ROE smooth tubes and straight pipe cat! DYNO results

[ASKYOURWIFE]

100% bone stock my 1999 rt10 put down 410 rwhp and 465 rwt SAE on a dyno jet..

today with ROE smooth tubes and no cats ( straight pipes)....ON THE SAME DYNO

She put down 428 rwhp and 473 rwt..

Well thought I would share my gains

 

[jwbond]

Thanks for sharing!

How loud is it now that the cats are off?

 

[ASKYOURWIFE]

I went ahead and told my muffler shop to remove the cat as well as the pre muffler ( resonator) in exchange for one nice long pipe...

He assurred me that since the pre muffler (resonator was not a true muffler and basicly just a straight through disghn that the true muffler right before the tail pipes would keep the sound nice and quiet.

So he finished the welding and I started her up..

to my surprise the muffler at the end of the rt10 right before the tail pipes did a fantastic job.

REMOVING THE CATS AND PRE MUFFLER ( RESONATOR) ON A GEN 2 VIPER WILL NOT MAKE THE CAR VERY LOUD LIKE MANY PEOPLE BELEAVE..

THE GEN 2'S STILL HAVE A MUFFLER THAT YOU CAN CLEARLY SEE FROM THE REAR UNDER SIDE OF THE VEHICLE RIGHT BEFORE THE TAIL PIPES..

It actually sounds slightly louder than stock. Like a mild after market exhaust is what could best be explained..

Then apon driving the car the first thing I noticed was that the car felt MUCH MUCH MUCH smoother in first gear. before this mod first gear was almost undrivable because of all the jerkiness with the slightest touch of the pedal. but now even in first gear the power comes much smoother and is much more enjoyable to drive through all the gears...

So i get on the freeway heading towards my Dyno shop. And my butometer tells me that their is defiently some added power here. Especially in the upper rpm's..

And sure enough i was correct...

On the same dyno jet were my stock 2004 c5 dynoed 299 rwhp and 309 rwt ( and then 378 rwhp and 370 tourque with a mild heads and cam set up)


My 100% bone stock 99 rt10 dynoed 410 rwhp and 465 rwt SAE corrected..

Now like I said today I eliminated the cats and pre muffler ( resonator) and also added ROE smooth tubes yesterday...


So bone stock a few months ago...410 rwhp 465 rwt SAE on a dyno jet

Then today after eliminating cats and pre muffler as well as adding ROE smooth tubes...

428 rwhp and 473 rwt

Yes from smooth tubes and no cats/resonator I gained 18 rwhp and 8 rwt on the same dyno SAE corrected....

Well I am extremely pleased with this simple mod..


i paid 75 dollars to have the ROE sooth tubes shipped and installed them my self and was charged 200$ for my muffler shop to take off the rocker panals and weld on some straight pipes..

Total investment was 275$ and I picked up 18 rwhp!!!!!!

Then to top this all off while going home on the freeway from the dyno shop their was an acident and traffic crawled at 5 mph for over an hour..

The last time this happenned my vipers temps got very hot ( close to red) and the cabin was smoking hot inside. As well as the jerkiness of first gear really taking a toll on me.

this time the temps stayed normal and the cabin didnt feel hot at all. as well crawling at 5 mph in first gear didnt have any jerkiness and was a very pleasing ride..AND TO TOP IT OFF WHEN I GOT HOME AND TOUCHED THE SIDE SILLS THEY FELT WARM INSTEAD OF THE USUAL HOT ( EVEN AFTER BEING STUCK IN TRAFFIC

Not that id ever daily drive it. but this mod is a must if you plan too...


SO I HIGHLY RECOMMEND THIS MOD

-BETTER EXHAUST NOTE WHILE STILL TAME
-BETTER FIRST GEAR SMOOTHNESS
-LESS CABIN HEAT
-SIDE SILLS DONT GET HOT ENOUGH TO BURN
-MORE HIGH RPM POWER
-DYNO GAVE ME 18 MORE RWHP WITH NO CAT/RESONATOR/ROE SMOOTH TUBES


I do have ROE 02 simulators but so far in 70 miles of driving today the check engine light hasnt came on. so until it dose I wont install it.

 

[98viperGTS]

Great numbers!

 

[PDCjonny]

No smell when sitting in traffic at 5 MPH?

 

[my viper]

Very nice. I have been thinking of going catless for a while [well, just need to find someone to do it as I'm not a DIY kinda guy] and will not also look into removing the pre-mufflers.

Thanks for the info and detailed experience write-up.

 

[FE 065]

A nice HP gain for sure..!


The resonators are 16" long, yet their core is only perforated for about 7" inside.


I was more than happy with the relatively quiet exhaust note of my '99 GTS without cats and having a pair of mufflers in the rear that are better than the OE rear muffler.

But later on, after removing my resonators, I found there was a obvious change in exhaust note..almost too loud, or at least too 'unmuffled' sounding.


So I wouldn't say the resonators don't do anything. Both the rear muffler and the resonators are a straight-thru design with a peforated core that you can look through. One isn't necessarily a more 'true muffler' than the other in their basic design.


Like many exhaust mods, the new exhaust note after a change can be subjective.

Thanks for posting your numbers !

 

[Asp Man]

Those are good numbers.
For anyone who's interested, here's a link to a vid of mine, first part is without cats, with resonators, second part is without either.

http://videos.streetfire.net/video/d4f402b3-51ac-49c9-a329-98160137c1bd.htm

 

[ASKYOURWIFE]

I noticed a slight smell when the car was sitting in the muffler shop. but no smell while on the freeway or at the dyno...

Now my c5 that had no cats or mufflers had a very bad smell. Sitting in traffic I could actually get sick..

Another benifit of this mod was that My vehicle is 20 pounds lighter. I know thats not much. been when your c6Z06 hunting every pound and extra rwhp counts.