Ok boys and girls, go easy on me here as I am a relative newbie.

In listening to what has been tossed around about the linear acceleration of the 350z and it's drive by wire system, what effect do you think the turbos will eventually have on this. I know of one in particular that is being worked on, but I was just curious as to what some of the serious engineer types out there thought the change in the driving style may be? Hopefully I won't get flamed too hardcore for this one.

OJ

 

Turbos = Torque. Torque is what throws you back in the seat upon depression of the fun pedal. The torque is what you feel most and gives you the most sensation of forward acceleration so adding turbos will change the entire feel of the cars performance. To get a "kick" out of the car in it's naturally aspirated form, you have to really get on the gas into the higher rpms. With forced air induction, half pedal acceleration will fulfill the typical excitement of moving. I believe the car will be a real work horse with forced air induction do to the amount of power the motor makes up top naturally.

 

So, linear accel basically goes bye bye. That's what I had suspected, but didn't know if the ECU might take over and limit the amount of acceleration. I can't wait to see what these cars dyno at with a decent turbo slapped on them.

 

I think there is a little too much credit given to the ECU on this forum. The ECU controls values, not power. It's not going to pull back power because it's coming from a foreign source. It will pull back power if it isn't receiving the apporiate data from the various sensors. So long as the MAF is showing the proper air flow, the O2 sensors and EGT sensor showing appropriate values, the ECU does it's job normally. With turbos, the ECU can be mapped to advance values due to air density, and should be set to run richer to work with the addition airflow.

 

Finally somebody that understands ecm-It cracks me up how many people think the ecm is going to boost hp that much.I work for a Nissan dealer-service, and the ecms will only need to be remapped when upgrades are made elsewhere.Bring on those TURBOS-so I can smoke some C5 a$$!!!!!!

 

Yeah, no more linear acceleration with a turbo, you will see a big spike between 3000-4000 RPM's. There is dyno of a Maxima floating around, it is t/c'ed and it has a HUGE spike at about that point, the Z would be similar.....

 

I personally like the linear power of the 350, great for track use. However the top end lacks the power I want. I personally will probably built it up au natural. If I do go FI I would probably go with a low boost turbo set-up, with a good boost controller. This way I will have power on the top end and the boost controller will smooth out the torque curve.

 

You will never get the full potential of a turbo system, without upgrading the ECU also. It's all about engine management.

If the ECU has nothing to do with it, explain to me how Audi got the 225hp out of the same engine as the 180hp model? Are you calling a 45hp boost "not that much"?

Nissan dealer-service eh? What are you a detailer?

 

180HP model has KO3 turbo.
225HP model has KO4 turbo.

Guess which turbo is smaller. Yep, the KO3 turbo. Of course, ECU tuning ALWAYS plays a huge role in getting optimum performance.

btw, most chips for the 180HP model will gain you only about 20 HP because of the small turbo.

 

Now you're comparing apples and oranges. In the audi bosch ECU system, the computer is not just controlling air fuel mixtures and timing. It's controlling boost pressure. Also you are talking about two different turbos as mentioned earlier. The K03 turbo is smaller and has a lower CFM flow of air. While both turbos may be producing the same boost pressure, the K04 is flowing more air. The ECU provides these cars with boost maps across the throttle band. Reprogrammed ECU's tend to increase boost pressure from .8bar (10 psi) to 1.2bar (18psi), as well as advacing the timing and more agressive air fuel mixtures. And due to the encryption of the bosch motronic systems, ecu tuners are forced to run extremely rich programs to avoid pinging and detonation.

I would imagine that turbo kits for the Z will either be packaged with ECU upgrades, or utilize a piggy back ECU for boost control and fuel management. But for mods such as air intakes, exhaust, pulleys, etc... the ECU does not NEED additional programming.

 

Garret Chip for a 1.8 TT



My point was and still is... ECU's make a difference. People are spending $1200 on exhaust systems for 6HP and exhaust note, but "crack up" at the thought of buying a ECU for $500 to gain 25HP...

 

Of course ECUs make a difference. EVERYONE knows that. The only reason higher-performance ECUs make such a big difference in turbo cars are because they can simply up the boost from the turbo.

But, you poorly backed up your point by making a false statement. 173fwhp still doesn't calculate to 225HP for a KO3 equipped Audi TT. Maybe awhp would, if they tested a quattro version, which is what I"m guessing. I believe they recently did acquire a 4 wheel dyno.

"but 'crack up' at the thought of buying a ECU for $500 to gain 25HP..."

Hearsay, hearsay. Sorry, I've never heard that before, and many of my friends own S4s, A4s, and other turbo cars that can easily bump HP with a cheaper ECU.

 

EVERYBODY KNOWS THAT?

This is what I took exception with... and granted the example was a little deceiving... but regardless 25HP is nothing to scoff at!

 

I would damn hope so, since a modern fuel injected car won't run with an ECU.
25HP is definitely nothing to scoff at with just a chip. You can easily get about 50-60 HP with just a chip in an S4, but boosting HP in a turbo car generally depends on the efficiency of the turbo. In an NA car, a high performance piggy back chip generally messes with the air-fuel ratio for optimum performance.

 

Garret is the Man... he is a VWVortex GOD!

I also have a 2 friends with A4s and S4s, and one friend who works at a VW/Audi dealership who let me take a 225 TT for a Sunday cruise... very fun! He's working on borrowing the S6

 

Yep, Garrett is a very good tuner...tends to run the cars a bit on the lean side with his chips though, from what I hear.

btw, GIAC (Garrett) is located in my town

 

Yes, the acceleration will be less linear. BUT, it's not like our car is all of a sudden turn into a honda civic. We already have pretty good power down low so it's not like we're going to be struggling. What really need help with most is our upper powerband and the turbo will be extremely helpful at this, not to mention the power in the already strong midrange of out power band.
Turbos
SC

 

Um...a supercharger will do just as well for power in the higher rpms.

 

Phreezee, my point wasn't that ECU don't make a difference. I had an S4 before this. I tested every ECU under the sun and I know what an ecu can do. My point was that people here seem to think that you won't gain anything from bolt mods without the ecu being retuned and that simply isn't true. You can get MORE out of a mod if the ECU is programmed for more aggressive values, but it's not necessary to see a gain.