I get a vibration through the car at higher speeds (approx 70mph +).

Now when i was looking at buying the car i noticed people said that BEC's with the quaiffe reverse do this and is something you have to live with.

Anyone have similar issues?

I was wondering if any MNR owners have the new MNR reverse as im sure ive heard it causes no vibration unlike the Quaife.

normaly a vibation at 70 mph is the front wheels are out off balance and if its 80 + is the rear wheels look ot see if it has any weights on the wheels a quick test is swop the front to the rear and go down the save bit off road

Eh? How can that work? If the wheels are out of balance they'll vibrate and when you hit the resonant frequency you'll get serious wobble. Surely it doesn't matter which end of the car the wheels are.

I agree re getting the wheels balanced though!!

Similar theme just not kitcar

I got the alloys on my Saab powder coated , at speeds over 80mph the car developed a "big thrum" not on the steering, it felt like an engine undertray had dropped down into the airflow.

Took it into a tyre specialist who told me it was not going to be the wheels (rears) as I suspected. When he removed the wheels and ran them on the balancer, the rear wheels were over 100 grams of weight deficient. "BIG THRUM"

He ate his words beleive me....

Fronts aswell as back needs balancing, get the rears checked.

If its not that your into propshaft balance, old UJs then maybe suspnsion bushes.

Also with kit cars there are a large amount of flat panels , which can also cause vibration quite easily. Take the car out with a friend and get them to rummage for the vibe....

Or at least try and isolate whatt side its on.

Thats my two penneth worth

Good Luck

if its the reverse box or wheels out of balance you should be able to notice if its speed dependant or rev dependant etc.. the vibe will still be there but just at lower frequencies - still damaging whatever - dont ignore it!
im having similar probs with my car now - going to look at reverse box tomorrow again - maybe the prop bolts that were loose have shaken loose other stuff

Ive checked all the bolts going to the box from the prop and all are tight.

It doesnt feel like a balancing issue of im honest it only comes after 70mph and then the car vibrates. you can feel it though the seats more than the steering wheel. So maybe the rear wheels but im not sure.