Why I THINK a tune isn't necessary 321WHP
 

Hey guys,

This has been BEATEN to death, yes I know...


Dynojet, highest was 321HP, followed by 319.8, and 318.4...
Tq was 266-268
WITH a CEL (TP related)

Mods:
Stillen G3
Megan Resonated TP's
Stillen CBE

NO TUNE
Mods have been on for thousands of miles though

While these aren't THE highest numbers ever... They're up there, I think people are hell bent on thinking a tune WILL give better numbers...
While I still believe that if you let your car make the adjustments, you'll do just fine
Maybe with the VVEL unlocked you'll gain more... But it is worth it?

Dyno sheet below



Oh and on a 7AT

You are not alone.

http://www.the370z.com/tuning/55417-...-thread-2.html

do you have a baseline to compare against on the same dyno? number don't really mean anything by themselves.

The tune is not just for the highest WHP/WTRQ gained but rather improving the variables under the curve. Also fan control/idle rpm/top speed limiter etc etc. There are other reasons for uprev/tune. The driveability also improved. In the end its your choice.

Those are pretty nice numbers for those three modifications.

Nope, sorry... I never, ever intended to dyno my car...
I think the guy has a dyno sheet from a stock 370 though

I do agree with those,
Playing with fan control and tunes for valets are nice...

But a LOT (dare I say) the majority of people believe a tune is necessary to squeeze the max HP out of the car

My car did also hit the limiter too, lol

So I guess a tune can lift that too (not sure how often you go over 155 though)

Everyday of my life.....Which i live a quarter mile at a time.....

This is a before and after of my custom intake manifold, hence the lower numbers:

http://i1127.photobucket.com/albums/...2119CCEEA9.jpg

Afr?

So maybe my numbers aren't totally unbelievable alot of people seem to think something was wrong with the Dyno I was on. Plus bc I don't have a stock baseline sheet either i was modded before my tune. My sheet just shows the curve before and after uprev but with mods. Similar to yours, intakes, test pipes and cat-back. Then a custom uprev tune. One day ill go back and re Dyno my car bc now I have HFC bc of state inspection screwed me, thought I could get by with out someone checking bc we don't have emissions where I am but they noticed I didn't have cats and failed me. The shop I go to said a retune wasn't really necessary by putting on the HFC since they were only 200cel it may have made the car a tad richer but nothing I needed to pay for a retune for.

^ this is why you tune

So many people are stuck up on dyno numbers. Run your car in the 1/4 mile and that is the true measure of horsepower (your trap speed). My car made 440whp on S&Rs dyno and then only 380whp on Z1s dyno before my retune.

Even if you run on 1 dynojet and then drive 10 miles to another shop that has a dynojet...your numbers can still vary.

low end/mid range torque will improve, as well as throttle response. peak hp is not vastly affected by a tune. happy afr's = happy car

I'm going to explain this a little bit more because I don't think the OP understands the importance of a tune with all those mods. Yea you will creep out a few hp more and have your CEL turned off but the biggest reason is to make all those mods work together with your Z. The Z tends to run on the lean side with all those mods and a tune really cleans it up. A good tuner should be able to show you how messed up your AFR is and how a tune can clean it up.

1st of all, HOLY CRAP, 60WHP isn't something to sneeze about...

I DO agree with you sir!

But 1/4 mile (trap speed) is still a test of the driver, weight, how fat my fat *** really is etc...

(How's the Viper? I haven't checked your thread in a while)

Yeah, S&R's dyno numbers are a bit skewed in my opinion. I've never used/heard of a Land & Sea dyno other than theirs.

You are correct in that there are variables that will effect trap speed... but with all things being equal, it will be a true read of horsepower. Just like dyno numbers have so many fighting variables as well.

(The Viper is down again. I had it back for 2 weeks during breakin before it blew again. The motor was starved of oil, so the bastards didn't put enough oil in. The motor is still being diagnosed...2 months later:mad:)

Fuckin' hell, I saw he bit about the spun bearing/rod thing...
SOB's... I hope they're fixing their f-up for free!

If you find any parts that are in CA that you need someone to inspect or ship parts out to you, I am more than willing to help you out and the poor Viper... I love that thing

Appreciate the offer!:tup:

This

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If you think tuning a car is only for getting more power, I can't help you.

^^^

True

*2 chains voice*

No, we can help. Tuning is not necessarily to get maximum gains. If AFR's are measured and are safe, then you probably don't "need" a tune. But like mentioned before, having the ability to adjust a host of other parameters is very nice. Elevation will be critical as well if it's vastly different and your car was running 13+ at sea level. It could spell doom when climbing up a mountain if the ECU can't compensate. These ECU's are an engineering masterpiece. They are smart as hell and will sometimes save your bacon if some asshat advances timing too far, or leans it out too much, it will gradually try and go back to what the motor likes.

My dyno untuned looks damn near identical to my tuned dyno. Not only that, I didn't gain a lick of power. Best tuned and untuned run was 310 whp (SAE). They were 9 months apart. But that tune fixed a lot of nagging issues I was chasing. I started at 280whp (with all my mods in August) on the first pull of tuning. That tells me the car was running like a$$ when at it's best was 36whp higher. Tuning helped me get back up to 304whp (DIN [300ish STD]). Four months later when GTM rolled it off the transport truck and ran a quick pass, it pulled 310whp STD.

Moral of the story, even though my numbers ultimately came out exactly the same, the tune is what got everything back to where it was. Sometimes running a dyno immediately after a mod isn't the greatest determining factor of improvement if 2 weeks later, the ECU starts doing it's own thing and throws a wrench in your spokes.

Poor guy, 2 blown motors..

How will you know if the car is running lean or rich? What are the signs and symptoms? So I will know if my AFR is just fine. Without the aid of diagnostics.

so far my exhaust tips are not black with carbon. But I smell unburned fuel everytime I start the car but someone said over here its because of the HFC.

If u put extra mods on the car you would be foolish not to tune. Clean under the curve, all the other little things and to make sure afr is good n not lean. The computer will always compensate but ur prolly making it more difficult for ecu to compensate. In the end a tune is like 500. After spending all the money on buying an Infiniti and the expensive mods for this car, why skimp out on the tune that will help greatly reduce detonation? Makes no sense to me.
Good luck, to each his own.

Beacause your cheap!!!:roflpuke2::roflpuke2::roflpuke2:

Depends on the car...

My first couple pulls pre tune (on mustang dyno) were 275-280whp.
After 301whp with a higher redline and a nicer curve.

For me, it was worth it. For you, going on inflated dynojet numbers, you think it isn't.

yeah its been said before but damn wtf wrong with people thinking that the purpose of a car and dyno's and tuning etc is just to hit a magical peak number so you can brag about the size of your **** you don't have.

Tuning makes your car run smoother, better, gives you more linear power, increases low end as well. All these are great benifits. And thats on a stock z.

Tuning with mods brings the car back into the sweet spot, can help gain back some mpg's, again maximize the effectiveness of the mods etc.

Its always a good idea to tune, just normally not as necessary unless you have many mods.

Maybe the Dynojet you were on the numbers were inflated but not all dyno's are the same,as for tuning they are a very good tool you just have to make sure that your numbers aren't altered.

i talked to uprev awhile back and they told me that i wont get that much gains with my current mods since the computer is able to adjust itself. they saw more gains with long tube headers.

This x1,000,000

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running a car lean will increase mpg's while rich will decrease mpg's. If you run your car too lean the engine runs EXTREMELY hot and will cause a catostrophic failure (so i've been told). example, my wifes altima (yes i know off subject but good for info) afr O2 sensor went out and normally gets 480 before low fuel light comes on, after failure it came on at 515. She got 550 miles out of a tank of gas in a 2.5 S 2008 altima.Downstream O2 was shot as well. Also replaced the evap control valve. 1100 in parts and labor. Hope this helps for info.

I always say this but a dyno should be used for comparison purposes and/or tuning. Doing 1 single run with all of your mods and hitting a magic number doesn't mean a tune isn't necessary.

I really think all he was saying is that a tune isn't necessarily needed to get good gains from aftermarket parts. That's all.

Tuning is absolutely necessary for you to get the most out of your car.

The best part about the tune (to me) is that it made my z much better behaved during city driving. There was a small flat spot in the lower RPM range due to wacky A/F that the ECU never corrected for on its own. I also gained 13 WHP and 6 WTQ. The chart is in a thread in this section somewhere and in my album (from 1.5 years ago).

Goin off topic: I installed the M370 and ART pipes about 120 miles ago and it is now running lean according to Torque app. AFR is about 13.2:1 reading from the stock o2 sensors at WOT and 15:1 at partial throttle. It is my understanding that our o2 sensors report somewhat richer than the actual value as well. Time for a retune!

Well, there's no doubt that in the traditional world, tuning (especially for spark advance and AFR) matters. What's at the heart of this debate for the Z, though, is whether our ECU's ability to dynamically tune spark advance (via sensitive knock sensors, mostly, I believe) and AFR (via the fast wideband sensors the ECU sees just in front of the cats combined with the MAF sensors) is so good that dyno-tuning for advance/AFR is unnecessary for bolt-ons.

Spark advance I believe was well-documented by UpRev to be basically self-adjusting even when set to insane values. You could adjust the target AFR map without a dyno if you want the ECU to attempt a richer or leaner AFR via its sensors at various pedal/RPM points on the graph. That people see gains or AFR changes when they do a quick dyno->mod->dyno cycle could just be that the ECU hasn't had time to adjust yet, and would've arrived at roughly similar numbers eventually. That people see whatever changes on waiting longer between the dyno runs and/or mods... once you wait a while conditions change and these are all relatively small diffs we're talking about.

Personally, I'm inclined to think it's pretty difficult to take this engine anywhere with bolt-ons that the ECU can't adapt to over time, although tuning the fueling maps and/or spark maps on the dyno will keep you closer to optimal right after each ECU reset so that it takes less time to adjust, and tuning the AFR targets without a dyno might be an optimization that's worth it depending on your setup.

Considering our cars do not have true wideband sensors, everyone thinking our cars computers are smart enough to correct them selves I am sure your correct....but it can only correct what it see's...

If your running super lean or rich (which you will with full bolt ons) I would not count on this to give you the optimal tune.

wait, are cars are true wideband from the factory? if thats the case, then why aren't people running a torque app thru their phone instead of doing a gauge setup to read afr's?

They're pretty damn good for on-board wideband sensors.

They aren't dyno-quality good, but they're good enough for government work.

I ran with an innovate on the car for a while and my factory sensors followed pretty well, albeit a little slower.