After the ecu tuning Adam's car underwent at Altered Atmosphere earlier this week (thanks Mike...Adam was pleased), we are now on the prowl for the next mod to compliment the setup. One thing we noticed about my current setup is the torque peaks somewhat early in the rev range compared to HP (very quick ramp up, with peak torque of 242.2 at 4700 rpm), but falls off sharply after that point. We were able to get HP up tp 247 at 6200 rpm, and the car is runing very nicely now...much crisper through the rev range, and better overall performance than what I began with prior to the flash.

We are planning on building a set of heads for this engine beginning next week - we have 4 sets of cams for the car currently at the shop, and will send them all up to our macnest, along wtih our goals to see what will work best for me.

However, one thing we really want to properly address is the torque falloff after 4700 rpm - we're searching for a much flatter curve overall, with a crescendo as it approaches the upper rev limits.....anyone have some suggestions for me as to where the resources would best be allocated?

 

Crawford Plenum and Headers.

Question answered.

 

The car is stock except for the tune?

 

Plenum seems like the logical choice.....headers I really want to stay away from until I have the head combo all speced out...not a job we want to do more than once

I have to say though, the only downside I see to the Crawford plenum is the strut brace..the stock one is clearly superior in design to theirs, and I'd love to retain it....other than that one minor downside, looks like the plenum might be the way to go.

Adam

 

no - Gruppe M intake, UR cats, UR Y pipe, Apex'i Megaphone exhaust, Unorthodox crank pulley, and Insane grounding kit are the mods on the power side

 

It sounds like you should wait a couple weeks for the LSDUnique plenum as it will fit without changing anything. That is for upgrades soon. As far as later, finish your heads and then we'll go from there. Also, one thing to mention is, what goals does the car have in store as far as power levels, mods (FI, NA, etc), what type of driving is is going to be used for (road course, drag strip, street, etc)?

 

I am interested in their plenum firt and foremost, as it retains (or is intended to) the factory strut brace....a good selling point for me.

Heads will get done in teh coming weeks....hopefully we'll have the set all spec'd and built by 2nd week of Feb (its the busy season for engines right now, so time is a factor - thankfully I am not in a huge rush).

As for power levels, looking for a legit 300 at the wheels, NA. Car will see mainly street use, though we do plan on more than a couple track day events too at courses like Lime Rock and Pocono.

 

Honestly, look REAL closely at your OEM bar. There are bends in it. I have see photos of Zs in accidents, where that bar is even MORE bent due to not being able to take the high stresses.

Dougs car flipped three times, trashing his engine bay... Didn't so much as dent his solution.

Think about it!

 

I hear what you are saying, but I am not talking about it from a crash standpoint...I could care less how it fares in a crash, I am concerned with how it behaves in the turns....and from that standpoint, stock is better....not that the Crawford one is bad mind you...not at all, just not as good IMHO....but I am still considering the plenum...thats the main goal afterall.

 

If you want my personal opinion, totally non-related to Crawfords...

I don't even run the strut bar... never wanted it, and pulled mine off once I felt how badly the car pushed.

The bar was an afterthought once the car was designed. G35s do not have this item... and you can see the plates which were added to the Z to accomodate this item.

 

With heads/cams, your bolt ons, whichever plenum you choose, and some headers (along with a properly tuned ECU for the setup) you will be right at your goal of 300. My setup is going to be similar to yours except with XERD headers instead of cats. Hopefully, NA, I will push close to 300 then I am trying to figure out if I want NO2 or a 12secZ style Procharger. I think I am not going to build the bottom end until I blow the motor. Hopefully, I will never have to build the bottom end!

 

thats where I am at too Fly By - I have no intention of building a full motor for the car..I already ahve enough "toys" and really don't need another at this point. Plus no matter what I do to this, it will never be as fast as my "other" Z

Xerds are nice and I would probably go with them if I could run decatted...but I want to keep it as legal as possible since I am in NY

 

I think the Stillen headers look pretty good. Equal length, nice finish, priced to sell, hehe.

I also think HF cats and some kind of plenum. The stock Y-pipe looks pretty poopy, so some kind of dual exhaust (I like the Borla) or a single with a new Y-pipe.

Really though, I think the cams are going to give you the biggest difference up top. Hopefully you can come up with a grind that gives great gains at the top without sacrificing anything down low.

Good luck!

-D'oh!

 

HF cats I ahve, also have a Y pipe already.

We are Stillen dealers, so am considering them.....but they need to work around the head combo...picking headers first would be going backwards honestly, so not sure what will nd up working the best yet.

 

Just remember that when your setup is running and you get it dynoed in, look at where the power is made most. If it is up high, don't get headers (or other parts) to make power down low to try and get a more even powerband. All mods like those will do is compromise each other and you will get the worst of both worlds. Mod to a goal, but also mod to an RPM range, whether it is all down low and torquey or high revving HP.

 

Totally agreed.......you'll see over the course of my participation here, I am not after the longest internet mod list My cars all tend to take a rather minimalistic approach, addressing only the areas that need addressing. Right now the HP range is definitely up top, but torque is in the middle of the range, so car feels nice overall....I am please with how it performs down low honestly. I jsut want to take the mid-upper range and increase it, especially the torque side to make it more resemble the HP curve.

 

Ahh, what Y-pipe? 80mm collector or does it match the oem 65 diameter at the flange?

 

I have the Ultimate racing Y pipe, which is 3 inch a tthe collector - which is the same diameter as the cat back I have (actually, same as most every aftermarket cat back I have seen)

 

From what we just learned from our engine guys our XERD header motor vs Nismo headers motor is up a lot in the tq department about 8 lbs and that was with the old map. They have worked on a new map and things should be really good.
BJ

 

cool - unfortunately I have to stay with cats, otherwise I would probably have them (again, assuming they would be well suited to whatever cams I inevitably run)