i was trying to wait until after christmas... i don't think i'm able to wait any longer...

Just do it! Economic stimulus is still in effect!

That is a really nice increase in area under the power curve, midrange especially.

Nice write up!....thank you for sharing....its great to see a product that actually works as well as advertised....lol..

perfect... very nice write up mcduck.its what we like to hear and see...thanks...

lol..i'm with ya on that... x-mas is coming early this year apparently...

OK... a full week of 'spirited' driving is in the books. At this point, it looks like the power gains come at a slight mpg expense, but this was to be expected. When the car was stock, my avg mpg was 18.5mpg with mixed highway/city/and occasional playing. Right now, I'm at 17.3 mpg for the last week. I should caveat that by stating the retune makes it much more tempting to play. My guess is I were driving exactly the same as before, I'd be looking at a flat 1 mpg drop. So a little lower, but still so worth it!



First... I thought more about this and was wondering what your mileage was when you baselined. Can you post that info here? My suspiscion is you got lower numbers and that you dynoed your car much earlier. I honestly felt my car ran slightly quicker at 4K miles than it did at 1K miles... maybe due to the engine having 'loosened' up after more driving. When your base run of 385-395 could be a reflection of this hypothesis.

It could be true Mcduck but I'm not entirely sure. I think ours car here in this region are making around 385whp to 405whp. The 20whp range will depend on a few factors. It would be enjine condition of different cars and temperature and humidity of the weather during the dyno run. Presumely, our country are very hot and humid. It really messes up the cars sometimes. We can get around 10whp more just by dynoing in the night but hardly anyone does that as most of the shops are close and its actually illegal to dyno run at night if i'm not wrong. I haven't tried it yet but I will.

On your theory that newer cars might make lower number, I'm honestly not entirely sure. It can be credible since machined parts are all runned in and rounded up. To answer your question, I did my baseline dyno when my car is around 2500km. That is around 1500miles. And I did my HKS GT570 run around 5500km/3500miles.

Perhaps other people could chip in and give their experiences on dynoing the car early run as compared to later perhaps after 5000miles.

I averaged 20.5 mpg on a 230 mile trip to Newport news from Maryland recently.... So what changed your mind mcduck? You seemed against the AP when I 1st instaled mine... It was the hunger wasn't it... Can't be quenched

wasn't really against... just wanted to see if there were any reliability issues. I guinea pigged a lot of stuff on my 350Z... one of the first Vortechs, the first car with cams and Vortech, etc, etc.... lots of trial and error and was very lucky with my selections. This time I'm letting others be the trailblazers. A lot of that has to do with the fact that the GT-R is my daily driver for the moment. Until I have another car I can use daily to get around, I have to be a little conservative.

As for mileage... before the Cobb AP, I got as much as 23-24mpg on my recent roadtrip up the coast (highway mileage). But the realistic average had been 18.5mpg. Mine has been ranging from 17.3 to 17.8 with the Cobb tune this week. Again, I am playing with it a lot... so it will likely settle down. And no matter what, the slight mpg hit is so worth it.

I know it is not fair to compare stock to modified, but with the GT-R and only the Cobb AP, I believe it can best pretty much all but a handful of factory stock cars. How many cars can claim that and still get over 17mpg???

BTW, very weather dependent, but if rain clears out early, I'm going to meet up with underpressure and hit the 1/8th mile in Mooresville, NC tomorrow. Keep your fingers crossed. if it happens, I will post timeslips here.

Good write up mcduck and thanks for taking the time to share.
Enjoy.

very true, I haven't sniffed 24 mpg it's winter so I'm busy with football, holidays and such ... Plus I am in car sales and it really sucks right now or else i'd be trailblazing more parts right now... Glad your having such a blast in your gtr and sorry I missed you when u were in DC... Stupid work

In theory ... the mileage got to be better at same speed, same driving conditions ? or am i wrong ?

Correct. At light cruise and idle conditions, there is no change in fuel. But with all this new power, and more boost at most throttle points, you are going to see a little bit less MPG when you drive the car harder. Plus, as McDuck mentions, it's oh so temping to play with the throttle. I say have fun! Gas is 50% off now, and the GT-R even when modded, is extremely frugal with fuel consumption, compared to some other cars out there.

The built 350Z's/G35's we produce, will still achieve 20-25mpg freeway cruise, but reports of MPG dropping to 12mpg with hard driving, is very common. There is no free lunch.

Looks like this will not be happening. 11:15am and still wet and rainy.. maybe another weekend...

Hi McDuck,

Thank you Sir for a very informative / honest review

keep up the good work


This is one item on my wish list for sure

Glad I could help... not sure how many mods I will do, but will try to keep documenting so everyone can benefit. This car rocks!!!

You have PM.

Two updates...

First, I was just out on Cobb's website to check on additional maps and noticed they list their gains as being at peak power. So, I guess I need to add an addendum to my review. Strictly speaking, I did not see the advertised *peak* gains with the AP. However, we do see those numbers as *maximum* gains. wonder if maybe the website just needs to be reworded or something. Still happy and the upgrade is well worth the money. This is just semantics at this point, but something worth mentioning.


Second update.
LOW MPG IMPACT!!! - OK... after the 'newness' of the tune passed and I settled back into my typical driving pattern, my MPG has risen back to 18.3mpg for mixed driving. It was 18.5mpg before the Cobb, so not much change at all for a substantial power gain! WOOHOO!!! :party:

Why? Well, if you think about it, the biggest gains are in mid-rpm ranges... from 3000 or so and on up to 5000rpm. This is the range you use when you are accelerating aggressively. In normal driving, the car typically shifts before 3000rpm (if you are in Auto mode) and cruising speeds fall from 2000-3000rpm. Since the power gains below 3000rpm are less, there is only a small change in fuel consumption.

Bottomline... you will probably only see a noticable change in MPG if you are thrashing your GT-R around all the time.

Been a while since I posted on this topic. Today I took my car in for the 12K maintenance. I don't know for sure if this is true, but was told part of the standard service is various engines checks and balancing... and that this is best done with the stock map.

So, I installed the Cobb AP v1.08 "Stock style" map before taking the car in. This was easy, took less than 10 minutes. And, of course, there was a noticable drop in midrange power. I can't get over how much better the car is with the Cobb tune on the ecu!

i detuned mine so i could get a baseline dyno - 400whp.

i took it out to warm it up before it went on, holy crap - i never want to drive it stock again.

anyway, i reflashed stage 1, and got 424whp. the torque gain at midrange is unbelieveable.

Is the solid lines run 1? How are they crossing at 4500 rpm?

They should cross at 5250rpm like all other proper graphs. What is strange though is it appears that on the 2nd run they do cross at 5250rpm.
??????????????weird.
I'm assuming solid lines stock, dashed lines cobb.

yeah, i noticed that as well... dunno.... all three runs were done exactly the same way.

yeah, run #1 stock.

runs #2 & #3 cobb.

It is almost like the 1st run was measured against speed (like 55MPH), not RPM, but then overlayed against run 2 and 3's RPM's. If the graphs were on the same scale, the increase wouldn't look so massive.. Nice gains though - love the Cobb (er, that sounded weird).

lol! yeah, that sounds funny... but when i line up the first run to crossover at 5250rpms, it is more in line with cobb gains... thanks!

That's a fat midrange improvement! Nice.

I am never going back to the "turd" map (OEM). Over my dead body.

thanks for the help over the phone on saturday.

and +1 on that going back to stock business... ain't gonna happen.

Sharif u said u can pick up cars from out of state am i correct? how much to pick one up from Texas?

PM sent!

new update coming!

First, I realize some of the image links on the 1st page are down. I'll try to get those fixed or repost the missing images this weekend.

As some recall, I took my car to Forged Performance back in November... at that time I dynoed 406rwhp stock and 434rwhp with CobbAP v.108b 93-octane tune on their Dyno Dynamics. Those were peak power figures with a much wider spread (closer to 60whp and 70wtq) in the midrange.

Tomorrow morning, i will be returning to Forged to have a Y-pipe installed and to get some of Sharif's custom tuning! Will post new figures, pics, dynos, etc. when I return.

As an added bonus, I will be going to zMax 1/4mile dragstrip soon (March 5th and/or March 14th) and will also follow up with updated 1/4-mile times. My best speed / time so far has been 11.6s @ 120mph with 1.9s R/T and a passenger in the car using no LC in RRR-Auto mode. It will be interesting to see what the new mods and new LC yield! Of course, this is just added bonus, I already know the GT-R is a fantastic road course car.

Just a quick update tonight as I am pretty beat after a long day of driving. Visited Forged Performance today for midpipe install and custom tune. End result is my car is just shy of 460awhp and sounds great. Net change in dyno numbers today was around 30hp peak and a lot of area under the curve. As usual, great job by Sharif and the gang at FP.

Until I can get dyno graphs uploaded and do a better write up, here is a vid of one of the dyno runs so you can hear the new midpipe update. The piece installed today is a prototype Y-pipe that FP is developing with another company. More details will be coming from them on this soon.


2009+GT-R+%2b+Y-pipe+%2b+CobbAP+custom+tune+%3d+456awhp

are you putting out 457hp

Andy,
That sounds about right. I started out with 380+ AWHP without Cobb program but with full exhaust from turbo outlet and back. Then when everything is said and done, I walked away from Sharif's shop with right about 470 AWHP. That's 93 octane with custom tune.
I can't wait for my next stage of upgrades....I probably won't make it to this coming Sunday's GTG, but you will get to see my new toys in April if you will be going to the April's C&C.

Yes... as soon as I can get the graphs scanned, I'll post them. Or maybe Sharif can email me electronic files (since he forgot to give me the torque curve graph anyway!)

Basically, it stacks up like this... My stock dyno was 406hp. With Cobb Stage 1 v1.08b 93-octane, we hit 434hp. So only 28hp at peak, but there were HUGE gains in the midrange (as much as 60whp in some places).

This time, we started the day hitting a best of 422hp with the Cobb Stage 1 v1.08b 93-0ctane tune as our starting point and finished with 457hp with the mid-pipe and custom Cobb tune for 93-octane. Gain of 35hp peak and gains larger than that in high rpm ranges.

There may be various reasons for the discrepancy between the final pull during visit one and the base pull during visit two... different days, different temp/humidity... first visit no mid-pipe, second visit mid-pipe baseline before tuning for it. Who knows. My guess is if yesterday had been a cooler day like my first visit, we would have seen 5-10hp higher readings.

For sake of argument, we'll be conservative and assume the base runs yesterday with Stage 1 tune were lower than 434hp because the midpipe was added and not yet tuned for. Under that, our most conservative assumption, I gained 51hp at peak (457-406=51) and bigger gains in off-peak areas of the curve. Not bad given the low cost of these mods.


yep... I think that makes sense. If I did the rest of the exhaust I may very well pick up another 10-20hp with a custom tune. I just can't see spending $4K+ on catback.... at present I have just over $2K in mods that have netted 50+whp. Paying $4K+ to gain *maybe* 20hp just doesn't appeal to me.

thats kinda my thought on the catback as well.... at least until a good quality one is available for much less... plus my car is loud enough as is

thats kinda my thought on the catback as well.... at least until a good quality one is available for much less... plus my car is loud enough as is

first up today... another video from the dyno runs. Got watching these on my PC and thought the sound quality was a little better on this one for those who want to hear what the car sounds like with the new midpipe...


same as before, different angle and better sound quality

dyno graphs coming soon...

Here are the latest dynos. The first just shows the actual, same day gains we realized going from Cobb AP Stage 1 v1.08b tune for 93-octane... to Cobb custom tune with mid-pipe...



and here are the graphs for total gains since I first visited Forged Performance. I've highlighted the same graph showing net improvement to area under the curve for both HP and TQ. Essentially, this represents pure stock to custom CobbAP tune (for 93 octane) with aftermarket mid-pipe installed (the midpipe is a piece FP is developing with another vendor... name and details to come). At this point there is a lot of significant improvement in output in mid to high range RPM... as much as 50-70hp in some areas of the powerband. Net investment for all this goodiness... under $2500

I cannot say enough good things about the upgrades and quality of work from Forged. Next on the agenda... finding out what these improvements translate to in the real world!

whp improvement...


wtq improvement...

Looks nice. Wow, didn't realize how much the car moved on that last run. Good thing we use lots of straps.

OK, this is gonna be a quick update for tonight because I am beat... just back from zMax dragstrip in Concord. For those unaware, zMax is a new state-of-the-art 1/4mile strip near Charlotte that has full concrete strips. Tonight was there first test & tune ever and it was slammed with people running. The event ran for 4 hours and I could only manage to get in 4 runs.

Two of the runs were busts as I used the new LC and experienced some wheelspin that dragged down my 60' and 1/4 mile times. Fortunately the other two runs were great and one was using LC and one was not using LC. So, without further ado, here is the timeslip data. I will get scans done before the weekend. My GF also videoed my fastest run, but she got kind of excited and the video is bouncy as hell.

Anyway, here are the times...

withOUT using the new LC...
R/T.... .126
60'... 1.965
330... 5.011
1/8th... 7.490
MPH.... 99.63
1000.... 9.649
E.T. .... 11.484
MPH... 122.18

WITH the new LC (and as added bonus, this run was against a lightly modded Z06 that ran a 12.861. hehe)
R/T.... .052
60'... 1.812
330... 4.804
1/8th... 7.250
MPH.... 101.16
1000.... 9.352
E.T. .... 11.122
MPH... 126.98

With a little more practice and better launch, I definitely have a sub-11 second run in this car. I really think a 60' of 1.7s is doable and with that, the E.T. should be just a hair under 11seconds.

And on that note, anyone know how to keep these tires heated up? The lines to stage were so long, it was literally 45 minutes between runs. Could not keep the tires hot and its not like you really can do a burn out like a two wheel drive car. Being able to heat the tires just before the run would help tremendously. Has anyone who has run a lot done an LC start to heat the tires, THEN staged and raced???

go through the water, then do a vdc off 3k rpm launch

Lower your tire pressures way way down. This will help you with the launch. I would try 20psi or lower.

11.1@127 with just our tune, and a y-pipe. NICE!

you ran those times in auto mode?

nice results andy!

may have to try that next time... just not too keen on doing back-to-back LC starts


I know lowering tire pressure will help, but then I am stuck having to drive around with low tire pressure until I can get somewhere that has nitrogen.

And, yeah, I thought that was damn impressive for just one minor exhaust mod and a tune. I imagine we'll be seeing a LOT of GT-Rs running in the 10s soon. I'm almost there with the little bit I've done.


Yes, all my runs were in Auto mode. Someone said they had pretty good success launching in Auto, then manually shifting to 3rd-4th-5th, but I did not try that.


Photos and vids coming shortly.

ok... first up, here is the video of the non-LC run...


my 11.1s 1/4mile run

and here we have me lining up with a Z06...



... and then making my run using the *new* LC. Apologies for the wobbly camera work. My GF was videoing and got excited by how quick I ran. I new this was going to be a fast run when my car shifted into 5th gear WELL before I crossed the finish line.


video

... and finally, because it is so hard to see in the video, here is a screen cap of the trap...

last but not least, the time slips for both runs...