that is one of the things we are waiting for Cobb to add to the software

never asked what a resonator is, simply asked if a resonator in a picture was the resonator. i know what a resonator is. and whats wrong about asking if headers makes the car louder? i actually found out the exact opposite of what i was thinking, the headers dont make the 370z too much louder, where as on my car they made a big differance in loudness. and im not sure whether or not i told u i had a 370z, but if i did it was just to make things easier so i dont have to explain myself. my dad is getting a 370z so thats what i was talking about. and i do do alot of searching the forum, only time i post a question is when i cant find what im looking for.

Fair enough, the general consensus would point you to GRD (Genesis Racing Development) for tuning on a COBB for the Chicago area. On the Sentra, there is a built in pre-cat on the header, hence the increase in volume replacing it with an aftermarket solution.

Enjoy

yes, thats true about the built in pre-cat on the sentra, not only that but that pos pre-cat is know to break up and get sucked into the engine, so on the sentra not only is a header a performance mod, but also an reliablitiy one too. also on the sentra se-r's intake manifold, it has two sets of intake ports, 8 total, one set is open all the time and the other set is closed off with butterfly valves untill the engine hits 5500rpm, then the second set opens allowing more airflow through and also making the engine louder and deeper. why doesnt the vq engine have this design? i would think it would allow more power.

There's no need for it on the VQ37 because it has VVEL.

even with the older generation vq engines, which did not have vvel.

Nissan engineers probably didn't think it was necessary or found better ways to make more power.

With the Cobb AP, can you change the revs per mile to correct speedo and odometer readings associated with different wheels/tires or is that something more mechanical?

no, that is not handled by the ECU

Thanks for the clarification. Its not a big deal, but a minor detail that I'm sure will bug me.

Has anyone actually had their 370Z tuned with a Cobb port?. I have the port but the tuner is having some trouble getting the software.

Yes, Cobb in Plano Tx tuned mine and I'm also having problems getting the software to install so I can read the tuning tables and learn the software. Typically do my own tuning and honestly have seen hundreds of cars tuned, but I'm about as lost as a big dog can be. Not being able to get the software working is one thing........the other is how the car responded to tuning.

The car was very rich on the top end (in the 10's) and should have picked up decent power from tuning. I have Stillen Gen III intake, Headers, Berk Cats and full Stillen exhaust so air in/out should not be an issue. Going from 10 whatever to 12.7 AFR produced absolutely no power gains. Calvin whom does the tuning was a bit stumped also. The only thing I can think of is the air intake temps were between 106-108 and the car does not like warm (really hot) air, or the computer somehow purposely limits the power until it learns. Dunno??

For some odd reason cars do not dyno well here in Dallas in the summer. Not sure if it's the heat or air quality, but I'm waiting for fall to give the tuning another shot. Take it back on the original dyno where I have my baselines in cooler weather and see what happens. If someone has any words of wisdom.....I'm all teeth n ears.

^ Good post. I'll post results when HPLogic tests out a tune on my car, or if they do. Hopefully results will be different, but thanks for your input Denny.

ouch... that's not good news... please post dyno results, denny

Done? Well maybe not. The dyno sheet didn't attach. Jeez...... I need a bunch of help. let's try it again.

OK........so that didn't work. If someone will host the dyno sheet I'll send it so you can post it. The really odd thing is the car did pick up some (as in tiny bit) below 4500 rpm when the air/fuel was pretty good. Did nothing where it was way rich.

Somebody.......help me. Anybody.

I have the cobb and they sent me a 370 6mt instead of 7 at.
Had trouble loading the drives/
Have not got a clue how to tune it

I have the stillen headers, berk cats, stillen exhaust and stillen g3 intake.

Excellent choice of mods I must say.

Normally you need a dyno with a wideband 02 sensor and the fuel/air is the first thing you tweak. Dyno's and widebands make the process pretty simple as in the "old days" it was pure experience/trial and error as there was no objective feedback except power output. Every car is different but 13 to 1 (plus or minus some) is where most N/A cars make the best power

I've tried to tune while driving the car and the only thing that happened is I lost power. Do the dyno. This was my first experience with a Mustang dyno and I'm sold on the concept as they put a more of a driving type load on the car.

After you've found the fuel/air ratio the car likes and the fuel air line is flat, you can play with the timing. For reasons not known to me the fuel/air can change if you tweak the timing so make the proper adjustments. I not gained much either way on timing but have learned as a rule of thumb to be conservative on timing but aggressive on fuel/air. Make sure you are logging the car while it's on the dyno to see where you're at and make sure your not so aggressive that it's pulling out timing. A "puff' of exhaust is usually denotation.

Doing each run the same is the key as things can change with engine temps so make sure your cool down and water temp is consistent each run.

Of course...... we need to figure out how to get the software to work and then why the cars are not responding to input.

BTW....... If someone with host the dyno sheet e-mail me personally @ dmclain@medserinc.com. Please.

...

I have an accessport for sale if anyone wants one.

Has anyone had any problems with Cobb Accessports and engine code for ECU not working correctly? Has anyone done any Cam tuning with the Cobb? If anyone has, please PM me I have some other info but this is too public.

there is no cam tuning yet

Here's Denny's dyno sheet.

http://i618.photobucket.com/albums/t.../DennyCobb.jpg

Semtex

I thank you sir.

Note this is SAE and not standard so the power is probably 5-6 hp less than what most people post. Regardless, low in my opinion. Bone stock with 300 miles on it the car made 275.4 (SAE) and with just a Y-pipe and Berk cat made 288.9. IF the two dyno's read the same, the car only picked up 15 hp from Gen III intake, Headers, full exhaust and tuning.

As mentioned.........I'm completely stumped and ready to punt. Step 1 is to call Cobb so I can get the programmer and tuning program working. Step 2 is a revisit to my origional dyno.

I've been to Cobb in Plano TX three or four times. In the beginning they used my car to read the ECU to get data so they could develop the softare. Every time I visit, get the impression they are completely standup and unlike most companies, do not overhype gains.

Most people whom tune do not give out secrets but after you've got the knack of doing a couple, it's not as much rocket science as you would think. Calvin whom works the dyno and does the tuning, was very knowledgeable and competent. He was very straight forward saying he didn't know why the car didn't more power and asked that I take it back to the original dyno for comparison.

Think it's more of an issue of everything being so new, there are gremlins to find and bugs to work out. Evidently the computers are very complicated and my gut says it's a matter of time. If not, there might be a new Grand Sport or Z06 Corvette on my X-mas list.

It just so happens that this is the reason UpRev gives for taking so long on development of their software for the 370. And VVEL adds an additional layer of complexity, apparently.

Was yours on a Mustang dyno? If not and it was on a Dynojet you need to add about 10% to the Mustang dyno numbers to get similar Dynojet numbers.

Wait . . . they didn't do a fresh baseline run on the Mustang prior to tuning? Like both runs 1 and 2 in this graph are post-tune?

Depends upon the software. Because the Mustang always reads lower than a Dynojet and people want big numbers, they tweaked the later software to read closer.

Another confusing part is Cobb had a dyno sheet for a stock 370Z that made 289 rwhp. That's 14 hp more than what my Dynojet stock baseline was.

"Confused like a big dog" is the key statemdent so many things don't add up. The power output really should have changed with the air/fuel ratio. The only thing I can do is get the software up and running and give it another swing at bat.

More confusion. If you look at the time the runs were made #2 was first and #1 was five hours of tuning later. The session started about 10:00am and it took a good 30 minutes to get the initial read. The run @10:40 was the baseline.

Kinky thing is the car improved on the low end where the air/fuel was close and did nothing on top where the most improvements were made. So...where is that dog again?

There is a lot of conjecture that can be made here. If you look closely at the dyno sheet there are slight changes around 4500 rpm, 7100 rpm and 7700 rpm. When I saw those, the first thing I did was check the fuel/air and then ask Calvin if the car was pulling out timing at those points. He said the timing was good and his feeling was the car was changing cam timing at those points and a lot more could be had when the VVEL software is perfected. You would see a puff of smoke every time it hit the 7100-7200 mark, so something was going on.

Also..... while I'm making blind guesses, might as well make a few more. Notice the slight improvements in the 2000 to 4500 range where Calvin thought the first VVEL table was. It did for sure improve slightly in that range. Is it tuning software, or does the car learn one VVEL table at a time? Will it pick up on top later?

The rev limit was set from 7500 to 8000 rpm and as you can see, it takes a sharp drop just past 7500 rpm. Is that because it needs to learn from never being there? Or, did the engineers pull back on cam timing to keep people from over revving the engine??

Is the tac accurate? I now see it hit 8200 and doesn't hit the limiter. Or, is the new rev limit not accurate?

Inquiring minds want to know.

Some interesting questions. One thing I remember regarding the RPM limit and the chart. If Im not mistaken, the shelf technosquare flash also ups the rev limit, but their hp curve climbed all the way to redline at 8100 or so. Then again, I don't believe anything that comes out of that shop, so it could have been bs too. Maybe it needs to learn, maybe it needs to be taught what to do after 7500. Perhaps The upper VVEL table is only programed for 7500 RPM where it tops out and becomes inefficient there after?

Can't wait to get some answers for the vvel tables, seems like there's some hidden power/response to be squeezed out by optimizing the timing. There's a really good chance that Nissan left that on the not so aggressive side in order to comply with emission regs...

Every performance car manufacturer is infamous for sandbagging. Look at the new Nismo. All of a sudden the redline is 7900 rpm and the car makes 350hp from a better exhaust. Will that be standard for all 2010 350Z sport models? What about 2011? There is more in the engine and it's in the computer. I seriously doubt they will do a redo on the engine for the next 4-5 years, just computer/bolt on tweaks.

Has anyone actually gotten the Accessport to hook up to their computer?

I've not tried to connect it to the car as it was just tuned, but I can't get the updater to work. Hence, no drivers etc. Just sent another request for the tuning software as my prior had expired and the links they direct to do not work.

Still that confused big dog. Their service disclaimer basically says to not call but go to their website. That was a lot of help.

You might want to try sending a PM to Sharif to see if he has any advice. Sharif wanted to do mine with Cobb, but I decided to hold off and wait to see what UpRev releases. Anyway, Sharif (Forged Performance) is a Cobb Pro-Tuner and might be able to help.

Ended up calling Cobb in Plano and they directed me to Dan in Utah. After redownloading the software, everything except for the tuning software is working correctly. That I should get again tomorrow and see if I can figure it out.

Was in MI all last week for the Woodward Avenue Dream Cruise (absolute off the scale hoot) so I hadn't had a chance to play with it plugged into the car. Damn handy tool is all I'll say and I'd probably buy one just for the others things it does.

It answered one question real easy......the tach is off on the cars. At a showing of 5000 rpm; the car really is at 4800 rpm (typical of most cars. My Vette is also off) and at an indicated 8300 to 8400 rpm, it hits the rev limit of 8000.

A feature I didn't realize it had was fuel/air ratio readings. I'll log it and double check it for accuracy with the talepipe windband 02 the next time I dyno. If it is accurate, I'd say most people could do a half way decent driving tune. Once the parameters for AFR that the car responds most to are public knowledge, all you need to do is log the runs and make the corrections with the programming software. Like WOW. Something else I may try and verify on the dyno as in the past, I've done more harm than good trying to do a rolling tune.

Also found the air intake temp pretty handy. With the ambient temp of 97 degrees after a bit of driving through the local hood, the lowest reading I got was 108. I'd be very interested to see what others with the stock intake are seeing in comparison to ambient temps. Sounds like one part of the acid test to see how effective these various intakes are. The rule of thumb is 1% hp increase in hp for every 10 degrees of lower intake temps.

About time the big dog smelled where home was and is going in the right direction at least.

I have had no issues getting my computer to recognize the AccessPort and I've even viewed some data logs that I created from driving around town. I've yet to do any actual tuning with it though. The only thing I've done is just flashed it with the Cobb 370Z stock basemap.

Your luckier than me. I was on the phone with Cobb three times yesterday and it's the tuning program that is still not installing. The first issue is both my main computer and main laptop are Vista 64. They do not have the software ready for Vista 64 yet. Lucky enough to have another laptop using Vista 32 and it will not load on that either. Basically ran out to time yesterday but will call them again Monday and let them troubleshoot the issue.

Also... A weather front came through the night before so I made a bee line to the original dyno (RPM in Lewisville TX) to get a better feeling for exactly what is going on with the car. Dyno sheets below.


370Z RPM run #10 - 317 rwhp std picture by dennylmclain - Photobucket

Note this is std hp and not SAE as per the first Cobb dyno sheet. SAE the car made 312 so either the car picked up 7 hp or it's a difference in dynos. It appears the car has learned in the 7500-8000 rpm segment and has picked quite a bit of power vs the fresh tune.

Only made two dyno passes (#9 and #10) as it was a learn vs a tune session, but the fuel/air readout on the Cobb Accessport is not accurate. Upon talking to the Cobb tech, he indicated the readout is based upon the narrowband 02 sensors of the car and would not be accurate but would be consistent for each vehicle. (it read about six tenths lower than the dyno wideband) I'll play with this some more in future sessions to see if it is consistent for my vehicle, but according to the tech each car would need to be hooked up with a wideband 02 to as he said each car would vary.

To not add too much material I didn't post the fuel/air but it varied between 12.8 on the bottom to 12.5 on top. Probably a couple more hp on top by leaning the car out some more.

On pull #10 we tracked the timing and found the midrange timing dipped thus the slight dip in the dyno sheet. Without knowing what the actual timing table is my only guess is either the car pulled out timing because it didn't like something or it's still learning the entire powerband. Next dyno session I should have that nailed.



Stock vs Bolt ons picture by dennylmclain - Photobucket

No brainer.....the car picked up 35-36 hp from tuning, intake, headers, cats and full exhaust.

Been hooted on because I've been very critical of manufacturers dyno claims. Well.... here ya go. Hoot on this......... as this is real world results from someone with no financial interest. About what I expected and typical of what most cars get from bolt-ons. Real shame what people do and say to get ya to buy their stuff.

After three calls to Cobb, I finally got the AccessTUNE program up and running. Not necessary overly complicated ,but a matter of learning new software and how the ECU works.

The biggest current issue I have is trying open the Cobb Plano tune to try and figure out why the logged timing/power output is so low in the midrange. Not sure exactly how it works, but Cobb in Salt Lake City may be different as the tune from Plano was locked and wasn't able to access the file. I can access the stock file fine, but the tuned program requires a new file sent in the Cobb universal tuning program.

In viewing the stock program the timing program is pretty uniform which probably means the car is pulling out timing. Now to get a copy of the current tuning program and see if I or Cobb in Plano can figure out why.

I have the Cobb but the sent me the race tunner program for a 6 mt and mine is a 7 AT.
I spoke to Dan and he is fixing this issue.
I have a stillen G3. berk cats stillen headers amd stillen CBE.
Do you have any maps for these mods.

thanks