Well I have had the Hks Hi-Power exhaust and SSV for a while now, but I recently installed a Weapon R intake and Utec and Stillen Grounding Kit. I decided to post a small quick review of some stuff and I have some questions at the end. For reference, I have an 05 G35 Coupe 6MT

Exhaust: As everyone else, I could not be happier with the quality and sound of this exhaust. It is not raspy at all and hardly noticable at idle/low throttle. WHen punching it; however, it sounds amazing, with a deep rumble.

Kinetix SSV Intake Manifold: Now im sorry, I am kind of lazy and did not dyno my car before and after this mod, but more on that later. The quality of this manifold is also top notch and drop dead gorgeous. The butt dyno notice slightly more power on the top end, but not much else. One thing i notice with this mod was that afterwards, my throttle response was improved; however "On/Off" throttle at cruising speed results in a slight jerk through the drive line. At high rpms, the jerk is not there, but around 2000-3500 it jerks when I come off the throttle. Another issue is the idle on my car is no longer smooth. It will try to stall and occasionally does Any one have any thoughts on this?

Weapon R Intake (I got the optional 3.5 inch pipe and 4inch filter): Wow, what a difference this intake made. There was definitly a little more top end and even a little more torque from this intake (butt dyno), but the intake sound is absolutly awesome. It is low and not a high pitched whine like some others ive heard. There is a slight "whoosh" at a certain throttle opening, like 1/4 throttle) but as soon as you pass that, its all rumble. Now, I know everyone is wanting a sound clip, and i will try and get a hold of a video camera to record some to post. But trust me, the G35 with the SSV, Weapon-r, and HKS sounds like a small block V-8 seriously. It roars at open throttle

Stillen Grounding Kit I'm not going to go into much detail on this one. LIke most people say, the engine runs a little smoother and it looks cool, that is about it...

Utec: Here is where I have some questions. I purchased the Utec with hopes of solving the idle issue and to gain some power due to the breathing mods. I had my car dynoed on a Dynapack 5000 by a place called KNowledge performance in Kennesaw, Ga and they are some really nice guys and have a nice shop. BeforeUtec, the car put out 238.8hp, 213lb/ft, and had an air/fuel ratio of like 15-16, so it was running lean as expected. I was kind of dissapointed with the low numbers though. The guy spent a few hours tuning the car and ended up with 246hp and 220lb/ft. The were considerable torque gains in the mid range, in some places about 20lb-ft. Yet, I am still slightly dissapointed with the overall numbers.
This brings me to my questions. I have had the tune about a week now, and I have noticed the engine bogs down at low rpms, while under heavy load. Much more than it did before the tune. The guy said he added fuel in the low rpms to help the idle, and the idle is better, but it is also higher, around 1200rpms. Also, everynow and then, when stepping on the throttle, there is a slight "hic-up" it seems before the power comes on. It happens at various rpms and does not happen everytime. Another thing that concerns me is the flat portion on the hp curve at 5000rpms where the power flattens off, is that normal? I do not know much about engine tuning, but I feel these are tuning issues and that the car needs more tuning. IF there are some Utec veteran out there that think they can help, please let me know. I'm sure if need be, I can figure out how download the maps from the utec and post them. So, to the experts, what needs to be done?

If anyone has any suggestions and advice, I would greatly appreciate it. Also if there are any other questions people have about some of the mods, let me know and i'll try and answer them. Overall I am still happy with my G35, and I'm serious this thing sounds freakin MEAN , and I will try to get a sound clip for u guys. I am willing to spend a few more thousand on the car, and want it to run good. I plan on installing an RPS flywheel and clutch soon and I have stillen sway bars on the way.. Here are some pics and im sorry for the quality on the dyno ones

 

Thanks for the reviews. I am considering the UTEC for my NA G35 so I am gathering as much info as I can get. The bogging down and 'hic-up' would concern me.

Question on your A/F ratio, doesn't a 15-16 AFR indicate a lean condition? Thanks for the info.

 

i say get rid of the SSV and i bet most of your headaches will go away.

 

again guys....15-16 A/F is lean but it depends where this reading is taken. if taken at the tailpipe/after cats it will be more lean. to get a more accurate reading shops can take this measurement b4 the cats...but rarely do...i think the A/F can be quite a bit off when taken after the cats which is the case like 90% of the time....

 

and i also agree w/ glex25 on getting rid of that Kinetix SSV....overhyped, overpriced and DEF. not a mod that provides the HP to go along w/ the $$ nor the headaches...

 

In this case would this AFR of 15-16 be considered unsafe if it was taken at the tailpipe? Thanks.

 

i'll bet 10 to 1 his A/F was taken at the tailpipe hence his higher A/F...your are correct though, if the reading was taken pre-cats then it wouldve prob. def. been around 14.x....which IMO is acceptable...but again..thats just my opinion....dont want this guy to run around w/ a bad tune and blame me if she blows!!

overall though with alot of breather mods (specifically cats/headers) you'll tend to run lean...it all depends on the mods and the car. 15 A/F might work with one car, whereas it'll cause BOOM on another!!

 

Yea I meant lean, my bad, I get them confused lol, ill edit it

 

^ I would also worry about unequal airflow using the SSV. That could explain your power drop off at higher RPMs.

Highly recommend trying stock manifold with your other mods... before/after dyno only way to know for certain.

 

if anyone wants a weapon r secret weapon intake i have 1 in 3.5' size with 2 filters and a jwt heat shield

 

Well there have been some interesting developements that u guys should know about... even though it is kind of embarrassing I have to admit...

So yesterday I decided to check my kinetix for air leaks as some had suggested. I had been meaning to for a long time, but just never got around to it. I discovered that there was an air leak between the kinetix and the throttle body, which i proceeded to try and seal. On further inspection I realized that the gasket from like 6 months ago when I first installed the manifold had broken and fallen into the middle of the throttle body (Kind of hard to picture, basically it was acting as a restrictor plate for the motor). So I had an air leak AND a restrictor plate on my motor for the past 6 months...

I fixed the seal, new gasket, even used gasket sealer and started the car up. I drove about half a mile really slow and decided it would be best to switch off my U-tec and run on the stock ECU. I know that the stock position is when the switch is set to 0, but i couldnt see under the lighting conditions, so i moved it 1 or 2 clicks and ten moved it back to the map it was tuned on, and figured I would switch it when I got home. When I stared the car back up, there was a unsettling puff of black smoke out the exhaust and so I went home slowly and parked it. I know my car certainly needs tuning because of the gasket, but when I got home I could smell the fumes from the car and it is running extremely RICH. Smells kinda like 114 octane racing fuel that u can find at some race tracks.

SO at this point, I am hoping that this leak/restrictor plate has been the cause of the driveability problems; however, I havent had a good chance to see yet, and that my engine is ok and no burnt pistons or anything... I am going to switch it back to stock ECU today and hope it runs. Also this will certainly free up alot of power, because my dyno was lower than it should be. I also have crawford cats sitting in the garage and RPS clutch/flywheel that need to be installed, and after this is all figured out I will post the developements.

 

Was able to switch the U-tec off today, started the car and let it sit and warm up for a while. Drove the car and everything runs GREAT! All of the driveability problems are GONE. Puurrrrrs like a kitten at idle right around 600rpms. The jerky on/off throttle is smoooth as was stock. As happy as I am, I still have to kick myself for not catching the mistake from the start and driving the car in such a hampered state for so long. My car must hate me, and its my fault, I take full blame. But now its time to go get the car dyno'd and tuned to really see what it is capable of. Should be done within the next week and I will post the results.

 

Keep us updated! That's great that you found the problem and fixed it. I'm eager to see what UTEC can do.