I asked this on freshalloy as well.

Looks like I have started the modaholic program as well. I only have the Z tube and would like to do some performance mods before moving on to suspension and wheels. I have looked through numerous posts and have narrowed it down to a combo of: exhaust, plenum, cats, pulley, & y pipe. It is difficult to determine the best combo of these mods.

On a $1500-$2000 budget what combo would you do?

1. Crawford Plenum ($400), Cats ($450), and JIC Y Pipe ($400)
2. Crawford Plenum ($400), Cats ($450), Pulley ($150)
3. Stillen Exhaust ($1200), UR Pulley ($200)
4. Stillen Exhaust ($1200) and Y Pipe ($400)

or other combos?

 

Based on personal experience. you will see the greatest improvement in driveability with the following mods in order of priority:

1. Anti-sway bars
2. 10 wire grounding kit
3. Tires
4. Wheels

although you will run out of budget before you get to the wheels.

 

If i had $2000...
I would get new exhaust, H-F cat/test pipe with resonator, & y -pipe first. I wouldn't recommand getting any plenum until you change ur stock exhaust.


04c/Black/AT/PIAA/AL padel/smoked clear corner/6th grounded-wire/z-tube/pop-charger/UR pully/Data grille/Gialla spoiler/15% tint/Kinetix test pipe resonator/Y pipe for $190 (group buy, pending)

 

Do you own a sedan? Does the sedan need a y-pipe with the stillen exhaust? I know that for the coupe you cannot use a y-pipe with the stillen...

<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>

 

I have the coupe but was told I could do the Stillen and Y pipe (good to know I can't). If that is the case then I may do:

- Stillen exhaust, pulleys, & RT cats.

Is the Stillen a good choice?

I plan to do sways, springs, and wheels after these perf mods.

 

Stop!!! Don't do RT cats!!!. Unless of course you want raspy sound from your exhaust.
How about:
APS plenum ($370??), Crawford cats ($450), obx Y pipe ($190), obx exhaust and midpipe ($365) (This is a fujitsubo exhaust copy). Grand total $1375.

2004 G35 Coupe/OB/Graphite interior/Premium and aero package/Popcharger/Z tube/Hotchkis sways/Tein H-tech springs/Kinetix plenum/Crawford cats

 

spend it on suspension upgrades.
you can have all the power the engine is capable of, but it's usesless if you cant apply them to the tarmac. Spend a little more and get some TEIN Flex Coilover system and a swaybar set.

Road Racers comply to how a car or bike feels in terms of handling. In terms of how to make use of what power the car or bike already has. the more power you make, the more time you'll have to take to get to slow, turn, or stop. upgrading your suspension will make use of what you already have in the powertrain, along with carrying out more speed in turns vs the stock suspension.

Basically it boils down to where you want to be fast in; in the turns or on the straights.


| Hawaii International Race School | Formula Hawaii | Drift Session | Mid Pac Road Racing Association |

 

Stillen is the best exhaust for our cars. (my opinion based on power gains). You don't need a y-pipe with it, it comes with the x-pipe.

I would get: Stillen exhaust, u/d pulley, Stillen test pipes.

The reason I say test pipes instead of h/f cats is, less money, more power, easy to swap back to stock for smog checks.
I think this combo would give the most power!

Congratulations! You have just won 1 million punches in the face!

 

Remember balance... you want to increase the air into and air out of the engine. The z-tube is a good start, a plenum would work well with either high flow cats or a test pipe. The y-pipe would be nice too, but if you want to spend the extra $800 for another 1-2 hp, get the Stillen Exhaust and forget about the y-pipe.

I'd say...
Crawford Plenum ($400)
Crawford Cats (~$400)
Y-Pipe ($300-$400)

Worst case you've spent $1200 and you'll probably gain 20-25 bhp (I gained 21 bhp with those mods on the dyno, but I didn't have the y-pipe at the time. Hopefully I'm closer to 25bhp with it, but I'll never know until I do another dyno...)

If you're a risk taker for another $200 you can even add the UR crank pulley. This should help with the throttle response a little bit, but I'd definitely do some research on this topic before I spent the money.

<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>

 

Most of the restriction is in the exhaust system. Getting those exhaust mods won't do much unless he has a full exhaust. He be better off getting the Stillen catback for $950~ which IS the average cost of it, and Ztube $60, Stillen CAI $200 and Pulley $180.

2004 Infiniti G35S, 6MT, Premium, Sport, DP
Mods: JDM Clears, 20% tint, Z-tube, Stilen CAI
Track: 14.32 at 98.79 mph 2.2032 60ft
Dyno 07-07-04 - 234.2 hp & 233.8 tq
http://www.g35world.com

 

I agree with Neffster 2 posts above.
Plenum, cats, probably Y pipe. Make sure to do the Z tube as well.

'04 6MT coupe

 

Most of the restriction is in the catback part of the exhaust. Why do those when you need to do the catback part first. All your going to do is bottleneck the exhaust.

2004 Infiniti G35S, 6MT, Premium, Sport, DP
Mods: JDM Clears, 20% tint, Z-tube, Stilen CAI
Track: 14.32 at 98.79 mph 2.2032 60ft
Dyno 07-07-04 - 234.2 hp & 233.8 tq
http://www.g35world.com

 

Neffster and JN both have coupes. The only real restriction in the coupe exhaust are the cats. Replacing anything after the stock cats won't do squat (except make it louder).

For the sedan, I would assume that the stock cats are way more restrictive than anything after the cats.

And restriction is not necessarily a bad thing NA, it helps with low end torque.

I don't recommend messing with the cats.

I would go with new rims and tires. At least you will be able to SEE an improvement. Get lighter rims and you might even feel an improvement.

Or upgrade the sound system.

2004 G35C 6MT Black. Killer.

 

This just caught my eye and was wondering the same thing. I have the S-tech springs and am waiting for sways.

I just did the wheels and tires thing and it definitley makes a huge improvement (from my seat of the pants dyno). Inital launch is much better and handling even feels better (just from the width of the tires). I went with 8.5 and 9.5 x 19. 245/35/19 up front and 275/30/19.

Now I get to decide if i want to spend and additonal 1500 on all that other stuff to get the additonal 20-25hp, w/o compromising low end.

 

Thanks for the responses. I am going to go with the cats, y pipe and possibly the plenum (it is back ordered at Crawford for 4-5 weeks!). I may add the pulleys as well.