Nct query

FranktheTank1 · 13-04-2017 12:28am #1

sorry if this is in wrong section. have a car with an open differential and nct is coming up during the week, I have looked everywhere and I cant get a straight answer. looking back on previous nct results I noticed. no brake test was done. so is that due to the differential or another reason it wasn't preformed?

thanks

grogi · 13-04-2017 8:58am

FranktheTank1 wrote: »

sorry if this is in wrong section. have a car with an open differential and nct is coming up during the week, I have looked everywhere and I cant get a straight answer. looking back on previous nct results I noticed. no brake test was done. so is that due to the differential or another reason it wasn't preformed?

thanks

95% if not more cars have open diff...

4odh4n · 13-04-2017 9:10am

is it 4WD?, i have a 4WD and its not tested for brakes, they just drive down the carpark with some sort of meter (g-force?) to access the brake performance

FranktheTank1 · 13-04-2017 9:14am

no its a RWD but the car does have rear wheel steer if that might changed anything.

Cee-Jay-Cee · 13-04-2017 9:18am

As far as I know only RWD and cars fitted with an LSD aren't brake tested although saying that I had several DC2 ITRs which were brake tested during the NCT over the years without any problems.

The vast majority of cars have open diffs and they are tested, an open diff means each wheel can turn independently of the other and so a brake test isn't going to effect it in any way.

FranktheTank1 · 13-04-2017 9:34am

I know that it wont do any harm. I have been through a good few tests with an lsd. only time I told them is when I had a tight 2 way. but I'm just curious as to why mine is didn't have it done the past 2 tests. would rear wheel steer make a difference

colm_mcm · 13-04-2017 7:52pm

They wouldn't be steering while it's on the rollers, so I can't see it making a difference.

CiniO · 13-04-2017 10:29pm

colm_mcm wrote: »

They wouldn't be steering while it's on the rollers, so I can't see it making a difference.

What if there's significant brake imbalance?

Could it not cause one wheel to lock and other still rolling on the rollers, causing potential damage to LSD?

Jack the Stripper · 13-04-2017 10:38pm

LSD can take fair bullocking, would want to be a 1.5 or 2 way diff Cinio if I'm understanding your post right.

FranktheTank1 · 13-04-2017 11:30pm

if it was due to the brakes locking then an open shouldn't be on it as only one wheel is being powered if I understand correctly. have still got no idea as to why my car was never brake tested

grogi · 14-04-2017 7:06am

FranktheTank1 wrote: »

if it was due to the brakes locking then an open shouldn't be on it as only one wheel is being powered if I understand correctly. have still got no idea as to why my car was never brake tested

What car is it?

turbocab · 14-04-2017 9:16am

[QUOT
E=grogi;103216751]What car is it?[/QUOTE] I have a Porsche 944turbo rwd with an lsd should I tell nct not to do brake test on this car when doing nct

FranktheTank1 · 14-04-2017 2:18pm

it says on the nct website any car with an lsd shouldn't be on the rollers

mgbgt1978 · 14-04-2017 3:11pm

But you stated in your 1st post that you have an open diff (not an LSD).

FranktheTank1 · 14-04-2017 6:28pm

this is where the confusion is coming from. I don't know why the brake test wasn't done.

mgbgt1978 · 14-04-2017 7:33pm

As already asked, what car is it ?

knifey_spoonie · 14-04-2017 11:12pm

OP id hazard a guess the tester just played it safe and worked on the basis that the car has a LSD. It also has the benefit of the decelerometer not being as strict, hence your more likely to pass.

Testing a car with a diff can not only damage the car, but i can also cause a car to jump/skip on the rollers.

Nct query

Comments