Well, I had my new '05 G35c auto dyno'd at Reinhart Racing here in town using a Dynojet in December. They really tune Ford products ('stangs, Cobras, Marauders, Lincolns, etc), but they are a Vortech dealer.

The news was the car yielded 222.5hp/220.7tq and 223.9hp/224.0tq. This is about what I expected, though the tq is about 5 units higher than I thought.

For comparison purposes, this first dyno above was done here in Jax. It's 65 degrees and the humidity is at 92%. My old car, a 2002 TL-S with intake, headers, chip, pulley ran a 233.7hp/196.7tq. This was done in Atlanta, and it was about 35 degrees outside with about 50% humidity (scalbert's help). That car also regularly ran 14.2xx-14.3xx at the track, though always had terrible traction problems--even with newer Cooper and Nitto tires.

Anyway, I just installed a JDM/Nismo CAI (really and AEM), Motordyne thermal plenum spacer, UR crank pulley and Stillen grounding kit and took it back to the same dyno...I'll post the map later tonight since 'big brother' here at work blocks photobucket...

Anyway, car hit 246.0hp and 222.5tq. That being said, the useable power has been TREMENDOUSLY AFFECTED. You will really have to see the graphs to fully tell, but here's a tease of what you will see:
car makes 200hp at 4650rpm (compared to 200hp at 5050 before)
car makes 225hp at 5500rpm (compared to 220hp at 5700 before)
car stays over 200tq until 6400rpm (compared to car above 198tq until 5700)
car stays over 210tq from dip at 3250 until 5800rpm (compared to falling below at 3000 and never getting back to it).

In all, the torque curve is extremely linear and fat and is often 15-20ft/lbs greater than stock. The hp gain is smoother and more linear for sure, and is a solid 7hp or so greater than stock until about 5700 when it really increases to its max of 22hp over stock.

My impressions from the seat of my pants? Well, the CAI and Motordyne were done at the same time, and honestly, I felt little if anything at all. However, I did just install the UR pulley and grounding kit, and I immediately felt a noticeable difference in the car. It just seems to climb more easily and freer into the powerband and I really feel the torque difference now. My friend drove my car—but only since ALL mods were done after having driven the stock car. Needless to say, he loves it and can’t believe the difference for only $1k in mods. .

My headers should be here any day. I'll get them installed and dyno again in the next 2 of 3 weeks after my trial…Maybe I’ll pop back down to OSW to see what times it’s now running.

Now, before someone asks, these were NOT SAE numbers (except the Acura). I got the original SAE numbers, but the chart is totally screwed up. The original SAE numbers were 216.8hp/217.1tq. The SAE numbers for this run are 238.5hp/215.7tq. The above comparo is done with uncorrected numbers only because the two graphs I have are for the uncorrected numbers. Either way, standard or SAE, the gains are relatively the same…

I hope to pick up 10hp/10tq from the headers, but we’ll see…I’m very pleased with the results so far and will keep you posted on more…

 

Nice! Wish mods gave me gains

 

Those are impressive numbers, can u post the dyno bc I want to compare it to mine.

 

Try uninstalling the CAI and see what differences you can feel...
Let us know what you find.

 

Why do you say this??? Look at what's to follow (maybe the reason why is in my question back)...

 

rofl...I had to get my wife to get these from .pdf to .jpg so I could get these up...




Now that you see these, and now I have had time to really look and think of them, what's everyone's opinion on my a/f? Over 13 with mods??? Seems awfully high to me...

 

Your A/F seems pretty normal for this engine. I've seen many much higher.

BTW, I have also seen many vehicles lose power because of the cai. Try a pre/post test of it to see how it does on your vehicle.

 

Thanks for the charts. Nice power and the air:fuel ratio looks good.

 

Thanks...I may or may not try Hydrazine's idea. Taking all the crap off was az really pain in the a$$...We'll see as my headers go on in a week or so...

 

From all the dynos I've seen of them, they did some funny stuff (wavyness) to the power curve with or without plenum mods. And when measured with an OBDII scanner, the air intake temperatures are often higher than the stock box.

 

Actually, mine went from wavy pre-mods, to rather linear with them...

 

Hydrazine can you suggest an air intake, i know there are 5346840 threads and all i have to do is search, but i would rather take the professionals opinion.

 

Ahhhhhhhhhhhhhhh!!! I need help!!!

Anyway, I've had my Strup headers on for a week and a half. Had the car dyno'd and it was disappointing to say the least. That said, I swear there is a problem. Even more of a problem, my dyno guy had massive computer problems and the email file he sent me of my plot I am having a hard time getting translated to post here.

Suffice is to say, the plot shows a peak gain of 3.7hp to 249.7 and a peak torque gain of 2.2tq to 227.2. However, in some areas I have dropped torque--especially around 3500 rpm's down to 205tq and the curve has gotten more wavy. However, the hp is still entirely steady and peaking, not losing power, and is at least one or two hp higher throughout the range until the peak. Further, the a/f is well over 14 until higher rpm's where it is back to where it was before, though it dips in the 3200-3750 range where my tq curve is dipping, too.

Now, I SWEAR I HERE A PROBLEM, but the car is not throwing a code at all and it isn't a massive 'wooshing' air leak kind of sound. To me, and now maybe my mind is playing tricks on me, the left side of the exhaust sounds louder than the right.

When my shop did my headers, they ordered a whole new gasket from Infiniti and they did tell me one of the header studs gave them massive amounts of trouble on the passenger rear--to the point of having to back it out or something. I guess my questions come in where I have no code present to alert of an issue, and secondly, I don't hear a typical leak one would normally hear, it just sounds really odd at lower rpms--almost like a coffee can with air running through it. Not raspy or anything, just weird in a not good kind of way. I've had headers in other cars of various iterations, this just sounds odd.

Now about the dyno: I only got two pulls in 3rd because the third he wanted to do in 4th for his own edification flapped up his machine in some way (still odd to me, but the car made 212hp/261tq in 4th!!!). Both were virtually identical. My VDC was off, but the slip light (LSD)came on for the second run and stayed on until the car left the machine and I drove it down the street and it then reset. It was 79 degrees outside per the weatherman though the car showed 84 in the shop and it was near 100% humidity. This was almost 20 degrees warmer and I know this makes a difference. Also, the dyno was over 25 miles in stop and go traffic from when I left my office to have it done, contrasting with the 5 miles I drove straight over early in the mornings the last 2 times. It was virtually boiling when dyno'd this last time as opposed to pretty cool the last times.

Now, I did not expect huge gains, but I would have thought to have seen more--especially in the torque gains. I can also say post install, the car felt roughly the same as it did before the install, and it was cold as a welldigger in the 50's almost every day afterward. Now with it pretty darn warm, it still feels just as good as before the install was done when it stayed pretty cold--as if the heat hasn't affected the power.

Now I also have to say the guys at Stage 6 are awesome. Dwight did the install and he also does Titan's work in Orlando on their supra(s). He has done a couple of Z's, just not a G, but is more of the supra guru. My dyno guy is a Mustang man and is the Vortech distributor here, he saw nothing out of the ordinary. Both have not deeply looked into the car post install because the car has been hot, but neither sees or hears and obvious problem and both think the code would cause the engine light to come on.

Any thoughts from you guys? Lastly, my only other planned mod until FI is going to be an exhaust (and I plan to go with the Vortech s/c kit), so I will want an exhaust to work with the s/c. I really wanted to keep the Strup headers with the s/c install, so my question is: before FI, do you see an exhaust opening up more gains post header install--as if the stock exhaust is limiting the benefits of the aftermarket headers as is? I was thinking the Borla or Stillen exhaust--any thoughts???

Sorry about the ramblings and sorry for the lack of the dyno plot, but thinking of all this is driving me nuts this morning...Just needed to unload.

In all, I am really thinking this is a dyno variance issue, but the sound has me all flapped up as does the wavy torque curve with some loss here and there, and the really high a/f (I would have thought it higher when cooler, not warmer).

 

If you have an exhaust leak of any kind you definetly need to get it fixed. It will cause exactly what you are describing.

 

I thought it might, but wouldn't that still throw a code or no? I don't think it's at the engine area itself, maybe the piping below, but I dunno. I wonder if swapping out the Y pipe now that I have aftermarket headers would solve this...

 

A code may or may not happen.

 

Just like what Tony has said, I have seen some dyno graphs where people with CAI losing power.. Thus, you might want to try a JWT popcharger or a Stillen CAI (it is indeed a ram-air setup).

Hope thsi well help, and btw, taking off the CAI and put back the stock intake shouldn't be that bad? just for yourself to justify whether you can do better without a CAI !!

 

do u hear the coffee can noise (rasp) if u accelerate fast or does it also appear even if u slowly accelerate? After my install of the alphawerks headers, hi flow cat, and y pipe i have this type of noise between 2-3K rpm but only if I mash on the pedal. I'm wondering if I have a leak also bc my dyno results were quite low (233hp) on my auto but I dont hear any hissing.

 

Wow--Cali gas/smog crapola sucks!!!

Anyway, I produce it best when I can put it in manumatic in 5th or 4th at about 35mph or so and give it a good dose of throttle. At WOT in a lower gear you can't hear squat but the CAI...