Weighing options with exhaust

MerkXRTurbo · Post by **MerkXRTurbo** » Tue Jan 04, 2005 3:56 pm

I am trying to make a decision on how I want my exhaust done. No matter which way I go, I will have an entire 3" system with a mandrel bent 3" DP, a high flow cat, and a straight through muffler. What I'm trying to decide is weather I'm going to do a crush bent cat-back, or spend the extra $$$ for mandrel. Anybody know how big of a difference I would notice with the mandrel?

Sock · Post by **Sock** » Tue Jan 04, 2005 4:23 pm

If you really want to be anal and get almost close to the same numbers as mandrel, you could always do crush bent 3.5" corners and then the rest in 3".

Hell, how many bends are there in your exhaust system? I've seen one with only one bend, and that was about 15* at that.

Are you going above the control arm or below? Side exit? Left rear? Right rear? Duals?

Just tossing some ideas out there.

Personally, I'm looking at 4" downpipe to 3" cat, to 3" straight through muffler... then I'm undecided about the exit.

MerkXRTurbo · Post by **MerkXRTurbo** » Tue Jan 04, 2005 4:35 pm

Definately duals.

edge · Post by **edge** » Tue Jan 04, 2005 6:37 pm

Here is an option http://projecthp.ford23.com. Mandrel bent 3" can get it in duals or a single. This is just the pipe from the turbo all the way back. You have to add the cat and muffler if you want them.
Last time I checked duals were 270 including shipping and I think the single was 240. I'm thinking about going this way if I don't have my buddy here at work take my car to the race shop and fab me up one, but he can't do the mandrel bends. Of course for me no cat

, and was thinking of a supertrapps at first but not sure now also with the dual setup.

Post by **John Brennan** » Wed Jan 05, 2005 12:30 am

I think that as long as your downpipe is mandrel, and your (hi-flow) cat inlet is 3", it won't matter much if you have crush-bent, 3" dual cat-back stuff. As there are two of them, the area is increased, even though the split to duals is a minor restriction. I would put more emphasis on the elbow, as I think that's the most critical point left to you.

MerkXRTurbo · Post by **MerkXRTurbo** » Wed Jan 05, 2005 9:18 am

John Brennan wrote:I would put more emphasis on the elbow, as I think that's the most critical point left to you.

Yeah, even if I do decide to go with that one cheap mandrel system, I will be using the sacramento mustang DP with the turbo flange and wastegate in it.

Mike McCreight · Post by **Mike McCreight** » Wed Jan 05, 2005 7:18 pm

Hey!
I didn't know Sac. Mustang was building an "elbowless" downpipe.... Anyone fitted one of these yet?
Mike.

Post by **John Brennan** » Wed Jan 05, 2005 11:10 pm

I didn't either-- hmm! I wonder how well it fits the XR; the Fox car has some different measurements. Although I believe their downpipe is the best on the market, it needs to be modded a little to fit really well on an XR.

edge · Post by **edge** » Thu Jan 06, 2005 2:52 pm

I didn't know that either. I went and looked, I think I'm sticking with a Bob's elbow, over 300 cheaper. I still want to put a flange on it though for easier removal, since you know it will have to come off for something (like the turbo, head gasket, etc..). Or my other option is to see if Stinger can do the elbow if I get the whole exhaust from him.

MerkXRTurbo · Post by **MerkXRTurbo** » Thu Jan 06, 2005 3:28 pm

As far as getting the turbo off, it's not that hard. I've done it without unbolting the DP. I have anti seize on the bolts that hold the elbow on, so I can unhook the actuator arm, and undo the 5 bolts, and the turbo is free from the exhaust system.

Varthlokkur · Post by **Varthlokkur** » Fri Jan 07, 2005 11:17 am

MerkXRTurbo wrote:Definately duals.

Now, I've read that splitting into duels is not really a benefit and if the splitter is poorly designed it can actually be a hindrance. What's the take on this? Ultimately, I would love to have duels just for the look.

MerkXRTurbo · Post by **MerkXRTurbo** » Fri Jan 07, 2005 12:20 pm

That's the plan. I realize that it does cause a little bit of back pressure, but I don't think it's enough to ever notice.

merkd-ya · Post by **merkd-ya** » Mon Jul 30, 2007 10:06 pm

i remember reading that rapido's dual gave an aproximate 20hp increase vs the 10hp increase of their single 3 inch... any comments?

Post by **John Brennan** » Mon Jul 30, 2007 11:06 pm

merkd-ya wrote:i remember reading that rapido's dual gave an aproximate 20hp increase vs the 10hp increase of their single 3 inch... any comments?

Ix-nay on at-thay... it isn't the case. All else being equal, a single flows a little better than duals in this application.

Luke, since this thread goes back a ways, I presume you're onto the bennies of JVL's Cossie exhaust housing?

Post by **DPDISXR4Ti** » Tue Jul 31, 2007 11:19 am

edge wrote:I think I'm sticking with a Bob's elbow, over 300 cheaper. I still want to put a flange on it though for easier removal, since you know it will have to come off for something (like the turbo, head gasket, etc..).

Yep, that's precisely what he's building for me right now. Basically, one of these, but with a V-band flange on it...