Slipping issue

[Phantomhalo]

Hey all! So I'm trying to figure out why my car seems like the clutch is slipping in 4th-6th when I smash it. A little backstory first. I installed my 3.2L KB a while back and any time I just smashed the pedal it sounded like an A-10 gun going off. So I would have to roll into the throttle. I thought it was because my clutch couldn't handle the power and have just been waiting it out until I replaced it. Well the clutch seemed to start slipping when I would smash it on the freeway to pass people. It just felt like rubber across glass slipping along. Last week I finally put a RXT in thinking it would fix the issue, but I'm still running into it slipping (or so it seems). My question is, what else would cause this issue? The clutch is brand new with 700+ miles on it now and if I go to pass someone in 5th or 6th at 80mph it feels like it's not holding the power. Even 4th if I'm not high enough in the rpm band it will do this. It's hard to explain, but does anyone have any ideas? Side note, what is everyone using now as far as spark plugs go and at what gap? I'm at 22+psi, running E85, and around 800rwhp. Thanks everyone!

 

[RBB]

That's strange....are your RPMs shooting up and you're not accelerating? Did you break the RXT in correctly? If your clutch is truly slipping it's pretty easy to tell. Smash the gas and watch your tach....RPMs will climb much more rapidly than normal and you won't feel any acceleration.

As far as plugs, I'm running NGK TR7IX gapped at .028 at about 18 lbs of boost. Good plugs, but I'd imagine you'd need to gap them down a little more pushing 28 lbs.

 

[Phantomhalo]

No, RPMs are not going up any faster. I'm not losing traction either. My other thought was maybe belt slip, but I don't see any black dust around the snout and it's a new belt. It's a stock belt from kenne bell and stock tensioner.

 

[Phantomhalo]

Side note, yes, as far as I know I broke in the clutch properly. Unless there's something different that McLeod does that others don't.
Thanks for the info on the plugs too btw. I heard the Brisk plugs were taking the spot of the TR7's?

 

[c0rn_fed]

Supercharger belt slip maybe

Sent from my Pixel XL using Tapatalk

 

[2001Cobrabuddy]

Datalog, maxing out your fuel pump duty cycle/injector duty cycle will cause some limp mode issues without throwing a code.

 

[RBB]

Side note, yes, as far as I know I broke in the clutch properly. Unless there's something different that McLeod does that others don't.
Thanks for the info on the plugs too btw. I heard the Brisk plugs were taking the spot of the TR7's?

I don't know. Lund tells me to run the 7IX so I do. I believe I read a thread last week where BJ was saying his car likes the 7IX better than the Brisk plugs too. You probably can't really go wrong with either one.

 

[Phantomhalo]

Datalog, maxing out your fuel pump duty cycle/injector duty cycle will cause some limp mode issues without throwing a code.

My duty cycles are good, but this is a physical rubbing feeling that you can feel inside the car. I'm leaning towards the belt slip, but didn't know if anyone else has came across this before so I can be sure before I throw more money at it.

 

[PistolWhip]

Be very careful going into boost in 5th or 6th at lower RPM. That kind of load will most certainly hurt the motor.

 

[JB_2010GT500]

Sounds like belt slip to me. I'd reach out to Van at Revan Racing and get a nice Gates belt on there. Those definitely won't slip as long as you get the right size.

 

[fullboogie]

I still don't understand exactly what the car is doing to make you believe the clutch is slipping. RPM's aren't spiking, so what is it?

 

[Pribilof]

Sounds like belt slip, not clutch slip.

Why are you mashing the gas in 6th to pass people on the highway?

"Even 4th if I'm not high enough in the rpm band it will do this"
Please define "not high enough in the RPM band." Maybe you're just bogging out.

 

[RBB]

I'd get a new tensioner. VMP makes a nice one, thinking of picking one up myself as I'm sure there will be a sale going on this weekend.

 

[Phantomhalo]

Sorry guys, thought the thread was dead...lol anyway, not necessarily mashing it in 6th, but just getting on it a little bit to pass a car here or there instead of downshifting. Rpms are around 2100 at 80mph in 6th. I talked to Van and he wanted me to smoke check the system to make sure I didn't have a vacuum leak or that the EGR isn't messed up. I'm guessing belt slip too, but I'm more curious as to why it happens in that range instead of when I roll into the throttle. I still roll into it relatively quick just not hammer it and the slipping doesn't happen. If I stab it quick it sounds like an A-10 cannon so I just let off. To define not high enough in the rpm band, I mean if I stab it at anything under 2200-2300ish it does this. Anything above that and it's fine. I'll try to get a video of it when I can. The weather isn't supposed to be that great here the next couple of days though.

 

[PistolWhip]

Could it be the bypass? The sound your describing sounds kinda like pressure backing up into the blower rotors

 

[Phantomhalo]

I don't know. It has happened since I installed the new blower so I'm hesitant to say that it is being that it's new. The car has 63k miles on it though. The belt is the new one from Kenne Bell, but it's my oem tensioner. How can I check just the bypass?

 

[PistolWhip]

You should be able to see the bypass function even in neutral with quick revs. You can also check the lines running to it and make sure they have vaccum. It would not shock me if the stock tensioner wasn't going bad with the big blower making it really worse.

 

[Phantomhalo]

All looks good on the bypass. So I'm going to get the gates belt and tensioner from Van on pay day. I'll report back with results!