Sorry to start a thread like this again but I want to know if I should spend my hard earned cash on mods or not.

In particular I am ready to purchase the Random tech cats. people seem to like them and supposedly they are dynoing 10hp+

So at the end of that controversy what was decided? I dont recall there being a resolution. IS it fruitless spending money on mods unless you get an ECU upgrade or what?

Is there anyone from personal experience who has made definite noticable gains from any mod other then pullies or flywheel?

This is driving me crazy. I want mods, but I dont
want to just throw money out the window!

Does our ECU negate modifications or not

 

Yes and no.

Yes because while cruising, the car will always attempt to maintain a stoich A/F ratio for fuel economy by increasing or decreasing the amount of fuel it injects, and 14.7:1 is not the best ratio for power.

No, because at WOT, the ECU goes with preprogrammed settings igoring everything else. At WOT, the ECU doesn't care what you've got on your car, it's going with what it's been told to do.

Now, if at WOT you are already running close to stoich and you add a mod that leans it out more then you won't see any more gains.

With that said, there has been no proof of the formerly proclaimed "loss of power after 3 months" rumor that was going around when we all first bought our cars. I personally think people were just doing ricer math before and were disappointed when the dynos didn't show they had 400 HP with an exhaust and CAI, but that's just my opinion.

 

Thank you for the reply, but what is 'stoich'?


Jesse I also know you are supercharged, but if you were not, do you think the Random tech cats would be a good mod for you?

 

It's a theoretical perfect air fuel mix.

stoich or stoichiometric is the condition where just enough oxidizer (oxygen) is present to convert all of the fuel molecules to products of combustion, usually CO, CO2, and H2O.

For unleaded pump gas, it's generally accepted that around 14.7 parts air for 1 part fuel is stoich. Although that is a generalization, because it really depends on the chemical makeup of the fuel you are using.

Still 14.7 is a good enough number for us.

If you are using higher octane fuel... race gas, alcohol, toulene, you need to add more air for the same amount of fuel because it contains more combustible materials to maintain stoich.

If you use air that has a higher oxygen content.... Nitrous, you need to add more fuel to maintain stoich.

 

I really don't know about the Random Tech cats, because I haven't really looked into them. Sorry.

 

The Random Technology High Flow Cats are probably one of the best mods you can do for the Z. Infact, I'd say it is the best one. Anything else you do to it seems to be a waste until you unclog the exhaust from the stock cats and get some RT High Flow's.

Infact, I just added them to my car with NISMO EXHAUST only and am headed to the dyno today around 4pm to see what the RT's added only.

I will be posting that dyno sheet later tonight. Ill also take video of the pull.

They do not get that raspy sound people with test pipes have experienced, and they do not smell at all.

Here are some clips with audio of the RT Cats for you.

Driving In Cabin RT Cats & Nismo Exhaust

Out side the car Start - 3000RPM back to 1K up to 6000RPM.

 

Short answer: No!

The best way to determine HP in the 1/4mi is trap speed.
My best trap with intake and exhaust= 99.68
My best trap with intake, headers, cats and exhaust= 102.64
I still have the stock ECU and these 50+ runs were done between 8/16-11/7. So after 3 months my car is getting stronger not weaker, therefore the ECU doesn't negate mods. However, you could possible gain more power by having your ECU properly tuned for your mods.

 

RT cats are an expensive but good choice. If you don't mind the sound, regular straight test pipes can be had for ~200 instead.

Throw in a UR crank pulley while your at it. You should gain at least 15-18rwhp for under $800.

 

I am from CA too Saint. So as far as test pipes are concerned fuggetit. I gotta keep this baby legal.
Sides, I dont know if its BS or not but supposedly highflow cats can be better than testpipes. Plus I can still keep a desireable sound.

AS for pullies, I have been chewing on the possibility for a while but since I will be getting the Vortech eventually I decided against it


Thanks for advice everyone, keep it coming.