3 inch exhaust solve problem?

[Djstorm100]

93 ls votrech, fully built motor. Ross pistion egale rodes 8.5:1, Elbrock heads, Eledbrock RPM II manfiold, Custom comp cam ect ect... You get the idea


well from 1-2.500 or even 3 rpm the car goes but once I hit past 3k it just hauls ass and breaks the tires loose ect ect.

I dont have a MSD Boost retard timing. So I'm thinking that since timing was taken out that was the problem. So I'm thinking If I put that MSD Boost retard box and get it retune that will solve my problem?


Also 1-3 gear I dont really get in to "vac" maybe 5 or so but at times my car is idling or is in boost. Just a few PSI like 1-2, barley pass the Zero mark. It is a electric gauge autometer. I got under the hood and saw the vaccum line was pretty long so I shorted it up. In 4-5 gear I can get in to vac just cruising The brakes work fine too.

Discuss please

 

[2000xp8]

I'm trying to figure out what a 3 inch exhaust has to do with this post.

 

[BlownFiveLiter]

I'm also wondering what a 3" exhaust has to do with the issue you're having? Depending on the specs of your cam, that could very much have an impact on your power coming in after 3k. My TFS stage 1 cam is like that as well, in the fact that it doesn't make very much low end power at all, but after 3 grand, it pulls all the way to the 6250 redline. Your cam could also have a dramatic effect on the vacuum you pull at idle/part throttle. You'll pretty much always be making boost with a centrifugal supercharger, as long as it's spinning.

 

[ninety15.0]

First off, let me just say that may have been one of the most confusing posts i have ever read. No, you shouldn't always be making boost. Centri blowers dont really start making boost until 3k rpms...which is why your car seems to come alive at that speed. Secondly your cam has a huge effect on your powerband. My car is also gutless below 2k rpm...and doesn't really wake up until 3k. The real question here is why arent you making more vacuum than that. i pull anywhere from 12-16" while cruising and between 12-14" when idling. I think you should be seeing more vacuum at least while cruising. Have you thoroughly checked for vacuum leaks? And how does the 3" exhaust question come into play here?

 

[Djstorm100]

My exhaust on the car now is 2.5 OD. I have bbk long tubs (forgot the size) I was thinking maybe the exhaust was restricting me. Before I got in to mustangs, I was in to imports. I built many imports and still have a few of them. Point is we would throw 3 inch exhaust on imports that ha da decent size turbo or supercharger. I remember on car that I built would not have any real power untill 3k's come to find out after throwing on a 3 inch exhaust, it solve the problem. It was a certi supercharger as well, not a root or twin screw.

 

[5spd GT]

If the exhaust was restricting you, you would feel it up top. And no it isn't restricting you

3 inch should really be looked upon in the 500-550+ range in my opinion, if that.

Your 2.5 inch exhaust will go a long way.

So did you call Comp and they made you a cam for the 302/306 with those heads and boost numbers in mind?

 

[Djstorm100]

yes they did

 

[Shamus O'toole]

seems the import crowd puts 3 inch pipes on everything from stockers to so called built motors. The small import motors make no torque and they make there HP at a higher RPM. So a 3 inch pipe will work ok on them. 2.5 inch on your stang will be fine.

P.S. Welcome to the real car world............

 

[Djstorm100]

ricers put 3inchs on them and call it a built motor and then watch them pull 17 quater passes. I on the other hand actually build the motor



P.S. Thanks...