could get clogged up due to the residual fuel. I asked him how I can pass emissions and he countered that I had UpRev. Being the noob I am asked how this matters, and he said that UpRev is made to fool emissions work. He said that to prove this, I should go get my emissions tested, he is sure that I would pass.

To review, passing emissions and getting rid of the fuel smell are the two reasons why I started this thread. So fine, I say, wouldn't installing the cats get rid of the fuel smell? He said no, because the problem, as some of you have suggested, is due to the faulty manufacturing of the Y-Pipe/ART flanges. They are not flush even though I used the supplied, not stock, gasket. I asked if this could be user installation error (me) and he said no, this is all on MD. Pics below. He said maybe MD would work with me, but a thicker gasket would work as well. He suggested I buy a Vibrant 2.5" (1457) gasket that is significantly thicker then MDs. I ordered two, one for each side even though only one side is the problem.

Pics are attached.

Action Items:
1. Install Vibrant gaskets to see if this eliminates fuel smell
2. Get emissions test to see if I pass w/o cats due to UpRev. Update: A local emissions shop just visually failed me. He only looked at what comes after the manifold and compared it to a printout from the FSM. He needs to see cat like objects there, not the straight pipes I have now and not universal cats down in the exhaust. Looks like I need to sell my Motordyne ARTs.
3. Update: Sell my Motordyne ART
4. Replace with HFCs
5. Return flowmasters

 

I did not have a problem with the gaskets from the art pipes to the Y-pipe. It is the actual o-ring gaskets from the header to the art pipes that causes a smell in cabin. Ive replaced them with brand new OEM nissan o-ring gaskets and while it did help, there is still a exhaust leak in that location.. Its such a pain to take the art pipes off again but i will do it and install Z1 thick gaskets. Hopefully they will create a much better seal.

 

what i did.... i put the o ring one supplied with the art pipes, and then i trimmed the oem one to fit around the art pipes. i was being ocd

 

just to be double sure, I bought the variant cat(or test pipe) and exhaust gaskets. Since I bought a Z1 HFC, it will come with the header/cat thick gaskets. Both will be used, and since the Z1 HFC is so inexpensive @ $388, i'm having the shop install it for $220.

I'll post again when its all done next week about sound and smell.

In the meantime, I will soon be selling my Motordyne ART pipes and hardware. It's less then 3 months old and only has 500 miles on it at most. I"ll make a post when I can take pics with my screenname, but fyi.

 

All,

Last night I took some side and underside audio samples of my current setup (K&N Dropfilters, MD ART, MD TDX2, 2007 350z HR, dynotuned 292 rwhp). In a few days i'm going to be taking the same thing, only with the Z1 HFCs installed. I'll update this thread when I have those. In the meantime, here are the MD ART ones.

Side view:

Underside view (Exhaust level)

 

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you will lose a little hp and gain a little torque putting the cats on