Hey y’all so I got a 2003 Nissan 350z with the tomei catback exhaust. I recently had a shop put on a set of Z1 high flow cats (got them off this forum for cheaper!)and now I can shoot these crisp blue flames which is nice ))I don’t have a tune yet either! the shop I took it too also did check up and saw my that spark plug 6 had bad heat range. I was wondering why my z shoots blue flames instead of yellowish/orange and saw in some of the threads that having bad spark plugs can create this. I’m about to change out my valve covers to new OEM ones and changing my spark plugs to the NGK6As instead of the OEM NGK5As. SO MY QUESTION,, will replacing the spark plugs remove my ability to shoot flames??? Or will my flames turn yellowish/orange instead of blue?? I attached a picture.... I have gotten bigger ones

My Z in MEXICO

 

Yes, maybe it’ll run correctly with good fresh plugs now.

 

Thanks for the response.
I know I’m probably running rich with all my exhaust work with no tune/intake yet. What do you mean by “run correctly”? Is having flames with no tune a good or bad thing?

 

Seriously?

Unburned fuel exiting from exhaust pipes is never a good thing other than in a race car running massive overlapped cam timing, turbo(s), etc.

 

To add onto Mic's comments, there should be NO flames from your exhaust- blue, orange or rainbow!! Running rich enough to produce flames means running SO RICH that unburned gasoline is pooling in your exhaust and muffler. This kind of inefficiency doesn't help when racing the 350Z on SCCA race circuits around the country, so please don't delude yourself into thinking you're getting additional performance from the flame drain. The VQ V6 is a precision built engine and running rich means fuel is probably running down cylinder walls (degrading rings) and into the oil (wearing rod and crank bearings) as well. Get it fixed before you damage that beautiful engine!

 

Yeah, what they said....no flames, it ruins your exhaust and cats! Doubt you want to buying those regularly. That stuff is for the IG kids that have a different car every year. Fuel should be burnt to make power not impress people on the internet, hell I just bought a set of expensive OKD coils just to make sure I burn my fuel lol.

 

OMG! This was the response/information I was looking for! I never thought flames would mean more HP I just thought they hella cool lol. I think I’m starting to understand everything. I ordered the Z1 valve covers/gaskets kit with new SPs and will be doing that in the next couple of days. Do you think new spark plugs will stop me running rich and/or do I need a good tune to make everything run 100% overall. I’m pretty sure i had the heat range in spark plug 6 before my HFC install and after that is when I could shoot the flames and the 3inch tomei catback doesn’t help either. Thanks you so much for the info/advice!!!

 

Nice pick on the OKD coils! Man it sucks nobody seems to want flames LOL. I have a shop near me that will can dyno tune with full uprev for around 800$. Will running a flame map with a tune hurt the engine?

 

Same difference, cats are ok with heat but not fire. Mufflers and resonators have a glass mat packing that can burn away with fuel/flames. All that said the choice is yours.

 

it may be wise to learn more about how engines run as a whole. Plenty of information on the internet (whether to trust it, is another thing).

yes - anytime you do something to the engine outside of what nissan designed from the factory it's hurting the engine.

With that being said - it's your car, it's your engine, it'll be your fault if you break your engine ... last time I checked, a good running DE engine is around $750 to $1000 for a donor engine and add another $1000 for install.

 

cliff notes..... op wants to be a flamer

 

Flames out the exhaust is right up there with the "pops n' bangs" crowd so prevalent on social media. Another imitation race car thing. A little natural burbling due to deep downshift and an aftermarket exhaust, fine. Tuning it in, not so much.

 

I have the full tomei catback. I did notice that the y-pipe is now all rainbow looking from the outside other than when it came brand new. Could this be from unspent fuel or just the heat?

 

Okay ya I’m starting to pick up what you guys are putting down. You’re right about the social media part, every car page has had at least one video of a Z going full tilt lol. That’s for all the input!

 

Ya that seems about right on the price, probably would be even more. But ya I’m just starting to understand everything and wanting to learn. The Z has a great engine and it’s a great platform to learn on and work on.

 

Why are you changing from OEM spark plug spec?

 

I saw that the 6As are better for engines that are modded. I already have full CB with HFC and within the next 2-3 months I’ll be full bolt on with tube so I figured it was a good move.

 

No reason to run colder plugs if you are not FI. I ran factory plugs at low timing and 6psi for a couple thousand miles without issue. Only fouled them when I increased my timing.

 

Okay ya I see that point, but they were around the same price so I’d figure why not just got with it.

 

If you haven't already purchased your spark plugs, you may want to read this thread. NGK has introduced a new coating for plugs that can be used with the Z:

https://my350z.com/forum/engine-and-...for-the-z.html

The thread lists part numbers and gives a short description on what the new NGKs are like. In short, these plugs will last over 100K and should be installed before you get a tune. One item to check beyond that is the type of fuel injectors being used in your Z. Some people have installed larger injectors with the idea that it'll automatically produce more power. That's not the way it works. Even with the bolt-ons you have, standard OEM fuel injectors are what you should be using.