When is a tune absolutely needed?
 

I have done the searching, and found out that you don't really need a tune for any of the bolt on's. But i have never seen anyone do all the bolt on's in one go. I just finished momentum headers, test pipes, FI CBE, already had G3's. My question is should i wait to put the motordyne manifold on until right before i get it tuned? I just don't want to do any damage to the engine if it makes it run too lean you know? So whats the scoop? Am i good to go, or what?

How much driving are you going to do before you get the manifold?

I have it now. Just debating on throwing it on or not. My apointment is mid march. Maybe 1000 miles worst case between now and then

Those manifolds don't make ANY more power and in some cases lose power my suggestion is sell the manifold and get a tune asap.:tiphat:

I'm interested to know this too.

Im really not interested in peak hp. What good is it anyway? I am interested in the torque increases throughout the curve that this unit seems to produce.

Well then sell the manifold and use the money to pay for your tune.

B/c if you tune your car with this manifold then change back to the OEM manifold you will need a retune I'm just trying to save you time and money.

2 of my friends had that manifold on and it was removed while the cars was still on the dyno.:shakes head:

.........I lost 2whp on the top end and picked up damn near 10whp and 16tq at 4000 with the manifold......Best damn decision I ever made. Talk to SS_Firehawk. He sold his and he regretted it very quickly and purchased another one a month later. Your top end suffers minimally while your midrange gets a huge kick in the ***. If you don't understand power curves and you think the manifold sucks, then go ahead and avoid getting one of the best power gains for our vehicle. I mean peak horsepower from 7300 to 7500 is much better then a power increase from 3500 to 7000. Even still my car pulls all the way till 8k. Hell i make my peak power at 8k still lol

With MY manifold!!!
LOL:bowrofl:

I'll kick your *** and steal another one if I have to!!!!! Worth the jail time bro!!

Im just wondering about the no tune at first. Im not going to blow my engine with all those mods at once will I?

No

I had a 3 month fist fight with my manifold before I came to my conclusion. Sum it up, something else was wrong with my car that was losing power, not the manifold. I say put it on, it should run safely without tuning, but I gained 99% of the top end power back and much more mid range post tuning. It's on the first page of my build thread. I'm about to go back and bold/increase font size of my review topics. I'm interested to see if it helps with your rasp too. Not that your car sounds bad, I had 3 eargasms in 30 seconds. It's a 60 min job, just need some deep sockets and hex's.

Looks like everyones already hit the nail on the head!

Reset the ecu to have it relearn your fuel curves. wont be perfect but itll help. none of the bolt ons we do force us to need a tune. it helps with gains and of course yiur car will run smoother. without a tune, your car just wont run at full potential but not enough is being changed to cause harm without it.

After reading the thread most people here don't know how to use Uprev and how are AFR's work,the correction factor is between 75%-125% with 100% being on the money if the ECU moves the AFR toward the 75% it is taking away fuel and toward 125% it is adding so the reason for tuning is to get the car to run as close to 100% as possible so the ECU has full range to adjust rich or lean depending on the information it receives from all the sensors.

If the ECU is not adjusted properly let say it at a giving RPM and load it is running 125% it is maxed out and can not add anymore fuel this is why it is VERY IMPORTANT to get it to 100% so it can do it job.

You guys get the point.:tiphat:

i understand what you're saying and it makes sense. funny thing is you say maxed out A.k.a. running lean. My car with all my bolt ons was running so pig rich at points hitting 10.9:1 in the afrs. my car was straight up dumping fuel without a tune. my mpg was like 17-18 without the tune. got it leaned out to 13:1 afrs and my mpg is back up to low 20's and the pulls like a beast. Maybe my car is an oddball but without the tune i was running stupid rich and needed to lean it out bad!

I swear I just got a case of deja vu. I'm not sure which post of culmination of posts brought you to the conclusion. But the intake runners are longer and the manifold is wider (except throttle body positioning). It's going to effectively move your peak power, hence the slight loss most experience up top. I still said he needs a tune afterwards to get the most benefits, but also, running the manifold isn't going to make his car go dangerously lean. I would say most of us know not to tune a car on the edge, or have a tuner push the envelope too far for a few more hp. At 2000ft, I was just over 13 AFR with out tuning. Until my Pre cat O2 sensor crapped, then it just ran rich.

Every tune from Nissan is the same but not every engine is the same,the fuel comp table in Uprev has a 16x16 grid,which has 256 differant cells to adjust the A/F, some cells maybe rich some good some lean yours must have had more rich.
But these cars are usually really lean down low and get really rich as the RPM's go up.

OP, put it on and get a tune...then enjoy the results!

super odd... glad its runnin good now!

The way I see it, there is a big resale market for these if it doesn't work out for you. When I tuned with the manifold, that was at 304whp and 243lbft/tq. When I installed my stock manifold and came back a week later, baseline was 302whp and 232lbft/tq. After tuning, I gained 4 more whp and tq. The gain was only after 7200 rpm. See below for final results and why I bought it again brand new. I plan on keeping it on with the superchargers too.

http://www.the370z.com/members/ss_fi...s-m370-din.jpg

that midrange gain is impressive!

Absolutely necessary?

If the ECU has to run excessively high fuel trims to maintain target AFR's (resulting in a CEL), there is knock under load, or driveability is poor.

What mods could cause this condition? Any major change to the intake or exhaust plumbing orientation, diameter, or flow.

Individual results may vary...

Im going to pop it on, and just drive her easy until the tune in march...

The engine will go into a 'mode' where it dumps fuel in open loop mode, if you add too many breathing mods without a tune.

The Nismo intakes (that I have) are one mod that if you put it on without a tune, it'll just go full rich, 10.5:1 or whatever the low threshold is on our O2 sensors. Even with their MAF spacers (which are just like the ones AAM includes in their intakes).

Strange, but I think it's a protection mechanism.

Good to know, didn't know that.

I am going to keep this very simple (I have made other posts about this subject and I don't feel like re-writing everything again):

If your mod is anywhere between the MAF and the 02 sensors, you very likely need a tune.

Good short and simple way of putting it!

sorry wrong post!

ROFL @ garageline. may have been better to advert your exhaust. I propose a new idea, new thread" Do I need a tune with wheel spacers?

Why is this post on a tuning thread.:shakes head:

Bring out the ban hammer :ban:

Of course, you need to retune for more torque due to the extra rotational mass. It will hinder your car almost useless otherwise.

LOL sorry guys wrong post.

I actually do have some input on this. If you keep the stock intake and filter in most cases you will not need a retune. The issue comes when you change the intake sytem. Most of them are made from off the shelf piping diameter which can been undersized. This will cause the car to run richer than normal.