Boost leak or broken boost gauge?
 

I have a CTSC on my car, and I was running the standard pulley, and I swapped it recently for a 4.0" (should make roughly 7psi.) Right after I swapped it, my boost was maxing at 4psi, at ~6k rpms, and not moving off of 4psi all the way to redline. I figured I just didn't connect something 100% and it was leaking somewhere. Now, it's hard to FEEL if I'm getting 7psi or not, or just 4.

So today I went over all of the connections, and I made sure the belt was tight, even snugged it up a bit. I also disconnected and capped the vacuum line from the wastegate that's installed on my A/C (view the wastegate thread here https://www.s2ki.com/forums/index.ph...ic=797352&hl=)

I took it for a spin, and now my boost gauge is going crazy. It's an Autometer brand gauge. My boost gauge shows vacuum, and then stays right at 0psi, until vtec hits then it shoots up to 4-5psi (split second, real fast) and stays there until redline. The car drives like it normally does with the SC, but I'm not sure if I'm getting my ~7psi or not.

The boost gauge is connected/teed to a line off my FPR. Until I swapped the 4.0" pulley on, the boost gauge seemed to be working with no problems.


Anyone have any idea what it could be, or places to double check? Think it's my boost gauge, or a leak?

dunno, but I have an autometer Boost gauge that used with my Greddy kit, I will send it to you if you want, white face one

Thanks!

I'm going to look at it more this weekend and try to figure out what's going on. If I figure out that the gauge is dead, I'd definitely appreciate it. :thumbup:

ok, just let me know, heck I can even meet up with ya and give it to you, your in Clifton, I am in Hoboken :)

Thanks Joey.



So I drove my car to work today and I'm noticing the boost gauge seems to be working more normally, but it still only shows boost maxing at ~4psi. My supercharger is making slightly louder "whirring" noises than usual (Might be due to disconnecting the wastegate, or it could be that I haven't driven the s2k in a while and forget what it sounds like, haha).

This weekend, I'm going to mess around with it more. Going to try to reconnect the wastegate, see if the supercharger is quieter, and going to mess with the boost gauge and try to figure out if it's broke/has a bad connection, or if I have a leak.





Just realized the louder SC noise is most likely due to me tightening the belt some.

I don't think its gauge if you installed it correctly. I would do boost leak test first, anyway you can also check your gauge at same time. What speed/gear/rpm that you pushed?

I checked over all of the connections. Everything is seated/fitted correctly, and all the clamps are tight. This random wastegate that's installed on my aftercooler might be complicating things. I ordered a wastegate plate cover thing, so once I receive it, I'm going to remove the wastegate completely.

Yea it seems weird that the boost gauge would stop working, especially cause it's a mechanical one. It's strange though, because I can feel power building, but the gauge will stick at ~1psi, then jump to ~4psi. Very strange.

I have had my Prosport play some funny tricks on me.. try disconnecting & reconnecting the wires while car is on.

Hummm If you feel boost is building then it prob not a leak then. But gauge works when there is pressure. if its broke, I'm assume it wouldn't even go up to 4psi? Idk.

I bet the belt isn't on tight enough, you should have about 0.25 inch deflection pressing on the middle part of the belt between the Sc pulley and crank pulley - it needs to be super tight.

When i had my car on the dyno the first time it would get to around 6500RPM @ 4psi then the boost would drop off - it was belt slip.

I have my vacuum gauge tee'd at the same as you.

It should gradually build up in boost and be around 6-7psi when nearly at the redline (some gauges dont read 100% accurate but should be there abouts), it should read vacuum in partial throttle 20-30 Hg.

The only other thing is to try and listen for belt slip (quite hard) and drive it at a constant high revs and see if it dips off.