06-22-2009, 10:40 PM
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#1
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Registered User
Join Date: Jun 2009
Location: VA
Posts: 221
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Quote:
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Originally Posted by loosecannon
I had the same problems with the exhaust systems on the market-too heavy and too expensive. I landed up making my own and it was so easy I made 3 versions now to fine tune the sound. For my 2004 986, I ordered 7/8" mandrel bent u-tube from Jeg's and after cutting it in half, I have two perfect exhaust pipes that bolt right up to the pipes left vacant by removing the stock exhaust. I'll try to get pics on here tomorrow but here's what I found: straight pipes without resonators or mufflers make an amazing race car sound-I guarantee that the hairs on the back of your neck will stand up as the car passes 4000 rpm. Imagine a Ferrari F430 and you get the idea. It drones from 2000-3000 rpm, especially with the top up but driving one gear lower makes it easy to live with. I made a resonator by drilling 8mm holes all around the pipes in a section about 6 inches long then slid a 2 1/4 pipe over top and welded it to the inner pipe, this reduced the volume of the drone and on a wide open throttle drive by a db meter 40 feet away, it reached 96 db. Since then I made a 3rd example with the only difference being the size of the resonator pipe increased to 3"-this IMO is nearly perfect. You can sneak up on someone if you keep the rpm low but mash the throttle and it makes an otherworldly sound. It still drones a little from 2000-3000 rpm but would only drive me crazy if I had to listen to it on a road trip, in which case I would just drive fast enough to get above 3000 rpm. I took the car to a local track day and two Boxster owners came up and demanded to know where I got the exhaust. One has commissioned me to make one for him and the other took my 2nd example as a template to make his own. I still have two more mandrel pipes so I can make two more versions. By the way, the whole thing with stainless tips weighs 8 lbs. Also, the tips play a big role in the tone of the exhaust, bigger tips lower the tone, smaller tips raise the tone. I will put the car on a dyno tomorrow night and get video but I doubt the audio will be good quality.
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just curious what is your whole setup from headers back? still running stock front CATS??? interested in the dyno results. related to my NHP thread.
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2003 Boxster S
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06-22-2009, 11:34 PM
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#2
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Registered User
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
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Grant,
I have a Flowmaster setup we have used for years.. makes the car sound like it is doing 9k rpm at 4krpm. Dual in dual out.. and I cap the out and access the center chamber for a center exit exhaust. Light, simple, cheap, effective. I believe I end up with $350 in them.. and they last..
Here it is on a 914.. imagine all this hidden well by the stock Boxster rear bumper. For some reason I have not shot pictures of it on a Boxster.. but Chris Murray runs the same thing on his "Cop car" Boxster race car.
B
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
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06-23-2009, 06:47 AM
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#3
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Registered User
Join Date: Jun 2004
Location: Des Moines, IA
Posts: 8,083
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I like the car but the muffler is pretty ugly! 
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Rich Belloff
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06-23-2009, 12:23 PM
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#4
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Registered User
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
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300hp 3.6L 993 engine in a 2300lb narrow body 914  It forces you to learn how to drive
Thankfully.. it is all under the Boxster when used. We don't have a lot of room under the rear of the 914!!
B
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
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06-23-2009, 04:49 PM
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#5
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Registered User
Join Date: Jan 2007
Location: Oklahoma
Posts: 631
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Quote:
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Originally Posted by Brad Roberts
300hp 3.6L 993 engine in a 2300lb narrow body 914 It forces you to learn how to drive |
How did you you shoehorn that beast in there? I want to put a 2.5L in a 67-69 VW square/notchback...that would be a runner.
Do you have any videos of your 914?
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06-23-2009, 05:59 PM
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#6
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Registered User
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
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Search Youtube for 914Club. I show a dyno pull of the orange car
It is a direct bolt up to the stock 914 trans Everything up too a 3.2l air cooled Carrera engine is a direct bolt in to a 914 chassis.. I can use ALL factory engine tin, oil lines.. blah blah from a 1970 9146.
B
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
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06-23-2009, 11:28 AM
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#7
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Registered User
Join Date: Aug 2008
Location: California
Posts: 76
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Thats what I'm talkling about. Something cheap, lightweight and functional. That would be perfect.
Quote:
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Originally Posted by Brad Roberts
Grant,
I have a Flowmaster setup we have used for years.. makes the car sound like it is doing 9k rpm at 4krpm. Dual in dual out.. and I cap the out and access the center chamber for a center exit exhaust. Light, simple, cheap, effective. I believe I end up with $350 in them.. and they last..
Here it is on a 914.. imagine all this hidden well by the stock Boxster rear bumper. For some reason I have not shot pictures of it on a Boxster.. but Chris Murray runs the same thing on his "Cop car" Boxster race car.
B
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06-23-2009, 10:57 PM
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#8
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Registered User
Join Date: Jun 2009
Location: canada
Posts: 12
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Quote:
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Originally Posted by 2K3_Boxster_S
just curious what is your whole setup from headers back? still running stock front CATS??? interested in the dyno results. related to my NHP thread.
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Oops, made a mistake, the tubing is 1 7/8". It's still stock headers and Cats. Anyways, here is a video on the dyno but I couldn't get any numbers because the dyno needs to read RPMs off the crank and that just wasn't possible without removing a bunch of covers. http://www.youtube.com/watch?v=aVMnjSyeyzQ
And some pics:
from behind 
Version 2.0 with smaller resonators 
Version 3.0 with larger resonators 
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