Dyno comparison between test pipes and catless x-pipe?

[momo3605]

Yes, I already used the button Couldn't find anything. Have any of you seen a dyno comparing the power output with the same tune on the same car?

[terahertz]

Also curious...

[BrewRifle]

You need to be more specific with regard to 1. Primary cats 2. Secondary cats 3. Resonator(s) for both setups.

Track pipes with stock x-pipe still in place (secondary cats/resonators exist) vs X-pipe with primary cats still in place, but no secondary cats and no resonator?

[aus]

Don't think it's been done. The stock X-pipe does have a lot of kinds and bends in it, so I could see an aftermarket X-pipe doing a few HP better, but not much.

.

[momo3605]

Originally Posted by BrewRifle

You need to be more specific with regard to 1. Primary cats 2. Secondary cats 3. Resonator(s) for both setups.

Track pipes with stock x-pipe still in place (secondary cats/resonators exist) vs X-pipe with primary cats still in place, but no secondary cats and no resonator?

Well from what I understand, resonators shouldn't affect hp. Anyway, I have test pipes and want to upgrade to an X-pipe. Likely a Dinan unit with 4 resonators but large 2.75" piping. So, the question is. How much hp is still sapped from the 2 200 cel secondary cats.

[Dave07997S]

Originally Posted by momo3605

Well from what I understand, resonators shouldn't affect hp. Anyway, I have test pipes and want to upgrade to an X-pipe. Likely a Dinan unit with 4 resonators but large 2.75" piping. So, the question is. How much hp is still sapped from the 2 200 cel secondary cats.

Very little...maybe 5rwhp at the most.

Dave

[Hujan]

Originally Posted by Dave07997S

Very little...maybe 5rwhp at the most.

Dave

+1

The highest I ever heard was Kitw saying it was around 9 whp. In any event, it's very little on an NA car. With FI, I'm sure the delta is magnified.

It also depends on the pipe. The MRF pipe seems to produce more power than other catless setups.

[Dave07997S]

Originally Posted by Hujan

+1

The highest I ever heard was Kitw saying it was around 9 whp. In any event, it's very little on an NA car. With FI, I'm sure the delta is magnified.

It also depends on the pipe. The MRF pipe seems to produce more power than other catless setups.

Whats funny is some of the highest producing rwhp cars were with testpipes not catless. Obviously a meaningless stat as different cars, different dyno but with the rear 200cpi cats on the OEM xpipe there is still some scrubbing going on.

Dave

[M.Hagen]

I've been on the fence regarding this same decision.

Specifically, replacing the primary cats with a straight pipe (ACM, Turner, etc) or going with an X-Pipe like the Challenge Sport that eliminate the primary cat location but retain the resonators and secondary cats.

From the research I've done, it appears that most aftermarket X-Pipes do not increase the pipe diameter, so the potential benefits would be due to smoother bends and/or weight savings (if any).

I'm leaning towards test pipes with V-band clamps welded on for ease of install and to revert back to stock easily at a later date.

[SflBimmer8484]

Our 100 cell cats rob very little hp. From our testings its around 5whp or so on an N/a Car.

[Detroit M3]

Originally Posted by BrewRifle

You need to be more specific with regard to 1. Primary cats 2. Secondary cats 3. Resonator(s) for both setups.

Track pipes with stock x-pipe still in place (secondary cats/resonators exist) vs X-pipe with primary cats still in place, but no secondary cats and no resonator?

+4

[momo3605]

Originally Posted by M.Hagen

I've been on the fence regarding this same decision.

Specifically, replacing the primary cats with a straight pipe (ACM, Turner, etc) or going with an X-Pipe like the Challenge Sport that eliminate the primary cat location but retain the resonators and secondary cats.

From the research I've done, it appears that most aftermarket X-Pipes do not increase the pipe diameter, so the potential benefits would be due to smoother bends and/or weight savings (if any).

I'm leaning towards test pipes with V-band clamps welded on for ease of install and to revert back to stock easily at a later date.

This is what I was thinking as well. Except I went with turner testpipes. I'm just wondering if there are any advantages to going with a fully catless x-pipe in the near future.

I will say though, if anyone is thinking about it, I was able to compare my test pipes+dinan rear with dinan midpipe+dinan rear this weekend andsurprisingly the test pipes+dinan(my car) was significantly raspier and also slightly louder than the dinan midpipe. The dinan midpipe has a more refined sound. I was surprised though, I expected the dinan midpipe to be way louder, but I think those 4 resonators really quiet it down.

[pbonsalb]

No surprise. Cats are a bit like mufflers and the test pipe deletes one pair while the Dinan mid pipe keeps two pairs.