Exhaust Upgrade

After 5 years, I decided to upgrade my exhaust to dual 2.5" all the way.

After the smog conversion, I really didn't like the feel of my steering due to the steering shaft needed for clearance with stock headers.

A while back, I picked a set of Renegade headers so I decided to use them with a new system, the old system was dual 2.5" into a single 3" to the rear.

The whole new system (headers back) cost me around $300.00 (Ebay parts), I used a combination of VBand and Torctite clamps and a box of miscellaneous 2.5" bends to form the down pipes, I used a pair of Camaro high flow cats and welded air pump fittings to the Renegade headers.

I decided to tryout an OBX muffler because I wanted a bit of rasp normally found on imports, it sounds really nice. The system sounds and performs very well, it has quite an aggressive sound with very little drone.

I also took the opportunity to fix an oil pan leak, that was fun

One thing that sucks, I cant use my high torque starter with the Renegade headers, I need to find one that has the same profile as the stock unit.

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Very nice.
Someday I will get around to doing the same....

Nice lookin' work. I need to do the same as I have nice headers but welded up a kludge of a y-pipe to connect to the 3" system made for the original engine.

Rich

It’s not too difficult, the combination of clamps allowed me to dial in the correct clearance between rear shocks and transmission; it is a bit tricky getting two 2.5" pipes through that area. You also need to use a rear muffler with about 4.5" Clarence between pipes; this provides good clearance through transmission and shocks.  

Dual 2.5" pipes at the rear does reduce muffler choices, but can also use two individual mufflers. The OBX muffler is quite aggressive, you get more of roar from dual 2.5s vs a single 3”, and I will probably play around with other mufflers.

Nice work! I have a single 4" on mine which was definitely way over kill.. it does make some people chuckle though when they look under the car . I initially was going to do a dual 2.5" system but went single due to ease.

Which transmission are you running, is that a 968 box?

Have you done any events with the San Diego PCA yet? Hoping to have my car out there later this year.

Techno Duck wrote:Nice work! I have a single 4" on mine which was definitely way over kill.. it does make some people chuckle though when they look under the car . I initially was going to do a dual 2.5" system but went single due to ease.

Which transmission are you running, is that a 968 box?

Have you done any events with the San Diego PCA yet? Hoping to have my car out there later this year.

I am running a 968 transmission and have been wondering if i should go to a 5 speed with LSD, the 968 transmission is tough but does not have the best ratios.

I have only been to Carlsbad cars and coffee on the last Saturday of the month, I have been invited to Qualcom for autocross but haven't made it yet.

I've got a dual 2.5" on my car. Seems to do well, but clearance over speed bumps is a bit of an issue sometimes.

docwyte wrote:I've got a dual 2.5" on my car.  Seems to do well, but clearance over speed bumps is a bit of an issue sometimes.

Yea, mine hangs quite low, It took me three tries to get the collector pipes high enough to be safe.

My car runs quite low, about 5.5" from bottom center of the rocker panel to the ground. The exhaust measures 3" to the ground by the cats and about 4" from the flex bellows back with the rear muffler sitting 7" from the ground.

This time around, I moved the cats back so I needed about an inch between body and cats. If the cats sit in the bellhousing area, the system can sit almost 2 inches higher.

Hey Pormgb- any chance you saved the component info and/or
seller info on where you got all the components?
I'm about to jump on building the exhaust and looking for the right recipe.
Yours looks great, tempted to duplicate.
Any info components/sources?

Many thanks-

- j a s o n

Jasonscottw wrote:Hey Pormgb- any chance you saved the component info and/or
seller info on where you got all the components?
I'm about to jump on building the exhaust and looking for the right recipe.
Yours looks great, tempted to duplicate.
Any info components/sources?

Many thanks-

- j a s o n

Here you go;

I picked up the headers a while back on this forum (Renegade), I do regret not using 3" V-Bands, those 3 bolt flanges are hard to seal.

All welds were TIG, welding is not my claim to fame but TIG creates very good welds.
The clamps allow me to rotate (45s) and adjust exhaust height. I also used lots clamps so I can easily change certain parts of the system (rear muffler) and minimize welding.


2.5" Torctite Stainless Exhaust Band Clamp Step Clamps
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x4, can use 6 if you don't use rear V-Bands. (2.5 pipe to X-Over, tips to rear muffler).


2 1/2" Exhaust Flex Pipe 2.5" x 6 Heavy Duty Steel Double Braid 6"OL - 25006D
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x2 (Between X-Over and Cats), help for future adjustment.


3.5" Round Bosal BroSpeed Exhaust Tip 2.5" ID Polished S/S 259-913
Universal 3.5" Round Tip 2.5" Inlet 259-913
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x2 (Many other options, I was trying to keep these cheap)


2.5'' V-Band Flange & Clamp Kit for Universal Turbo Exhaust Downpipes
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x4 (Flex Bellows to X-Over, rear pipe to dual bends).


2.5" inch universal Tailpipe bend Kit "Mandrel bent"
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x1 (Seem to be the most cost effective way to get lots of bends), provided 4 x 45 degree bends for rear pipe to muffler, also provided enough bends to make down pipes.


Walker Straight Exhaust Tubing 2.5" OD 7.5 Ft Length Aluminized Steel 47974
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x1 (rear 2.5 straight pipes), lots of length to make rear 2.5" straight sections


10 PACK. O2 Oxygen Sensor Nut Bung PRE-CURVED 02 M18 x 1.5 THREAD
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x1 (O2 Sensor Bungs), I have six O2 sensors, you will need a minimum of 4, lots of spares.


OBX 2.5" Dual In & Out Oval Muffler Resonator Universal (Length 19.5")
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x1 (rear muffler), a bit of an experiment, has the smallest distance between pipes, great for 45 degree bend clearance, not so good for tail pipes (maximum of 3.5"). Many other options available like two single mufflers.


UNIVERSAL ALUMINIZED CROSSOVER X PIPE EXHAUST 2.5" Diameter 2 1/2"
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x1 (X-Over), X-Overs seem to be the best for a higher pitch and performance.


Universal muffler / Pipe Exhaust clamp 2.5 inch Fits VW and Audi
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x2 (45 degree bends to muffler) Had these hanging around from a previous project, non stepped Torctite clamps can also be used. Using long clamps make up for the difference in pipe length caused by staggering, no need to weld in extra pieces. These clamps also allow an easy switch of rear muffler.

Wow- you rock! Thanks for the info-

I just complete my first long drive, Wow, what a difference.

I have read many articles about short tube headers not being much better than stock, but the Renegade headers with the new system is impressive, I can't imaging what long tubes would be like. The motors response is significantly better, I actually surprised how quick the motor revved.

As for the sound, awesome!! I also think the Y pipe creates a higher more refined pitch than a H pipe, the OBX muffler is quite loud even with cats but produces an awesome sound.