255 tips?

[gadget73]

You really want to create an H pipe on that thing. It will help improve torque production, and that motor needs all the help it can get. The standard fix for the 255 is to install something else. Short of that, I'd make sure its properly tuned up, maybe try re-curving the distributor or tweaking the carb to see if that can eek out any extra performance, and basically just run it like it is.

[marquis_82_withneons]

my original plan was to rebuild until i found out how pointless it would. a carb rebuild may be in her future but definitely a good tuning... as of now it takes a good 15 pumps when its cold out to even start and it usually stalls. once running shes good though. so a tune up is coming headers and thats about it. i cant do much with the H pipe... 150 bucks while probably good deal is out of my range being unemployed.. ima have to do some ghetto fab work and use my original downpipes

[marquis_82_withneons]

might put my own H in custom.. but i have to see how much pipe i have

[turbo2256b]

probably needs a timing chain among other things

[88Vic]

Do you have factory 2" duals on it now? You said glasspacks, indicating you already have duals but maybe you meant only one. Anyways if you want to you could just straight pipe where the cats were and scrap them, then run stock duals into glasspacks, that will flow a lot better than stock. I put stock duals on my Lincoln, but kept the cats and ditched the mufflers. I should have ditched the cats and had catless downpipes made but oh well, it was my daily driver and taking the manifolds off and adding headers to use a Mustang H-pipe would have taken more than a day so that wasn't an option, but next time i'll grab a set of Mustang shorties and have downpipes made to fit my Walker stuff, maybe use 2.25" to 2" straight pipe all the way out, might not sound bad but i'm rambling and hopefully giving you ideas.

Anywho the 255 could greatly benefit from deleting the cats and using stock duals, that would help keep torque low where you need and and it'd flow decent at the hp peak.

[marquis_82_withneons]

i literally have an elbo coming off the manifold into a 3ft section of straight pipe, no H or Y or X pipe just 2 separate 2 1/4 pipes into 2 separate thrush glass packs.

my plan is to use all the stuff i currently have. but swap in the headers and weld up my current pipes to get rid of my curreent leaks. and extend the pipes to exit one on each side in front of the rear wheels.

[marquis_82_withneons]

the headers are OEM mustang 5.0 shortys.. and when i put the straight pipe back in im gonna weld in a piece to connect the 2 sides thus creating my own H pipe

[fmansfield444]

That's kinda like my setup I have temporarily on my car. I have mustang shorties into 2 2.25 inch down pipes which go to some cheap dynomax mufflers and dumped at the axle.

I basically took the whole setup from a mark vii I found in the junkyard and welded it up to make it fit ok. I was pretty lucky to find a custom no cat setup.

If your downpipes are going to be 2.25 inch it should be fine. I don't have an h pipe or anything connecting my 2 sides and it doesn't sound bad or feel like a restriction. You would probably want one eventually though.

Only bad thing I can say about the shorties is my passenger one melted my o2 connector a little, but that was my stupid fault.

[marquis_82_withneons]

i dont have that worry cause o2 sensors are for EFI correct?.. i have a carb conversion from the prev. owner..

[sxcpotatoes]

Part of the reason for the crossover, H or X pipe is that with true-dual (seperate pipes) exhaust, the pipes will resonate and drone like a sonofabitch at certain speeds/rpms. You don't want to be going 55 down the road and your inner ear being messed with (can make you dizzy/give you one hell of a headache).

[sxcpotatoes]

Oh, and are we supposed to number our tips? I don't see how we can get up to two hundred and fify-five of them!

[marquis_82_withneons]

upon taking the manifolds off. ive found that i had a factory 2" input into the cats. i dont know if it was 2" out.. im assuming so but i dont know. that went to a Y and out the back..

my setup i cut the cats off and used 2 1/4 from there back..

will my 2" pieces off the manifolds fit on the new headers?.. if not.. im shit outta luck for exhaust for a while..

[marquis_82_withneons]

Part of the reason for the crossover, H or X pipe is that with true-dual (seperate pipes) exhaust, the pipes will resonate and drone like a sonofabitch at certain speeds/rpms. You don't want to be going 55 down the road and your inner ear being messed with (can make you dizzy/give you one hell of a headache).

try 65 down the highway with the glasspacks under the back floorboards... yeaaaaaa

[pantera77]

Dead silent at 70.

[fmansfield444]

upon taking the manifolds off. ive found that i had a factory 2" input into the cats. i dont know if it was 2" out.. im assuming so but i dont know. that went to a Y and out the back..

my setup i cut the cats off and used 2 1/4 from there back..

will my 2" pieces off the manifolds fit on the new headers?.. if not.. im shit outta luck for exhaust for a while..

If you have 2" down pipes bolted to your current manifolds they will not bolt to mustang shorties. The mustang headers are 2.25 inches. Stock anyway I'm not sure about any aftermarkets.

And yeah o2's are for fuel injection.

Also without an h pipe I do have some resonance at about 15-20 mph but its not that bad.