Having more back pressure has never helped to produce more torque. Read what the real experts say on this.

 

You'd have to measure your tip, you need a 115mm (4.5 inch) ID. You'd also need a hole to mount it, but you can always drill that.

 

They also make them for 90mm tips.

 

So I dynod the car yesterday at the Rotarytuner.net dyno day at modacar, and the silencers barely limited my power at all, infact they may have added some torque. First two runs were with the silencers in and the last was with them out but WinPEP puts them in the order of 1,3,2 so read more carefully.

-Andy

 

AWESOME! On A`PEX-i's dyno it was a similar result when using a PS Revolution, a stock exhaust, and a R95.

 

we have turbos; turbos supplies all the backpressure you need to not lose any torque you're thinking you'd lose by getting a big exhaust


i missed this post ^
exactly what i'm saying

 

I may be wrong about the torque, but I swear I read it in one of my mags when they did a test on it, but hey it's a good system to help cure the noise levels, and you don't suffer too much power loss. They also developed it to help make the beginning throttle response kind of light.

 

do you have any bigger pictures of yours?

 

These photos are of the day when I installed the exhaust. It was used for about two weeks, and I bought it from RX7fashion when they went out of business.

 

It didn't come with the adjusting tool, so I had to go to A`PEX-i USA and get it through them. It was like $10 from them, and they only had like 2 laying around.

 

Finally! I've posted at least twice asking about the ps-revolution. I have a rediculously large Ti exhaust. w/o a cat i set off alarms everywhere. w/ a cat i set off alarms in a 2 car radius. i've had my eye on the ps-revo for about 2 1/2 years.

 

Here you go:

http://www.rx7store.net/A_PEXi_PS_RE...%20exhaust.htm

If I were you, I'd call them first though, or PM Jason. He might be able to get you a DEAL on it. I don't know. He always saves me a little more than I would have thought.

-Jeff

 

I just dyno'd the LS1, lost 10 hp with the ats on motor (425ish rwhp without) and about 20hp on the bottle (525ish rwhp without).

 

Hmm mine was more like 2-3, maybe I'll redo my test next time on the dyno. Because I did do the first run with them in and then took them out for the second two so maybe heatsoak was affecting my unsilenced runs.

 

keep in mind he's trying to silence ~425whp worth of exhaust flow with it. you were only silencing ~285whp worth of exhaust flow. its going to be more of a restriction the more HP (exhaust flow) you're making.

 

I just wanted to post my experience up with the ATS.....I recently installed an Apexi GT rear section expressly to have the ability to mount the ATS.

In my limited use of it here in the NJ winter, it performs 100% as advertised

Very quite at cruise (it's scary it's so quiet actually) and at idle I can hear more racket from my engine bay than from out the exhaust! At WOT it seems to open up at about 4000 rpms, and she screams as loud as ever, the car feels to have the same power.

Best part of the whole thing? I can r&r it in about 3 minutes time. 2 thumbs up

 

just what i wanted to hear, sweet.. seems like ti works very well, i guess i'll take off the HKS and put the apexi Gt spec back on and order the ATS. It seems that with your results and the dyno grap above it shows a lost of about 1-2% so with my 500rwhp it should 5-10hp, i can deal with that...

Do you have a link to where you bought it from?

 

how does it effect spool? i'm guessing not a lot as the size of the exhaust wouldnt need to be as large during spool up... due to less volume of exhaust being exited. Plus its at the end of the exhaust and not close to the turbo like the DP

 

From my understanding of fluid mechanics, it might decrease spool because of the additional pressure build up that this type of system would cause in the section between the turbine and the exit.

Turbochargers operate primarily off of changes in pressure across the blades, by building up pressure downstream of the turbo, you will decrease the delta-P across the turbine, so in my mind, that would decrease spool.

 

I dont mean to take away from the credibility of this statement, but I don't think that its really an apples to apples comparison between a V8 naturally aspirated motor versus a rotary turbo application. I suspect on a turbocharged engine of similar power, there would be a much more significant power loss.

It is my understanding that n/a and turbo engines require different exhaust tuning approaches.

On a n/a car, you would want to choose an exhaust diameter that would bring out ideal exhaust scavening characteristics such that it actually aids in the removal of exhaust gases from the cylinders.

For a turbo car, you would ideally want an exhaust that promotes maximum flow and minimum pressure drop to maximize the delta-P across the turbine and reduce energy wasted pushing the exhaust gases out of the exhaust system.

Based on this understanding, I am skeptical that anyone would see a real gain from this product. Any claims so far seem to be entirely within the realm of statistical deviation associated with dyno measuring tools. That being said, I think its very neat and I'd consider one for street application if I had an Apex'i exhaust.

 

I used to have one. (lock it on someone took my bolt off and stole it) It was great at night comming in and out of the house took the noise down a little (not as much as youd think. but at wide open it let loose. I never dynoed the difference but i cant imagine the slight airflow disturbance at the end of the system stealing more then 3 or 4 hp at full out.

LOCK IT. seriously mine was stolen in front of the mto (DMV for the us) i drove there i can't believe the guy didnt burn himself but when i was leaving started the car it was louder then i thought it should be got out to check its missing and the bolt is laying nicely under my car.

 

wow robbed in London!

i lived there 4 years and never had a single theft..


Back on subject..


I have an Apexi ATS as well...

but it looks nothing like that Anus in the picutre above..

mine is the 115mm (coupled with the 120mm spacer)

looks like this:



are you guys referring to a diff model?

 

I have exactly what you posted above Ottoman^^^

 

ah ok..

and you're right..

It's EERY quiet!

like the car is off or something..


I dunno if it's just me.. but I could of swore.. the car felt laggier to me (non-seq)

and I also felt guilty ragging on it.. like I was forcing air thru choking the motor..


and when u stand behing the car at idle.. the pressure of the exhaust comin out of that small hole is crazy!

my pants leg will "flap"like a flag in the wind..

and u can stand pretty far away and feel it still


perhaps if I get off my lazy butt I'll throw together a Before and After video of it..

 

Turbochargers need the least amount of back pressure behind the turbine for maximum spool and power to be achieved. So no, any increase in pressure behind the turbine blades would cause a loss of spool and of power. This is the reason a larger downpipe decreases spool. The effect on spool time is less the further away from the turbo a restriction is placed. but i have a feeling this device will still have some kind effect on spool in a negative way.