Hey Guys,

I recently picked up an athens blue (i think) g35 coupe with 99k on it. I'm aware of the rev-up OC issue; so far after putting about 1500 km's on it (since fresh oil change), the level is still right near the full mark on the dip stick. I'm just wondering, is there any way to find if this motor is a replacement?

Secondly, my front bumper has a few paint chips on it, so i'm planning on touching it up and having it 3m'd. Does anyone have recommendations for what is best to get 3m'd on these cars?

Lastly, the car seems pretty decent performance-wise, definitely not the most torquey thing on the road though. After searching I've noticed the CAI's are generally not a great idea. Would a drop in filter & stillen exhaust be sufficient for small gains?

Thanks for all your help and I look forward to browsing through this forum!

 

Welcome to G35 Driver from sunny/warm SoCal and Congratulations on finding one of those beautiful AB coupes! It's a good idea getting a clear bra and 3M is about the best. If you have a lot of chips on the bumper I suggest you have it painted, wait 30 days then get the bra. A bad job trying to fill chips will show thru the clear bra and look fugly. If you have the 6 MT Revup motor the best performance mod is Motordynes MREV2 and 5/16" spacer. That's advertised/promised to add 18+ whp. If you get a true dual cat-back exhaust along with high flow cats, you'll be able to tell the difference in your drivers seat!
Gary

 

congrats on the purchase, I am still looking for my G, on a 10k budget so I am probably looking at the 03 models I heard those engines oppose to the rev-up engines have more low end torque.

 

Welcome to G35Driver.

 

You're better off doing the better filter(k&n $30) and just a Z-Tube from Stillen($60), the exhaust on our car is more than sufficient for NA mods, with the Z-Tube you'll get the little bit louder sound from the car, but keep the overal same "note" of the stock exhaust.

If you still have some money to burn, get a Plenum Spacer from Motordyne and you'll be good. Not too much more in the modding department to do until you go FI

 

Thanks for all the replies guys!

For the Z-tube, is it best to just order it online from stillen? Same question with the spacer, should I order it from their site?

 

What the hell? No offense man, but you just recommended literally the 3 worst power mods for a rev-up and gave a ton of false info. Z-tube does literally nothing for the exhaust note or power. Plenum spacer also does literally nothing to a rev-up engine. Drop-in maybe a 1-2hp gain. Also:



1. The exhaust is the MOST restrictive part of the car. Specifically the cats. ART Pipes will provide substantial gains with a tune, especially when paired with the TDX2 exhaust. We're talking a decent amount of power here. I personally don't like Stillen, the TDX2 is much better both in performance and sound, but also more expensive. TDX2 is by far my favorite mod to the car however

2. MREV2 will provide a good amount of mid-range hp/tq, probably about 10-14 hp/tq and it is pretty noticeable on the butt dyno. Makes you realize how much the car chokes in the mid range. However, the MREV2 will take away some power from the top end. This is solved by adding the Motordyne 5/16 Spacer, which will give you back your top end and some extra while keeping the midrange.

3. K&N filter and Z-tube have always been debated. Maybe 1-3 hp from the K&N filter($50) and most likely zero from the Z-tube(Humboldt Resonator). Both are mostly for an increase in induction noise.

4. Power can be gained from cooling down the plenum, preventing heat soak. This can be achieved with Motordyne's Isothermal spacer(specifically the Aramid Gasket), and further enhanced with isothermal gaskets($65) in between the runners and heads. This is effectively your cold air intake, and will significantly reduce heat soak. I also noticed this helped increase my gas mileage.

5. Headers can net you an extra 5-8hp but the install cost is pretty high. Unless you DIY or have the engine out, which makes it extremely easy, the gains are typically regarded as not worth the cost.

6. Finally, an Osiris tune will help you get the most out of your mods. Rev-up G's typically start at around ~230whp and finish around ~275-280whp depending on the dyno. Adding cams can further increase power into the 295-300 whp range. Here's where N/A is typically maxed out. You can get more creative, but it's more expensive. I think the current most powerful G/Z is 320whp with upgraded internals and all of the above, and the past most powerful Z was 350whp using ITB's which are extremely hard(maybe impossible) to find.




Hope this helps OP! Also, you can go down the nitrous road as well. Supercharging is probably the best gain for the money, but then you're starting to comprise the reliability without forged internals.

I would just 3M the front bumper, but that's because I hate the orange peel and edges on clear film if they're pre-cut(which most are). Also, if you want to add a decent amount of handling, get some sway bars.

 

Thanks for the detailed info! I'm definitely not going FI with this car, it's just a daily.

where would be the best place to order the exhaust you speak of as well as the sway bars? Thanks!

 

I bought most of my stuff used and saved a good amount of money that way, but it depends on your budget. I would however recommend B2AutoDesigns, the guy I deal with is Charles and he has excellent service and is well known in the community. Great prices as well, with free shipping in most cases.

-I picked up the Motordyne TDX2 exhaust used for 1,200+shipping, new is 1,600/free shipping. Trust me, words cannot describe how this sounds. I would not want any other exhaust for the car. Makes it sound like an exotic V8, fairly loud but not deafening at all. Videos do not do it justice as most of the note is very deep and hard to capture on film, but it will give you a rough idea. I'm running it with stock cats at the moment and love it. I think the gain was about 9hp/12tq from the exhaust alone on stock cats. Others have seen higher.


-The Motordyne MREV2 I got used for about $350 shipped. Good bang for your buck.

-Motordyne basic spacer was $135, brand new from a local guy who never installed it. Keep in mind the spacer is useless unless you have the MREV2. I bought the Aramid Gasket separate for $40 shipped. The gasket replaces the OEM gasket under the lower plenum to keep the plenum temps down. Installing all of them at the same time will save you a lot of time. So about $500 for the complete package, about 18hp gain total.

-Motordyne Sway Bars were $309 shipped through Charles from B2auto during a group buy. I believe they are $350 shipped normally.

-K&N filter is $50 from Amazon. I would check how dirty the filter is that came with the car.

-Isothermal Gaskets for in between the Lower runners and Cylinder Head are ~$65 and are available from a site that sells them for Maximas. The G35 shares the same gaskets for that spot. I forget the website name at the moment :/

-ART pipes(replace the cats) are ~$550 shipped and will require a tune within about 6 months of getting them as they will throw off your A/F ratio slightly.

-Osiris Tune costs $600 at my local Osiris Certified tuner, which includes dyno tuning and the product.




The order I would buy the parts is:
-TDX2 Exhaust (You'll just love driving the car)
-Motordyne MREV2/Isothermal Spacer + Lower Isothermal Spacer
-Motordyne Sway Bars
-Motordyne ART pipes
-Osiris Tune

All of this should put you at ~275-280whp. Up to you how much money you want to throw into it and how you want to mod it, loud/quiet/power/handling/looks. And if you're wondering why I support Motordyne so much, it's because it's independently proven to be the best for our cars, made out of top quality materials, and all the products are created by literally an ex-rocket scientist. BTW I pull about 28mpg on highway with these mods, although I do not have ART pipes or the tune yet.



Sorry about the long post, hope it helps Since you read this far, here's a free mod you can do to the car that will make driving it better. You may have noticed the clutch catch point is very vague and weird. There's 2 springs in the clutch, one that operates the clutch and one that "smooths" the motion. The 2nd one is the problem, once you remove the spring, you can actually FEEL the clutch engaging and it makes it A LOT easier to drive around smoothly. You just need a couple tools, about 1 to 1.5 hours of spare time, and to be able to twist in and reach it. Definitely a must do mod. There's a DIY floating around somewhere.

Also, you can buy the RJM Clutch Pedal Bracket($165), which is even better and replaces the whole stupid spring assembly and makes the entire motion feel better. The only other mods I have are a Stillen Engine Damper(~$40, eBay), and the Z-tube, both of which I am glad to have, but only have slight benefits and I would buy last.

 

You are a GEM!

As I live in the freezing cold province of Alberta, chances are the car won't be on the road for another month at least. I'd like to put a couple thousand more k on it as i just got it before having to put it away.. just want to ensure there aren't any bugs to work out. It passed numerous nissan/infiniti mech inspections, so i'm sure there shouldn't be any surprises.

I'd like to keep it as reliable as possible, so i'd rather stay away from doing anything with the ECU. If i were to just do the TDX2 exhaust, plenum spacer (plus spacers you specified), & a drop in K&N, would that require any tuning? And is this exhaust a good enough fit that I would be able to just take it into my local exhaust shop and they could weld it up with no issues?? I would just be keeping the stock cats correct? I may go ahead and do the cats anyway.

Maybe i'll keep my eyes open for some used parts for a few weeks, but otherwise I don't have much of an issue going new with the exhaust / spacer.

Thank you so much for your help my friend!

 

No problem brotha, always happy to help

One important point is to choose the correct Motordyne 5/16th Spacer, there are 3 versions, Basic, Isothermal(adds Aramid Gasket), And Copper Isothermal. The copper isothermal contains everything plus a copper throttle body spacer which coolant goes into. This prevents the throttle body from freezing in cold temperatures(since the plenum stays so cool ) as an extra safety measure. The copper is a bit more expensive though, around $250 I believe. I'll post a dyno at the bottom to give you an idea what happens. Keep in mind the spacer by itself does nothing.


Also, Osiris will not lower your reliability, it should stay the same with a certified tuner. You will have access to up to 5 maps I believe, which you change on the steering wheel. You can have: Econ, Power, Valet, etc. Many people report the car runs better and smoother, and you can gain ~7-8hp on a stock, unmodified car with Osiris. Still, it's not necessary for the mods you listed. I don't have it either, I'm waiting until I replace my cats. The stock ECU can adjust for the exhaust, plenum and intake mods, but changing out the cats puts it a bit out of it's normal range. I would just stay on the stock cats unless you want a tune.


Finally, the TDX2 exhaust does not replace the cats, it's a cat back, so no tune needed. However, I would check the laws in your area for loud exhaust and talk to some people. I actually got mine from Canada, and the seller said he needed to sell because he got a ticket. Sounded like it was unique to his province(or whatever) though.

As far as the fit, great question. No, it's not perfect. It's pretty close, but there is very little room down there. Probably about as close as they can make it. There's a W shaped subframe that can either be spaced down 1/4" to clear, or taken off. I had the shop cut mine off as it was damaged from the previous owner and unremovable. I did not notice any decrease in handling at all, or any difference whatsoever. I know other people who have done the same.

The other problem area is the sway bar, but this isn't a big deal. I went to the store, bought a short length of radiator hose, and put it over my sway bar where the exhaust would possibly contact. I secured it with 2 hose clamps. It should be noted that Motordyne sway bars are designed to work with the exhaust, and gives an extra 1/4" of clearance. If you can, have them installed at the same time as it is MUCH easier to install the sway bar when the exhaust is off of the car. Also, you have 4 options of tips for the TDX2, the burnt rolled Ti tips look the best by far. All of the tips are the same price and included with the exhaust.

Here's 2 clips of the exhaust and the spacer/mrev2 dyno. The first clip talks about/shows how the exhaust fits, the 2nd is a sound clip. Keep in mind brand new exhausts are slightly louder until the glass packs in the resonator settle after a couple hundred miles. Also, the first video includes ART pipes(louder), and the 2nd is on stock cats:



This actually does a somewhat decent job of showing the actual sound of the exhaust when he's driving. Still muffled and can't get all of the bass, but it gives you a rough idea. It's not raspy at all btw, which you can hear when he revs it on the jack stands. The rasp goes away after ~100 miles.

 

welcome to the club. cant wait to see your progress