My car: 2003 G35 Sedan, Mods: 5/16 motordyne spacer, throttle body spacer, clutch fan delete, OBX Exhaust (knockoff).

Dyno done on DynoJet with tailpipe sniffer to read AFR
Tunning was done using S-AFC

Over all I'm disappointed with low gains around 8whp or so, but I guess it looked like I was a bit lean so now AFR is in much safer range.

 

how did they tune the car?

 

S-AFC Apexi

 

Honestly, there is something slightly wrong with your car.

I remember you back from the days when you raced the moron with the Audi TT, and it all makes sense now.

 

Whats makes sence?
I think dyno numbers are about right
I would of thought there was somethign wrong with my car, but I raced a friend of mine here with an 04 AT sedan, I was ahead maybe 5 ft til 90 or so,,
his car is bone stock. So I guess that would mean there is nothing wrong with my car,,Maybe its just slow in South Dakota after all we are at 1500ft and its really humid .

 

It just seems that the car is a little down on power. Honestly, I would look into some quality parts (Borla TD or Motordyne's upcoming exhaust, and a nice set of resonated test pipes) if you really want to open it up.

I did a recent dyno run after replacing a set of crap Pulsar spark plugs with OEM's and put down the same numbers as you with a Motordyne 1/2" spacer and an 05/06 mid-pipe. I have since added grounding wires, and an exhaust.

The thing that gets me is that you say that you're even with an 04 that's stock. It shouldn't be like that. You've also switch the fans to electric which is good for 10 or so hp. It's weird that you're only at 229whp. I walked the crap out of an 06 g35x from a highway roll with my mods, and you should've done the same to the 04 you raced. Elevation may also have something to do with it, but I think it's the parts you've installed.

 

Looks to me that your puting down close to same numbers as mine,
if you look at my AFR before tune its Lean so that will limit the mods somewhat,, Now Im at 230 rwhp so thats around 20 hp gain over stock with all my mods which is ok .

 

Do you have the SAE corrected numbers?

 

did they give you the runfiles? they would have had to chosen std, sae or another correction factor, not both at one time.

 

Its a standard correction

 

I see that from the graph but the SAE figures are typically regarded as more accurate (most always lower than STD) as they correct for enviromental conditions. Forget the printout if you dyno again, get the runfiles then download the winpep software and be able to see for yourself.

 

Keep in mind of some things here. Comparing your dynos to his is a waste. I can go to 4 differents shops with Dynojets 232s here in Kansas City on same day and I will get 4 very different numbers. A guy here in KC actually did that with his 01 LS1 Z28 and saw variances of 10whp to 20whp between like machines. It only reaffirms that you need to use the same dyno everytime.

I don't believe his 03 is down on power at all. 230whp/220wtq is pretty healthy for just a spacer and a little tuning. Remember that when it comes to that e-fan swap, there is no dyno proof that they actually make gains. The 10whp statement was from DaveO years ago and when I asked for dyno plots from him, I was given the cold shoulder and told to not knock the mod unless I tried it. He would not post any dyno plots and he admited most of his "testing" was via an on-board accelerometer which kicked out power numbers which is a poor way of testing, IMO. A couple years ago, another member dynoed with the e-fan swap and his plots were inconclusive. If someone shows me a before and after dyno of an e-fan swap and it shows 5+whp, I'd do the swap in a heartbeat.

IMO, the S-AFC probably isn't benefiting the car that much and it looks like it took 7 dynos to get to the final numbers. Seeing that these motors typically show progressive increases in power with each successive dyno run, I'm left to wonder if most of the increase in power between plot 001 and 008 is simply the VQ35 adjusting to the dyno. Gains of 5 to 7whp/wtq between runs isn't uncommon at all with these cars and is something you have to watch closely or else the user may incorrectly attribute the gains to a particular mod. Tony at MD would probably attest to this.

If I were infinitialex, I'd make a 2 hour drive to the drag strip just south of Omaha and get some runs in this fall. Dynos and G-tech data is fun to look at, but it's no replacement for true 1/4 mile times. The strip south of Omaha is pretty nice and pretty quick.

As for future mods, I'd yank the OBX stuff and put the OEM muffler back on with either the coupe midpipe or 05/06 sedan midpipe. I swear my car feels quicker with the 05/06 sedan midpipe, but maybe it's because it sounds so good. I'd also do the TS ECU flash and also HFCs.

 

I already had the OEM muffler back on after I thought after market was not flowing as good, well it is just as good or better, now OEM is out. OEM muffler causes this high pitched rasp in certain RPM's without a resonated pipe. The setup that i have now sounds perfect, not too loud , just the right growl and no rasp, although I did have to tune down the volume just a bit with a glass pack resonator. (Now maybe the glass pack should be the suspect for some lost power)

As to the E-Fan conversion, honestly I noticed no gains , although theoretically i should gain 1-3 hp with this mod.

Also DAve if you noticed it looked like my car was running kinda lean there without a tune, and most cars don't make power at 14.7 but at around 13 to 13.75 range, so tune was something that was needed.

also if you noticed on the dyno print out the barometric pressure is way low at 28.8 or something,,, with that low of a pressure my correction factor should of been around 1.11 not 1.07 and this is with SAE correction

 

I think that must be the actual baro pressure right at the Dynojet station (considers elevation into the calc) because the conditions on 7/8/08 in Sioux Falls, SD at 3:56pm were:

wunderground.com
Elevation: 1480'
Baro: 29.91
Temp: 84
Humidity: 28% (48 degrees)

Calculated DA was around 3,600' and the calucated correction factor is in the 1.06 range. http://wahiduddin.net/calc/calc_hp_dp.htm I agree, conditions were pretty pitiful, but the numbers are being corrected to standard conditions.

FYI-

SAE:
"SAE (Society of Automotive Engineers), USA. Power is corrected to reference conditions of 29.23 InHg (99 kPa) of dry air and 77 F (25°C). This SAE standard requires a correction for friction torque.

STD:
STD is Another power correction standard determined by the SAE. Power is corrected to reference conditions of 29.92 InHg (103.3 kPa) of dry air and 60 F (15.5°C). Because the reference conditions include higher pressure and cooler air than the SAE standard, these corrected power numbers will always be about 4 % higher than the SAE power numbers. Friction torque is handled in the same way as in the SAE standard."


So essentially, if you corrected to SAE, you're numbers would be 221whp/211wtq.

 

if sae does not take pressure into correction , i would say that standard correction would be the more accurate one