So i know riss racing has been having problems and what not. But despite this, what are people's opinions on their downpipes, specifically catless? Would you say they are a bolt-on for power?

Also how is it compared to other downpipes?

 

Catless is the most practical way to make more power with the downpipe. No cat of course means less restriction! I uh... know someone that has one... and there is definitely a difference. The only issue with the catless downpipe is that you might throw the P115D code, which is a code calling out an error in air/fuel metering caused by having no cat. You can always clear the CEL (check engine light) and it won't come back for a while. On the other hand, you're guaranteed to get the P0240 code. It's no big deal though, your MINI will still operate very well and make full power.

I hope you have a ScanGage or an Auterra DashDyno or something similiar. When you start modding the powertrain of the R56 expect to throw a code sooner or later especially with downpipes.

 

I would not do this mod until you have added a new cam and few other mods to your engine....too much of a good thing too soon. And if this is your daily driver, continue doing your research already started.

Contrary to what you may have heard, engines do require a certain amount of back pressure to function properly and provide performance.....Maybe get a decent cat back exhaust for now to start out. My 2 cents.

 

Yea and a head will run $2500. Less backpressure is best for turbocharged vehicles since you'll get quicker spool up on the turbocharger. However, I wouldn't go over 2.5" on the downpipe.

 

Have to completely disagree with you.

If you're going to only do a few things to the car, and downpipe+exhaust should be one of them. Bolt on wise...a downpipe, exhaust and intercooler will give the most gain for your money.

 

+1 Thumper. Stick with those basic bolt-on mods. Getting big power requires an even bigger wallet. Might as well invest in some high performance drivers education before that.

 

I have come to the conclusion that a 3" Exhaust is optimal if you're making a large amount of power witht he R56 motor, but I haven't seen any R56s with ridiculous power quite yet...

What is the optimal size for an R56 with around 200-220whp?

 

no smaller than 4.5 inches.....



But seriously, 2.5 or 3 should be just fine. Mines 3" turboback but I bought that more for future modifications that I am building up to. Id rather purchase a bigger exhaust now than have to buy another one later.

 

2.5" to 3" is best. Unless you manage to put a 15L diesel engine in the MINI any bigger is a little ridiculous LOL!

 

Ok, I received my catless downpipe, but am still awaiting resolution (Adam and I are trading emails...) for the rest of the exhaust which was shipped around Halloween. I can tell you that the catless d/p makes great power and gives a 0420 code every 100 or so miles. I don't mind re-setting the code using my Scan Gauge II, but would be interested in an O2 Sim (fix) when they're available.

If you use a catless d/p with the stock exhaust (like I am), the car sounds kind of "ricey" and a lot like a "fart can type" exhaust. If you've heard one, you'd know what I'm talking about. Many posts here state that the whole exhaust would be too loud w/o the resonator, but I'll play around with the different configurations (entire RR exhaust and catless d/p w/o resonator, and with the resonator) to see what appeals best to me.

The polished finish on my d/p appeared to be a crudely applied chrome plating, but I'm not terribly concerned about that. I do intend to wrap the turbo and down pipe, but have yet to do any research into the d/p wrapping material.

Thats all for now,

Ciao from Italy,

Jeff

 

Wow thank you for all the feedback.... So basically RR catless DP would be a good choice to add power, and ill be happy with it as long as it doesn't throw a P115D, and i can just get a o2 sim to fix the 0420...

I do have a stock exhaust still, so i hope it doesn't sound too "ricey"... I do intend to get a catback down the line (probably one on the quiet side to counter-act the loudness of a catless DP )

 

I would ask Adam at Riss if it clears the P115D code. I'm sure it does since everything is PERFECT in the Riss Racing community right? I wouldn't invest in that O2 sensor till it underwent thousands of test miles.

 

i'd invest in the O2 sensor if the waiting list weren't so damn long ><

 

Okay, Adam claims there is no P115D codes with the catless.... And the catted is going to throw a p0420 anyways, so i might as well go with the catless since it makes more power

 

Cattless is very LOUD at wot, for exhaust have a local shop custom make a 3 inch one with 2 baffled resonators, one just after the downpipe and one after the chasis brace and put a turbo muffler to replace the rear muffler .

 

RR Cattless is a huge power gain didn't realize how much till i had to
remove it to get inspection. Had the pipe on several months car actually
makes a few extra pounds of boost with the downpipe.

 

I wish the oem turbo on a jcw picked up boost with the catless downpipe

 

Does it sound ricey? What about with stock exhaust?

Blahh! I'm trying to decide, catless vs catted... If they were the same price, which would you go with? If catless is 20hp gain and catted is 18hp gain, ill go with the catted... But if catless is 20 hp gain and catted is like 10 hp, i may go with the catless

 

I wouldn't trust the numbers people are throwing out there since each car is a little different from the next. I think everyone can agree that if there is no restriction in the downpipe from a cat you'll definitely make more power. If you can live with resetting the CELs every now and then, replacing it for inspections, you already know what you want...

 

catted may see a gain over stock if it has less cells. I would guess the riss catted downpipe would make 10 hp more than a stock jcw downpipe.

 

Oh I just meant, do you think it would sound ricey with downpipe + stock r56 catback...

But yea it seems that catless vs catted downpipe the difference is a couple of HP and sound... Oh and catless is cheaper, i think thats a big reason why people go with it

I'm sure the catted dp will still be louder than the stock r56 downpipe, and offer a significant power gain. I think it may be worth it to just go catted to avoid the trouble

 

Costs more money and makes less power,that sounds good to me.

 

Yea but causes more CEL and emission problems...

I'm actually choosing between catted and catless which are just around the same price, so price isnt actually a factor in this case

It's more of, do i really care about the 2-3 hp? In order to avoid the obnoxiously loud exhaust and CEL that could send my car into limp mode

 

more like 10+hp diff without a cat,maybe more on a cooper s than a jcw.the catted one may give you 2 to 3 hp which you will not notice in seat of pants butt dyno.

The cel does not affect performance or drivablity.

In a state with emission testing i would still go catless and just change out the downpipe when needed(takes less than 15 -20 minutes)

 

Supersprint has a real nice made in Italy catless downpipe on sale for under 300 dollars.

Just say NO to cheap stuff made in China !