Yes! Please do NOT get a shorter belt, haha. I got a longer belt* . Thank you.

 

If it helps my HKS charger slips when cold (engine and oil up to temp). Once everything gets nice and toasty under the bonnet it tends not to slip then

Like others say, don't over tighten the belt otherwise you will break things so I'd rather it slip then snap the shaft/bearings.

 

EOE, now this is why these forums are worth their weight in gold!! Thank you. All this makes a lot of sense to me. Nice and thorough, and I'm more comfortable going in this direction.

I received a new belt in the mail yesterday (Continental Elite), and I'll try that over the weekend. I also got some belt renewer from CRC, as some people have used that to (refresh the rubber and) make it more sticky.

One thing I don't get, though, probably from not having done this replacement yet but only seen YouTube videos of the procedure and reading the service manual; where is this bolt and tensioner that people talk of tensioning with a crowbar? I thought there was an autotensioner on the belt, which should be providing (according to service manual) more than 26.2NM / 19.3 lb/ft of tension to the belt. Not intending to go the crowbar route, just want to know so I can check what has been done before.

Thanks.

 

Oh, and one more thing (for completeness for people searching); I tried running the car without an intake filter, as some people reported that had been a problem. No effect except maybe a little more efficiency, as I was running a tiny bit leaner suddenly, but other than that no effect on the boost drop.

I also did a boost leak test with a compressor and tester attached to the intake of the SC; found a decent leak around the seal on injector 4 that MIGHT cause overall lower boost (and/or a rich condition during boost specifically for cylinder 4, as some air escapes through this hole and the AFR is off). I don't believe this causes the boost drop, though, but have ordered a seal kit to get it sorted.

 

"EOE, now this is why these forums are worth their weight in gold!! Thank you."
- NP! @s2000Junky is the OG with this and many others I can't remember anymore so a lot of info came from him. The rest comes from me owning this car since I was 18... and I am like, super old now.

"I also got some belt renewer from CRC, as some people have used that to (refresh the rubber and) make it more sticky."
- Let's hold off on using that

"I thought there was an autotensioner on the belt, which should be providing (according to service manual) more than 26.2NM / 19.3 lb/ft of tension to the belt."
- What supercharger setup do you have?
-- See that red arrow? Tensioner is the bracket in front (to the right) of it. The nut with a bolt is holding the tension. You can see the channel the bracket moves back and forth on, the bolt&nut is holding it in place.


"I tried running the car without an intake filter, as some people reported that had been a problem. No effect except maybe a little more efficiency, as I was running a tiny bit leaner suddenly, but other than that no effect on the boost drop."
- Makes sense that it didn't make that much difference. If the filter was 10yrs old and covered in mud or you were making 1000HP then maybe.

"I also did a boost leak test with a compressor and tester attached to the intake of the SC; found a decent leak around the seal on injector 4 that MIGHT cause overall lower boost."
- When we, Rennlisters, are testing 996TT and 997TT cars for boost leaks (I got your PM), we don't usually push past 20PSI during a steady test from what I read. What PSI were you pressurizing at? Just makes me wonder how high you went with the S2000... leaking injector I've never heard of, but then again I don't own a mechanic shop so my experience is limited.
- It might be worth checking again, I heard if you retained the SC Aftercooler with Air-Pump nipple channeling to the air pump, the pressure escapes/bleeds through the port that is supposed to spark up the cat, so into the exhaust. Someone please correct me on this if needed.

 

I have no idea which SC kit it is, only that it’s a Paxton 1220 with a 3.4” pulley. Will take some pics tomorrow to see if it can be identified. Kit was on the car when I bought it.

Re. the boost leak, yeah it’s definitely around the bottom of the injector closest to the firewall. With some pressure applied, cupping my fingers around the base of the injector I can both feel and hear the leak. Let’s just say I can’t even get it past 5psi with my tire inflator attachment to my compressor.

 

Is the fuel system primed while you do this? Fuel pressure is what holds the injectors down and seals them to the port.

 

I believe it was, but can’t remember for sure. The leak is only from one injector, though. All the other ones are 100% silent. But it’s a good point. I’ll re-run the test after I’ve swapped the belt. Thanks.

 

I've never experienced or heard of a boost leak out of the base/cushion of a fuel injector, that's rather intriguing to me. Though I've never done a pressure test in a static situation either so maybe the injector cushions are the weakest link in that scenario, or you simply over pressurized and blew one out. How many psi did you perform the test under? Keep in mind the SC depending on the pully is only pushing 7-20 ish psi. But regardless I couldn't imagine a injector cushion weep would be sizable enough to see any measurable pressure loss, but I might expect to see some fuel escape/leak if your cushion is blown out enough. Also I will say that fuel pressure is only pressurizing the fuel rail side, not the manifold side, so any air pressure test you run for boost leaks there shouldn't have anything to do with whether or not you have rail pressure or not, its isolated. You can literally have fuel rail pressure and pull the rail with all the injectors still intact and stuck in/pressurized in the rail. So I'm not sure how yamahaSHO comment relates. You guys might be thinking of two different angles on this.

There is no auto tensioner on any conventional supercharger kit for this car I am aware of. You need to manual tighten the sc belt and the adjustment systems are different depending on which kit you have. The pic above is the original old Comptech kit and are not the best system, but there are some different techniques you can employ to insure you get enough proper tension with those, and I had my preferred method that worked for me. On the Science of speed kits the tensioner system is more conventional and much easier to adjust.

 

I don’t know what to tell you. Pressure leak around the base. Couldn’t get pressurized over 5-6 PSI with the compressor / delivery I used, as it’s fizzing out too fast. So not a problem of overpressurizing. And yes, fuel pressure has nothing to do with boost pressure / air leak.