Techno Torque Part 2.

[lbrown2009]

read much of the threads and i'm not sure if the techno torque made a difference for anyone with a 2.7. I'm about to add FvD's muffler and the underpulley, considering adding the techno torque 2. Jaays graph shows a power loss with the TT, anyone else have results on a 2.7 they could share?

Lance
2001 black/tan
18s
FVD dme program
50k miles

[coolbreeze551]

Hope this isn't annoying to bring this up again but I take it no one has a TT on their 2.7 that they would like to share any info on? I am also looking into getting a TT and was wondering about the results? Or maybe Mr. Raby found some enlightening information with his testing that he might be so kind as to share with us?

[ddb]

I too would love to see any empirical data on the TT2 installed on the 2.7. I have one on my car, but don't have any quantifiable results to report. I installed mine after doing the exhaust work in my signature, and feel like it contributed positively. It has been over a year and the car has never felt better. I'm glad I installed it.

[insite]

i posted this back in 2008 on 6-speed with respect to the RSS version of this 'plenum'. IPD never responded. when an intake system or improvement is DESIGNED versus mocked up & sold as a gimmick, pressure sensors are installed in the runners near the cylinder heads to ensure the intake performs as planned. IPD apparently did not do this; i would gues that pedro didn't, either. bottom line is that i believe these modified feed pipes can actually destabilize the pressure balance present in the factory design:


i'd like to introduce some engineering perspective here. for some background, i designed and tested some intakes on formula SAE cars and used to design subsonic compressible flow networks professionally. there are some things that confuse me about what this 'plenum' supposedly does, and some misconceptions that we can maybe clear up.

first, that IPD piece isn't really a plenum; it's a feed pipe to the two plenums on either side of it. second, the OEM plenum feed pipe on the M96 / M97 motors wasn't designed as a bullnose tee by accident, it was BY DESIGN. it is actually desirable for diffuse rather than laminar flow to supply an intake plenum.

the purpose of the actual plenums in these or any car is to stabilize the pressure at the intake runner heads so that each cylinder has the same supply pressure. a poorly designed intake will cause some cylinders to run rich & others to run lean. this can lead to all sorts of problems.

a well designed intake will ensure equal pressure at the runners. an extremely well designed intake can vary plenum size and runner length to take advantage of the harmonics that allow tuning of the intake system to a specific range of RPM's. porsche's varioram system does the former. varioram effectively increases the plenum size AND bridges two plenums into a single plenum. this allows the intake system to use harmonics to reduce disadvantages of static intake system designs. when designing an intake that does not vary runner length or plenum volume, there are compromises. one must choose whether one wants to use the intake to increase low end grunt or high end power, always sacrificing the other in the process. systems like varioram attempt to have it both ways.

to this point i've been talking about plenums and runners, but haven't really addressed the feed pipe. look at the IPD feed pipe. i believe the y-scoops will cause vortices to form INSIDE the two plenums that they feed. these vortices will occur near the center of each plenum, creating local low pressure areas just in front of the center cylinder in each plenum. in theory, this would cause the center cylinders on each bank to run lean and the outer two cylinders on each bank to run rich. this is not an improvement over the OEM design.

i haven't weighed in on this for awhile because fluid flows do funny things and it's not always easy to predict an outcome without running flow tests. the thing that always through me for a loop are the little pipes that seem to go across the inside of the IPD unit. i thought there might be some magic to these things, but was never really sure.

how 'bout you IPD guys chime in and explain the engineering thought behind this design? how have you verified the performance of the flow networks with and without your part installed in the network? have you actually used sensors in each runner to verify you've maintained or improved the OEM intake network's balance? what types of modeling have you done? any other tests besides dyno runs?

[The Radium King]

from what i understand, the ipd version actually disables one of the intake resonance flappers (designed to tune the intake at low rpm) the idea being to flow max air at high rpm (gets all obstructions - like resonance flappers - out of the way). as a result, the ipd plenum is acknowledged to have a low rpm torque dip (lots of dialogue at planet 9 where there are more cayman applications) presumably associated with the loss of low rpm tuning. ipd's solution to this is to use a larger throttle body which works like a sprint booster - more throttle sooner - to get you past the dip quicker.

comparing ipd (softronic make something similar) to the tt, there were some fluid analysis graphs posted in a similar thread, and my take was ...

air flowing from the throttle body hits the plenum and turns left or turns right into the two manifolds.

the stock plenum has a hard surface on the outside of this turn, and a 90 degree hard corner on the inside of the turn.

the airflow will adapt to this by cavitating on both the outside and inside of the turn, reducing cross-sectional area available for airflow into both manifolds.

the big offender is on the inside of the turn, where the turbulence on the inside of the bend dramatically constricts the airflow.

on the outside of the bend, the area of cavitation looks remarkably like the little piece of plastic pedro puts into the tt. my thinking is that the airflow will naturally do that the tt tries to do, and that there is no benefit.

the ipd product addresses the inside of the bend also, by replacing the 90 degree hard corner with a gradual, smooth curve. this will improve airflow.

given that, one would think that a muffler shop could fabricate a y-pipe with an aos bung to do exactly the same thing. as initially noted, however, some low rpm torque is lost with this approach.

[insite]

Originally Posted by The Radium King

from what i understand, the ipd version actually disables one of the intake resonance flappers (designed to tune the intake at low rpm) the idea being to flow max air at high rpm (gets all obstructions - like resonance flappers - out of the way)...............

interesting. i didn't realize they were doing that, too. this is again misguided, IMO, since the point of the resonance valve doesn't have anything to do with flow, only with NF.

i hadn't seen the flow field charts; that would be interesting. the biggest piece of data missing, IMO, are graphs of pressure vs. RPM at each intake runner. betcha dollars to donuts ANY of these items will create an imbalance. the intake really needs to be analyzed as a system.

[The Radium King]

i'll modify my bs slightly. the 987 series have a second resonance flapper on the plenum; the 986 does not. the ipd product does away with this flapper on the 987; it's a non-issue on the 986. so, perhaps no issue with low rpm tuning to add an ipd plenum (or equivalent) to a 986?

here is the thread that i referred to earlier; scroll down a little over 1/2 way to see a quick simulation of airflow through a stock plenum - see how the sharp inside bend reduces airflow by over 50%:

linky

perhaps someone could confirm, however, that max airflow is not required? ie, that the engine recieves sufficient air as designed. i ask as i read somewhere that the 987 has smaller manifold intakes than the 986, so revising airflow pre-manifold on the 986 (with smaller engine) may not be worthwhile?

[JAAY]

Go to the dyno. Go stock, go IPD and see the difference in the power. It Is not a max HP number. It smooths out the overall curve and its real R&D must have been where we kick to high cam. No more dip in power just and increase. That is there big 25hp claim and it is there. The Softronic piece looks to be awesome! Big money and would not work on my car because it is too old. I would do it though if I had the chance. I wish I had as much knowledge as you all do on this subject but I have tried all the mentioned and the IPD has caused no problems and has fixed the dip in power when we switch to high cam. Sorry I have nothing to say about fluid dynamics or scoops or cavitation.

Anyone know how to change the oil?

[Johnny Danger]

The problem for most of you guys is that you haven't tried the new RRJ III super plenum yet. It gives you real seat of the pants power .