Hi folks, I attended a local dyno drag yesterday, and thought someone might benefit from seeing the vids and dyno graphs of my runs. BTW they have a contest at these events: pull twice, guess your third pull. Whoever is closest to their actual 3rd pull wins 10% of all income for the day! I won, guessing 0.2whp over! Just in time for Christmas too...

Anyways, here are links to the vids, I will have the graphs up tomorrow(waiting for them to email them to me) ASAP.

Basically netted 7.22whp/6.82tq over baseline. Not as much as I had hoped, but I still have nothing against the exhaust. So I'm at 133whp, uncorrected. Factoring 18% drivetrain loss puts me at aroud 162chp if my calculations are correct.

Enjoy, stay tuned!'slip

Click here to see Video

::edit:: I lost a vid, but here is one! ::edit::
Modified by slipnfall at 11:52 PM 9/13/2006

Cool stuff! How much did you win?

What did your a/f look like this time around?

Well entry was $55 and I won $187, so I brought home $132. They had 34 cars dyno Saturday, from 9AM to midnight....

heh, my A/F was *more* lean than last time. Roughly 0.25 more so untill 5100. From 5100-5500, A/F's were about equal, then after 5500 it was back to 0.25 more. Pk.lean now looks to be about 13.7 at 3500rpm.

I'll elaborate more when I get the pic's up, it's hard to describe a graph w/out seeing it.

FWIW I recently installed a much-needed oem cap/rotor and a test-pipe(long story, didn't want to mess with rusted nuts/bolts on my OE one). Also the baseline was only a single run(so it may have gained more the 2nd/3rd run)

VID links arent working.......Atleast this gives me a cool estimate on my rear wheel power with my 2.5" exhaust system.
Modified by Bigvinnie at 8:29 PM 7/19/2006

Yeah sorry, the hosting server is having problems! I've updated the first post with alternate links.

OH I also failed to mention.... You stated that drivetrain degredation loss is 18%. On most nissan drivetrains that use the werner synchros drivetrain degredation is about 15%.
Modified by Bigvinnie at 6:24 PM 12/5/2005

Only reason I used 18% was because it landed me at Nissan's advertised crank hp rating, from the baseline dyno. 126whp/0.82=roughly 155chp.

Also isn't that drivetrain loss a function of the dyno? I was told by the operator that 15-18% was typical on a DynoJet.

slipnfall wrote:Only reason I used 18% was because it landed me at Nissan's advertised crank hp rating, from the baseline dyno. 126whp/0.82=roughly 155chp.

Depends on what gear you are in.People claim that the RWHP for stock is 129RWHP, could be from filter, dunno?

I just scanned my printout instead of waiting on the runfiles... run1 is baseline, run4 is w/BRM.

well. I suppose this finally settles 2.5" vs 3". Looks to me like 3" is undeniably better for an NA application.

Depends... better for performance? Yeah, I agree entirely. Better for practicality reasons? Not for me. Unless you live in the backwoods or the cops are really lenient, it's too loud for around town/city driving. This is a daily driver, and cops around here aren't exactly lenient on aftermarket exhaust... I'll sacrafice a few ponies for less attention.

Just my 0.02.

InsanityInc wrote:well. I suppose this finally settles 2.5" vs 3". Looks to me like 3" is undeniably better for an NA application.

i would have to see a 3" on his car on that dyno and on that day before i made an assumption like that.

skatanic28 wrote:i would have to see a 3" on his car on that dyno and on that day before i made an assumption like that.

It's irrelevant. All dyno graphs are adjusted for SAE compliance, so "on that day" won't matter much at all. Plus, there are two separate dynos of a 3" making over 13whp with the only other mod being an intake (which he has).

Quote »Depends... better for performance? Yeah, I agree entirely. Better for practicality reasons? Not for me. Unless you live in the backwoods or the cops are really lenient, it's too loud for around town/city driving. This is a daily driver, and cops around here aren't exactly lenient on aftermarket exhaust... I'll sacrafice a few ponies for less attention.[/quote]Mine isn't really that loud. The obnoxious and loud sounds that aftermarket exhausts make are almost always due to:

Exhaust leaks****ty mufflers

So, provided you get everything sealed up right, a BRM will be fine as it uses a quality muffler. I've never been pulled over, and I drive all over the place. I'm also assuming that you get the resonator, that's a big one too.

Just to clarify, I don't have an intake. Regular 'ole FRAM drop-in to stock box. I have removed all resonators and their piping however.

InsanityInc wrote:
It's irrelevant. All dyno graphs are adjusted for SAE compliance, so "on that day" won't matter much at all. Plus, there are two separate dynos of a 3" making over 13whp with the only other mod being an intake (which he has).

ive seen dyno's of bone stock KA's vary by 15 whp, my point still stands.there is no conclusive proof of a 3" system making more than a 2.5" across the powerband. comparing systems on 2 different cars is just not good enough.

slipandfall: did you ever do a pull with your car stock?

Yeah, that's what run1 is on the graph. Stock baseline, with only intake resonators removed. Run1 and Run4 were done about 2months apart. Only addition to Run4 is the BRM, and a new cap/rotor.

::edit:: I should say BRM+test pipe ::edit::

And guys, this will not turn into a 2.5" vs 3" thread... the issue has been beaten to death plenty of times already. Please take that discussion elsewhere.

InsanityInc wrote:
Mine isn't really that loud. The obnoxious and loud sounds that aftermarket exhausts make are almost always due to:

Exhaust leaks****ty mufflers

Actually California DB testing has proven that most of the 3" after market exhaust on the market do not pass Db testing. There are a few that due pass with restrictions to the resonator, and muffler ( which actually decreases HP and flow numbers), but then it becomes a toss up to purchasing a 2.5" with fewer restrictions to the resonator (if it would even come with one, my 2.5" doesn't come with a resonator at all) and the muffler.

Bigvinnie wrote:Actually California DB testing has proven that most of the 3" after market exhaust on the market do not pass Db testing. There are a few that due pass with restrictions to the resonator, and muffler ( which actually decreases HP and flow numbers)

Link? Also, most 3" systems don't use a resonator and use a canister muffler, which do jack **** for reducing noise levels. BRMs use a long resonator and a real muffler, both of which are a perforated design which creates no meaningful backpressure. A cop has never even harrassed me over my exhaust system, and I live in CA, in a city with real d!ck cops.

InsanityInc wrote:
Link?.

Here you go..... http://www.pointhappy.com/cvcars/calregs.htm

InsanityInc wrote:Also, most 3" systems don't use a resonator and use a canister muffler, which do jack **** for reducing noise levels. BRMs use a long resonator and a real muffler, both of which are a perforated design which creates no meaningful backpressure. A cop has never even harrassed me over my exhaust system, and I live in CA, in a city with real d!ck cops.

Damn you are one of the lucky ones... Here in the bay area it is all politics. The county makes there money for citing as many people as they can for modified exhaust. The rule in order to make sema happy was to allow any exhaust to have a 95Db or lower. We all know that most 3" exhaust will well exceed that 95 Db without resonators or muffler that has perfrated pipe for sound deading.I happen to buy the pacesetter exhaust it was one that unlike the BRM only has perferated pipe in the muffler, instead of using a resonator as pipe. The pacesetter uses shiatty welding at the muffler, but I really didn't care it serves it's purpose, and probably get just as good HP results as the BRM.Does anybody else have pics of there exhaust set up?????

Bigvinnie wrote: http://www.pointhappy.com/cvcars/calregs.htm

I meant a link showing that most 3" systems failed. (If that link has it, I can't find it)

Quote »Damn you are one of the lucky ones... Here in the bay area it is all politics. The county makes there money for citing as many people as they can for modified exhaust. The rule in order to make sema happy was to allow any exhaust to have a 95Db or lower. We all know that most 3" exhaust will well exceed that 95 Db without resonators or muffler that has perfrated pipe for sound deading.[/quote]I think it's more the fact that my car isn't really that loud. I doubt it's any louder than a stock Z28 camaro or mustang GT.

well I can state for people that do own the apexi N1 exhaust depending if it is single or dual, people that own the exhaust have left statements that they make 98~101Db from 3000~5000RPM, and does not pass at the california requirements. Using a silencer tip the Apexi can drop 7 Db's from those peaks. So technically a 3" can pass, but you will need the silencer.

Bigvinnie, do you have any sound clips of your car from outside? I'm wanting to do an I/H/E on my car, I already have a 3" BRM setup with 22" resonator, and wondering how it'll sound with headers.

Bigvinnie wrote:well I can state for people that do own the apexi N1 exhaust depending if it is single or dual, people that own the exhaust have left statements that they make 98~101Db from 3000~5000RPM, and does not pass at the california requirements. Using a silencer tip the Apexi can drop 7 Db's from those peaks. So technically a 3" can pass, but you will need the silencer.

Apex'i N1s use canister mufflers and no resonator, just like I said, and they only fail by 3-5 dB according to what you said there. A real muffler and a resonator will reduce noise levels by FAR more than 3-5dB.
Modified by InsanityInc at 8:48 PM 12/13/2005

InsanityInc wrote:
Apex'i N1s use canister mufflers and no resonator, just like I said, and they only fail by 3-5 dB according to what you said there. A real muffler and a resonator will reduce noise levels by FAR more than 3-5dB.

Modified by InsanityInc at 8:48 PM 12/13/2005

My point exactly! I don't see how you can compare an Apexi 3", to a BRM 2.5" by any means at all. The BRM uses all noise restricted equipement which we all know will decrease HP. Like you stated the Apexi has a canister (Not a muffler). Like your sig "back pressure is never good, ever", it is pretty accurate, but also understand the back pressure and resistance that is created in those BRM exhaust using perferated pipe as a silencer. I mean really how much HP could it cut back?In my mind in order to compare 2.5" to 3" to determine where power is made in the power band both exhaust's would have to use zero restrictions, and just a canister.Although the BRM may not be optimal for peak HP, I will admit that the BRM is one of the better quality exhaust on the market, and is 100% streetable under the 95Db......

Bigvinnie wrote:My point exactly! I don't see how you can compare an Apexi 3", to a BRM 2.5" by any means at all. The BRM uses all noise restricted equipement which we all know will decrease HP.

I'm comparing my BRM 3" to it. Also, it has no more restrictions. Perforated mufflers do not create restrictions, baffled mufflers do.

Quote » Like you stated the Apexi has a canister (Not a muffler). Like your sig "back pressure is never good, ever", it is pretty accurate, but also understand the back pressure and resistance that is created in those BRM exhaust using perferated pipe as a silencer. I mean really how much HP could it cut back?[/quote]The perforated pipe doesn't work by increasing backpressure, that's how BAFFLED mufflers work. Also, the increased chamber size of a larger muffler can't possibly increase backpressure.

Quote »In my mind in order to compare 2.5" to 3" to determine where power is made in the power band both exhaust's would have to use zero restrictions, and just a canister.[/quote]Once again: perforated core resonators and mufflers cause NO meaningful exhaust restrictions. Canister mufflers are usually perforated, though sometimes they're louvred, which will actually make a canister muffler both sound worse and perform worse than a normal perforated core muffler.