Based on all the ECU posts, are not all mod HP gains "negated" by the ECU?
In other words, unless you reflash, replace, or piggy back the ECU, its a total waste except for looks or sound in some cases?
Forced Induction excluded.
True?

 

some mods lower weight.

 

I don't know about you guys but I definitely feel a change in power with the few bolt ons that that I have. I haven't dynoed my car so I can't back that up with numbers but after driving my car every day for almost 2 years I don't think I need those numbers.

 

Nope. Yes, our ecu is not the greatest, but I really do not believe that it just magicly "reverts to lower power". I would guess that if it does it is b/c of a cel or something else that is upsetting the engine.

 

i am very disapointed whit all the n/a mod i did i say if you wanna spend money for some real gain just save your money and get some boost

 

The mods won't be "negated" by the ECU unless the mods put the inputs going into the ECU out of spec range. There is some wiggle room and the few bolt-on mods exploit this fact.

However......the hp gains certainly are not additive with components, nor are they anywhere close to what some claim. I have the same breathing mods as you except the cats. Yes it feels a little faster, but that's not due to significantly higher peak hp, it is due to a redistribution of power within the power band that makes the car feel like it is revving a little more freely.

stock dyno: 236hp/229 torque
dyno with intake/headers/exhaust: 247hp/224 torque

This basically means my peak torque is lower but I'm making more torque higher in the power band, hence the feeling of a harder pulling car as the revs rise.

I do like the feel of the motor more now than stock, but I doubt it's even the tiniest bit faster objectively by the numbers.

 

theres a guy on here that runs 13.1's w/ basic bolt ons w/ out headers and cams...so yeah are ecu may be crap but not that bad

 

ops nvm he has a reflash

 

Don't be disappointed. It only means that the stock engine is pretty well designed to begin with. 287-300hp from 3.5 liters NA, in this price range, puts this car in a class by itself. Remember, this same basic engine started it's production run putting out 240hp a few years back. Nissan has already "modded" it quite a bit to squeeze out the extra 47-60hp.

 

Thanks, great info.
SO if I understand what most of you are saying is that an exhaust or intake mod will give a N.A. some small hp gains and a redistribution of the powerband.
However, once you start adding more mods or a more significant mod that adds a moderate to large amount of hp, it puts the ecu out of spec, and thats where problems arise.
Thus, is it safe to say an 03 350z with Stillen True Dual exhaust and a K&N Filter is about 7hp to 15hp above stock?
What "performance" mod would you suggest next that won't be negated by the ECU?
Does anyone have any boundry or limit formulas or even estimates that show at what point the add ons dont gain anything because fo the ECU?
Thanks

 

N/A is a waste, I took my parts off to go FI.

 

^+1

 

this is further reason to not mod the car don't you think? The gains will be minimal because nissan has already made most of them.



Anyway, for those of you that think the ecu is just fine. That's ok, go with that

It's not to say you can't make gains because you can. The low 13's, high 12's times without cams or headers are cars that are using racing tires and have a lot of practice. Meaning if they had normal street tires and a normal driver, expect to be doing mid 13's - which ISN'T all that much faster than stock.

You can put a few bolt ons on and you WILL make power. However, after you go past a certain point, you WILL start losing power. So be very aware of how your car drives after each new part. Be very aware of if it seems to drive great for awhile, then after a few days/miles seems to drive slower than before....


My car has tons of NA mods on it at the moment. If you're planning on going this route that's fine, but here's some things to think about because you WILL need to address them to make this setup work.

- You will need to upgrade your fuel system. All of it. It needs to be a return style system, new fuel pump, and larger injectors. The stock fuel system won't handle an extra 60-70whp very well.

- You will need to address the engine management in some way. Getting a TS or AAM flash is fine, but you will have to have them flash it for higher injectors and really get the car tuned. So be prepared for LOTS of mailing your ecu back and forth and spending LOTS of money in shipping and dynotime. Or you can get an A/F gauge with datalogging along with an O2 sensor mounted in the cats. The alternative is to get an EMS or piggyback and get it tuned. I would actually recomend getting the L-spec flash from TS and then something to tune the car itself, but there's some issues with the sensors in the car that will feed the ecu info that it's out of normal spec range and start pulling timing and fuel etc to meet the emissions levels it was programmed to meet.

- Be ready to deal with horrible gas mileage if you get all the NA parts - tilton, 3.9 final drive, cams, headers, raised idle, etc. Seriously, I spend like $150/month on gas and I'm running 1-2 bars lean because the fuel system is maxed. I can send my ecu back to TS and tell them to add more fuel, but my fuel system can't physially deliver it. So it'd probably be more like $160/month if I was running good A/F. I think I used to spend $100-120/month on gas when the car was stock.


I'm getting the APS TT kit because I'm frusturated with NA on this car. The APS kit comes with all that stuff. New fuel system, engine management, "intake" (twin cai intakes), "headers" (exhaust manifolds) and even crank/cam wires. It is even somewhat proven to be fairly safe. I bet it's actually safer than how my car with a million NA mods is currently running - because I didn't think I'd have to upgrade the fuel system etc for NA. Back when I ordered all my parts, only a couple people were running 280+ whp so there was limited knowledge/experience

Do I regret going NA? hell yeah I do. I didn't think there'd be this many things to fight against. FI takes care of all the issues

 

so even a reflash is no good?

 

sorry, I edited my post and made it twice as long with more info so reread it


The reflash is fine assuming your fuel system can handle the whp you're putting down - and it probably can't since the stock system just kinda sucks and is inconsistent in how it delievers fuel.

 

If you think there is a lot of things to fight against with N/A, wait until you go F/I.

 

please to explain.

 

i have several mods, and i take my car to the track after each one, stock i was running 14.1 with the mods i made i slowley but steadily came down to a 13.5 and my ETs went up about 3mph, i have just installed HF cats and an ApexSAFC and i garuntee i can run a 13.4 or better, my car pulls so much harder now, and im running on my volks the exact same way id be running on the street, my friend has a stock Z who i have raced and spank, depending who gets a better launch is one thing, but once we hit 2nd and especially third i just pull on him........... my NA mods definatly make a differnce

 

I can't think of a possible thing to fight against that isn't straightforward other than (suprise) the ECU

If you want more power, you increase the boost so long as the turbo kit is able to handle that amount of boost or the fuel system is heavy duty enough to feed the engine enough fuel or the engine's parts are strong enough for the power you're running.

seriously, there's MORE issues to work out with FI, but they've already pretty much been solved other than the ECU issue is still there, but you have a piggyback anyway.

NA there is still the ECU issue, but there's also the problem of trying to get a maxed out NA design to make more power - to really do it would require around $30k and still not have as much power as FI and would actually be riskier since how many people are running 4.3 stroker kits or have the knowledge to work on them. Not only that, but at the end of the day, you have a crazy expensive engine - and if something went wrong with it, that's a big chuck of change to part with vs a part on a turbo kit going out on you. Or even worse case scenerio, you blow the block and lose your block, sleeves, pistons, rods, rod bolts, and labor which is closer to around $10k vs $20k for a installed and custom tuned 4.3 stroker kit.

Just do some basic bolt ons - cats, exhaust, plenum, intake, maybe clutch or pulley, but once you start getting into headers and cams or more, you're going to run into some issues where YOU alone get to pioneer and try to solve the issues at hand vs a reputable company who put in a lot of time and tuning and R&D already to work out all the possible issues with a FI kit so long as you follow the standard safety precautions with FI. Companies like APS has engineers with a million times more experience than me.

For anyone who's a hardcore engine expert, this thread won't interest them anyway cause they probably already know exactly what probably needs to be done from the start to build a hardcore NA machine, but for the rest of us who want maximum NA bolt on parts - be prepared to deal with fuel and ECU issues and good lucking finding the perfect fix. The EMS market for the 350Z right now isn't so hot. There's very few options and fewer people who have experiece with the 350Z and the current EMS's on the market.


Yeah my car runs around 13's, but it doesn't run very well. I'm way too lean without upgrading my fuel and some more tuning. I always get check engine lights, my car misfires at low rpm's, etc The Tilton clutch is a ***** to drive with on a day by day basis, I get pretty bad gas mileage, and my engine runs hot from running lean. That's my NA experience and I've taken it fairly far as far as NA.

 

You need a ton of money to build a high horsepower NA engine on this car, and it still won't even be as fast as a bolt on FI kit that costs half as much...