parkern

Hi, I'm new to this forum, I used to have a 2008 G35X sedan and was on G35driver a lot. My G35 had K&N SRIs, Ark Grip true dual exhaust, and an Uprev tune. I just replaced it with a 2012 G37XS sedan, which is completely stock, and it feels noticeably faster than my G35. I've also driven some Q50's and they felt faster too. I'm talking specifically about acceleration from a stop. My G37 throws be back harder than my G35 did.

I don't know if this has already been answered, but I've read posts for hours and hours trying to find answers to all my questions, and this is the only one that I'm still unsure about. I don't care about making my G37 faster, I'm satisfied with that part of it, I just want it to sound more like my G35 did. Is there a way to do that without losing low end torque (and without going FI)?

Based on my research on this forum, I don't think that's possible, it seems like adding aftermarket intakes and exhaust with a tune will increase HP but will always decrease low end torque. Is that right? If that's the case, would an axle back exhaust have less of an effect on low end torque than a cat back?

parkern

Does anyone know the answer to this? If it's impossible to get a better sounding exhaust without losing low end torque, then what would be the way to do it with the least amount of torque loss? Completely guessing I'd say an axle back exhaust and then a tune would have the smallest negative effect on low end torque. And then something like a CAI, HFC, and CBE would hurt low end torque more, even though it would increase horsepower. Does that sound right?

VIVID

iTrader: (12)

To be honest I didn't know that HFCs or a catback would diminish low end torque. Particularly with a tune. Can't you have one of the maps set up so you get more grunt at the bottom?

I'm interested to see because I have the CAI and will at some point (come on FI with that build ) have the HFCs, Catback and tune.

So I'm subbed for more info.

Sean

parkern

I'm not sure about HFCs but I've read that both intakes and exhaust will hurt low end torque, so I assume HFCs would too. I would also think that after a tune you'd get that torque back, but from what I read, even with a tune it only helps on the high end.

Lego_Maniac

iTrader: (3)

Just use more throttle. The engine revs up fast enough.

Thirty_Seven

iTrader: (5)

For what it's worth, I have HFC's and a full catback (CAI too) and after my tune, I had +15 tq overall and I was up +3 tq from 2-3k RPMS.

qmantran

+3 tq?

Lol thats not enough to be considered a gain. Dyno runs can fluctuate that much between 3 runs

parkern

Dang, that's pretty good. What CAI and exhaust do you have? Even if that's just fluctuation from one dyno run to the next, that pretty much means you at least didn't lose any torque.

the_wolff

I don't think he was posing it to brag about gain, just mentioning that he didn't see a loss, which was what OP was concerned about.

ram18962

iTrader: (3)

I haven't done an actual dyno on the car. But I have a Tanabe Medalion axle back exhaust, Megan Racing Y Pipe, and Fast Intentions Resonated High Flow Cats with an Uprev Tune. I feel like I definitely have not lost the torque at the low end. I don't have to push as hard from a start to get it moving and I would still be below 4k.

parkern

Well that's good to hear. I've just read so many threads saying people felt a decrease in acceleration when adding exhaust/intakes. And maybe the G37 really is just noticeably faster than the G35, but I'm just surprised that my stock G37 feels faster than my tuned G35. I also had some 19" AG wheels with 11" rear tires on the G35, so that may have hurt the acceleration a bit too.

Thirty_Seven

iTrader: (5)

That's between 2-3k, and an average of 3 runs pre tune and post tune. Are you not familiar with how tuning works?

I have Stillen HFCs, a Motordyne cat back, and a takeda CAI, I'm tuned on uprev. And yeah at the very least I didn't lose anything. The car felt much more peppy down low after the tune too.

ScrewstonNismo

I've got the full Motordyne Shockwave on my G, and if anything it felt like it added some low end grunt, as well as peak power. Next are ART Pipes, Intake Manifold, and then tune.

parkern

I'll have to check out the Motordyne. It always makes me nervous to buy a new exhaust system. Well based on your guys' experiences, it seems like I'll probably be fine getting an exhaust, and won't have to worry about low end torque.

qmantran

Im familiar with tuning.

I wrongly assumed you were comparing your highest post tune to your lowest pre tune dynos