PirateViper
Enthusiast
Ive ran this by a few very experienced viper people and now ill take it to you guys.Anybody running high flow cats on your gen 4 and whats your experience or problems.Thanks.
high flow cats on a gen 4.
- Thread starter PirateViper
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Timnineside
Enthusiast
I don't have High Flows but I did pull mine completely. MI does no inspection so I figured why not. Sounds amazing. Throws a CEL code but that's nothing the Performance ECU won't solve.
-Tim
-Tim
ViperGTS
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no problem with the mopar pcm here
HobokenViper
Enthusiast
I have high flow cats on mine and aside from the rare code it may throw, it is awesome and passed the strict New Jersey emissions inspection with flying colors! Only catch is that you may need earplugs driving with the top down or windows open when on a highway, especially if you are next to the barrier. It really makes the car so damn loud!!!!!
PirateViper
Enthusiast
Good to hear Hoboken....mines throwin CEL now and hoping it goes away!
Timnineside
Enthusiast
Weird. I pulled mine off and still not happy. Putting Borla mufflers on this weekend........
Timnineside
Enthusiast
SilveRT8
Enthusiast
I ran Roe Racing High Flow cats as a single mod for a while and the 08 Vert Viper ran great, could feel some extra power and the sound change was similar to adding a catback exhaust. Got a rare cell light when cruising lightly for long periods, HF cats do not get hot enough and throws a cell, wich I removed with a combo code reader and gauge like the Dashawk. No more cell with the Mopar PCM added later.
Dynoed the car Stock at 545 HP and 505.8 TQ
Dyno with Roe H/F Cats and Mopar PCM at 563.4 HP and 533.9 TQ
Same day added the K&N Typhoon double air filter kit and dynoed 551.1 HP and 522.7 TQ (lost 12.3 HP and 11.2 TQ)
Added Belanger Header with HF cats and got 575.8 HP and 548.6 TQ, still with OE mufflers
Here's a video of the car with Roe HF cats and Mopar PCM
Dynoed the car Stock at 545 HP and 505.8 TQ
Dyno with Roe H/F Cats and Mopar PCM at 563.4 HP and 533.9 TQ
Same day added the K&N Typhoon double air filter kit and dynoed 551.1 HP and 522.7 TQ (lost 12.3 HP and 11.2 TQ)
Added Belanger Header with HF cats and got 575.8 HP and 548.6 TQ, still with OE mufflers
Here's a video of the car with Roe HF cats and Mopar PCM
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Timnineside
Enthusiast
Awesome info^^^^^. A lot of questions I was going to ask on here!!! I'm throwing my Borla on then going in for numbers.
F
FrgMstr
Guest
Before and after dyno runs....same dyno, very close environmental conditions. That said, I did not have enough miles on the PCM for the computer to "learn" the new system is what I have now been told. Will dyno again and find out.
Before (red) was with Corsa catbacks being the only mod. Dyno Video here.
After (blue) was with Mopar PCM, Belanger headers, cat delete, and straight pipes. Dyno video here. Video here with decibel meter showing comparison. This comparison video was shot with the same camera, same mic, from the same distance.
Port and polish intake next to put about 20HP on it from 3000rpms to redline.
Before (red) was with Corsa catbacks being the only mod. Dyno Video here.
After (blue) was with Mopar PCM, Belanger headers, cat delete, and straight pipes. Dyno video here. Video here with decibel meter showing comparison. This comparison video was shot with the same camera, same mic, from the same distance.
Port and polish intake next to put about 20HP on it from 3000rpms to redline.
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bmw2nv2000
Enthusiast
I need to move to TX. Viper seem to make more Hp on the dynos there
purplesnake
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Hey fellow Aero-Vert friend. I have R/T metal high flow cats and corsa exhaust. When I did the exhaust upgrade, I put on the mopar pcm but did not like losing the decel burble. (totally quiet when you let off the gas) So, I went back to the stock PCM and occasionally throw a code which I get rid of with with my code reader. Worth the trouble to me to get back the great sound.
PirateViper
Enthusiast
where do you get the code reader?
345s-bspinnin
Enthusiast
Kyle, I find it very peculiar that you show virtually no gain on the dyno after all those mods. However, didn't you manage to go about 15mph faster (170 to 185mph) at the Texas Mile? That increase in speed is indicative of a very substantial gain in power.
BTW, great runs at the mile. 185mph is smoking fast.
F
FrgMstr
Guest
I think at the time of the dyno the Mopar PCM had not fully "learned" how to tune for the mods. I was told I likely did the dyno too early into the process. I will do another dyno soon and see if there is any difference. These numbers were from the same dyno, but the dyno had been relocated to another shop building, so there is likely some deviation there as well. I did like how the Mopar PCM smoothes out the HP/Tq across the RPMs.
That said, what gains that were shown were in the RPM band that was being used on the TX Mile run and the extra 100rpm before the rev limiter had to help as well. The car did 170.9mph last year in basically no wind or mods beside catbacks. This year it did 175mph with a 10mph headwind. It did 185.9 with a 20mph tailwind.
That said, what gains that were shown were in the RPM band that was being used on the TX Mile run and the extra 100rpm before the rev limiter had to help as well. The car did 170.9mph last year in basically no wind or mods beside catbacks. This year it did 175mph with a 10mph headwind. It did 185.9 with a 20mph tailwind.
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rw99
Enthusiast
Great data in this thread. Subscribed!
Rich
Rich
Are you running any intake mods like a dual K&N kit or stock air box?
F
FrgMstr
Guest
Stock air box. I never could find any real evidence of added HP from aftermarket filter setups.
It was brought up to me that I when running the Texas Mile I should have pulled the rain deflector out of the hood as you could gain up to as much as 10HP from a "ram air" effect once at speed. Of course that would never show on a dyno. And if you could get even 5HP from taking out three screws it would be worth the effort.
I have the Roe HF's with a custom magnaflow exhaust on my Gen IV. Really woke the car up from a sound perspective! And zero drone still!
Only bummer is that I am getting a CEL. I would have straight piped it if I would have known that it would still throw a code.
Only bummer is that I am getting a CEL. I would have straight piped it if I would have known that it would still throw a code.
purplesnake
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Got mine at Harbor Freight, but all the auto places have them.
ViperGeorge
Enthusiast
Just added ACR-X headers, high flows, and Mopar PCM to my ACR. Heading to the track this Saturday to see if I've picked up any time. Already had ported intake and ported heads.
CitySnake
Enthusiast
I'm suprised to see such a gain on a Gen 4 just from a set of HF cats. But I certainly don't mind the claim.
I have Roe's HF cats on my gen 4 with all else exhaust completely stock and due to an installation tweak, have never thrown a code. Suggest you call Chuck Tator to learn the "tweak". The exhaust volume is increased, but IMO, not quite to the volume of an aftermarket cat back. If there is an actual HP increase, it's not significant enough to "feel".
But it's a great mod nonetheless.
I have Roe's HF cats on my gen 4 with all else exhaust completely stock and due to an installation tweak, have never thrown a code. Suggest you call Chuck Tator to learn the "tweak". The exhaust volume is increased, but IMO, not quite to the volume of an aftermarket cat back. If there is an actual HP increase, it's not significant enough to "feel".
But it's a great mod nonetheless.
PirateViper
Enthusiast
My set up is exactly like yours CitySnake but Ive got CEL...will Chuck give up the tweak?
cashcorn
Enthusiast
Why is the installation tweak of HF Cats not shared? It would seem like a win/win to me.
Westxsrt10
Viper Owner
Why is the installation tweak of HF Cats not shared? It would seem like a win/win to me.
Subscribed......^ ?
____________________________________
08 Coupe, Belangers w/HF cats.
cashcorn
Enthusiast
bump..............
CitySnake
Enthusiast
Sorry CC. Missed the response.Why is the installation tweak of HF Cats not shared? It would seem like a win/win to me.
Didn't mean any intrigue. It's not any particular secret, but I'm not a mechanic. And Chuck's "tweaks" are never mine to publicize. By all means give him a call and he can explain or do the minor work for you. 914 763.3136
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