CFM Dyno Test: SVT Stock Cat vs. Offroad Pipe vs. High Flow Cat

[jr_psychologist]

Originally Posted by WuNgUn

Those gains in the lower/midrange are totally from a tune, and nothing but a tune!!
A hi-flow cat should make improvements to the top-end of the rev range, when, coincidently, there is a hi-flow of exhaust gasses...
I'm just not seeing that...
If it muffles the sound (like the stock cat) I'm sure it's also stifling flow...
ORP...FTW!!!!
lol

As he said, no tune change between the dynos.

Also, as you obviously missed it, the dyno includes a graph against the ORP which has essentially no significant gains at the top end - just like every other dyno of ORP's or high flow cats we've seen.

[Rodewaryer]

Originally Posted by DeltaT

Why do some people ONLY look at peak numbers? You sir, are an idiot. The gains between 3k and 5k are HUGE.

And if driving whilst seeing the red mist the car hardly gets back 'down' to the 3-5 grand rpm range......the improvement might be good there the 'one' time you pull through that range then that's it. Daily driving is where that would pay off.

Just a note regarding inspections, mine passed emissions in a fairly posterior retentive state with the ORP. No codes, no worries, car passed fine and I didn't waste my time putting the 20 lbs (or around 10 in the case of a high flow) of ugly fat back on......hopefully never again. If your state is more retentive than mine and sticks the mirror under there anyway, well, you're unlucky then.

[1loudsvt]

my state (DE) is pretty tough with emissions and i passed with an orp, 2.5" flex and borla back on friday...

[CaysE]

You guys should put this dyno on the product page on your website.

[Andy Tsai]

RT cat is crap!No weld inside the pipe.Now my st170 sounds like something broken in the pipe!!!
Dont get RT cat..
Just go with CFM Cat or ORP!!!!

[CaysE]

Andy, we've known that for years!

[blackbird]

Since the thread was bumped, I just recently installed the CFM high flow cat and their flex pipe on my otherwise stock SVT. I had a chance to dyno the car on the same dyno that I used when the car was new and there were some decent gains. Before the car started to heat soak (it was in the mid-90's) and comparing the best runs, looks like a good 8-10 ft-lbs. in the mid-range and also a small bump near the very top. It sounds noticeably louder but it's still fairly reasonable in normal driving (the rest of the exhaust system stock) and it doesn't drone or have any other issues.

The welds look okay, everything fit fine, packaging was great and the directions would be good for anyone who hasn't removed the stock cat before and didn't know to be careful about the front O2 sensor. Overall I'm pretty happy and it should be a little more beneficial to me once the Vortech blower gets installed. Like most bolt-on parts for the SVT, don't expect massive gains, but for the money this provided a healthy increase in mid-range without negatively changing the exhaust note (in my opinion).

[the machinist]

Thanks for the review! It was very informative. I'm also interested in one in the future but their website always says it's on back order.

[CFM Focus]

Thanks for the review blackbird!

We currently have a few left in stock...

[blackbird]

No problem. For others concerned about an off-road (cat delete) pipe on a daily driver or installing one (an ORP) on a car that already has a louder aftermarket exhaust, I think this is a good compromise. Reasonable gains and a little extra edge to the exhaust without any open exhaust type downsides. Also although it is technically not CARB legal for use in California, it should still pass the sniffer test and be less likely to get you flagged for an exhaust that is too loud (roadside inspection or come smog time) and if an officer did bother to look under the car you still have a cat.

I also finally installed your lower transaxle torque mount at the same time I did the cat/flex pipe and that had a bigger impact on NVH (noise, vibration, harshness) than the exhaust and was a lot more noticeable (a little more vibration and noise transferred to the car at idle but well worth it to better control powertrain movement). The only suggestion for the high flow cat is that it would be nice to see an option for an extra bung for a wideband. I'm not sure if that's something you already offer on a special order basis, but I didn't see it mentioned on your web site and already ordered my pipe when I remembered it.

[CaysE]

Emissions laws aside, it's just good to not have a car that smells like gas all the time and piss off the people behind you.

[BlkThunder]

Theres tons of 14 year catless ford 351 trucks running around that do that from the factory, not to mention soot snorting diesles. BTW, my CFM high flow cat was one of the best investments that I got for my car hands down.

[Dads03SVT]

I prefer my CFM ORP.....with my Magnaflow exhaust....Luv it LOUD!!!!

[bmylez]

Yeah, my HKS screams pretty good with the ORP. I'm thinkn of putting in a cat along with an electric cutout so I can have a compromise.

[Dads03SVT]

LOL glad to see i wasn't the only one thinking of doing this...