kbarker1985

Hello members!!

Well I hope some experienced member can help me understand Cobb tune, without starting a war!!
I had Cobb AP for 2 months now. I have nothing but good things to say about Cobb's power and car drives a lot smoother then stock.
So I went up from Cobb Stage 1 to Cobb Stage 2 ( FVD 200 Cells Cat exhaust system ). Now recently I just had a Cobb Dyno Pro-tune..
Here is something I do not understand.I have contacted Cobb but then answer they gave, lets say " user friendly"
Of course I understand," at the end of the day hp gains are different for everyone and there are many variables that go into play when measuring those numbers, fuel type, temperature, different dyno's will give you different numbers, etc."

Ok . From Cobb Website it says Stage 1 gain about 10% HP 8%TQ. So that will be 480HP out of the box + 48 ~ hp should make the car around 528HP.
Now the Stage 2 require an aftermarket exhaust. gain about 17%hp more will make the car about ~ 561HP

Now after the Pro-tune. The Car now makes 550HP ( 450 WHP ) and 500TQ, The tuner told me he picked up about 50HP over the Cobb stage 2…
BTW the Pro tuner was a great guy to work with...
For my car the Stage 1 and stage 2 almost same power..
So my question is .. Protune pick up 50HP that make the Cobb stage 2. 500HP. Which only 20 HP more then the stock? Also on the dyno Cobb stage 2 showing 400WHP… 400X1.23= 492HP . What happened to 17% to 24% gain?
I have a friend who has the same car as my, and runs with GIAC stage 2. On dyno it came out close to 600HP and a lot more TQ than the Cobb.
Please do not get me wrong, I love the Cobb AP and power.. just want to understand where all the power went?
Here are the dyno sheets.
Thanks for all your help...

Flewis763

Dude you got issues with your car. Boost leaks, bad plugs, something. Your graphs are all over the place. You have issues outside the tuning imo.

kbarker1985

Mmmm just had plugs changed. boost I got from car is like 18psi +

Kevin

Did you reflash your car back to stock and get a baseline dyno?
Did you "datalog" you dyno runs? It's really important to see what your engine is doing.
Were fans placed on each intercooler for all the runs? What were your intake air temps?
Did your friends car dyno with your car (same day same mods) same exhaust, and Tiptronic?
It's a known opinion that Dyno Dynamic dyno's will produce very conservative numbers >>infact lower than the top three dyno's..
You really have to look at the power gains "delta" vs the peak HP number on this dyno..
BTW, From what I have seen over the years these engines do not produce 480HP running 91 octane on the stock file.

To recap, getting your cars stock file dyno sheet "runs" should produce a better picture.

RoscOtis

OK not that it's worth it but here's my 2 cents, lol. I've got the Cobb Access port on my 997tt Tiptronic car. I purposely bought my car as an auto to drag race it along with some road course fun. The Cobb tunes never specify HP, just % gains. There are several reasons for that. Anyone with some experience will tell you the Cobb tunes are conservative because they have to be. Me, personally, I've been working with Fabspeed to help with a "drag" tune. They've been very helpful and from a price standpoint I thought were very reasonable. As Kevin asked above, have you done any "Mods" to the car? Fans on the IC's make a HUGE difference on the dyno. My car really picked up when I went to the Brombacher straight pipes off the turbo. If you don't mind the resonance they are a great buy! I also added the BMC filter which people will say does nothing but we noticed a small gain with it installed over stock. To date my car been a 10.95 @ 124mph on a stage 2 Cobb tune. The Fabspeed tune picked up 6 mph but I blew the tires off (all four, lol) out of the hole on a nicely prepped track to get an accurate ET. My advice is get it to an actual track and data log the pass or more if you can. You don't need to hard launch it for data. Then get that data to people who really know how to read it! It's worth it!

kbarker1985

I will check the date...
What is HP and TQ now with Cobb stage 2?
Thank you

kbarker1985

I will check the date...What is HP and TQ now with Cobb stage 2?
Thank you

kbarker1985

Sorry for the late reply
Yes find out my friends car has upgrade Intercoolers ... Yes he also has Tiptronic but tubi exhaust
I do not know all the temps for all the runs
now the car makes about 571HP and 500TQ..
Is there anyway can make some more TQ or HP out if?
The thing I do not understand is here is from GIAC website. A lot more TQ then my Cobb.
Sorry for all the stupid Q...
again like what you said. these engines do not produce 480hp on 91 octane..
I will do dyno both on Stock file and Cobb file..
ThanksInfoGIAC Stage 1 Plus adds horsepower, torque and more throttle response throughout the power band. ... moreOEM Horsepower
and Torque480 HP 460 Ft-LbsGIAC Pump Mode*560 HP 560 Ft-LbsGIAC Race Mode**590 HP 590 Ft-LbsInfoGIAC Stage 2 adds horsepower, torque and more throttle response throughout the power band. A AWE Throttlebody, intercoolers... moreOEM Horsepower
and Torque480 HP 460 Ft-LbsGIAC Pump Mode*570 HP 570 Ft-LbsGIAC Race Mode**600 HP 600 Ft-Lbs

RoscOtis

I haven't had this car on the dyno. The track has been my dyno for this car. According to the math and what my car weighed in at (3850 with a half tank of fuel) the HP was 539 to the wheels. Remember, you HP numbers are on motor, not at the wheels. Add in the drivetrain power loss average of 15% and your numbers will be close. So with that said, my Stage 2 Cobb tune puts me at 618HP on motor at the crank. Now that will fluctuate due to the average number loss of 15% could be more or less but still very close. According to some with much more experience than me the drive train loss could be more on the awd tiptronic cars. As much as 20-25%...https://www.6speedonline.com/forums/...explained.html

I use Wallace ET Calculator online - http://www.wallaceracing.com/et-hp-mph.php

The Fabspeed tune picked up 6mph so according to the math that's 607hp at the wheels. Accounting for drive train loss that's 698HP on motor. Not bad! I haven't used the dyno on this car because the numbers at the track are all I really care about. Not only that, the track gives you realistic data in real driving conditions.

AudiOn19s

Dyno Dynamics are also read notoriously low compared to say a DynoJet which is more of the industry standard. If your before and after on the same dyno show good results then you are doing just fine.

That said, as others have stated that power curve sure doesn't look "right"

WaltB

I would go run some acceleration comparison tests with your buddy. Dyno's are inherently inaccurate and are highly dependent on what data is plugged into them. Comparing the numbers of one dyno to another would not yield much.

Walt

Srm engineering