what you need to do is post a baseline on the maha before the cobb then do 1 with your gains to really analyze the access port.

 

sounds like i keep hearing good things about goodspeed from people who have experiences there. please post up those timeslips when you do your runs.

 

maha dyno sheet:

http://www.goodspeedperformance.com/...g37%20cobb.pdf

 

Was that 3 separate runs listed there? If so your car has nice consistancy in power because they are all 3 nearly identical. Lookin good

 

I think we need to learn more about this dyno. There is no way we are loosing 26% to the wheels? 264.5 / 354.5 = 0.746

 

I'm sorry to inform you, but we are. This is the MOST accurate dyno in the world. There are only 4 in north america. This is the dyno that all supercar manufacturers use. Read this link for more info:

https://www.myg37.com/forums/engine-drivetrain-and-forced-induction/187689-some-interesting-information-on-dyno-s-educate-yourself.html

 

correct!

you should talk to John at Goodspeed and setup a G37 dyno day and see how everyone else pulls on that dyno. If all the G37s are getting high drivetrain loss then that will answer the question of oct2274. It's hard to make comparisons because you are probably the only person on this forum that has dyno'd their G on a Maha. So maybe setup a Dyno day to see what everyone else pulls and compare dynos. I'm sure they'll do the same special as last month, 3 runs for $50 bucks.

 

or you can hop on another dynojet dyno to at least see what your tuned numbers are on what the rest of the world uses. i will be doing a dyno comparison pretty soon with my inhouse dynojet 248x

 

the reason i challenge the loss the maha is calculating is because if you look at properly set up dynojet dyno outputs. for almost all unmodded manual cars you can take the dynojets output and divide that by the factory's horse power rating and consistantly get around 15%, 17-20% is common for rear drive vehicles, loss for manual transmissions on two wheel drive vehicles in stock form. We aren't just talking about g37's here. I'll just give two examples here. First is the very first dyno in the dyno area here on my g37, a stock g37 with a manual trans.

https://www.myg37.com/forums/ecu-tuning-dyno-data/178750-myg37-com-member-dyno-sheets.html

our car is rated at 330hp from the factory. obviously these numbers get fudged sometimes by the manufacturer, but typically when that happens the community finds out very quickly and it becomes common knowledge. An example of this was the RX-8. When the car was first sold, they told people the engine had 247hp, people started dyno'ing their cars and found that the numbers weren't adding up. Mazda then revised the hp rating to 238hp. You can read more about that here http://ezinearticles.com/?Mazda-RX8-...versy&id=47018 . This isn't the case with our cars by the way. So in that dyno you see he is averaging around 277 whp. 277 / 330 = .84 which means he is seeing 16% drivetrain loss. This is what is to be expected from a manual transmission vehicle, not just a g37. Of course various things can effect this such as wheel weight, rotor weight etc, even the car being strapped down too hard on the dyno! but it's usually around 17% give or take a few percent on a dynojet from what i've seen when the dyno is done properly.

My last car was a Mazda 6s which is rated at 220hp from the factory. My friend had the identical model with a manual trans and had his dyno'd on a dynojet. He got 186hp at the wheels. 186 / 220 = .85 which means he was seeing 15% loss.

Now obviously temperature and other variables come into play when getting the dyno numbers and I believe the Maha does a better job of taking these variables into effect then the dynojet. But..............a manual transmission is a manual transmission under no circumstances should the maha be saying that one car with a manual transmission is only lossing 14% and some are loosing 25% when they are in stock form, and you will see that from the dyno's that shown on goodspeeds website from the Maha. There just isn't that much difference in manual transmissions. Maybe your wheels had concrete in them! <----sarcasm. So we are obviously missing something here that the Maha is seeing. I'm very curious because it seems this dyno is changing everything people have seen as normal in the past = 15-17% drive train loss on a manual vehicle and showing our cars with a crazy drivetrain loss number for a manual transmission. We need way more info on this if we are expected to forget about dynojet numbers and very consistent drive loss numbers for manual transmission from vehicle to vehicle when dyno'd on dynojets. It just doesn't make sense that the dynojet consistantly sees the same parasitic loss from the same type of transmission and the Maha not see the same thing! What it really boils down to in the end though is making sure you keep using the same dyno when modding and trying to keep the variables as close as possible when dyno'ing so you aren't WTF'ing haha.

 

His G37s is not the only car on a Maha showing more then 20% drivetrain loss. There are other vehicles they have dynod that are also above 20% drivetrain loss

His G37 dyno RWD
http://www.goodspeedperformance.com/...g37%20cobb.pdf
81.1hp/354.5hp = 23% drivetrain loss

Porsche 996 Turbo on the same Maha Dyno AWD
http://www.goodspeedperformance.com/...s/997%20TT.pdf
120.7hp/516.2hp = 23% drivetrain loss as well

Volks GTI FWD
http://www.goodspeedperformance.com/...OJET%20CAR.pdf
46.5hp/341.1hp = 14% drivetrain loss

BMW 335i RWD
http://www.goodspeedperformance.com/...0STAGE%202.pdf
57.4hp/391.3hp = 15% drivetrain loss

The G37 isn't the only car showing high drivetrain loss, granted the Porsche is AWD and the G37 is RWD. But here are 4 cars on the same dyno, 2 show high and 2 show normal. Maybe the G37 is known for bad drivetrain loss but hasn't been discovered yet because nobody has dyno'd their G37 on a Maha besides azG37?

 

I mentioned this on the other thread also...

It seems like your peak HP is only at 6900rpm on the Maha.

 

you just made my point with your post. The dynojet does show consistency for the same types of transmissions = manual, auto, 2wd vs awd, including a normal drivetrain loss of 16% for the g37, the Maha doesn't. The porsche is awd and therefore should have that kind of loss btw. Our cars could never have the kind of loss an awd system has.

 

what you really need to do is dyno a stock g37 on the maha and calculate #s from that.

 

dyno day on the maha!

 

Hi Guys, I just wanted to chime in here. These numbers are very accurate. When we run bone stock cars they are always within 5 hp +/- the factory numbers at the flywheel. This would not be possible without accurate drivetrain loss numbers.
If you notice the dragloss line is not flat, as the rpm increases so does the resistance. Anytime anyone states driveloss numbers the first question you should ask is at what rpm.

The drive train loss on this dynochart is 23.4% at, and only at 6910 rpm. oct2477, you where comparing corrected flywheel numbers to uncorrected wheel numbers. It should read like this; 264.5 / 354.5 = .765. These are measured values, not calculated.

As far as the rest of the world, Dynojet or Mustang is just not used. MAHA is the standard and Dyno Dynamics is just behind.

Please feel free to call Jon or myself if you guys have any questions.

Joe