Anyone have Magnaflow 3" system on a '65-66?

[Cannoball888]

Just wondering is everything fits right or will I have problems after the mufflers?

 

[fasttback]

My 2.25" mandrel bent exhaust is tight after the rear axle. You might run into problems with the rearend vent hose and brake line on the driver's side (you probably already know this).

I see you have your exhaust exiting the valance, I don't think a 3" exhaust is going to fit between the gas tank and frame rail on the drivers side. I think there was a post on this before and there might be some pics along with it.

 

[Cannoball888]

I'll probably have to go with smaller pipe near the end. From what I've read and heard from experts the reduction at the end will still give me more horsepower than having a reduced diameter through the whole system.

 

[66HertzClone]

I don't know about the Magnaflow kit, but this knucklehead put one on his car. Talk about being proud of yourself....

http://jmichael.info/SHELBY.htm

 

[Cannoball888]

^I just got off the phone with him. He said his 3" fit without any major mods, but he didn't think it would work with an exit through the valence. He suggested I go with 2.5"

 

[66HertzClone]

Be prepared, you are going to start getting tons of email or phone calls from him. The emails will be long stories about what he is doing and then get to the point, invest some of your money with me. I should have warned you ahead of time, sorry.....

 

[Cannoball888]

I phoned him, but I didn't email him so he hasn't my address

 

[SoCalCruising]

I have 2.5" through the valence. 3" won't work unless, maybe, you use oval sections to fit along the gas tank/frame rail. The real question is why 3"? You'll want at least 1.75" primaries on your headers, I should think, to not have them become your restriction point.

 

[fasttback]

My 2.25" mandrel bent exhaust is tight after the rear axle. You might run into problems with the rearend vent hose and brake line on the driver's side (you probably already know this).

I see you have your exhaust exiting the valance, I don't think a 3" exhaust is going to fit between the gas tank and frame rail on the drivers side. I think there was a post on this before and there might be some pics along with it.

My mistake...it looks like some people did get 3" by the gas tank and out the valance (see other post). I would like to see a pic of the exhaust between the frame rail and gas tank.

 

[Cannoball888]

I'd like to see that too.

 

[LUCAFU1]

your car doesnt make enough power for 3" exhaust so why use it? my cobra is making over 500/500 at the wheels and im still at 2.5".
unless your making some serious power your gonna loose some tq with 3". not only that but youll save money too.

 

[Cannoball888]

The general consensus is that cars making over 400 should upgrade to 3"

 

[allcarfan]

we had a customer install one of our 3" maggy kits, and he didnt care for it. he said it made the car have a great tone, but when he stepped on it, it felt like it wasnt going anywhere. He had a mild 302. he swapped back to a 2.25" kit and likes it a lot better. Just some FYI and my $.02

 

[LUCAFU1]

The general consensus is that cars making over 400 should upgrade to 3"

i would say that is incorrect IMO.

 

[Cannoball888]

Well, I finally decided to go with 2.5" but only because I need the exit to be through the valence and I want to avoid any fitment issues also with a TCP SFC center brace.

 

[Rusty67]

How much HP are you making/trying to make ?

If the exhaust system is properly done you should not be losing much if any with a 2.5" system. Turbo cars benifit a lot more from a larger exhaust in the 400hp range then a N/A motor could ever hope for. Size isn't the only factor when you deal with exhaust pipe. A mandril bent setup makes a difference for sure, crush bent is just.... nasty.