Flyingscot

Another thought I've had on ECU/ECM/chips.

Being that the Z is a OBD II car, I believe a chip replacement will be necessary for anyone contemplating performance parts. The reason for this: we need to be able to fool the OBDII system so it doesn't throw those awful "check engine light" errors that only the dealer can clear.

My experience in this area is limited due to the age of the cars I work on, so does anybody have more thoughts on this?

crayons

Actually the replacement of the OBD II chip isn't really to not get the "check engine light" switches. In regards to performance parts like intake, headers, exhaust.. all these provide the engine with better air flow. However, the OBD II chip will register this, and retard the engine timing to "compensate" for the different conditions.. and there go all your hp gains in the toilet.

But yeah.. I'm not sure how much the OBD II chip in the Z will affect aftermarket performance mods, but only time will tell .

articfury

VQ-

Did they dyno the same car again several weeks later? The discussions I have seen on this subject said that there was a learning period for the ECU. Just wondering...

JD

ITZBITZ

Every passenger car sold in the US since like 1995/96 is ODB-II, as required by federal law.

And you can easily get high HP on a laboratory dyno test by unplugging the ECU for 10-15 minutes to reset it, and then plug it in (reconnect the car battery) and quickly run a cold-engine dyno test. You'll get higher than normal numbers until the ECU relearns the air flow parameters and then it's back to 'wasted-your-money' numbers.

To get consistent, reproducable numbers, you need to fool the ECU into thinking things are great, even when they aren't. And that means dyno time and adjustments to get it working smoothly or you can end up with a poorly tuned engine based on a stock "hot-rod" profile with a snap-in ECU upgrade.

That being said, I would guess that you could get 20-40 hp with an exhaust/header/intake/ECU combo package. It would be emissions illegal so only states with no smog checks would really enjoy the benefits without 'issues' regarding testing.

Boomer

Flyingscot; do you have a list of mods prioritized; where do I start first, you can recommend? I wouldn't want to start in the middle and get bummed out when the car mods don't seem to effect performance at all.

Boomer--I know this post is late, but I'm a slow learner.
BR/FR/AT

Flyingscot

Boomer, I can only give you one opinion. Perhaps you should start a new thread and let the community speak to this subject. I personally plan to just enjoy the car as is for at least a year and probably longer. My time and money is more focused on my "racecar" at present and I don't expect that to change anytime soon. A stock Z is more than capable of getting you into trouble with the local Bobbies. By the time I get around to modding the Z, we'll all know (from the pioneers among us) what worked and what didn't. I would also wait until Nismo has a more substantial line of parts before jumping on board, unless you are one of the pioneers of course.

But since you ask, I've developed a few suspicions since I originally posted the Nismo Poll and so I'll share them now:

1. A Cold Air Intake will probably buy you very little as the stock one looks quite good. Maybe we are talking +4HP at the very most, which equates to 1.4% of the total crank HP (i.e. 287).

2. Stock Headers look good too, so unless you plan to remove the CATs, which is not street legal, I think there is little to be gained. Nissan headers are pretty good usually. But lets say the best and the brightest (with CATs) gets you 5HP (1.7%).

3. Exhaust: Now this looks like a more promising area, although, I think more people will upgrade it for sound reasons rather than power. I would estimate +8HP (2.8%).

4. ECU: I think this could be where additional HP can be "unlocked" as hinted at by J. and others but at the expense of sailing through emissions tests. This could possibly be a first upgrade for me.

5. Pulleys: I really haven't seen or heard of any down sides to under-drive pulleys other than cost vs gain arguments. The early reports indicate the Z already is free reving so 6HP is probably a little optimistic.

6. Supercharger/Turbo: Very expensive! + Will the car pass emissions? are my initial thoughts. However, you could easily spend $1,500 on 10-15HP or $5,000 for 100HP. Using these numbers, the $5,000 is more palatable.

7. CAMS: One of my personal favorites. More aggressive cams (with ECU and a slightly lumpy idle) might be a good alternative over the supercharger/turbo for those that would like to see the original numbers of 0-60 in 5.2 and 300HP.

I made some changes to my car that netted a 8% gain in mid range and peak HP. The effect was noticable but didn't blow my socks off. Any mod providing less than a 5% increase somewhere in the powerband is just too small to feel. Hopefully, Nismo and others will only offer parts that do better, but, watch out for inflated claims.

This leaves suspension, brakes and wheels.

Wheels only make sense if you are getting a lighter, wider setup (style issues aside).

Brakes: I went for the Brembos in case I go FI. You can never have enough stopping power and fade resistance. I know this from people who have added turbos to their cars.

Suspension: I once said on this site "Speed is more about maintaining it than getting there". With a good suspension setup, you don't need lots of HP because you won't be slowing down for the turns

So there you have. But by all means start a new thread on this and let's find out what others think.

Fly

Boomer

Thanks, Flyingscot, your insight is valuable. I don't intend to do much, if anything, to the Z until I've driven it for a while. We both know Nissan got most of the extra power, over Altima, Maxima and G35 by improving the intake, exhaust and cams to get to 287 or whatever. I think I will see how the mods NISMO comes out with work for some of the more adventurous souls than me.

Boomer
BR/FR/AT

Flyingscot

You're a wise man Boomer. Modding is so often more about psychology than it is science, especially in the power department.

TDOT350Z

This car seems to be pretty quick out of the gates. I'd wait a while for the engine upgrades (except CAI/exhaust) and slam that car with a set of race designed coilovers and then stiffen it up with struts and sway bars. The quality of the parts will be way better in a year or so compared to when it comes out.

articfury

TDOT-

Do you really want to do intake and exhaust without an ECU upgrade? This is what we have been discussing. As my previous reading has indicated, and as pointed out by ITZBITZ, without "tricking" the ECU, any benefit from these upgrades will shortly be mostly nullified by the ECU.

JD

ru4real

You guys could be underestimating what a turbo kit could do for the 350Z.

"Turbo97SE" a Maxima.org member, installed a custom T04e on his 4th gen 5-spd Maxima a few months ago.
The car is a 1997 model, otherwise completely stock engine, exhaust, and transmission.
He used a Turbonetics T04 turbo, HKS/Greddy/etc blow-off valve, Tial/Turbonetics wastegate, Spearco front mount intercooler (core size 20x7.8x3.5), and a Vortech FMU. The battery has been relocated to the trunk.

This is now sold as a turbo kit by PFI Speed



A stock 97 Maxima at the flywheel, makes 190 hp @5600rpm, 205 ft-lb @4000rpm from it's VQ30DE. That's a 3.0L without the variable intake manifold that the later VQ30DE-K had on the 2k and 2k1 models.

His dyno numbers (at the wheels):
176 hp 190 ft-lb Stock with CAI and Y-pipe
268 hp 272 ft-lb @4 psi
278 hp 281 ft-lb @5.5 psi
352 hp 349 ft-lb @9.3 psi

Here are the dyno charts @4 psi:




These results could show the awesome potential of a turbo (T3/T4?) on the 350Z.

ru4real

VQ30DE in 97 Maxima dynos 372hp, 369 ft-lbs

He hasn't run at the track yet.
The VQ35 in the 350Z should have just as much potential. Who wants a 350Z with 350hp? Not at the flywheel... at the rear wheels!

Dr Bonz

iTrader: (1)

I DO! I DO!

TDOT350Z

that would be lovely. GO Z!

Xer0kool

I would, without a doubt be willing to pay $6,000 for a turbo setup, but not one that gives approx 100hp. I could go to one of the serious performance shops in the area, and for that price be putting out around 500 hp to the wheels. another thing to consider with the ECU is it's cancelling out of the electronic speed limiter. (my guess is that the top 155 would quickly become about 170mph) Though many of the people who buy this car will be simply "enthusiasts" there are people, such as myself, who'd love to be whoopin on supras all day long.

Just my 2 cents though

nickdtm

I would hope the turbo and supercharger would give more than 110 and 80 hp!

The current front-runners in M3 forced induction add 180 and 120hp, respectively. Nissan tuners should be able to match that at least.

Flyingscot

\

Better to aim low but shoot high don't you think

dvlad

Ok, so the VQ engine can handle a turboe set-up. It is fessible to have 350 rwhp on the Z.

But the real concern on my part is the drivetrain. How will the Z's CF driveshaft, transmisson, diff, etc. handel this? Does anyone know of the max hp the drivetrain can handle? I've hear that the TT can handle 500+ hp.

Anybody?


dan

jreiter

iTrader: (6)

Isn't it torque that actually matters when dealing with stresses on drivetrain components?

Since horsepower is basically just torque applied over time, it seems like horsepower wouldn't really matter. Say you have an engine that puts out only 200 ft-lbs of torque, but you can rev it to 10k rpm. That'll likely give you some huge horsepower numbers, but the transmission won't have any more stress on it than if you were only revving to 6k rpm. (Well, transmission parts will be spinning faster and thus causing more stress... but that's different.)

But now take an engine that puts out a monstrous 1000 ft-lbs of torque but only revs to 1500 rpm. (like the big turbo-diesel Cat equipment like bulldozers, dump trucks, etc.) Those things really don't put out much horsepower due to their low rpms, but if you put a typical car transmission and/or driveshaft on them, you'd break them into little pieces instantly.

Flyingscot

It's true that torque is the real killer when it comes to transmissions. However, it's basically just semantics to try and destinguish between torque and HP when talking FI. By its very nature, FI produces a lot of extra torque to go with that extra HP.