My new Bipipes and ofcourse before and after logs

[2001S4NY]

Finally got a chance to install my new bipipes, I was amazed how these don't even weigh anything at all.





Here are the Logs, Same Road, Same IAT, Same Software no change..

RED= CATS
PINK= NO CATS
BLUE= NO CATS NEW BIPIPES

As you can see i gained more top end power :) guess the stock pipes are too small for GT turbos and choke them up.

[WingsnHorns]

Very nice!

[MiniRS4]

very informational post.
any impressions of the before n after? like spool, feel, sound, etc...

also, how much did they cost and where can i get them?

[revhards4]

Don't worry JDM, haters will still bash it because your a no name...oh well, I think everyone will eventually sucumb to the Generation X products tho:)

[BastardS4]

how close to the stock fan are they? looks tight

[AB18]

^ Don't think theres a fan there anymore :).

[AudiSportB5S4]

yeah no, greg has a thing against the stock fan lol, but i think genx mentioned somewhere else that it will be like a 1/4 inch away ..? correct if im wrong!

[generationjdm]

He will have one on the motor with a stock fan to see what the clearance is soon

[Nexus1155]

Don't worry JDM, haters will still bash it because your a no name

It shouldn't matter if hes a no name if his products are good theyre good,

Sadly in the audi scene its not like that. SSP and other starting companies still gets bashed by other companies when its they who should be getting bashed...

[cjk]

Looks like another nicely made product with results! :)

[b5s4tt]

nice logs, real world facts are better then advertising a product with no stats like others do

[kido81]

generationjdm- These are the pipes you have been working on??? when are you going to be making these?? i am def. down for a set...

[Das General]

Nice.

Would merging the bi-bipe by the throttle body into one straight pipe to the throttle body, allowing for just one coupler from the throttle body to the bi-pipe...would that benefit at all? Considering there would be less of a chance for any leaks by only having 2 clamped down areas, as opposed to the 3 that the current setup/tbb has?

[BlackS4TT(Josh)]

Ok... looks like the pipes did nothing. They're pretty though...

[Das General]

Up top acceleration is improved, which is where it was being held back.

[SoSlow]

these new pipes have a bigger ID, right? if so then i dont doubt an increase in power

[SilverSurferS4]

The aluminum bi-pipes does not taper down to 1.5"! Its 2.0" through-out the length of the bi-pipe!

[Tifosi]

He will have one on the motor with a stock fan to see what the clearance is soon

IMO, this will be the key point of this set of BiPipes. If they do not, you are looking at a very limited set of customers that will be able to use them.

I would also prefer to see them mate up to a RS-4/late model Allroad-like metal TBB as oppose to Samco or other flexible TBBs.

[ladedruck]

The aluminum bi-pipes does not taper down to 1.5"! Its 2.0" through-out the length of the bi-pipe!

GENJDM said it is actually 1.92 id. in the other thread fwiw.

Now since I said i would I just did a quick test on the flow bench. VERY QUICK and plenty of room for error but I did all 3 set ups twice. Using a stock throttle body with a stock boot on it I flowed it at 10" of vacuum. The stock tb with boot and no pipes flows 295 cfm.(This adjusts to about 493cfm @28" I believe) with the stock bi pipes in it flows 260cfm. With two 2 ft straight sections of 2" ID pipe jammed into the boot it flows 290cfm. I don't know what a bent 2" id pipe or 1.92 would flow.

[generationjdm]

1.92 I.D the 1.52 on the stocker was I.D also... So the 2 inch pipe flowed over 10% more.. On the car theres tons of other Variables..

[SoSlow]

seriously, you have no idea what you're talking about. why don't you stop your bench racing and try something out before talking all this garbage?

the 300zx community which has a very similar setup to the s4 tried switching all of their piping all the way from the air filters up to the throttle bodies (and everything in between) from 2" to 2.5" ID and saw gains of 10-15whp, WITH NO OTHER MODIFICATIONS.

[JayyyyyC]

Looks like APR is going to have to discontinue their bi-pipes! =D

[Tifosi]

Looks like APR is going to have to discontinue their bi-pipes! =D

Probably not, as most people buys APR BiPipes to avoid TBB tears or TBB popping off under boost and other TBB-related malfunctions, not for the purpose of performance gains.

[SoSlow]

um, that's dual 2" piping on a v6 twin turbo 300zx there, chief

so you've been racing since '58? that makes you at minimum 70 years old

[SoSlow]

what is the ID of the ic piping and intake piping? consider that, then ask yourself if having 1.5" piping is contributing to some restriction aside from the obvious which you mentioned

[generationjdm]

Soslow, don't waste your time there was a dozen key points he never answered, this is purely entertainment fun for him....

[raketeS4]

anyone willing to hack up their APR bipipe and tell me what the ID is?

[Nexus1155]

why would you need to hack it up lol just get a set of calipers to measure it...

[pzp107]

This is actually a very simple flow calculation you would do in any freshmen thermodynamics class. You are increasing the volume of air traveling through the bi pipe. You are WRONG in saying that the throttle body and everything else is the same restriction which would net no increase in horsepower. If you want a an example like your garden hose problem think of the throttle body now acting to take the larger volume of air and increase velocity by forcing it through a smaller hole. This would in turn help feed high rpm power. This is a common principle opposite of a diffuser, guess what it is? You are right in saying a larger throttle body, manifold, porting etc would be beneficial. But thats about the extent of your correctness.

[2001S4NY]

yea umm i didnt launch my car i never launch on my first run..

Marc why you still trolling

[ladedruck]

the thing that gets left out in the modern times is the poor old cylinder head. People get so lazy and think that turbos will fix all. the bottom line is flow thru those valves is where the power is made.
Seriously though 12s????

[2001S4NY]

yes 12 couldn't go again since the track got rained out. I know for a fact if i would of launched my car would of beat my time and trap

[2001S4NY]

marc im not responding to this thread anymore it might as well be closed.

[AB18]

I had a strange feeling about this Tipsy character. Marc at his finest.

[BITRBO]

This is actually a very simple flow calculation you would do in any freshmen thermodynamics class. You are increasing the volume of air traveling through the bi pipe. You are WRONG in saying that the throttle body and everything else is the same restriction which would net no increase in horsepower. If you want a an example like your garden hose problem think of the throttle body now acting to take the larger volume of air and increase velocity by forcing it through a smaller hole. This would in turn help feed high rpm power. This is a common principle opposite of a diffuser, guess what it is? You are right in saying a larger throttle body, manifold, porting etc would be beneficial. But thats about the extent of your correctness.

Uhhh, I don't know about "simple", but I know what you were getting at Actually, you have forgotten the other major component to the Q=V/A story... Velocity. By increasing the diameter you do increase flow, however, you also decrease velocity (for a given temperature & pressure). This is all in a perfect world of course, but as we all know there many "real" world factors that can effect these values in either direction. Let's just suffice to say that the charged air supply entering the TB may have more volume, but it's entering at a slower rate (unless the pressure is increased). And may I ask where the hell Double Nutz is at a time like this???

But to "Tipsy's" point, there is no denying that there is only so much the stock S4 heads can physically flow (per increment of time), based primarily on volumetric limitations and timing; the valves can only pass so much air before they close, indicating that flowable volume, smoothness, and architecture of the intake track play a critical role in the whole event. Then you have to contend turbulant flow, eddies, etc., etc. and then it get's really messy. I would venture to guess that Z-German engineers who designed this engine sized the bi-pipe within marginal limits of the engine's flowable capacity (I'm also guessing that APR realized this also, hence their I.D. size is approx. stock too).

Therefore, it is entirely possible that genjdm has taken out some of this proverbial "fluff" in the system (at a particular engine speed, intake presure, temp., etc.), and provided another piece to the puzzle. Now my guess is that if Gregg threw a cam in there with a little longer intake duration, things would start to get interesting.

But as entertaining as this may be to "Tipsy", he does have some valid points. Although controversial, he is actually asking good questions that we should all be asking ourselves anyways. Otherwise, how else would we push the envelope gentlemen?

[BlackS4TT(Josh)]

So i'm supposed to believe that a .5G increase in acceleration up top (according to those logs) is primarily a result of the bipipes?

[revhards4]

Wow! So many fools...can the guy get a few more trips to the track for some fine tuning without every douche bag here getting his panties in a bunch over the ET and Trap, gosh!

[generationjdm]

Wow! So many fools...can the guy get a few more trips to the track for some fine tuning without every douche bag here getting his panties in a bunch over the ET and Trap, gosh!

What they didn't hear is he only made 1 half ass run where he was still was 3mph faster in the 8th then the last run when he rolled out of the whole...

[ToMMyRsK04]

trolling FTW

[Kindbuddy]

Just to add my 2 pennies...(tipsy) If you add more flow behind a certain restriction, you get more flow through that same sized restriction. Even if it's a fraction. I learned that through ten years of speaker box building and port tuning.