Belt slip? Need help, video attached

90tbirdsc

Registered User
I'm having trouble with my sc, after changing the fuel pump and injectors and swapping on a ported late model and a mp inlet and a bigger intake system and fmic I'm not making good power or boost. I took off all the ic piping and cleansed them and still no change in boost or power. So then I took them back off and added ulta black rtv to the couplers and it still didn't change. I've also unplugged the bypass valve and there still isint a change. So I re-sealed the sc hat and there was still no differene in boost or power.

I have tried everything I've thought of, I even filed down the sc pulley. I need help:confused:

Here is a video of my car doing a short pull

http://www.youtube.com/watch?v=39GfVD437Jc&sns=em

Any help is greatly appreciated.
 
You Dont need rtv on the silicone couplers, that has to be a mess BTW. You should make sure the return plenum is sealed perfect, along with the sc top. Did you pressure check the FMIC tubing? Also, the shaft on the bypass butterfly leaks big time on some plenums. That thing is pretty weak on boost. How does your fmic tubing attach to the return plenum?
 
Usually with belt slip you'll see the RPM jump as you get up there I'm boost, which does not seem to be the case here (though I may be wrong). I would check all of your piping. Chances are there's a leak in the system

Tom
 
You Dont need rtv on the silicone couplers, that has to be a mess BTW. You should make sure the return plenum is sealed perfect, along with the sc top. Did you pressure check the FMIC tubing? Also, the shaft on the bypass butterfly leaks big time on some plenums. That thing is pretty weak on boost. How does your fmic tubing attach to the return plenum?

It attaches on the bottom of the factory ic tube, its been pressure tested and I can't hear anything or get any bubbles to form anywhere. It made 15psi with a stock early model and stock ic so I know it's not the return plenum cause I didn't have it off.

How can I seal the butterfly? It's a brand new mp plenum.
 
Is your air filter dirty, what throttle body are you using? Who ported the blower?

Clean filter, 75mm professional products tb, Logan butler ported it and coated the rotors

And the bottom ic pipe has been epoxied and then a silicone coupler is clamped to it, I thought this could be the source of a leak so I did some finer grit sanding and then put rtv on it and it sill didn't change anything.
 
Clean filter, 75mm professional products tb, Logan butler ported it and coated the rotors

And the bottom ic pipe has been epoxied and then a silicone coupler is clamped to it, I thought this could be the source of a leak so I did some finer grit sanding and then put rtv on it and it sill didn't change anything.

Epoxied? you lost me, get some pics up of the plumbing
 
Epoxied? you lost me, get some pics up of the plumbing

Where there was a slight cut in the stock lower ic pipe for the bolts to go through for the clamp from the factory, I epoxied those and then sanded them so it's perfectly round and has a good clamping surface.

I'll try to get some pics
 
I'm having trouble with my sc, after changing the fuel pump and injectors and swapping on a ported late model and a mp inlet and a bigger intake system and fmic I'm not making good power or boost. I took off all the ic piping and cleansed them and still no change in boost or power. So then I took them back off and added ulta black rtv to the couplers and it still didn't change. I've also unplugged the bypass valve and there still isint a change. So I re-sealed the sc hat and there was still no differene in boost or power.

I have tried everything I've thought of, I even filed down the sc pulley. I need help:confused:

Here is a video of my car doing a short pull

http://www.youtube.com/watch?v=39GfVD437Jc&sns=em

Any help is greatly appreciated.

I looked at the pictures and watched the video and everything looked pretty good to me. Looked like boost was instantly going to about 10 psi and peaking at around 14.5 which isn't too bad.

A tune can make all the difference in the world, and if the A/F ratio isn't close to where it needs to be the car will feel like a pooch. Do you have a chip or QH with a custom tune ? Do you have anyway to monitor/datalog what the various sensors are reading ?

I'm also curious if this ported blower has already been on the car and performed well in the past or if this is the first time you have used it ?

David
 
I looked at the pictures and watched the video and everything looked pretty good to me. Looked like boost was instantly going to about 10 psi and peaking at around 14.5 which isn't too bad.

A tune can make all the difference in the world, and if the A/F ratio isn't close to where it needs to be the car will feel like a pooch. Do you have a chip or QH with a custom tune ? Do you have anyway to monitor/datalog what the various sensors are reading ?

I'm also curious if this ported blower has already been on the car and performed well in the past or if this is the first time you have used it ?

David

First time using it, my dads stock sc beat me. At around 2000rpm it makes about 7psi and then at 5500rpm it will make about 15 and then once it shifts again it drops back down again. With my stock early model it had about 12psi at around 1800-2000 and then would peg the gauge and shift and keep it pegged. OD hashing changed.

I have a quarter horse chip with a Dave dalke tune with binary editor and a innovate lc-1 wideband
 
First time using it, my dads stock sc beat me. At around 2000rpm it makes about 7psi and then at 5500rpm it will make about 15 and then once it shifts again it drops back down again. With my stock early model it had about 12psi at around 1800-2000 and then would peg the gauge and shift and keep it pegged. OD hashing changed.

I have a quarter horse chip with a Dave dalke tune with binary editor and a innovate lc-1 wideband

Well if youre sure its not belt slip, and you're also sure its not a boost leak, I'd say that blower was butchered in the porting process in some way.

The coating looked perfect in this pic, surprised you messed with that.

 
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I think it's interesting how the boost seems to stick at 5 or 6 psi until the car goes over 3,000 rpm, then climbs very quickly. I would think that belt slip might be one explanation. A bad porting job might be another explanation, but I think it would have to be pretty bad. Also, you say you unplugged the bypass valve to rule it out ... but are you sure the butterfly itself is closing all the way? Maybe it is bleeding boost back into the inlet.
 
I'm far from any kind of expert, but I know that the Professional Products throttle bodies have been known to leak, usually under vacuum, but I was reading a post where the guy said he returned 2 of them to PP because of leaking issues. I have no idea if a leaky TB would cause the symptoms you're having but I thought I'd mention it. I actually bought the same TB, but I've decided not to install it after reading some of the issues guys have had with them.
Good luck...hope you figure it out. Nice SC BTW!
 
I think it's interesting how the boost seems to stick at 5 or 6 psi until the car goes over 3,000 rpm, then climbs very quickly. I would think that belt slip might be one explanation. A bad porting job might be another explanation, but I think it would have to be pretty bad. Also, you say you unplugged the bypass valve to rule it out ... but are you sure the butterfly itself is closing all the way? Maybe it is bleeding boost back into the inlet.

It closes all the way, I even adjusted the little stopper screw around and it didn't change any, it was already adjusted right.

The supercharger porting pictures are on the photobucket with the piping pictures. Mabye someone could post them? I can't seem to get the image to show up:confused:
 
Im sticking with my original conclusion I say you try another rotor pack I guarantee you it changes. Somone with more technical knowledge than I have can explain it but at low rpm I dont think the rotors ar meshing just right but the more rpm they turn the closer it gets to being in time. Also this is one of the byproducts of the mp inlet to a certain extent mine really came alive over 3000 rpm but was slow to build up to that point, I liked it because the power was more managable. If you want to stay in the power keep it around 2500 to 3000 rpm and dont let out of the gas and lift. Unless of course its an auto then you dont have as much control
 
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Im sticking with my original conclusion I say you try another rotor pack I guarantee you it changes. Somone with more technical knowledge than I have can explain it but at low rpm I dont think the rotors ar meshing just right but the more rpm they turn the closer it gets to being in time. Also this is one of the byproducts of the mp inlet to a certain extent mine really came alive over 3000 rpm but was slow to build up to that point, I liked it because the power was more managable. If you want to stay in the power keep it around 2500 to 3000 rpm and dont let out of the gas and lift. Unless of course its an auto then you dont have as much control

How hard/easy are the rotor packs to get out? And it's a auto and is low on power everywhere
 
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