odurandina

i added a resonator (not a glasspack, just a hollow tube chamber that opens from 2 1/2" to 4"), and something really weird happened. my 968 now sounds like the 4-cylinder equivalent of the car in the video clip below.... you're all going to tell me i'm nuts, but just wait until you hear the car....


if any of you show up at Lime Rock tomorrow, you'll get the chance to hear one of the best sounding 4 cylinder exhausts for the street/track -- mine. it's a low, "throaty" sound at idle, similar to a V8, but when you get on the throttle it begins to turn into an even deeper "roar," and finally, like something you've never heard before at full throttle... not quite like a 4 cylinder running straight pipes, nor a V6, nor V8....


the sound is rather, quite shocking for a 4 cylinder.


maybe one of you guys can help me post a demo on youtube, as i haven't a clue how to do that properly.


you're all going to tell me i'm nuts for posting the youtube clip, but honest, it's the closest thing i could find, in a Porsche... my car sounds eerily similar to a 4-cylinder version of this Carrera GT.




http://www.youtube.com/watch?v=g3XEr...layer_embedded




about the exhaust:

I recently had my exhaust made with one consideration; Carl Fausett's supercharger.


Have you guys ever held a 968 cat in your hands ? Don't believe everything you hear... What a pile of JUNK !... ummm... the rest of exhaust that came off [after the header] is built for World War THREE. It weighed about a zillion pounds. The new one that went on is maybe 30 pounds... The goal was something light that will flow. but a real accident happened.



My new exhaust is straight 2 1/2 inch pipe with two mild bends into a 3 inch Hooker Maxflow muffler w/ 3" to 4" tip... This muffler has the highest flow characteristics of any mufflers tested that are still streetable, but costing hundreds of dollars less than a Borla... It's extremely well built, and at idle/normal acceleration the sound is amazing...



But when you really step on it, the variocam runs the way nature intended... characteristics similar to an optimized [bypass] system will be observed... As Jeremy would say, "the results are astonishing..." and the numbers are confirmed in tests... In the first link you'll see that the Maxflow muffler is sending the same amount of gas as straight pipe... 521 cfm...


http://www.broaderperformance.com/mu...flow_tests.htm



here's another link, the Maxflow and the Borla are the clear winners, though the Maxflow is louder at WOT. but with the resonator all is WELL !!


http://www.carforums.net/showthread.php?t=51203


The results in HP order on Mustang:

1.Flowtech Warlock (open) 374.2 hp/ 333.1 tq
2.Bassani Real Street 373.7 hp/ 333.8 tq
3.Hooker Maxflow 373.5 hp/ 333 tq
4.Borla XS 373.3 hp/ 332.6 tq
5.Magnaflow 372.8 / 332.5 tq
6.MAC 372.3 hp / 331.5 tq
7.Flowtech Afterburner 372.3 hp/ 330.1 tq
8.Hooker Aerochamber 372.1 hp/ 330.4 tq
9.Bassani 372 hp/ 333.5 tq
10.Spintech 371.6 hp/ 332.2 tq
11.Edelbrock Performer RPM 370.9 hp / 331.3 tq
12.Borla XR1 370 hp/ 334 tq
13.Flowtech Terminator 369.5 hp / 331.3 tq
14.Dynomax Ultra Flo 369.4 / 333.2 tq
15.Flowmaster 369.4 hp / 331.8 tq
16.Flowtech Warlock 366.3 hp / 325.3 tq
17.No muffs 365.2 hp / 330.1 tq


Sound Off in Quietest to Loudest (Decibels):

1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).


I am not suggesting you all run straight, 2 1/2 inch pipe into a large, glorified glasspack, as I have done... but my set-up is making at least an additional 20-30hp [w/ the K & N filter]... Highway acceleration from 70 to 100 mph is ridiculous...


The photo I added is a 4" Maxflow. the large inlet/outer diameter makes the muffler look very small. The muffler is bigger than the photo indicates..


I am willing to bet that this type of exhaust will make the Carl's supercharger work better than the hp gain he's getting with the stock exhaust....


/

odb812

that's a pretty strong claim there

PorscheDude1

Lol
Any dyno charts on your exhaust setup?

I think you are feeling the placebo effect from a louder exhaust note.

ryan@usaimage.com

A lot of people think this car needs some back pressure to hold a good torque curve. Will you dyno to see what you think you have? I hope your right.

savvas944

actually,getting rid of the cat and putting a 2.5 inch pipe with 1 straight through muffler from the point of merge of the manifold and a 3 inch pipe from the middle and a 3 INCH flowmaster40 with a 4 inch tip
yields fantastic improvements ,with a promax 7700 CHIP, and a KN 3 inch KN CONICAL FILTER,
sucking from the hole in the bumper, left when you remove the bend snorkhel.

for those willing to try,bypassing of the hot water trottle body pipes,machining the inside of the manifold
to 72 mm and installing a 64 mm BMW TROTTLE BODY, with a 3 mm steel matching flange,and an adjustable FPR, AT 4.15 BAR,
His claims could be CONSERVATIVE.

Jfrahm

With a friendly dyno operator, sure.

savvas944

No dyno run, are misleading most of the times.
Real world testing on , F1 track in Bahrain , inner circuit.2.44. km

Before-std- only panel KN FILTER- 3.04 to 3.07 minutes, - 2 laps
after with above mods-2.53-2.54 minutes -2.laps.

Coil over suspension and wheel /tires same.

i would say its working.As i said if willing to try.
i forgot one thing also, Alu speck flywheel. 7.2 KG LESS.

lsinlv

wow....you gained on average 10 seconds a lap with only 30 whp?!?!? sounds a bit unbelievable.....that is a huge difference, for that small of a power increase.

hell, 10 seconds a lap is just HUGE period.

Fox944

LOL @ these claims.

Lemming

Do a search, I've posted many dyno's of my track car showing that this is just not true, ymmv.

odurandina

Thanks for the interesting replies. I am willing to concede that low-end power appears to be unchanged compared to what I had before... hp and torque gain might turn out to be a flat over part of the RPM range... But when the variocam kicks in at higher rpm, the power is unbelievable and it's not a placebo effect...

I will dyno this setup sometime after the first of the year, but I do have one empirical result so far...

My speedometer under reads my actual speed by about 1% with the 275-35-18 tires that I run. My arithmatic predicted that I would get this result when the circumference of the tires was calculated... all was confirmed by checking 100 miles of mile markers on the interstate proved that my odometer is exactly 1.5 % under the actual mileage... I am FINALLY able to reach the the limiter in top gear. I had the car at an estimated speed based on the tach of about 159-161 mph on the interstate on a long straight when it the liimiter kicked in... Obviously we need proper dyno tests.

savvas944

i did not say plus 30 hp.
pls check the mods carefully,and do the maths.

plus20- 30 you can get with the chip,no cat,kn filter in std housing.std 60 mm body with its 8 mm dia shaft and 2 mm thick throttle plate,.without, opening the inlet manifold,and removing the heater pipes from the th. body, on a good engine with no leak down.

the fact that you have 7.2 kg removed from the rotating assy,of the engine, (appx 11%)with the highest moment of inertia,counts
a lot on acceleration and decceleration,in and out of a corner, plus the optimum so far(4.15 from 3.8 bar fuel pressure, tells that their flow has been maxed with the chip at the std pressure and more could be utilised, appox 12 %) .More passed air in the engine needs more fuel.

That translates to power , wouldnt you agree?

A simple comparison of the 968 with the std 951 injectors, is that their flow is almost identical at their given operating pressures, and we all know that otherwise std 951 2.5L engines make over 300 BHP with just a 3 bar FPR, a klr/dme chip and KN or other free flow filters.

Has anyone noticed also that the 968 std filter housing sits on top of the radiator, and the temp of the bottom straight after a hot run and how hot the engine bay gets with the std 83 degree thermostat,with the top 3 rows of the radiator totally blocked by the plastic cover,effectively blocking the airflow to them, and what a difference it makes on the through the gears acceleration, wrapping the exhaust headers with insulation ?

if you havent tried any of the above ,dont knock it, until you try, and all that with less than 1,000 usd
spend, the costlier beeing the flywheel

A individual THROTTLE BODY manifold ,should also raise the power level,much more .
you only need to examine the BMW M series engines for their high specific output to see.

Cannot wait until someone markets one for a reasonable price,.

Fox944

924/44 have diff exhaust plumbing then 968's. Your Dyno results cannot be applied to a 968 for this reason. a 944 with a 968 Motor can run a bigger header then whats avail and will fit on a 968. This bigger outlet is key. Stahl Makes 2 headers, one bigger then the other. The bigger of the two will not fit a 968, but will fit a 944 S2 or any 924/44 with a 968 motor.

Fox944

This has been discussed for many years. It will cost an arm and leg to develop the system. It will also require the use of stand alone engine management (which it self costs an arm and leg). No one will be developing a ITB system for the 968 anytime soon. And the ones that do exist are used on race cars only that need rebuilts constantly. ITB system does not make sense for a street car, nor would it pass emissions.

odb812

i wish i knew this before i sunk all that money into my 951. and to think, all i needed was these three simple things. i must be making at least 550 hp. better go to the dyno...