The outlet for that traction fluid line, is it free of kinks and stuff? It looks like it could be in that one pic.

The kit does come with a restrictor. It is the black circular thing next to the pulley in the kit overview photo further up. It is required to have the restrictor fitted, for the kit to be legal in Denmark. Somehow I must have forgotten to put it in. Let's hope I don't keep forgetting it :)

I haven't done any boost leak testing. I'll try to make a tool, and get it done.

You're right, in one of the pictures, the outlet hose looks squashed. That's not the case, there is a nice gap between the charger and the bracket :)

Any chance your belt has become glazed? Or your pulleys?

i took off the belt to check. This is how it looks after 200-300 miles
https://cimg1.ibsrv.net/gimg/www.mia...76c1bbb502.jpg
That looks very worn, doesn't it? Almost like the teeth have been ground down.

I've indicated the belt routing in this photo. Note that the three center pulleys are flat, and the belt runs teeth in on two of the three pulleys. That's probably not ideal, but would it cause belt slip? I've also indicated the tensioner direction with an arrow.
https://cimg6.ibsrv.net/gimg/www.mia...c7b5543296.jpg

Any suggestions?

I have no experience with this, but maybe switching the bottom smooth pulley with the center ribbed pulley would help? Just a thought.

All three pulleys in the center of the photo are flat. Only the charger and the crank pulleys are ribbed.

That might be part of your problem.
Flat pulleys are OK on the outside of your belt, but not really on the inside I think.
The important thing here is belt tension: you need tension to prevent the belt to slip.
I am afraid the flat idler pulleys sort of squash the high ribs of the belt and prevent you from getting proper tension.

without any prior knowledge, that sounds right. :)

I have tried changing the belt routing by rotating the mounting of the tensioner, so the tensioner movement is more downwards. Illustrated here.

https://cimg5.ibsrv.net/gimg/www.mia...b81235a61f.jpg

This setup also doesn't seem to work, since the tensioner doesn't move sufficiently down to take out the slack, even with the shortest possible belt.

I'm lost here. Help.

If it's a cheap hose, a stock Miata at idle will collapse a silicone inlet. My old MP62 setup used to do it. I would hope the kit the OP has included a quality hose.


Something's really weird here. Did you buy this kit new or used? It almost seems like the bracket and tensioner system is not compatible with your setup...like the kit is for AC or No AC and you have the opposite.

Do you have proper check valves on all the vac lines? Could have one going bad that burps at ~6.5psi

Also, what kit is this? Every other one I've ever seen has the SC mounted significantly higher, plus I notice the one tensioner pulley in your system seems to be a good 6-7cm below the main crank pulley...

All the charge tubing and intake are silicone. Looking back over this thread, I'm still sayin its those hoses collapsing at 6000rpm.

Do you, or someone you know, have a go-pro or something similar? Would be easy to see if it is the hoses that way.

Kit was bought new, some 25-30 cars run this kit in Denmark. However, almost all run with a chunky restrictor in the inlet, and noone is facing the same issues. The charger is mounted in place of the AC compressor. So no mixups there. But the setup is probably not ideal for belt wear, given that the belt ribs are running on the flat pulleys in two locations.
https://cimg6.ibsrv.net/gimg/www.mia...c7b5543296.jpg
I have no valves in the system, except for the recirc valve seen in the photo below. Which vac line would I be concerend about?
The kit is a Danish offering from small company CCR Racing. You are right, it is a very low mount. The tentioner pulley is the top one in the photo above, with the tensioning direction marked with an arrow.
https://cimg1.ibsrv.net/gimg/www.mia...bbb4299948.jpg
Just so we are on the same page here, only the hose between the filter and the charger would be capable of collapsing at full boost right?

I have a gopro, I guess I could fit it and see what happens. Are you suggesting I remove the hood for the trial? Or put some light under there?

Nope, pretty sure it could happen on any of them. Not likely in the charge pipe, but if there is some issue with supercharger response... who knows.

honestly why would you run without the restrictor if thats how its supposed to be installed?

Put it on, no more hose collapse. I cant believe this problem has persisted so long lol.

I also cant believe a company can sell a kit of such terrible quality. When i first saw this thread, i thought you had cobbled together random cars silicone inlets, and done a diy bracket and pulley setup.

I would think that you'd need check/one-way valves on most of your vac lines and PCV, otherwise when the manifold goes into boost, you'll be pressurizing the entire vac system and the crankcase. Plus, you are missing the crankcase vent hose in this picture, so you're boost is probably just getting blown through the valvecover. I'm guessing right around the 6k mark is where the SC just runs out of puff after pressurizing the charge pipe, intercooler, manifold, crankcase, and the whole vac system. Try capping off the vac lines and the PCV port and I bet it fixes your issues.

Also this, I can't believe they would decide to mount the SC so low, when 1)everyone else mounts it much higher and 2) the company themselves stress the importance of having the SC be the highest point in an oiling system that is critical to its function.

Background info: In Denmark we have this lovely rule, than any changed component on a car is illegal, unless it has been verified by the German testing lab TÜV. And I mean everything, wheels, air filters, steering wheels. The lot. For example, I run 1.8 brakes on my 1.6 car = illegal. As you can appreciate, running a boosted car in Denmark is not easy. CCR has put the kit together and has had it tested at TÜV at great effort and cost. As such, this one kit is the only legal way to boost a Miata in Denmark.

For the TÜV approval to be valid, the car has to run with the restrictor, the stock ECU and the stock injectors. This gives a lift of 116->150 flywheel hp. This of course sucks. Therefore, I have chosen to run this kit without the restrictor using a ms2 and bigger injectors. It will then look legal, but I can hope to make maybe 210 fly hp when everything is tuned properly.

I appreciate your comments about the kit, but they only add to my frustration about the Danish laws.

I never came across anybody mentioning the need to run additional valves even with high boost Rotrex installs. I don't believe the come supplied with the American kits? The photo above was from when I was finishing the install. The crankcase line was connected before first start of the car with the kit. Looks like this now:

https://cimg0.ibsrv.net/gimg/www.mia...7687b7f745.jpg

^ah ok. But I still feel like there was more than one reason they used the restrictor. Did you try running with it back in to see if the problem persisted? You could still tune it for more than the kit legally can make, even with the restrictor.