I noticed quite a few cars at this years GS nats in bowling green. What I noticed though was that quite of few guys had the "x" mounted all the way to the rear , just in front of the mufflers. I talked with my "X" pipe supplier and he told me that the "X" needs to be up front, as close to the collector as possible. The normal location on the installs I have done have been just behind the trans mount. He told me that having the "X" way at the back will not give you the performance benefits that it was designed for. Just thought I'd pass on some information here. Jim Burek
When I bought mine, I was told that the most important thing was to get the mufflers as far back as possible.
My X pipe is installed as close to the header flanges as the kit will allow. I love the sound it makes!!
Any guess why? I can understand why an "H" pipe needs to be up front, but I would think that as long as the pulses go through the "X" before they hit the mufflers, they will have the desired affect. -Bob Cunningham
I think it has to do with the pulse of the motor after so far the exhaust temp drops and the effect of scavenging the exhaust to the other side will diminish greatly after so far to the rear.. Just an opinion but it sounds logical!!:Smarty:
Wasn't there a guy on the Board that manufactures x pipes and sells them (for other cars too) who claims to have tested for the best position?
Bill: That is the guy. What I kind of remembered is that he does not sell anything less than a 3 inch x pipe because he says the smaller diameter is a waste of money. He seems to say that if you have a 2.5 inch muffler system go to the 2.5 after the x and stay with 3 inch pipe before. Well what if anything do you do if you run stock exhaust manifolds? Does that not limit the inlet pipe to the x to 2.5 inch?
Everyone seems to be running x pipes with headers, is it worth my time and money to run it with stock manifolds?
Re: He does make them! Interesting His website says " Note, click here to learn why we do not sell 2.5 inch x-crossovers" Did he sell you any other pipe to complete the job? What differences in sound and performance did you notice?
Re: Re: He does make them! When I talked to Nick, he explained he initally did the 2.5'' X-pipe thing for the Mustang crowd (something written in their rules which limits exhaust to 2.5'' diameter). I also told him of the 2.5'' exhaust rule for the F.A.S T. and PSMCDR crowd. He agreed it was worthwile to update his website that he has 2.5'' systems. Guess he didn't yet. Nick's X-pipe system is the X-pipe and 4 45 degree bends. It was $230, plus shipping. The X-pipe came too far back when we tried to fit it into the downpipes with no modifications. We ended up cutting about half off each downpipe (from Torque Tech) to move the X-pipe as forward as possible (right after the trans). The pieces we cut were used to lengthen the other two 45 degree X-pipe outlets to the mufflers (as you can see in the picture above). My exhaust was 2.25'' OD, with 2'' OD tailpipes. The crimping was extremely bad over the rear axle and I wouldn't be be suprised if only 1.5'' got by that area. Basically the car was breathing through straws. Along with the X-pipe, I put in a 2.5'' mandrel bent exhaust system, Gessler ported exhaust manifolds, 17749 Walker mufflers, and a John Osborne 1971 800 CFM carb. I cannot isolate anything to the X-pipe alone, but the car is much more responsive. :laugh:
Marco - Nice exhaust system. What did you pay for the complete system, including installation (down pipes, x, mufflers, and tailpipes)? Also, did you need to send your old exhaust manifolds to Gessler as a core exchange? I have a '71 GS 455 in need of a complete exhaust system. Thanks, Erik __________________ '71 GS 455 Convertible
Hi Erik - Thanks for the compliment! This V8Buick Post should answer all your questions about my new exhaust. And yes, I believe Greg wants your cores if he's porting manifolds for you. I bought a 'used' set from someone who just installed headers.
Thanks Marco, I must have missed your previous post, as I was one of those anxiously waiting for you to sum up your experience and costs. I definitely like your setup and will probably mirror your components, however, I need to also purchase 2 1/2" N-25 tips, so my exhaust system will run over a grand...Ouch! Erik _______________________ '71 Buick GS 455 Convertible
Marco : I have almost everything as you did before the conversion except for the Gesslar ported exhaust manifolds and the x pipe. How much was the porting and did he not have to match that to your heads? Apparently not from what you said. Also was the exhaust noise level much less after the x pipe? Since Nick' s ( X-forces)website still kind of poo poos the benefit of an x pipe connected to a 2.5 inch upstream system, are you aware of any dyno runs on a 2.5 inch system to verify that persons are not experiencing a placebo effect ? (I understand that dyno runs have made on a 3 inch system and accept their reported gains as fact)
The problem with hooking an a 3" pipe to manifolds is that they don't fit well.. I'm not saying it can't be done, but the manifold was designed to accept a smaller pipe, that was "flared out". But I can't say that I have any experience with attempting it, so I will defer to folks that do. Big gain with a 3" pipe... prolly not, but depends on how much air the engine is trying to flow, and for sure, the only motor that would see a gain would be those with STG 1 Alum heads, in my opinion. Otherwise the manifold/head port is the limitation in airflow, long before it gets to the pipe. Once again, just opinions, but recent testing seems to indicate that the iron head exhaust port is our biggest enemy here. I think Marco's system looks just fine, but I do like the extra plate welded to the top and bottom of the "X" that the Dr-GAS setup has.. that's what we use here. It helps to spread out the weight load of the rest of the system, on the X.. which in reality, becomes a "twisting point" for the rest of the system. JW
