RT/10 side exhaust upgrade interest?.....

[Sean Roe]

Hi All,
Our '94 RT/10 has had "build new side exhaust system" on its list long enough and I finally got around to building it up today. The stock exhaust sound did not match the car well (in my opinion) and I felt like there was some performance improvements to be gained if I changed it.
After doing some research, I found that there weren't too many side exhaust options out there and all of them required welding (including the Borla cat-back side exhaust which retails at $1,238.99). Not too satisfied with what I found, I set out to build an exhaust system here in the shop.
I cut the factory exhaust off just forward of the catalytic converter. From there I installed a short 2.5" id to 2.5" od pipe, round high flow catalytic converter, a 2.5" to 3" venturi tube to make a smooth transition (the exhaust comes out of the cat hotter, so I figured we could use a little larger pipe diameter for the increase in volume), a Borla XR-1 5" round with 3" inlet / outlet stainless steel race muffler, rear muffler hangar rods and a 3" stainless steel turnout.
In these pictures, it's all tack welded together. As a finished product, I welded everything except the forward pipe which slips over the original exhaust pipe and the turnout. To install the completed assembly, I slid the muffler end all the way back into it's hangar, then slid the assembly forward to connect it to the stock exhaust pipe. it was very straightforward. I used a clamp to fasten the turnout so that I could set the pipe in the center of the factory side cover outlet.
The car sounds great now and I'm sure it picked up some more power. I'll dyno test soon, but it should have been worth about 20 HP.
My question is, are others interested in side exhaust upgrades like this? I can make a jig and copy what I just built. I figure the total price would be about $950 for both sides completed with the fore and aft clamps.
Let me know.

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[SlayTay]

Hi Sean,
I would like a 3 inch set to go with at set of 3 inch Borla headers for an early 93. Will your jig make a 3" system? Shall we call you at the office?

 

[Sean Roe]

There are several different ways to go. For example, you don't have to go with the high flow cats (it would be about $220 less without the cats), we could supply the parts, you build the system, etc.. We can sell the Borla XR-1 Stainless Steel Sportsman Race mufflers alone for $180 each.
I think this particular option would be good for those who want improved performance, sound, an easy bolt on exhaust and must have cats to pass emissions.
We actually have a few different exhaust projects going on at the moment. For example, I'm not sure if the Borla header # 17112 or #17113 headers will fit the '94 (Borla isn't sure either) as both are spec'd for 1996 and newer. So, we're going to test fit a set on the '94 after dyno testing this new manifold-back setup. I'm also putting a set of Borla #17113 (larger tube header and collector) headers on the GTS to dyno test against the #17112's. Lots of options

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[Vip-RT10]

I am defenately interested, but would like more info first. Does it run cooler and what is the HP gain. I know that you will see soon, keep us informed. I will be ordering the Xenons from you really soon too.

 

[Robert1994]

Excellent ! What would the system run with longer pipe
from the manifold to the muffler with out the cat in the
middle ? Do we retain the stock flex pipe ? I haven't
paid much attention to how it is attached on either end.

 

[FUSCUCLA1]

How about the sound, can we maybe get a downloadable sound file.

 

[Hisser]

I can tell you from experience that on the gen 1 the sound is pretty loud but the exhaust flow will almost blow you away so stay away from gravel roads unless you want a dust storm. Dyno results with Sean's set up without the cats will be right at 14 RWHP. Don't know with the cats. Now on my gen2, I ordered Sean's round cats and I love them. The side seals are at least 75 percent cooler. No way to discolor the side seals with the cats. I have taken the rear muffler off and the resonators and I am just running the cats and the sound is more like the hot rod sound but not as bad as my gen 1 without cats. The gen 1 you could hear me coming from blocks away my friends say. Going this route would be a very happy medium. If you have a 98 like mine you will hear the cam even more than before. It sounds just right and the computer does not throw a code of any kind. But to add more of a deep tone you will need some type of non restictive straight through muffler for that. Have fun experimenting...

 

[Qualitywires.com]

Count me in...good timing..I'm looking for an exhust system..

 

[STOUT 1]

I like the setup. Is everything stainless?


Jason

 

[Sean Roe]

Thanks everyone for the input.

I plan to go to the dyno sometime soon and can record the sound of the exhaust during the run. Anyone have recommendations on a good recorder? I've never recorded sounds and uploaded them on the internet.

Based on the input, I can see two different options, both of which would cut the factory exhaust at the cat inlet end (retaining the factory pipe and flex pipe forward of that).

1. Stainless steel exhaust pipe with 2.5" id at inlet to slip over the factory pipe, then a short transition pipe to 3" welded on the inlet of the Borla race muffler, muffler hangar rods (mild steel) and then the 3" turnout. The assembly can be welded together with the exception of the forward end where it clamps to factory pipe and the rear so you can set the outlet pipe in the middle of the factory cutout. This would be about $750 complete. Like Wayne said, it would probably be pretty loud though.

2. The system as described in my first post with one exception. The venturi tube I used was aluminized mild steel from Flowmaster. I would replace that with a stainless pipe for "production" and the entire system would be stainless. A lot better sound and performance than stock, not as loud as it would be with no cat and it would pass emissions. The price would still be around $950. There's a lot of cutting, fitting and welding to be done to make it an easy bolt on for someone.

I did forget to mention one other exhaust project. We're going to make a dual 3" rear muffler replacement pipe set for rear exhaust cars soon. Basically, it will be the last two pipes from a Borla cat-back with polished angle cut 4" round tips with 3" centers and an adapter set to slip it onto the stock rear pipes. We're shooting for the $400 range on that one.

Thanks again for all the input. I think we can put these packages together pretty reasonably and make some nice new exhaust options. Let me know about some recorder recommendations.

 

[Newport Viper]

I'm in. I am looking for an easy bolt in cat back at a resonable price. I want sound quality, not just loud. 20 to 30 hp increase and nice sound send it.

 

[Sean Roe]

Using the notes I made from building the first exhaust set, I made up a jig today and test built one more side. I just tried it on the car and it fit perfect. So, it looks like we should be able reproduce this exhaust system without any trouble. Getting the outlet angle perfect is a little nerve racking, but we got it

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So, if anyone would like a kit for their side exhaust car, let me know (phone or e-mail). We'll get the parts in from Borla and build you a set. It may run a little less than $950 for the set with the high flow cats. Should take about an hour to install both sides.

Meanwhile, we'll do a dyno test Thursday or Friday and see what she's making now with about $2K in mods (VEC1, smooth tubes, S&B filters, high flow exhaust with stock manifolds and an aluminum flywheel on a '94 RT/10). I'll see what kind of recorders Comp USA has to make a wav file of the dyno pull.

 

[Vip-RT10]

Sean, I'll be calling you tomorrow to speak to you for a few items and extra info about the new exhaust you just built. I like them a lot! I'll get your # from the board......Hear from you tomorrow...

 

[Gear Grabbn Gary]

Sean,
Would it be necessary to have a viper tech make the new side exhaust change or would a local muffler shop be able to put the system on?

 

[Newport Viper]

Once you do an upgrade like this do you have to reset the computer???

 

[Sean Roe]

There's no need to reset the PCM because of the exhaust change. Our '94 was the VEC1 R&D car and had the recalibration system in it already.

As far as the exhaust installation goes, it's a snap.
1. Remove side sill.
2. Cut factory exhaust 10" back from leading edge of frame rail, just in front of the cat. A reciprocating saw (sawzall) does it in about 1 minute.
3. Pull front of exhaust away from car and slide forward, out of the rear hangar bracket.
4. Slide new exhaust into the rear mount, then pull forward to slip onto factory pipe. Clamp.
5. Loosly clamp outlet pipe on.
6. Loosly install side cover and adjust outlet to center of side sill hole.
7. Remove side sill, tighten clamp and reinstall side sill.

That's it!

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Our shop phone # is (904) 733-5469 if anyone needs more info.

 

[Sean Roe]

Here's a picture of what the completed system looks like per side for 1994 and 1995 RT/10's. For earlier RT's with the spring style hangars, we will delete the two hanger rods at the rear of the muffler (we'll leave the other part of the mount). The installer can drill two holes to mount the spring style hangers or the updated mount as shown in the illustrated upgrades on this site.

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[Vip-RT10]

That is much better, thanks for the clarification Sean. Remember to please call me when you get the new batch of Xenons and a set of these exhausts for a 93.

 

[Jason-Middle Tennessee]

Sean did you ever sell the rollbar that came out of that car?

 

[Sean Roe]

As long as nothing Friday the 13th-ish happens

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, I should be on the dyno tomorrow afternoon.

Regarding the sound, I've been trying to upload a sound file and just e-mailed it to Patrick Hiebert for him to put on the media site. Once it's up, we'll get a link.

Also, a number of rear exhaust owners have been asking if this system could be used to convert a rear exhaust car to side exhaust. The short answer is "YES". The only difference would be in the rear hanger behind the muffler. It would have go around the corner to utilize the stock mount. You'll have to cut your own side exhaust exit.

Jason, I do still have the roll bar and rear trim panel cut out for it. $400 plus shipping and it's yours.

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[Newport Viper]

Sean,
When will you have a chance to see what the performance numbers will be? (dyno)
What is your best description of the sound?