Headers & Cats installed

[richardyoo]

I failed the scientific method and I don't have a good before/after data point for you.

This I do know - if you are going to be doing pully swaps and thusly cramming more air into the motor - you'll need to get more of it out... and it would be technically prudent to let it exhale better with headers...

In my experience, headers are generally expensive for what you get in return in power... if you're looking for maximum value, AFAIK nothing beats Nitrous for HP per $

YMMV

 

[WVsunnydays]

The Other Option - Manufacture and Sell XLR Headers Myself

I don't know why, but nitrous oxide just doesn't appeal to me. I don't think I want to go that route. I have a 2006 XLR-V with a 3" Spectre "Y" tube that I built. (I will start a thread on how I built the Spectre in case anyone is interested.) I took the Corsa off of my 2006 XLR before I sold it and put it on my "V". I had my "V" dyno tuned and it put out 406 RWHP, which was pretty good considering I was down to 9.75 psi of boost due to increasing air temperature during the dyno tuning process. So, I'm thinking that I would install the smaller pulley on my Eaton M122 to regain the boost that I loose in hot weather.

Actually, the other option that I'm thinking of is to have the headers manufactured for me and I would sell them. I've been in discussion with a very reputable header manufacturer who would make them for me. After several discussions over the phone and swapping proposals, I am meeting with them this coming Friday, January 8, 2016 to see if we can make this work.

It would cost me some big bucks to do it and my biggest dilemma is would I be able to sell enough to at least get my money back out of the venture. My guess is that I would need to sell about 50 sets of headers. The potential market is small and I would need to get at least 10 interested XLR and XLR-V owners to commit to buying a set. Right now, I think I can sell long tube headers with high flow CAT's for $1,895, which would be less than D-3 charged for them when they were having them manufactured. The headers/CAT's would fit all XLR-V's and all 2007 - 2009 XLR's. The manufacturer would use my car as the prototype to build the headers. If things make economically viable sense, I would be ready to market the headers in April 2016, assuming there is enough interest from other XLR owners.

So, if any of you XLR-V and 2007 - 2007 XLR owners are interested in headers with high flow CAT's, I need to hear from you.

Last but not least, I want to thank you for your post on installing the D-3 headers yourself. Your positive review is what encouraged me to begin pursuing putting headers on my "V".

 

[Stella]

Just to throw it out there. What about buying a set of headers from a LS motor and modifying those to work. Exhaust flanges should be the same and engine bays are just as tight? Vettes have almost the same exhaust layout. Haven't seen underneath a cts v to say? ALOT cheaper and quicker than start up production.

 

[BusaMan]

Just for my edification, what is it that precludes their fitting on the 2004-2006 base models?



Tim

<snip>
The headers/CAT's would fit all XLR-V's and all 2007 - 2009 XLR's.<snip>

 

[rexster314]

Just for my edification, what is it that precludes their fitting on the 2004-2006 base models?



Tim

Still not quite the answer you're looking for?

 

[onalaska]

Just to throw it out there. What about buying a set of headers from a LS motor and modifying those to work. Exhaust flanges should be the same and engine bays are just as tight? Vettes have almost the same exhaust layout. Haven't seen underneath a cts v to say? ALOT cheaper and quicker than start up production.

LS vs Northstar = no similarity whatsoever except they both burn gasoline.

 

[Stella]

I stand corrected. It's the lc3 platform which is in the xlrv and the stsv. Then switched to the LS platform. Would think their might be more aftermarket parts but might be just as rare with short production. Great car though!

 

[Popbigguy]

I took the Corsa off of my 2006 XLR before I sold it and put it on my "V".

How'd you do that? The rear hanger on the H-pipe is different for the V's from the XLR's. Did you change out that hanger?

 

[WVsunnydays]

Corsa changeover from a XLR to a XLR-V

How'd you do that? The rear hanger on the H-pipe is different for the V's from the XLR's. Did you change out that hanger?

I explained this along with pictures in a response that I made to another thread circa Sept. - Oct. 2014. I don't know how to find it but I'm sure that if you search you will do better than I.

Anyway, I see my thread to determine interest in XLR headers looks like it is not stirring any interest. How about it guys & gals?

 

[cubby558]

The problem is the cost per horsepower ratio. Almost $2000 to add maybe 10-15 hp is nit economical as compared to spending about 600-1000 on a pulley change on the supercharger (for the V's) to add almost 100hp. Still researching this, but more viable than the headers in my opinion.

""."....."................
Anyway, I see my thread to determine interest in XLR headers looks like it is not stirring any interest. How about it guys & gals?

 

[David_B]

https://www.xlr-net.com/forums/cadillac-xlr-parts-for-sale-wanted/8113-4-sale-oem-cat-back-exhaust-system-for-2006-07-xlr-v.html#post58171

I explained this along with pictures in a response that I made to another thread circa Sept. - Oct. 2014. I don't know how to find it but I'm sure that if you search you will do better than I.

Anyway, I see my thread to determine interest in XLR headers looks like it is not stirring any interest. How about it guys & gals?

 

[Stella]

Another thing to think about is will it actually get you positive results? Headers would help with moving the air out " less restrictive usually larger too". Well going to much on the exhaust and not having the heads,and intake to compliment it could make your car slower. You need backpressure to some degree until you get to the point of open header pipes. Which is a whole other ball game. Base models make their power after 3k. You wouldn't see any improvement before and little if any at w.o.t. Now you would get a cleaner,louder sounding exhaust. That's about it.
A V model would be more beneficial in the fact of flow numbers. I'm sure the heads flow ALOT more cfm. If you plan on doing other mods like new supercharger,head work,etc. yeah great idea. Not many are willing to. Good luck try researching the 1st gen STS v. More sold,more options,same exact engine.
Second most talked about subject on this site is aftermarket warranties ,kiss that option goodbye with a set of headers.

 

[WVsunnydays]

Long Tube Headers for XLR's

Richard, I've followed this thread with interest for about a year now hoping to learn whether or not putting long tube headers on my XLR-V would be worth the cost and effort. I've been waiting to see what your dyno results showed for RWHP boost due to installing the D3 headers, but alas, nothing has been posted.

FYI, I called D3 on 4/23/15 and ordered the headers with high flow cats for $1995. They said the headers were discontinued but they would be making a run early in the summer of 2015 and took my order. I waited and heard nothing. When I finally called them in June, they said they could no longer get the high flow CATS, and, oops, the headers would cost $2500 now if I wanted them. I have other options at significantly lower cost now.

So, back to my original question, are the headers worth the cost and effort? If the headers only add 10 RWHP, which is what my dyno engineer says, that is pretty expensive. What say you?

Sorry for the delayed response. Don't waste your money. Since I put out my request in early January 2016 to determine interest in long tube headers for XLR-V and 2007-2009 XLR's, Ive received no interest. Therefore, I'm not pursuing manufacture of the headers. See my original posted request below in this string.

 

[nbw123]

Sorry for the delayed response. Don't waste your money. Since I put out my request in early January 2016 to determine interest in long tube headers for XLR-V and 2007-2009 XLR's, Ive received no interest. Therefore, I'm not pursuing manufacture of the headers. See my original posted request below in this string.

What about designing and building test pipes to replace the cats? That should offer nice HP gains for those who are interested in pullies and other mods

 

[David_B]

I'm installing the Magnaflow exhaust manifolds/cats and can't find the part number for these studs that go in the end of the manifold and have springs on them between the exhaust manifold and the intermediate exhaust pipe.

Any part numbers for the studs, the springs, and the nuts would be appreciated. Thanks!

 

[richardyoo]

Would you post a photo of the Magnaflow exhaust manifolds/cats? I'm sure everyone would like to see them!

 

[David_B]

Would you post a photo of the Magnaflow exhaust manifolds/cats? I'm sure everyone would like to see them!

They certainly aren't as nice and clean as the pictures. lol

So, there aren't springs in between these studs, just the studs.

Here's what I've done so far.

I got all the bolts off the heat shields. I'm moving the heat shields around to get to the manifold bolts/nuts.

I've loosened the right bottom 4 bolts, the front one is hard to get to, luckily they all are turning. The second one back from the front was tricky to get to, I ended up temporarily removing the front right suspension travel sensor to get to it.

But now I'm trying to do the upper bolts, and they aren't being very cooperative. Not much room
to get to them, and they are at a bad angle to get to from the top, plus there is an AC line right in the way

Guess I'll spray it with PB a little more and let it soak.

 

[David_B]

Ok, what a pain. Magnaflow sent the wrong size bolts. Now I wonder if the mounting holes in the manifold will be too big and the manifold won't center very well on the heads? I know the new manifold gasket has flanges on both sides, maybe that will line them up enough if I'm careful?
Still working on the old bolts little by little. I don't want to get in a hurry and round one off, so when it doesn't budge I squirt it with PB Blaster and let it soak overnight and start fresh the next day.
I can't do much anyway once I get them off, until Magnaflow calls back and sends the correct bolts.
I already bought new manifold gaskets (rocket auto had them closed out, $10!)
I ordered the Corsa exhaust too on friday, should be in next week, so I'm not in a huge hurry to get the manifolds off. Long as it all goes well I don't care if it takes 2 weeks of nights and weekends..
I couldn't decide if I wanted the loud sound or not, I put way to loud pipes on my Motorcycle 4 years ago, but those are right at the back of my head.

Now I'm also thinking of doing the tunnel heat shield purchase. Although everything I've read says that only helps in extending the time before it gets hot, and I've been taking 3000 mile 2 week driving vacations the last 3 years.

 

[David_B]

24lbs vs 13lbs.

Now i just need the odds and ends..