shosovr

Question: Are there any other signs of belt slippage **other than** black residue (like brake dust) on the supercharger pulley ?? My current set-up is a Vortech T-Trim with an 8-ribbed 2.75" S/C pulley and a 8" crank pulley (yeah, I know that it's a large pulley LOL). I was having a discussion with other local car enthusiast and they all swore that there is No Way that I could NOT be having belt slippage with my pulley combination. The only indicator that I know of belt slippage is residue on the S/C pulley which *I Do NOT Have*, but I can not be sure if that is due to me not running it hard often enough (I usually only do a pull from 3rd to 4th gear, and not often at that). A Vortech Tech said that with my entire set-up, and depending on the efficiency of my motor, I should be seeing mid to low teens of boost. I am seeing around 9-10 lbs, which is cool with me. If I "knew" that I was having slippage then I would look into a 10-ribbed pulley set-up, but If It Ain't Broke, Don't Fix It, as the old saying goes. Back to the original question: are there any other indicators ??

Kevin Blown 95 TA

I would say that if it stops building boost when it still should be at high rpm, then it might be slipping. Mine slips a little when I let off (you can hear it), but nothing ever breaks. I have a t trim with a 8 rib 7 1/4" crank pulley and the 2.75 pulley on the SC and it doesn't really slip and makes 15+ boost with a little more head and less cam than you have. I'd say you should see at least 15# on a high 3rd gear run, but maybe you can log the pressure and see what it's doing.

shosovr

Thanks For The Reply. I imagine that it is slipping, because I am seeing nowhere near 15 lbs. It was suggested that if I wanted to get more boost, to shift at a higher RPM, but even that did not work. I have not noticed any unusual sounds when I let off. I guess that I was being really optimistic in thinking that my motor was VERY efficient and breathing good, resulting in the lower intake manifold pressure. LOL !! I will probably be calling ASP to order a 10 rib set-up with a slightly smaller crank pulley. Thanks again. It's always helpful to hear of someone else set-up for a comparison.

JakeRobb

Did they give a reason, or were they just pulling random claims out of mid-air?

97WS6SCharged

You can check the belt and see if it's worn down on the pulley side. I doubt you would hear any noises over the sound of the supercharger.

Kevin Blown 95 TA

What blower are you running Chris?

These T-trims are pretty quiet. My S-trim was a quite a bit louder than the T-trim is. I actually wish it was louder because it doesn't sound much like a blower car since I installed it- it sounded a lot cooler when it had the smaller blower turning slower. Now I've heard the Prochargers and they seem louder than the small Vortechs. Now I've never heard mine slip when the engine was screaming, just when I let off after a banzai run and it cant slow down fast enough for the drive system.

shosovr

Kevin, I have not heard a Procharger, so I can not compare the two, but even in my little video you tell that it has some sort of gear driven mechanism under the hood. I get asked often enough at traffic lights and parking lots what type of blower do I have. Chris, I will also check my belt for wear. THANKS

97WS6SCharged

I have a t trim on mine but I'm running a 7"/2.5" (or was it 2.75"?) pulley combo so it's spinning pretty quick even at idle. It's nowhere near as loud as the S trim was but it's not quiet by any means.

CALL911

There are a couple signs of belt slippage:

#1 If you look at or around the belt, take a clean shop rag or towel and wipe it down. If it is slipping, it should show some "belt dust" that can be seen.

#2 Usually you will notice the RPM's not being linear to the boost (usually seen at higher RPM's).

If you are not seeing either of these, I would say you are not slipping. FWIW, the boost you are seeing seems to be about right for your setup IMO.

BIGCATPOWER

there is always a degree of slipping with a serpentine belt even if you see no signs of belt dust. the only way to prevent slipping is cog's or gear drive. you can push a serpentine belt pretty hard but they do have limits. i tried to spin my ysi with a 8.5" x 2.75" combo at 7k rpm. belts would only make 4 runs before the came apart like a bomb. switched back to the old 8.5"x2.95" combo and have probably 40 runs on this belt with no signs damage.

shosovr

Since my original post, I had yet another opti go bad (this is "after" a coil-on-plug conversion, but I suspect an oil seal leak to be the culprit), so I had a shop install a Holley HP-EFI (engine management) to get rid of the opti altogether. Also, using Vortech's "impeller speed calculation", my pulley combo (8" / 2.75") was over spinning my T-trim at 5800 RPM's, so I had ASP make me a 10-Rib 7.5" crank pulley and I stayed with the 2.75 S/C pulley. The Result::: I went from making 9-10 lbs., to 5-6 lbs (it's actually slightly less than 6 lbs.), and I lost about 60 RWHP. My motor's C/R is 8.5:1, so it really needs some air to make decent HP. The bright side is .... I am positive that I have eliminated any doubt of "belt slippage". LOLlll My next step is to look into buying a Vortech YSI. And "yes", I and several others have examined my I/C pipes for possible leaks. I have no other questions, it's just funny how *similar* car set-ups perform so much differently (like night & day difference). Thanks for everyone's previous replies.

97WS6SCharged

If the Ysi doesn't make 20 lbs nothing will.

shosovr

Sorry for raising the dead (3-1/2 year old thread), but if someone does a search for their problems (as I try to do), then there are no expiration dates on a solution.

My Camaro has been throwing tantrums over the past few years which ended up being parts/combo not matching properly. For some reason, you can not simply buy performance parts for a car. All of the parts need to match (work together). Go Figure.

As far as addressing "belt slippage", I went with a 10-rib pulley set-up (7.5" crank pulley & 2.5" S/C pulley). New pulleys require a new supercharger (Ha!!), so I upgraded to a Vortech YSI. While replacing my intercooler piping, because you can not use old intercooler pipes on a new S/C (Ha!!), I discovered that my Vortech Mondo bypass valve had blown off a rubber o-ring from inside. Note To Self: a malfunctioning bypass valve is a sure fire way to lose boost.

I am back to being a Proud LT-1 owner in a sea of LSx cars.

My last dyno pull of 700 RWHP is not bad for an outdated LT-1

Purple Poncho

What did you have to do to go from the T trim to YSi fitment wise? Same bracket?

shosovr

Direct replacement. Yes, it uses the same brackets.