|
|
Post by kiwicanfly on Feb 10, 2019 23:41:27 GMT
I know nothing about the size or grade of this specific bolt.
So I made a stab at 12mm and I made an educated guess of grade 8.8, seems to be the defacto automotive grade.
Looking this up on a standard torque chart I got a torque of 77Nm.
Looking the same size bolt up but at grade 12.9 I get 128Nm.
As I said earlier armed with a torque table and known sizes and grades one does not need to search forums or ring up "professionals" for every nut and bolt.
|
|
|
|
Post by jason82 on Feb 11, 2019 7:51:53 GMT
Maybe MEV could finally clear this up by putting the torque values in the build thread ? I think it's a crucial part of the build & would take the hunting & guess work out of it. Especially the chassis bolts as they can not be found accurately.
|
|
|
|
Post by kiwicanfly on Feb 11, 2019 9:05:43 GMT
What size and grade are those bolts?
|
|
|
|
Post by jason82 on Feb 24, 2019 17:28:51 GMT
Progress has slowed a little at the moment for personal issues. I have decided to keep the kit & sell it after my iva next month as this makes more sense. I have changed a few things from my previous posts regarding the fuel pipe clips. Initially I had fitted twin 15mm plumbers pipe clips to the ppf frame, but the more that I thought about the clips, the more that I hated it. So I replaced the plastic clips with 14mm stainless rubber p clips, keeping the same 8mm bolt fixing them to the ppf. This looked so much better, the only thing that I had to do to make it work was to slightly enlarge the fixing holes in the clips to take the M8 bolt. Another thing which I changed was which direction the bolt was pushed through the ppf. The bolts needed to be long enough to show a few threads beyond the nyloc, which was not an issue initially, however, once the engine & gearbox were fitted the bolts now slightly touched the prop shaft, so I was really lucky that I had the bad feeling about the old clips, as I would have never known until I failed my iva in 26 days time. To rectify this, I simply put the head of the domed bolt on the prop shaft side of the ppf & put the nut on the p clip side. I must admit, this job took ages to do as I could no longer move the prop shaft to one side as I could when I had no engine & gearbox. I have also been swatting up on the iva manual in my very little spare time, & luckily for me once again I came across the rule for mandatory rear reflectors. I had forgotten all about them to be honest & I cant recall seeing them fitted to an Exocet, luckily I had a pair of rear reflectors left over from my Haynes Roadster. I also contacted IVA technical to confirm that this is still the case, here is their response........ (double click on the image to enlarge it).
Here is the rule from the manual (once again, double click on the image to enlarge it)
So I decided to mount my rear reflectors on the rear top shock housing. They fit the regs perfectly & I secured them with some M6 bolts. I could have used Tiger seal as well, but preferred something more mechanical.
I am still waiting on my rear spoiler from somewhere in china, so I have been looking at options on how to mount it to the car post iva. I have decided to go with using 19mm box section which comes up from the tank to chassis mounts & makes an a frame type setup with a horizontal support between the two a frames which the spoiler will bolt to. This will be done pre iva, and as my rear pod is white, I will put some bathroom sealant over the fixing holes to hide it, then pick it out of the threads to drop the spoiler on if & when I pass. I will post some pictures up once I get some new parts for my worn out welder. I have used my rage chopsaw, so I will put up the dimensions etc as soon as I get my welder working. My bonnet pull forward & tilt project is also on hold for the same reasons. I will need to look into strengthening up the bonnet aswell as I am worried that it might fatigue and start to develop stress cracks.
Last up, I have purchased a new set of alloys. The ones that I bought right at the start of the build were a little rough, so I thought that I would round the build off with a nice set on Enkei alloys. The only trouble now is that I need to buy some new ET40 spacers from somewhere. My car came with 50mm spacers originally, but they are now too wide.
|
|
|
|
Post by jason82 on Feb 25, 2019 11:06:29 GMT
I have had one of those days where random things pop into my head. So I thought that I would share my thoughts.
Flexible exhaust tubing
I don't understand why this would be a viable option on any kit car ? After getting fairly technical with my cylinder head polish and porting, making sure that the inlet is smooth, but ever so slightly roughed up in a spiral effect to get the intake air to be more turbulent, then the exhaust ports dead smooth to get the air to flow out better, why you would then use a corrugated stainless flexible pipe as an exhaust ? Surely this would reduce airflow as it's not smooth ? There are loads of pockets etc on the inside to disrupt the airflow, which reduces the power. I understand that it's an easier job to install the exhaust, but surely you would want the car to flow as freely as possible ?
Wheel spacers
I don't understand the hunt for a zero offset. The Exocet needs wheel spacers as the wing mounts stop the wheel going onto the hub if you don't use them.
I have had an MX3 & 2 MX5s on the road, both of them running 40 et40 offset, & I must say, these were probably the best handling cars as standard that I have owned. Mazda never released spacers as standard, and all of their standard wheels carried a fair amount of offset. So if Mazda did not issue spacers, why is there the need to chase a zero offset ? If a zero offset was that crucial, surely everyone would run a zero offset ?
Wheel spacers are quite expensive, especially the bigger you go & I believe that it's maybe a pointless hunt. Everybody raved about the MX5 handling, so why not say that the Exocet requires a standard 20mm spacer for wing mount clearance ?
My Enkei wheels are ET40, & I have decided to only put a spacer on the car to make things clear.
I am not a pro, but building this kit has left me with a thirst for knowledge, & I just don't understand these points. I may be wrong, this is why I am posting this, for clarification.
|
|
|
|
Post by Stewart on Feb 25, 2019 14:22:31 GMT
A zero offset wheel will improve handling on the car. Mazda designed the car to appeal to the masses. Those who modify and upgrade find the best options to increase handling and performance. In the same way freer flowing exhausts, aftermarket air filters and forced induction. There's a good post here: www.mevltd.co.uk/forum/discussion/14/do-i-need-wheel-spacers?new=1 explaining the reasoning. We run 20mm on the race cars because we're not allowed any wider, so running a lower offset wheel lets us get as close to zero as possible. We can make and supply any thickness spacers you like, and they're listed here: freakyparts.co.uk/collections/mazda-mx5-mk1-mk2-na-nb-spacers-spigot-ringsFor example, a set of 40mm spacers would be £190.00 plus shipping. |
|
|
|
Post by hammy3601 on Feb 25, 2019 20:07:22 GMT
I agree with Stew on the offset issue and on yours with the exhaust. My current exhaust set up uses spiralled stainless as a temporary solution but the car made great BHP at Skuzzle. Like you I'm not a car pro but I am an ex soldier and was a Sniper and can comment on spiralling as spiralling inside a barrel (rifled) stabilises air and the round travelling through the barrel and sets it off on a more stabilised path by spinning the round. Not sure if that has an effect in the same way here but like you I'm always thinking of this type of stuff. Cheers and good luck with IVA soon.
|
|
|
|
Post by kiwicanfly on Feb 25, 2019 21:44:21 GMT
Then, of course, we have the old hairy tennis, or dimpled golf ball, effect.
Both of those travel faster and further because the rough surface retains a boundary layer of air which results in an easier passage through the surrounding still air.
I believe the spiraling on rifles barrels is to effect spin on the bullet which makes it fly truer rather than increasing velocity though, it must reduce barrel velocity but accuracy supersedes velocity in that case, same way american footballers spin the ball when trowing.
However in the above examples we are talking about a solid object moving rather than a volume of gas.
I too like exploring those ideas even if the experience of others highlights my own ignorance.
|
|
|
|
Post by kiwicanfly on Feb 25, 2019 23:26:35 GMT
And my curiosity was further piqued by the wheel spacer question. I was curious why NZ limited the width of adapters and found this
(There's a bit before and after that is not actually relevant)
Whilst the MX5 is heavier than the Exocet it is not substantially heavier thus we would limit adapters to 30mm or 25mm for motorsport (separate regs).
No such limit under IVA?
|
|
|
|
Post by jason82 on Feb 26, 2019 7:24:06 GMT
I have gone through the manual a few times & have not come across anything regarding this. However, I have seen a few discussions on wheel spacers causing wheel bearing failure. Not sure if this is right or not, but it kind of makes sense as the wheel is moved further out than the bearing, causing unusual loading which the bearing was not designed to take.
|
|
|
|
Post by hammy3601 on Feb 26, 2019 8:33:45 GMT
I believe the spiraling on rifles barrels is to effect spin on the bullet which makes it fly truer rather than increasing velocity though Thats correct mate |
|
|
|
Post by Stewart on Mar 2, 2019 9:09:32 GMT
I have gone through the manual a few times & have not come across anything regarding this. However, I have seen a few discussions on wheel spacers causing wheel bearing failure. Not sure if this is right or not, but it kind of makes sense as the wheel is moved further out than the bearing, causing unusual loading which the bearing was not designed to take. We’ve been manufacturing the bolt on wheels spacers for coming on 15 years now. I’m yet to hear from a customer saying they’ve suffered premature wheel failure due to having spacers fitted. I only know of one MEV owner personally who’s had a wheel bearing failure, and that was Micky in his race car. I put that down to driver abuse  |
|
|
|
Post by tojeiro on Mar 2, 2019 23:55:10 GMT
Yes there is a formula that will tell you extended hub will increase radial load and bearing life, however, you also need to think that kit cars are somewhat lighter than the original design and on top of that bearing calculations are very conservative. Given normal mileage of kit cars I think you’d be very unlucky to have a failure due to wear.
I got my spacers from freakyparts a couple of weeks ago and they are superb.
|
|
|
|
Post by Stewart on Mar 3, 2019 13:21:24 GMT
Was also going to add, the kit is approximately 1/2 the weight of the road car, so will be much gentler on bearings and other components than if they’re compared to the road car.
|
|
|
|
Post by daydreamer on Mar 3, 2019 17:30:59 GMT
I had my rear bearing fail after about 3000 miles on my sonic, two highly probable causes ,
A - did not tighten the driveshafts and therefore the bearings enough , maybe only half the required torque
B- I do give them a lot of abuse, after all that's why I have a kit car....
From my experience ( which is limited ) the biggest factor is tightening the shafts and thereby setting the bearing preload properly, ideally using a decent torque wrench and then checking after 50 miles or so.
While I have 50mm spacers on each rear and I think that was a factor , I also think that my numpty mistake of not doing the shaft nut up properly and driving style on track are more significant.
|
|
