So how much hp did the cats and exhaust give? Did you dyno on the one that gets 250hp or 290hp stock?

I'm not sure I understand your question. Did you read post #67?

http://www.the370z.com/intake-exhaus...html#post46196

I missed that post on my iPhone. Nice bump in hp.

Wow very impressive, I'm liking this motor more and more now. Great job documenting this stuff for everyone as well.

Yeah, well lets see what happens. I am going the same route as you are, we are just around a week off on timing though :) I may do headers as well.

Yea guys Ben and I were extremely surprised by the amount of power made by this combo! The looks on our faces was priceless LOL like a no f'n way is that possible! Ben was like this is ricer math results! For reference my car made 254.2hp bonestock which is about right for a stock car. I look forward to bens future upgrades! :)

I recall someone with a G37 with full exhaust (Headers, HFC's, Catback), CAI, and custom tune putting down 342 HP on the dynos. There were so many people stating that was not true; the dyno is wrong, etc....

I am not saying 342 on a dyno is possible, but I am saying that this car can be made MUCH more power as we have seen. I cannot wait to see one with the intake, full exhaust, and tune on a dyno. Wait until the turbos start dropping....

Do we know roughly how much of that 37whp was the berk, and how much was the cat-back?

370Z Engine (VQ37VHR) > 370z.com > 370z.com - Magazine

"Past the catalytic converters the exhaust merges into a single exhaust feeding to a larger transversely mounted muffler with twin outlets. As a note to tuners when we examined the car closely on a lift, we noted that the exhaust from the catalytic converters rearward is exceedingly small in diameter for an engine of this displacement and power output. It is almost as if Nissan wanted to artificially limit the power output of the engine for some reason by choking off the exhaust. We feel that a larger diameter, less restrictive exhaust may free up quite a few horsepower from the 370Z's motor."

I'm hoping that the cat-back accounts for most of your gain, since that represents a pretty easy and cheap bolt-on compared to installing hfc's and/or headers. I hear the latter is a PITA on these Z's. Awesome article, btw.

No offence, but I don't like these numbers with those mods

Nice car very nice

Well, that's the funny thing. Stillen claims +18 whp from their cat-back. Berk claims +19 whp from their HFCs. Now, we all know that we can't expect to just add the two together and expect a total gain of +37 whp, right? Yet . . . that's pretty much bang on what happened. If we use the 254.2 that Mike got from bone stock as a baseline just minutes before I put my car on the same dyno, then we have a gain of 37.5 whp. 'Ricer math' actually appears to have worked in this instance! So, to answer your question, if we go back to the claimed numbers from the manufacturers, it would appear that it's almost an even 50/50 between the two components.

What don't you like? You realize this is a Dyno Dynamics, right? They come in lower than even Mustang Dynos. 291.7 on a Dyno Dynamics = approx. 344 on a DynoJet!

Give this thread a read if you haven't seen it yet:
http://www.the370z.com/vq37vhr/2199-...alculator.html

Semtex,

These numbers are sweet. I'm expecting my cats tomorrow and will have them and the Stillen exhaust installed sometime this week. I'm looking around Austin for a dyno to hopefully get before and after numbers on the same car.:stirthepot:

Sweet. well done Semtex....

Cool! Pls post your before/after results to this thread, if you don't mind. As more people get this combo, it'd be nice if we can use this thread to compare everyone's experiences and results. I know that thus far, this thread has been all about my car only, but that's just because I'm the first one on this forum to try this combo. My intent is for this thread to be open for everyone who tries this combo to post their impressions and results.

Those are some impressive numbers! Even though its not exactly a direct comparison, I am glad that these results back up my results with just the Berk HFCs!

Let me know what you find. I live in Austin and am picking up my Z tomorrow! :)

Well, my YouTube video is drawing some skepticism judging from the comments left there. It kinda irritates me when people imply that I'm being dishonest just because they're not used to seeing such significant gains. I'm just to sharing my results for the benefit of the community, after all. I invited them to join the forum if they want to discuss.

YouTube - 370Z w/ Stillen Exhaust & Berk HFCs: Dyno Results

LOL.. do yourself a favor.. don't argue with folks on youtube.. they have a lot more time than you can possibly imagine..

Some hating on our video as well. It seems like a large number.. and it is! Let them call BS.. :)

YouTube - STILLEN 370Z Dual Cat-Back Stainless Exhaust System

Interesting numbers.

Semtex, do you have any plans on racing? I'm curious as to what your times would be with those mods :)

Not having much luck finding a place that will do the dyno for me, and my install is scheduled for Thursday. We'll see what happens.

Semtex, thanks for all the reports.

I'm impressed by the gains. Looking forward to seeing the intake results on top.

hey Ben I bet sharif would let us dyno again but this time we would have to wash the entire GTR! LOL hehehe

Yeah I sent him an email today, actually. The received the G3 intakes today and should have them on either tonight or tomorrow, so I want to do another dyno to see what gains they yield.

You got the intakes too? Cool. Let us know! I'm calling 302.4hp.

Sorry semtex for responding a little late. I'm not talking about being pulled over for the exhaust. I agree. The Stillen exhaust does look like stock. It's when you bring in your car for smog check (which is about 5 years later from what year the car was made or bought - not too sure). They will test by sniffer and also visually inspect the catalytic converter, if it's in placed or changed. You may pass the sniffer, but will fail by visual.

Back to the topic... those are nice numbers! :tup:

They have NO idea what the car is supposed to look like...

^Yet

Thanks for explaining. Thankfully, I don't live in CA and they're nowhere nearly so thorough in GA. All they do here is hook up an OBDII cable and as long as your car hasn't thrown any recent CELs, you're good to go! No visual inspections, no sniffers (unless it's an older car with no OBDII interface).

Say whaaaaat?! :eek:

Thanks semtex for all the postings on this. That is extremely awesome results. I am sold on that combo now. Can not wait to hear what the intake adds.

Nobody has mentioned pricing yet. What did you spend on the exhaust and cats? Do members here get some sort of discount? TIA.

STILLEN : STILLEN 370Z Dual Exhaust System

http://www.the370z.com/importpartspr...html#post46131

Thanks!

got my combo installed...
 

Got the Berk cats and Stillen exhaust installed yesterday. Had a few fitment issues: the x-pipe wasn't matching up to the muffler inlets. Called Stillen, and they gave excellent advice as to how to correct the situation. Turns out my mechanic didn't see the line in the instructions (printed in bold) about using a jack stand to hold up the exhaust while you tighten it up. Hey, he gets paid for his wrench skills, not his reading skills. I should also mention the shop doing the install doesn't normally do this type of job. (But it's right next door to work..couldn't beat the convenience factor.) Also, the cats came off with no problems--I warned the guy about the trouble people are having.

I think I'm going to take it to a muffler shop and have them weld a few of the seams and take out the U-brackets to make sure they don't leak. There's just barely enough metal to close some of the gaps, and I'm afraid of developing a leak as everything settles. This is probably overkill, but it will make me feel better in the long run.

I'm very happy with the quality of construction on both pieces, as well as the support I got from Stillen. The sound is unbelievable. Really comes on after 3K rpm. The video clips don't do it justice--you have to hear it in person.

I'm planning on changing the oil this weekend since my break-in period is over, and I'll really see what it can do next week. So I can't really comment on the power gains since I haven't thrashed it yet.

Overall, I highly recommend this combo, and many thanks to Semtex for the extensive coverage he provided. That was definitely a factor in my buying decision.

^ Cool! Yeah I agree the video clips don't do the sound justice. It's like the sound of race cars on TV vs. actually going to the track!

Where did you get your install done? Im almost set on the same combo as well.

I'm actually up in Round Rock. I have a mechanic shop next to me called Carl's Automotive. Some of the old timers there used to drag race back in the day. I'd highly recommend them. (Especially since he's done one install already!)

nice, thats close to me :)

i cant see the videos! :(