xcgxl

I couldnt find an exhaust forum so I hope this post is welcome here.

I have an XC with Genie try Y extractors and before you tel me to get rid of them let me say that I have just had them ceramic coated so they are here to stay.

My question is: Is there really anything to gain by installing a 2.25" exhaust when the extractors collect into a rather long 2" pipe?? My engine guru has reccommended a 2.25 twin system with straight thru mufflers and a X pipe. Anyone run similar? Any good?
I am steering towards a 2 inch: 1. because of the extractors and 2. because I have a rather nice set of N.O.S genuine Ford stainless steel exhaust tips which look fantastic. The motor is a fairly warmed over 351 with a largish Crow cam, roller rockers, ported heads, balanced, 750 Vac. etc. Will I be selling my self short with a 2" system or will it not make that much difference. I think it will look weird going from 2" collector to 2.25" exhaust.
And before anyone tells me to buy them, I used to have the 4 into 1 Hurricane headers and they had a 3" collector going into a 2" exhaust and I hated the way they scraped on everything. Noticably better top end, but you had to give it more throttle to get off the mark.

XC351

fOR A FAIRLY MILD MOTOR LIKE THAT THE 2INCH ARE OK. IF you go 2/12 you will lose bottom end like you did with the 4 into 1's. How would I know? Ive tried every combo known to man kind over many years. My xc runs high 11's with tri y's.

xcgxl

Dp you know anything about X pipes? sposed to be the beez kneez

XC351

only what I've read. I know NASCAR's used them in the 70's. They also use 180 degree headres if you want to get real trick!

xcgxl

wtf are 180 degree headers??

XC351

The 180- degree headers give a V-8 the same sound as a 180-degree crankshaft or V-12. They also look impressive. They do have some tuning advantage and a few more horsepower. But, this design almost allways comes out with very long primarys.

andrewcrocos1

I run twin 2 and 1/4 pipes, fed from pacemaker tri -y with tripple flow mufflars and no cross over pipe. The last dyno was 200rwkw. The engine dropped off at high revs because of the tripple flows. I have been recommened to run straight through mufflers and a balance pipe or upgrade to twin 2 1/2 with tripple flow mufflers. Since the exhaust is new, I'm going for the balance pipe and straight through mufflers. I should do this before xmas. I let you know how I go.

ebxr8240

X pipe is the way to go as it ballances out flow better and actually quietens exhaust so restrictive mufflers to quiet them down is not nessessary...Imo 2 1/2 with X pipe...

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xcgxl

yes, so I have been told but is there anything to be gained by going to 2.25 inch over 2 inch when my extractors have long 2 inch colector. For those with little or no maths: 2.25 = two and a quarter inch. This question did not seem to be understood judging fromt the replys.

brenx

Get the exhaust shop to change the extractor collector to 2 1/2", then go your 2 1/4" system. If thats what you want?

I run 4-1 pacemakers (3" collector? It's big), twin 2 1/2" system, balance pipe, tripple flow mufflers and did 230rwkw on Hallam Performance's dyno with a slipping auto. Which equated to my 12.95@105.96 (pipes on, aircleaner on etc). Basically I ran 3500rpm histall and 4.11's and the 60ft's sucked (1.9's). I've changed quite a bit since and should run sustancially faster next time.

Bottomend power is where clevelands lack. The induction system/heads don't flow well @ low rpm. They get going around 2500rpm. It also depends on your camshaft. No point putting in a performance cam for bottomend. As all performance cams do is require an increase in rpm to work. So install hp cam bang, you need more rpm.

[edit] more flow will always equal more power but only if your engines exhaust flow currently being restricted.

Brenden

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