Sequential gearboxes, and IVA.
Discussion
What's the latest on this? I've heard some cars are failing due to excessive noise, at idle, in neutral.
I realy can't see why this is a safety issue.
I'm building a new car, and I was planning to use a sequential box. If I have to use an H pattern box it will be an expensive excercise to change it after IVA, as the box I want to use doesn't have a straight swap.
Anyone in the know?
Cheers,
Mick.
I realy can't see why this is a safety issue.
I'm building a new car, and I was planning to use a sequential box. If I have to use an H pattern box it will be an expensive excercise to change it after IVA, as the box I want to use doesn't have a straight swap.
Anyone in the know?
Cheers,
Mick.
Edited by mickrick on Thursday 22 July 18:01
IVA isn't just about safety. If a car is too noisy it will fail on noise limits, not 'safety'. If I were you I would build the car the way you want to and have it tested. If it fails on noise alone, not only will you be a very lucky person, but you will have just one issue to deal with, and there will probably be more than one possible solution which doesn't involve changing the gearbox.
Oh I'm under no illusions, and I expect to be picked up on s few things.
But I'm just wondering if this is now a no no. As a change of box would involve a chassis mod, and a different propshaft.
I doubt geartrain noise at idle would exceed noise limits anyway.
But I know some have failed becuase the tester deemed it to noisey.
But I'm just wondering if this is now a no no. As a change of box would involve a chassis mod, and a different propshaft.
I doubt geartrain noise at idle would exceed noise limits anyway.
But I know some have failed becuase the tester deemed it to noisey.
mickrick said:
Oh I'm under no illusions, and I expect to be picked up on s few things.
But I'm just wondering if this is now a no no. As a change of box would involve a chassis mod, and a different propshaft.
I doubt geartrain noise at idle would exceed noise limits anyway.
But I know some have failed becuase the tester deemed it to noisey.
I don't believe it's the tester's opinion, it's all done with a noise meter. If the noise meter says you are over the limit, then you would need to deal with it. Does this noise come direct from the gearbox? What about some insulation, is it really that noisy that you couldn't stop enough of the noise from reaching the sound meter to send it over the limit? How about some rubber sheet over the transmission tunnel, with some carpet over that, and maybe some more rubber sheet bonded to the alloy panel under the gearbox (assuming there is one, otherwise add one?But I'm just wondering if this is now a no no. As a change of box would involve a chassis mod, and a different propshaft.
I doubt geartrain noise at idle would exceed noise limits anyway.
But I know some have failed becuase the tester deemed it to noisey.
Specificaly gearbox. As an example, Caterham have had to drop the Quaife sequential from their option list.
If it was a case of wrapping it in a blanket then I think they would have done something about it.
I'm wondering if this is a specific test center, with an over zealous tester, or am I going to encounter the same problem?
I'm not fitting the Quaife by the way, but am looking at spending in the regoin of around 12k for a box. So you can understand, I'm feelining a bit twitchey about it.
We're talking specificaly about clatter at idle, in neutral.
Has anyone got one through in say, the last month or so?
If it was a case of wrapping it in a blanket then I think they would have done something about it.
I'm wondering if this is a specific test center, with an over zealous tester, or am I going to encounter the same problem?
I'm not fitting the Quaife by the way, but am looking at spending in the regoin of around 12k for a box. So you can understand, I'm feelining a bit twitchey about it.
We're talking specificaly about clatter at idle, in neutral.
Has anyone got one through in say, the last month or so?
Remember that Caterham have to (or at least have chosen to) ensure that their cars are permanently compliant.
At risk of upsetting Singlecoil and some of the others on the 'IVA dodgers' thread that's currently ruinning, I'd point out that you only have to find a solution that will work for the duration of the IVA test and without subjecting the car to any sustained mechanical stress.
For example:
The other problem with straight cut boxes, of course (it's the straight cut gears and chatter from the dogs that's the noisy bit, rather than the sequential engagement), is that they can add to your noise problmes on track days, too, but that's another story...
I have a straight-cut box in my Westfield, and a noise meter, and for what it's worth it will pass circuit noise tests quite happily (93dB at 75% revs) whilst actually being painfully loud in the cockpit, but boxes (and sound paths in individual installations) vary considerably, so the only real way to be sure would be to install and test it.
At risk of upsetting Singlecoil and some of the others on the 'IVA dodgers' thread that's currently ruinning, I'd point out that you only have to find a solution that will work for the duration of the IVA test and without subjecting the car to any sustained mechanical stress.
For example:
- Creating a box around the gearbox, packed with fibreglass silencer wadding.
- Fit an ultra-quiet exhaust for the test itself, so that the overall noise levels are reduced.
- Fill the gearbox with very high viscosity gear oil (I wouldn't go so far as suggesting the old back-street car trader's dodge of filling the box with a mix of gear oil and sawdust to quieten it down, but you get the idea...).
The other problem with straight cut boxes, of course (it's the straight cut gears and chatter from the dogs that's the noisy bit, rather than the sequential engagement), is that they can add to your noise problmes on track days, too, but that's another story...
I have a straight-cut box in my Westfield, and a noise meter, and for what it's worth it will pass circuit noise tests quite happily (93dB at 75% revs) whilst actually being painfully loud in the cockpit, but boxes (and sound paths in individual installations) vary considerably, so the only real way to be sure would be to install and test it.
Sam_68 said:
At risk of upsetting Singlecoil and some of the others on the 'IVA dodgers' thread that's currently ruinning, I'd point out that you only have to find a solution that will work for the duration of the IVA test and without subjecting the car to any sustained mechanical stress.
That doesn't upset me in the slightest, and I am so fully in agreement with the idea that it only has to be in compliance on the day that I didn't think to mention it, I thought it was obvious.As I have already said in the other thread, there are aspects of the IVA that are tedious and nit-picking, but I think it very unlikely that anyone would, having made their car copmpliant for the test, actually remove the safety features and good practice elements that they have to build in for the test. They might well remove some of the other stuff though
mickrick said:
.......I'm wondering if this is a specific test center, with an over zealous tester, or am I going to encounter the same problem?.........
The way the test is carried out is quite specific so the reading you get is what it is.There are a number of companies that supply sound deadening material. Have a search around the Land Rover forums as there are lead lined blankets to drape over old & noisy diesel engines. When you have the right material you could permanently line the inside of the transmission tunnel without causing an overheat issue then cover the underside for the test and remove later to avoid overheating.
Steve
Thanks for your ideas. 
My job is engineering in the private yachting industry, so I do have access to some very effective sound/heat insulating materials. Specificaly the lead lined (Or equivilent) sound deadening stuff.
I think it will be a good idea to line the tunnel befor fitting the box.
Thanks again for the input.
Cheers,
Mick.
My job is engineering in the private yachting industry, so I do have access to some very effective sound/heat insulating materials. Specificaly the lead lined (Or equivilent) sound deadening stuff.I think it will be a good idea to line the tunnel befor fitting the box.
Thanks again for the input.
Cheers,
Mick.
I failed my SVA last year, the only failure was noise not at idle but during the noise test.
In order to pass I ended up lining the whole of the engine bay with a self-adhesive acoustic foam, I also had a to fit a 'massive' Volvo silencer to the exhaust system. The silencer has now gone but the acoustic foam remains., the foam is not cheap but very very effective
In order to pass I ended up lining the whole of the engine bay with a self-adhesive acoustic foam, I also had a to fit a 'massive' Volvo silencer to the exhaust system. The silencer has now gone but the acoustic foam remains., the foam is not cheap but very very effective
"What's the latest on this? I've heard some cars are failing due to excessive noise, at idle, in neutral"
Think you're all missing the point here - noise test will be carried out at something like 5,000 rpm, depending on max power rpm you've stated & they've accepted as being correct. The "idle chatter" of a straight cut box won't be there at anything over a few thousand rpm - the box might be horrendously noisy on the road at speed, but they don't check that. TTBOMK there is no noise test at idle - please correct me if I'm wrong.
Think you're all missing the point here - noise test will be carried out at something like 5,000 rpm, depending on max power rpm you've stated & they've accepted as being correct. The "idle chatter" of a straight cut box won't be there at anything over a few thousand rpm - the box might be horrendously noisy on the road at speed, but they don't check that. TTBOMK there is no noise test at idle - please correct me if I'm wrong.
Hi there Mick,
Have you considered using the Sadev 6 spd sequential box?
It's a type 9 derivitive.
I believe it's a bit quieter than the Quaife equivelant, and a good deal better too - on my current build, I'll also be taking advantage of the paddle change too!
I know you're a few miles away from me (I think, 1300!) but if you need a metre or so of pro sound deadening, I'm sure I could sort it out for you?
ATB
Steve
Have you considered using the Sadev 6 spd sequential box?
It's a type 9 derivitive.
I believe it's a bit quieter than the Quaife equivelant, and a good deal better too - on my current build, I'll also be taking advantage of the paddle change too!
I know you're a few miles away from me (I think, 1300!) but if you need a metre or so of pro sound deadening, I'm sure I could sort it out for you?
ATB
Steve
Edited by Steve Hignett on Friday 23 July 22:58
Hi Russ, I hear some cars have failed specificaly for the chatter at idle.
Thanks for the offer Steve, I have considered the Sadev, but have been told by someone who has fitted one, that it's "as noisey as hell at idle" I've pretty much made my mind up to go for the Drenth DG400. Although even the Guys at Drenth say the Sadev unit is a quality piece of kit.
Thanks for the offer Steve, I have considered the Sadev, but have been told by someone who has fitted one, that it's "as noisey as hell at idle" I've pretty much made my mind up to go for the Drenth DG400. Although even the Guys at Drenth say the Sadev unit is a quality piece of kit.
Hi Mickrick
I would pay a visit to the test station and have a chat with the tester (he may not see you straight a way if he is busy, if so he will give you a time to come back - at least that happened in my case (couple of years ago when I was building my RS200).
He will give you the info you need - they ARE helpful people who love new/different motors - but they also follow the letter of the law which can look like knitpicking.
Ask him what (common) sort of thing others are failing on and also check out your perseived problem.
I would pay a visit to the test station and have a chat with the tester (he may not see you straight a way if he is busy, if so he will give you a time to come back - at least that happened in my case (couple of years ago when I was building my RS200).
He will give you the info you need - they ARE helpful people who love new/different motors - but they also follow the letter of the law which can look like knitpicking.
Ask him what (common) sort of thing others are failing on and also check out your perseived problem.
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