This is for information purposes only & my newbie experience with bracket racing a ProCharger! I've got 63 passes on this supercharger combo. With a good many round wins; I'm definitely not disappointed with choosing this set-up.

Now, lets get on to the drive belts. Everyone, including ProCharger said I needed a cogged belt drive system. While I have no experience with a cog belt. I understand the supercharger head unit doesn't like drastic rpm changes, hard on the head unit. I like ripping the throttle playing the game on the back half. So, I decided on a 12-rib drive belt for some slippage while ripping.

Now, I didn't have an issue with the Gates RPM belt I started with; one of the better grip belts out there. I was going to order another, but ProCharger didn't have one in stock. So, I went with their standard grip belt & broke it in as recommended.

Anyway, I ran it this past weekend & the car ran the quickest/fastest it has been. But it didn't feel right between 6,000 & 7,100 rpm, it was flat or laying over. The 1st thing I started checking was the plugs, nothing alarming. I made 13 passes with no problems, other than it didn't feel right. It made the semifinals this weekend!

Today, I found out what was going on after looking at 2 or 3 data logs. The boost is staying the same from 6,000-7,100 instead of climbing like the higher grip belt does. Regardless, it has exceeded my expectations for the local bracket slow tune I wanted. Plus, well on the way to the quicker tune I wanted for the Big $$$ races. I only have one more race weekend to finalize a tune I want to use for the Spring Fling Million.

If all else fails, I'll switch back to the mid 5.90 winning tune I used in the fall of 2022.

2BKING needs to get another Gates RPM belt ordered for back-up!

I have a cog system on my F1r blower and rip the gas all the time and put over 300 runs on it with no issues

Side Slinger F1R cog system and I rip away.

Id bet its slipping with the 12 rib drive belt up in the higher rpm range.

This standard belt maintained 9 lbs. from 6,000 - 7,100 & the car was consistent. I'm putting the RPM belt back on for the next races, that has shown no signs of slippage at higher rpm. Regardless, I'm not trying to set the world on fire with this combination & it's very consistent with either belt.

Here's a run from this past weekend during our local points series. I wanted a 9.20 - 9.40 tune for the local stuff & I got that with the standard belt. The other tune, I'm working on is an 8.70 - 8.90 tune for the bigger $$$ races. I will use the softer compound RPM belt for that tune.

Thanks for the information, it's appreciated!

2BKING

I’d order a few and probably change as normal service after so many runs but congrats on sucsess with new package

quote:

Originally posted by Top355x:
I’d order a few and probably change as normal service after so many runs but congrats on sucsess with new package

Thanks Top!

I have 2 standard belts, but I know they are limited to 9 lbs. of boost! The time slip posted above, I got out of the throttle past the 1000'. It has ran quicker/faster & has been 145 mph with the standard belt. The good belt, I've made 15 lbs. of boost & I only have one of them right now.

Yes, the new combo is going rounds & collecting checks. The ProCharger is really being restricted, by my B...astardized tuning with the EFI. While I'm pretty happy with the tune, but there's so much more I have to learn.

2BKING

Poking my head in here for information.

I'm running a 12-rib setup with an F1A.
7.65 lower , tested on a 4.00 and 3.75 upper on Saturday

7.65 & 4.00 is 191% over (61,900 RPM @ 6,000)
7.65 & 3.75 is 204% over (66,100 RPM @ 6,000)

4.00 pulley:
--60: 1.765
-330: 4.989
-660: 7.696 @ 91.37
1000: 10.024
1320: 11.987 @ 115.07

3.75 pulley:
--60: 1.664
-330: 4.783
-660: 7.428 @ 93.08
1000: 9.720
1320: 11.669 @ 115.59

What's weird is how much the pulley picked up down low, but the MPH hardly changed.
We do know it's very fat at the top end (0.626 lambda with the 3.75 pulley) and might be laying over from that. I'm also running a 5" x 6" round K&N filter on the inlet, and an A2A Intercooler with 3" piping.

But other than that, I'm wondering if I might be running into belt slip? I'm running a Gates FleetRunner K120786HD (3622MX).

For reference, this is on a 408 SB Mopar weighing 4,450 pounds. Powerglide with a 1.98, 4.10's out back on a 28x10 M/T DOT Radial Pro tire.

Time , erpm1 , erpm2 , erpmdiff , drpm1 , drpm2 , drpmdiff , kpa1 , kpa2 , kpadiff
_0.1 , _2777 , _2945 , __168___ , ___19 , ___19 , ____0___ , _103 , _115 , __12
_0.5 , _3758 , _4071 , __313___ , __436 , __627 , __191___ , _120 , _128 , ___8
_1.1 , _4039 , _4377 , __338___ , _1062 , _1288 , __226___ , _123 , _132 , ___9
_1.8 , _4606 , _4954 , __348___ , _1708 , _1973 , __265___ , _128 , _140 , __12
_2.0 , _4778 , _5022 , __244___ , _1905 , _2252 , __347___ , _130 , _143 , __13
_3.1 , _4352 , _4605 , __253___ , _2619 , _2831 , __212___ , _127 , _136 , ___9
_4.1 , _4571 , _4803 , __232___ , _3089 , _3336 , __247___ , _129 , _139 , __10
_4.8 , _4762 , _4940 , __178___ , _3445 , _3696 , __251___ , _131 , _141 , ___9
_5.8 , _4961 , _5089 , __128___ , _3869 , _4101 , __232___ , _133 , _143 , __10
_6.8 , _5098 , _5238 , __140___ , _4261 , _4484 , __223___ , _136 , _145 , ___9
_7.5 , _5221 , _5347 , __126___ , _4499 , _4713 , __214___ , _137 , _147 , __10
_8.5 , _5341 , _5471 , __130___ , _4820 , _5026 , __206___ , _139 , _148 , ___9
_9.9 , _5584 , _5700 , __116___ , _5229 , _5398 , __169___ , _142 , _151 , ___9
10.5 , _5694 , _5813 , __119___ , _5375 , _5517 , __142___ , _143 , _153 , __10
11.7 , _5937 , _5986 , ___49___ , _5642 , _5745 , __103___ , _146 , _154 , ___8
12.0 , _5987 , _6019 , ___32___ , _5712 , _5798 , ___86___ , _147 , _155 , ___8
12.3 , _6040 , _6108 , ___68___ , _5786 , _5872 , ___86___ , _148 , _155 , ___7

I'm a rookie at this ProCharger/EFI deal. I'll try & post some comments on your combination tomorrow, along with some more information on my combo also.

2BKING

This is what my combo looks like. Figure I have about 12" of belt contact on the crank and at least 7.5-8" on the blower pulley.

The 4150 intake was hogged out on a friend's bridgeport to fit a 4500 throttle body; the piping between the A2A and hat progressively steps from 3" to 5". Thus, generally speaking the induction is very free-flowing and high-volume. As a result, I'm moving more CFM at less boost - so the numbers can also be considered skewed in that manner as well.

It's just so odd that the MPH didn't pick up.

https://photos.app.goo.gl/UaJtmmepWmp6edwG6

https://photos.app.goo.gl/czxtBq5EaGUdvcHw5

https://photos.app.goo.gl/LTMotnUoDyPLYNfy6

quote:

Originally posted by Magnethead:

It's just so odd that the MPH didn't pick up.

The fact that MPH is calculated in the 66' between the mph cones and finish line shows that your combination isn't changing how long it takes to travel that last distance. In other words your HP level is just about the same at that point with the two different combinations.

Sounds to me like you answered your own question. If it will slip when ripping throttle it will slip under power and any slippage will cause power loss and inconsistency.

I just have a couple observations/comments on a couple of areas.

Belt: I've never ran the fleetrunner/green belt, but from my research that belt has the most grip of the 3 or 4 belts ProCharger recommends. The downside is it has the most stretch. You might be running outside of tensioner range when it stretches & with that long belt; I would be looking there. A camera mounted on your radiator support would give you some data on what the tensioner is doing. Another option is to try using a Gates RPM belt, good grip minimal stretch.

Pulleys: I've never heard of the stock ProCharger crank pulley causing belt slip. Now, when you get around the 4" & under pulley dia. on the supercharger pulley it starts becoming an issue. Belt tension & pulley wrap becomes a big player.

What was your Lambda reading up top with the 4" pulley?

2BKING

I'm sure you've watched this vid from ProCharger, but just in case you haven't; it's the basics!

https://www.procharger.com/vid...d-tension-your-belt/

quote:

Originally posted by B KING:

Belt: I've never ran the fleetrunner/green belt, but from my research that belt has the most grip of the 3 or 4 belts ProCharger recommends. The downside is it has the most stretch. You might be running outside of tensioner range when it stretches & with that long belt; I would be looking there. A camera mounted on your radiator support would give you some data on what the tensioner is doing.

I was running a Dayco 78.8 belt and actually shredded it when ripping the throttle - the tensioner took up the slack until the belt rubbed the base of the tensioner. The green belt has no marks, so it hasn't made contact yet. In static position I have the tensioner at almost full rotation with the 4" pulley - about 1/4" left. Just enough to be able to loosen it to pull the belt off. So just a little more with the 3.75 .

The 78.6 (78.625") green belt is actually about 1/2" shorter than the Dayco 78.8 belt I had (79.125).

So, what's your plan going forward?

Here's our mockup with the spare motor, not that it's going to help with your situation. If we don't run the idler pulley closest to the crank pulley. The belt will rub on the base of the tensioner & comes really close to the water pump motor. I think this was taken with our 4.75" pulley & we have our 4.25" pulley on now.

I don't have the room for the ProCharger style tensioner - with it being 1/2" thick, I'd have to build a whole new crank hub to space everything out 1/2". I don't like how they mill the plate down to fit the tensioner in. Right now I have about 1/4" between the belt and the 1/2" aluminum plate.

Given the information available, I don't think the belt is slipping then, even with the 50% wrap on the crankshaft. I checked my backlog emails, the tensioner is a Dayco 89453 for a 2003-2004 Freightliner. No spec on the spring rate.