Ok so I finally got my speed engineering longtubes installed ! Pain in the *** according to the shop lol but I’ve noticed and I don’t know if this is normal that I have like a vibration under the car when I accelerate hard. Sounds like something is moving idk. The shop also installed the energy suspension motor mounts for me.

I have a 94 Transam lowered on Stranos and koni oranges with a panhard bar and rear LCA and relocation brackets. Rear and front sway bars. Magnaflow catback.

Car feels quicker and more responsive !

I just don’t know if it’s normal or not ?

 

Highly possible the collector on the drivers side is not clearing the trans mount/brace. Notorious problem for longtubes. I ended up grinding on the brace until the collector cleared. The shop were being whiny baby boo boo bitches. Longtubes are not that difficult.

 

I second this. Nothing difficult at all about putting long tubes in these cars.

 

Poly mounts also transmit vibrations more than what you might be used to.

 

SE headers sit very close to the k member on the passenger side. Check on that side as it could be close enough that when under torque the engine is shifting just enough and hitting, causing the vibration. The last set I installed on my car was barely touching. I also have poly mounts installed.

 

Shop that I had mine put them on complained about the fit too. Mine has a vibration only noticeable at idle. My k-member took a heavy hit at some point in its life so I'm pretty sure that has a lot to do with it.

 

To summarize, I was charged $500 from another shop that claimed to have worked on Fbodies and they couldn’t install the headers because they were the “wrong headers” so I ended up getting my money back with the bank. No shop here in chicago wanted to do the job until I found ppl in the forums mentioning a gentleman and his shop that can do the job. He did it and was real kool. It was a pain in the *** he said . It took him a whole week.

Any bad issues I can have if I don’t take care of this ?

It only happens on very hard accelerations which I do a lot lol it sounds amazing.

 

A week to install? I hope they were just working on it here and there for that week and not continuous. It may not be the easiest job, but it's also not that bad. Jack your front end up high and on jack stands, get under it and look if the headers are hitting anywhere. Where do you feel the vibration the most when under acceleration? Can you isolate a side, front, or middle? Check the driver side collector and make sure it's not hitting, also check the passenger where the header passes the k-member. The SE headers have good clearance around the steering shaft so it shouldn't be close there. Is the exhaust hitting somewhere and not the headers? You'll have to get under and look around.

 

Yea it was here and there I’m pretty sure. It’s a performance shop. The guy has worked on LT1s and he just told me they were a pain in the *** and had to make some adjustments cuz they were hitting everything. I’ll look under tomorrow when I have time to see what it’s hitting. I feel it and hear it on hard accelerations and it seems like it’s coming somewhere in the middle of the front of the car under the shifter.