Guys,

I just installed my Alta Exhaust system. There seems to be some serious vibration coming from the center of the car. It looks as if the Exhaust is hitting the Center plate that holds the exhaust up.

Do I have to cut the plate back to clear the exhaust? Also, has anyone installed this with a B&M short shift kit before. Seems like there may not be enough clearance.

It seems louder than I anticipated but I will wait to see if I can get the vibration to stop.

Help is appreciated!

 

I installed the B&M short shifter and my Alta 2.5 sportone at the same time a few months ago. The B&M for my MCS required the install of that new shifter housing cover that drops the bottom of the shifter housing about 1" into the exhaust channel. Unfortunately, the Alta exhaust has a rather thick resonator in exactly that same place... about 12" forward of the square black frame on the bottom of the car w/ the backpipe mounts on it (6 bolts hold it in place).

I had a massive vibration issue.

My solution was to get a new resonator... a bottle-type unit made by Vibrant. I had the Alta resonator cut out and had the new one welded in place. Resonator was about $70. Welding labor was about $150, I think. Vibration went away!

 

Look here for pics of my fix: https://www.northamericanmotoring.co...postcount=1211

 

Yeah, after looking under there today, I realized where the problem may be. I just found on the web that it suggest cutting away about 6" to clear the resonator. Do you think cutting this away will help? The resonator is pretty big but Alta didnt say it wouldnt fit with B&M.

 

Thanks for the reply. I guess the resonator will do the trick.

Seems a shame that I have to cut off the nice powder coated exhaust to modify something that I just purchased. I would have gone with a different exhaust system that worked out of the box.

 

So those w/o B&M shifter will do fine?

 

I thought I read that the resonator could be mounted the wrong way by mistake. In other words, it is not centered on the pipe so if you mounted it turned 180 degrees it would be riding too high and have clearance problems. Could that be the issue? I hope I am not thinking of the wrong exhaust.

 

On my 2.5 Sportone, you can see the old resonator on the right and the new one on the left.



The Alta exhaust should prove no problem for someone without the B&M short shifter or for almost any other short shifter, but the B&M with the extended housing just happens to cause some issues.

You can't blame Alta for a bad design... nor can you blame B&M. It's just a bad combination of mods that causes the problem. They just weren't built to go together. That's the nature of customizing a car.

 

Okay! I have a few questions... And, they may be remedial, but... Just want to make sure it's the right way to go.

I know the resonator creates back pressure. Alta obviously put the big resonator on the car for a reason. (Which, I am not sure why). My guess is to get a deeper pop?. But, if I change the resonator out for a smaller type, will this mess up emmissions testing?

I really hate to have to modify a perfectly brand new exhaust.

I just finished modding my car with a 17% pulley, exhaust and an Alta CAI. The car is just sick over stock! Just this final touch to fix or replace the exhaust and I will be a happy camper.

Help is appreciated.

 

i have the alta 2.5 inch exhaust , all i needed to do was flatten the center aera of the square cross member that holds up the resinator . it did not need that much more room to stop the rattle.

 

I will be taking it back apart this weekend on a lift and seeing where it's hitting. Hopefully with some slight persuasion, this will fit.... I appreciate the input.

 

you will not see it hitting any where , mine would only touch when i was in the car on the ramp with the E-brake on. as i let the clutch out , the resinator would just touch the cross member that bolts the resinator into place. it took very little bending to fix it.

 

because I had the b&m short shifter, my resonator was firmly clamped against the bottom of the new shifter housing.

My local shop had a lift that you drove onto and it lifted the car by the tires... Great for reproducing the rattle under more normal conditions.

Good luck.