Exhaust Manifolds

Has anyone had any luck making a cast iron manifold work on a conversion? The 2011 Camaro manifolds look like they might work.

Finding a path for the gases on a 968 LS conversion borders on art. I tried early corvette (98) manifolds and one off a GTO (as I recall) The right had some promise but the left was way off. I spent a year thinking about this an came to the conclusion that it has to be done right, after all it is a Porsche. I bought 3/8 flanges four bungs for O2's and lastly a couple of fours into 3" collectors. I got a local firm to bend up a bunch of 180 bends 2.5 and 6" R's. Then I started piecing parts together, first using duct tape and then a flux core POS rental welder. At least now I have my MIG in place and I just bought my 2nd bottle of gas. The left side took forever, I'd guess thirty hours. Once I figure how to post them and when i get them off the motor i'll take some pics. The end result is great, #1 tucks back against the block behind #3 , this way it's behind the steering rod and not an issue. #3&5 go alongside over the stewing shaft and #7 ducks down and sits on #1 and then they go into the collector. I think i'll get the right side done tomorrow, I got a spool of .023 wire and thats a bit easier to control than the .035 I was using for structural. The right side is pretty well pieced together and the overall lengths of the left and right are within a couple of inches. The objective of equal length primaries is not IMHO achievable so the next best thing is velocity and I'm really pleased how it worked out. I can't imagine doing it over though.
It's going to get really cold up here in a couple of weeks and that keeps me out of the garage until March so the headers are a priority as the steel rusts and that causes more problems. Also it gives me time to get them to a local guy for ceramic coating inside and out. So Gene are you coming to the dark side? BTW I have my eyes on that wing.

Gene, did you sell the headers and exhaust off of the yellow car? You know Admin is producing a set of long tube headers. I looked at those manifolds on an engine. They don't look like they will fit.

Arthropraxis wrote:Gene, did you sell the headers and exhaust off of the yellow car? You know Admin is producing a set of long tube headers. I looked at those manifolds on an engine. They don't look like they will fit.

I still have the headers and I'm looking for a quieter solution. The new Camaro manifolds looked promising to me for both performance and quiet.

Jim, I've been on the dark side awhile and in the process of building a street car as the last build project was a track only car.

And, the wing is still available!

Gene

If you want quiet, you could do a round mid muffler and a large oval muffler out back. If you use a straight through design for both it won't lose power but it would be quiet.

If you dont mind adding the extra steering shaft universal Im sure you could get the LSA manifolds to work, they tuck up really nice and dump pretty far back. And as a bonus they make like 450 at the crank(from a post on LS1 tech)

Mark

Someone needs to mod a set of Pacesetter 2001 C5 mid-lengths....

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Yes, it has been done using f-body manifolds. ACORAD on this board bought his car from Craig Hardy who had the stockers modified. He had to do this, as I will, because of the laws in California. This mod was done with the help of RH. It does require another joint in the steering shaft as well as a modified engine upright. I believe that the flange of the header has to be surfaced as well to give it about a 10 degree canter toward the block. I have some photos in my gallery of Craigs driver side with the stock monifolds. I would really like to see ACORAD's set up in person.

I have tried just about every manifold that is made for the LS motors. Everything from the Camaro to the trucks. Nothing is a bolt on deal. The only thing that comes close is the Camaro manifold. Although it does take modifications on both sides. Drivers side is the most extensive. IF you can find someone that will machine the flange surface for you, you'll need to make some sort of holding jig and no telling what else just to get it set correctly in the mill. It needs nearly 10 degree angle just to come close to clearing. also the exhaust flange needs work on both sides. Then you'll need to add a joint to support the steering rod and an extra joint to the shaft itself. Once your all done you will have a set of "NOT SO GOOD" flowing exhaust.

The headers are not what makes the car "loud" it's the rest of the exhaust system. If you need it quite, install a resonator and a large muffler. That's all that is really needed.
I have a 928 in the shop that we just finished and the owner wanted to retain the stock muffler. It has headers and dual 2.5" exhaust. With the car running you can barely hear it at idle. it only starts to make noise when you get into the throttle pretty heavy. It's a little raspy on top end , but I think it sounds good.

In addition to quiet I wanted to kill the "tinging" sound that headers make vs the cast iron.
Eric, have you tried the 2011 Camaro manifolds as well?
Thanks for all of the input.
Gene

I have not tried the 2011, But what I've seen, they don't look like they'll go on without heavy mods either.

I'll be adding a resonator to my exhaust system. It's not bad on the street, but on the track it's so loud that I can't talk to or hear a passenger even with my intercom volume at maximum.

ive got a 2011 ss camaro and was comparing mesurements and looks like it would work on pass side but drivers side would b tight as to clearance with steering shaft i might consider gettind rid of my stock manifolds when swap for some headers the bottom of drivers side manifold is about 6inches down from top bolt on 3cyl back and they snug the block tight

I've often wondered if one of these would work...

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In a Mustang yes, 944 No. if you look at a set of C5 long tube headers you will see why. they follow the motor and bell housing very close. The ones you posted go straight back. Will not work that way.
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Oh, those usually cost around $1600

Bluemach1, I have the Craig Hardy manifolds and modded steering shaft off the car. Happy to take any pics or measurements or whatever that you like.

Please post pictures!

[You must be registered and logged in to see this link.]Not sure exactly what you all want to see, but here are some pics.

The thinner manifold-to-engine flange on the right is the driver's side manifold:

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Driver's side collector flange at the top of this pic:

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Admin wrote:In a Mustang yes, 944 No. if you look at a set of C5 long tube headers you will see why. they follow the motor and bell housing very close. The ones you posted go straight back. Will not work that way.

yeah...and from this sale item it looks like someone aleady tried LOL

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acorad wrote:Bluemach1, I have the Craig Hardy manifolds and modded steering shaft off the car. Happy to take any pics or measurements or whatever that you like.

If you are not going to use them, please let me buy them from you! I have been collecting the parts for this and have been dreading modifying the manifold. If nothing else, maybe I could borrow them to use as my template?

Well, I won't sell them until after I'm convinced I can get smogged w/o them (the PO got the car smogged with the present aftermarket headers in place...not really sure how he did that...) but maybe we can work something out to use them as a template.

excellent. I have a full machine shop here and I can get my guys to do this easy mod. We can work out details in PM.

The LSA manifolds and Hooker 8501 (which was just released) were recently mentioned on ls1tech as good candidates. Anyone have any experience or see any potential problems on a 944 with these?

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acorad wrote:Well, I won't sell them until after I'm convinced I can get smogged w/o them (the PO got the car smogged with the present aftermarket headers in place...not really sure how he did that...) but maybe we can work something out to use them as a template.

That's where you go to your firend the smog tech and he just does the sniffer test.

Thanks Dawg, several others have said the same thing. Am I the only one here who has no smog tech friends? I suppose I'll have to start cultivating some...