Hardtop installation noise

[lamborghinikid]

I have just installed a hard top on the spider it is really nice. It takes away alot of the road noise and is great for winter driving my problem is in 4th and 5th gear there is alot of noise around 40mph and up to 50mph after that it gets quite again, kind of like a drone may be its the exhaust its like the top amplifies the sound I don't notice the sound with the soft top. Any ideas?

[spidernut]

Harmonics?

[mdrburchette]

Maybe an exhaust vibration? I have the same problem with my X19. It buzzes at a certain rpm but every single one I've owned has done it.

[Sunracer]

What happens if you roll down the window a bit when it's making the noise?

[perthling]

My 124 coupe has always suffered from this in the rear at around the 80km/h (approx 50mph) mark. Not really noticeable from the front seat though.

[Exit98]

With modern sun roofs cracking a window helps.

Other than that, unless the top is vibrating probably not much you can do.

[lamborghinikid]

Think its the exhaust and there are mounts where the back hooks up that are in need of being removed they are rubbing on the car and not of any use. Well that problem doesn't really matter at this point it is ticking really loud. The engine is old I've got the original block I guess its time to put an engine together. Where is a good place to get the rebuild kit? I'd like to put a mild cam in it and the highest compression pistons I can get away with street purposes. I have to save some money for the exhaust. I haven't finished the countach yet its going to be difficult two projects going at once. Guess I will be reading the engine and performance section. Well at least I am looking forward to some good reading. I'd like to get hold of a Guy Croft book.