When to upgrade to 8 rib setup

[WhiteFaleen2001]

I have a few questions on when to upgrade to an 8 rib setup, as I want to limit/prevent belt slippage. Currently I am experience none. I am running a 6 rib 3.33 pulley and want to make more power. To get the impeller speed where I would like it on my Vortech, I can either swap out the 3.33 for a 2.87 pulley or get a 3.125 pulley and get a 10% OD crank pulley or keep my 3.33 pulley and get a 15% OD crank pulley.

What is the best course of action?

People seem to say that you should upgrade to an 8 rib when you are seeing more than 12 lbs of boost. Is that correct?

How long does it take to swap out and replace all the pulleys if I was to go to an 8 rib setup.

Thanks again.

 

[01yellercobra]

I made 14psi on my D1 with a 6 rib set up. That was with an overdrive crank pulley (7.5") and 3.9" blower pulley and stock tensioner. I had a small amount of slip as evidenced by the dust under the blower. But the boost always held all the way up the RPM range. Personally I prefer running the larger pullies for more belt wrap. If it were me I'd get the 15% overdrive and keep the current blower pulley. But since you're probably not going to stop there I'd get the crank pulley as an 8 rib for when the time does come to swap the rest.

As for how long it depends on how lucky you are and how good you are with tools. Swapping the pullies isn't hard. A couple hours at most. What takes the time is getting everything aligned so you don't throw belts.

 

[WhiteFaleen2001]

Also I am seeing a discrepancy between IW website and my own math.

I had thought the stock mustang crank pulley was 6.87. But apparently that is the outside lip, and not the inner rib section which is 6.55. Can anyone confirm this?

So I had 10% OD as 7.557 crank diameter and OD 15% as 7.9005 crank diameter based on 6.87 being my starting point.
However, if that is true. 10% OD would be 7.205 (although IW shows 7.25) and 15% OD would be 7.5325 (although IW shows 7.5).

 

[01yellercobra]

I always thought it was 6.5" for the stocker. But I don't have a stock one to measure anymore. I do know the overdrive pulley on my bench is 7.5" and I'm looking to sell it.

 

[MOTOWN M]

I did the 8 rib swap with a IW 18% O/D balancer , 96-99 front cover , Thump 3 bolt tensioner , and a A&A Vette 3.0 pulley (RR TYPE) which finally stopped belt slip , thats on a YSI @26 psi.

 

[quick60]

I have a 6 rib with 3.2 rr pulley and inovators 10% crank, have seen as much as 19 psi at 7000 rpm boost was going up just stoped at 7000 rpm thats when i shift

 

[Bradleypro]

I have a few questions on when to upgrade to an 8 rib setup, as I want to limit/prevent belt slippage. Currently I am experience none. I am running a 6 rib 3.33 pulley and want to make more power. To get the impeller speed where I would like it on my Vortech, I can either swap out the 3.33 for a 2.87 pulley or get a 3.125 pulley and get a 10% OD crank pulley or keep my 3.33 pulley and get a 15% OD crank pulley.

What is the best course of action?

People seem to say that you should upgrade to an 8 rib when you are seeing more than 12 lbs of boost. Is that correct?

How long does it take to swap out and replace all the pulleys if I was to go to an 8 rib setup.

Thanks again.

Belt slip occurs below 3.2 the od balancer and a larger pulley is best bet.

 

[98 Saleen Cobra]

I run a 3.33" and a 15% O/D on my setup.. I recommend going that route.

 

[WhiteFaleen2001]

That's what I am planning on. What size belt do I need?

 

[04DeadShort]

Does a larger o.d. crank pulley affect the "initial" boost? What I mean is my boost comes in at about 5psi then climbs to 11psi. Im on stock crank pulley and 3.33 pulley on the S trim. Just curious.

 

[WhiteFaleen2001]

Also does anyone know if getting a 15% overdrive crank pulley will wear out my accessories faster? such as my alternator.

 

[Brutal Metal]

Also does anyone know if getting a 15% overdrive crank pulley will wear out my accessories faster? such as my alternator.

I'd do a 10%, your gonna have to do some grinding of the timing cover for the 15%, what boost level are you seeking?

 

[WhiteFaleen2001]

Don't care so much about boost number as I am power number. I don't mind grinding the sensor down a bit either.

Right now, I am making 486 at 9 lbs I think. I am looking for 550.

 

[Brutal Metal]

Don't care so much about boost number as I am power number. I don't mind grinding the sensor down a bit either.

Right now, I am making 486 at 9 lbs I think. I am looking for 550.

I was asking about boost do determine if you even need to go through the trouble of converting to 8 rib, I'm at 14 with 6 rib no slip using a 3.1 Reichard and ATI 6.75

 

[WhiteFaleen2001]

Ideally, the current vortech 3.33 pulley I have with the addition of the 15% od crank pulley will get me to max out my v3si head unit. Soooo at the moment, I don't need to upgrade to an 8rib, because I would have to upgrade my head unit as well.

 

[Brutal Metal]

Go for it man I'm betting you won't have slip. FYI when I switched to the ATI crank damper I put a fresh Dayco belt tensioner on and changed out the idler pulley that was squeaking when I spun it in my hand..

 

[Stanger00]

That's what I am planning on. What size belt do I need?

I run a 3.1 and 10% overdrive with 113" belt. With what you want to run I'd say it will be the same size if you're running a 3 bolt tensioner. If your using a single bolt tensioner then 108" belt is the size that will fit.

I think I'm getting some slip with my setup now with the 6 rib. I hear little sputters at high rpms. I never heard it before but sounds like the BOV has tiny amount of venting starting around 13ish lbs of boost. My motor shows 16 lbs when it shifts in 2nd and 17 in 3rd when rung out to rev limiter 6800.

 

[procharged 99]

I'd do a 10%, your gonna have to do some grinding of the timing cover for the 15%, what boost level are you seeking?

What and where do you have to grind on the timing cover I was about to order the 15% for my 99

 

[Brutal Metal]

What and where do you have to grind on the timing cover I was about to order the 15% for my 99

you'll see some pieces of aluminum that protrude near the damper, it's not a huge ordeal just make sure you have clearance..

 

[procharged 99]

you'll see some pieces of aluminum that protrude near the damper, it's not a huge ordeal just make sure you have clearance..

Okay thanks