Powerdyne BD-11a versus Powerdyne XB-1A dyno numbers - need some input

[MuscleJunkie]

I've attached three dyno sheets from my experience (so far) with the Powerdyne BD-11a Supercharger and the Powerdyne XB-1A supercharger.

Obviously, the dyno results from the XB-1A are just preliminary dyno tuning numbers and I honestly feel there is a considerable amount to pull out of this setup. Hoping the community here can take a look at these past results and give some input

• RWHP 303.07 - Torque 336.51
• • This was the last dyno of the BD-11A before the rebuild by Jon Bond Performance and original bearing failure.
  • I was running the following pulley combo for this pull
  • • 2.7 (2.65) SC Pulley and 6.5 (6.485) crank pulley
    • Stock Impeller, stock belt and stock bearings
  • Pull cutoff RPM was ~ 5000 rpm
  • • Max blower rpm 36,712 - 37,319
  • Boost level observed with this pull was right at 6lbs

• RWHP 287.50 - Torque 337.08
• • This was the 1st dyno after the rebuild of the BD-11a by Jon Bond Performance
  • The following work was done by Jon Bond
  • • New bearings
    • Billet Impeller
    • New internal belt
  • I was running the following pulley combo for this pull
  • • 2.8 (2.86) SC Pulley and 6.5 (6.485) crank pulley
  • Pull cutoff RPM was ~ 4800 rpm
  • • Max blower RPM 33,195 - 33,985
  • Boost level observed during this pull was in the high 5lb range.

These are the next dyno runs with the new Powerdyne XB-1a and 16 fin MID billet impeller (Si Trim)

• RWHP 268.06 - Torque 304.89
• • Pull cutoff RPM was 4800 rpm
  • I was running the following pulley combo for this pull
  • 3.1 SC Pulley and 6.5 (6.485) crank pulley
  • • Max blower RPM 34642 - 34722
    • The approximate boost level observed during this pull was in the 4lb range
• The next 3 runs were with the below SC and crank pulley combos
• • RWHP 295.31 - Torque 325.30
  • • Pull cutoff RPM was ~ 5600 rpm
  • RWHP 296.17 - Torque 326.34
  • • Pull cutoff RPM was ~ 5600 rpm
  • RWHP 297.52 - Torque 329.53
  • • Pull cutoff RPM was ~ 5600 rpm
  • The pulley combo I was running for these (3) pulls was
    • 2.7 (2.65) SC Pulley and 6.5 (6.485) crank pulley
  • Max blower RPM 46511 - 47279
  • The approximate boost level observed during the last 3 pulls was in the 6psi to just at 7psi range

So initially I mentioned that we thought there was a boost leak in the WTA intercooler. The WTA intercooler system was leak checked (up to 20 PSI - maybe 5 to 10 minutes?) and no leaks were found. It was determined that the cap on the intercooler system reservoir cap was letting expanding intercooler coolant escape through the pressure hole. Remember, the intercooler cooling system is a closed system. No leaks were found in that system. Installer thinks the system was filled too high and is going to come up with a revised system for the reservoir. A smoke test was also performed and nothing was noted. We are still investigating what other issues there possible could be.


Obviously, I think we all expected to see a bigger/better result from the XB-1a. At the moment, they do not feel there is a boost leak. They think "maybe" this could be related to belt-slip with the 2.7 pulley and we are further investigating this. Belt tension is going to be checked and additional pulls with the 2.7 and 2.8 pulleys will be made with a full boost level recording (since the dyno boost gauge during the tuning pulls wasn't functioning consistently ) and see where we are at that point.

 

[Blown]

I am sorry, but that thing is kicking ass!

The HP numbers seem great to me. 300HP at the wheels is likely 400HP or more at the crank!!!!! 330ftlbs is like 412ftlbs at the crank.

You got some 285ftlbs at 3,000rpm!!!!! You could get a wilder cam, gain HP at higher RPM but lose the low end torque that is great for everyday driving.

The AWD has it's advantages and disadvantages. It does eat power. I use 25% and it may be a bit more. I am going to swap in the F150 transfer case. It fits what I am using the truck for best.

My calcs show higher boost levels for the amount of HP/Torque yours is showing. I would guesstimate it is making closer to 8lbs.

 

[MuscleJunkie]

I am sorry, but that thing is kicking ass!

The HP numbers seem great to me. 300HP at the wheels is likely 400HP or more at the crank!!!!! 330ftlbs is like 412ftlbs at the crank.

You got some 285ftlbs at 3,000rpm!!!!!

The AWD has it's advantages and disadvantages. It does eat power.

6lbs of boost

I agree - especially with the numbers from the BD-11a. From everything I read, you realistically could not see much more than 6lbs from the BD-11a. But with the XB-1a I'm expecting that I should see much more as it is supposed to flow much more CFM. Another thing is I'm told the XB-1a supposedly could be spun up to 60k rpm but I've been advised to not exceed 50k and it has been written that way as well.

One quote from Jon Bond Peformance regarding the XB-1a says "Powerdyne XB1A is the only gear drive blower that is oil fed and is limited to 48,000 rpm no matter how it is built. Tooth thickness is the limiting factor. Mounting must be within 45 degrees of the pulley side at the top. So while they fit BD 10,11, 11a , and 12 brackets, always pay attention to the mounting for reliability. Maximum HP is around 500hp with stock impeller." I do not know how accurate that is.

From the builder of my XB-1a he says "
Yes, you can use same pulleys as fit the BD, but would start with 3.10" on this one, to see what boost you get with that since XB step up ratio is 3.45 vs. 3.05 for BD.

Spin it as slow as you can, to get the boost you are looking for. We recommend keeping impeller rpm under 50K."

And from the original release material of the XB-1A
"Backing up the gear whine is a much-needed boost in, well, boost. The belt-drive blowers are good for 9 pounds of intake pressure while pushing 800 cfm of air, but the gear-drive is good for at least 18 pounds at 1,200 cfm. That's a huge increase, and it opens the upper reaches of street supercharging to Powerdyne. In other words, while the belt-drive blower can deliver nice street power in the 400hp range, the gear-drive will hammer out the tunes all the way up to the twilight zone of street power, say 600 hp or greater. Any more doesn't really matter, as a street tire can't hang onto that much power anyway, and for all-out racing the XB-1a isn't going to compete with the 2,000-plus-cfm Mondos, Novis, and ATIs in any case. But for thumping out the street and street/strip good times, the XB-1a appears ready to play with the big boys."

 

[MuscleJunkie]

**Some additional info to answer the questions and comments by Jon Bond**

The company who bought the Powerdyne rights from 02 Force is now making new Powerdyne XB-1a Superchargers

Here is a quote from them - "What had happened was".... the company that bought out Powerdyne was looking for a another company to start re-making the XB again, for them, before they also ultimately threw in the towel as well, and sold out to us...(they just bought the company as an investment, they got in over their heads, they were not very knowledgeable 'car guys' )

They came to us with a proposal, and to TorqStorm - but since we ended up buying them out, TorqStorm couldn't make the XB, as it was, without patent infringement, so they came up with their own version,looselt based on the XB, with different internal sizes, bolt patterns, etc, etc....so it looks similar to a BD / XB, but everything is altered just enough...

Anyway, They made their modified version of it with a much smaller impeller, so they could spin it faster, like a turbo, but it also does not perform well - b/c you cannot spin a turbo sized impeller fast enough , WITH GEARS, to make it reliable. They mainly market it to old school hot rods with old, large motors, but it only makes 5 or 6 pis at best, as well, like the BD. "

Here is the XB-1a that they built for me -

They offer different impellers and trim levels on the new production XB-1A blowers - Quote from them - "As I stated before the impellers are just like Vortech trims / external sizes, so do your research on the different trim levels Vortech offers, and these are the same albeit slightly different aftermarket designs, but same external dimensions, and you could expect very similar performance.
7/7 fins - best flow at higher rpm, loss at lower rpm
8/8 fins - best flow at mid rpm, closest like stock
16 tall fins - best flow at low to mid range, loss at high rpm "

Here is another guy with an XB-1A that upgraded to a YSi trim level on that blower during a self rebuild?. In the video he says that they make Vortech Parts to fit on the XB-1A. I do not know as much as you do, but you might be able to understand better from the video. He seems to have the and upgraded impeller. He does a comparison between the factory and replacement impeller

Also, more from their build spec sheet regarding Impeller Trim - Quote "A (STOCK) (3.00 ID) - Si Trim (3.08 ID) - T Trim (3.25 ID) - Ti Trim (3.50 ID) - YSi Trim (3.70 ID)

Here is a video of three of the last dyno runs -

Here is a video of the XB-1A just after installation and final fitting -

and just after I received the XB-1A -

 

[MuscleJunkie]

When you mention your Calculator shows something about a higher level of boost, can you explain a little bit better and what you’re using to come up with that. Thank you so much.

 

[Blown]

I figure 250HP before boost with the work we have done.

14.7psi should about double power (not getting into additional friction, higher temps etc etc etc.) Half that amount of boost should get you about 50% more power or 375HP. You are getting more than 375 out of it.

Kenne Bell's history with the 5.0 says you should get 16-19HP per pound of boost in a Mustang. 7lbs X16 = 112 7lbs X19 = 133
Both of those figures are below what the dyno shows. We are not getting the same HP as a Mustang could on that higher end of range at 19HP/lb of boost, so I use 16HP/lb of boost.

I think 9lbs will get us 400+

 

[CDW6212R]

That sounds reasonable, the friction losses of the 4R70W trans, the AWD and front drive parts, those are eating a bunch of the flywheel hp.

I hope your guys find some more little things to improve, I'd like to see that in the 350rwhp level. I think the IC and decent IAT's should help hit better numbers, how are the IAT's doing?


Off topic, I learned something new about the NP149 AWD transfer case this week. It was suggested as a possible upgrade project, I learned that the input spline count is 27 on all of those. They are very common, larger enough to be desirable for 500+ hp, but the spline count is a problem. I found that they(GM) guys already are swapping some GM transmission and to use the NP149, a company re-splines OEM input shafts to 32 splines. Out 4R70W and the BW4404(and BW4406 etc), all have 31 spline shafts. So to make that upgrade possible, we'd have to discover that that NP149 shaft could be reworked into a 31 spline shaft. Then it still would have to have a fabricated trans extension adapter. So for all who have thought of the AWD from a later GM SUV, its a great thought, but whew that would be hard to do. I got a person at the Zombrota rebuild place to tell me some about the splines and input shaft. He said to figure out if the shaft is possible, they'd need to know the actual outside diameter of the transmission's output shaft at the splines. If it's not too large, then it may be possible to modify an NP149 input shaft.

 

[MuscleJunkie]

That sounds reasonable, the friction losses of the 4R70W trans, the AWD and front drive parts, those are eating a bunch of the flywheel hp.

I hope your guys find some more little things to improve, I'd like to see that in the 350rwhp level. I think the IC and decent IAT's should help hit better numbers, how are the IAT's doing?


Off topic, I learned something new about the NP149 AWD transfer case this week. It was suggested as a possible upgrade project, I learned that the input spline count is 27 on all of those. They are very common, larger enough to be desirable for 500+ hp, but the spline count is a problem. I found that they(GM) guys already are swapping some GM transmission and to use the NP149, a company re-splines OEM input shafts to 32 splines. Out 4R70W and the BW4404(and BW4406 etc), all have 31 spline shafts. So to make that upgrade possible, we'd have to discover that that NP149 shaft could be reworked into a 31 spline shaft. Then it still would have to have a fabricated trans extension adapter. So for all who have thought of the AWD from a later GM SUV, its a great thought, but whew that would be hard to do. I got a person at the Zombrota rebuild place to tell me some about the splines and input shaft. He said to figure out if the shaft is possible, they'd need to know the actual outside diameter of the transmission's output shaft at the splines. If it's not too large, then it may be possible to modify an NP149 input shaft.

My IATs are seeing at most sub 120 max under full boost in hot conditions. Real world 90s to low 100s on the road in boost.

From the previous research that I did, it seems that the all-wheel-drive should be able to handle at the 500 hp range. I guess we’ll see as time goes along. So far so good though.

I honestly think with this new blower, I should be able to easily get to 350 or more rear wheel horsepower. Something is currently holding it back – perhaps it’s belt slip or something else that’s being missed. The tune is doing real well. Right now it just seems that this will be a much more stable blower since I don’t have to worry about an internal belt snapping.

 

[CDW6212R]

That's very good, below 120* for IAT's is a success. I'm counting on that for mine to be able to not need meth/H2O ever. Keep working on the possibilities your shop suggests, hopefully there's something not yet perfect. I've had one person who was involved in the development of the early KB Mustang cars, to say they needed a lot more exhaust than people thought. The airflow has a harder time getting out when it's so much going out the small ports. You might drill a hole in the cat pipe to measure the pressure out of curiosity.

 

[Blown]

IC???
No intercooling here, I am running higher octane when running higher boost. In spite of what has been taught about other cheap boosters, Lucas Octane boost is a good one. It gives 3 full octane points taking the 91 available here to 94.

IAT's,
Ha, It's getting cooler out, nice fall weather, so I can switch to my 9lbs pulley. I'll not get 400HP because of exhaust restrictions at high RPM and flow..........................but it sure pulls like hell up too 4500rpm......................................after that, she runs out of exhaust. I'll likely get to more exhaust work, but it will only be for high RPM and an additional 25HP. The T-case swap is more important to me.

 

[MuscleJunkie]

I am sorry, but that thing is kicking ass!

The HP numbers seem great to me. 300HP at the wheels is likely 400HP or more at the crank!!!!! 330ftlbs is like 412ftlbs at the crank.

You got some 285ftlbs at 3,000rpm!!!!! You could get a wilder cam, gain HP at higher RPM but lose the low end torque that is great for everyday driving.

The AWD has it's advantages and disadvantages. It does eat power. I use 25% and it may be a bit more. I am going to swap in the F150 transfer case. It fits what I am using the truck for best.

My calcs show higher boost levels for the amount of HP/Torque yours is showing. I would guesstimate it is making closer to 8lbs.

Having some interesting discussion regarding this topic at Corral Net.

Regarding driveline loss and the issue as a whole I wrote

Quote:

Understand what you’re saying about the all-wheel-drive.

From what I’ve been told with the Explorer, 302 paired to the 4R70W and the Borg Warner 4404 AWD system, I should account for at least a 25% loss and maybe more (30%)

Using those figures and applying them to the Dyno numbers of the previous sessions - at the motor I perhaps have:

At the motor:
Stock - 215 HP - 280 Torque (Dyno 168.75 - 147.50 HP 210 - 196 Torque)

Stock BD-11a 2.7/6.5 pulley: 405 - 434 HP and 449 - 480 Torque (Dyno 303.07 HP - 336.51 Torque) - just over 6 lbs of boost

Jon Bond rebuilt BD-11a 2.8/6.5 pulley: 383 - 410 HP and 450 - 482 Torque (Dyno 287.50 HP - 337.08 Torque) - high 5 lbs of boost


So comparing this to the high run of new XB-1a, I am seeing close to the same numbers and I’m using the same pulley and perhaps observing the same boost as the BD-11a. Shouldn’t I see more with everything else being equal or perhaps I’m just not spinning the XB-1a fast enough?

The stock BD-11a supposedly flows 800cfm and the stock XB-1a supposedly flows 1200CFM

2023 XB-1a 2.7/6.5 pulley: 396 - 425 HP and 439 - 471 Torque (Dyno 297.52 HP - 329.53 Torque) 6 to 7lbs of boost

Here I was spinning the blower at 46511 - 47279 rpm at 5600 engine rpm but the max hp of this run came at 5.08k rpm (41594.22 - 42281.22 blower rpm). Horsepower dropped slightly between 5100 and 5600 rpm

 

[Blown]

It would be nice for your tuner to datalog boost with HP and Torque! If you can spin it faster safely, it sounds like it will produce more boost. I think you have everything in place to try for more, but for maybe exhaust.

The exhaust needs to handle 2.2CFM per horsepower or 2.2X400=880cfm. I know my single 3" exhaust comes-up short above 4500RPM. We beat my exhaust to death in a more recent thread here.

 

[MuscleJunkie]

It would be nice for your tuner to datalog boost with HP and Torque! If you can spin it faster safely, it sounds like it will produce more boost. I think you have everything in place to try for more, but for maybe exhaust.

The exhaust needs to handle 2.2CFM per horsepower or 2.2X400=880cfm. I know my single 3" exhaust comes-up short above 4500RPM. We beat my exhaust to death in a more recent thread here.

Our next Dyno session will measure boost at multiple points

Just after supercharger and before intercooler core

Just after intercooler core and before throttle body

After throttle body

In the manifold

If you notice in the last Dyno session, the horsepower peaked at 5000 and dropped slightly up to the 5600 RPM cut off. Boost leak, belt slip or ??

I have true dual exhaust with OBX headers and X-pipe with no restrictions between collectors and mufflers. How could I determine if I at this point have enough exhaust??

It’s now being suggested to me that I go with a bigger crankshaft drive pulley. Current is 6.5” Problem is I do not know how much room I have to make it bigger. Take a look at this picture. This is how much clearance I have to the water pump pulley. Do I have any options?

 

[CDW6212R]

That clearance to the WP pulley looks like a good 5/8", I'd say anything under 7.5" might be good. Not many people have a blower drive pulley larger than 7", that's the size I had made for my final combination.

What emissions laws do you have there? Now you may be needing an improvement of the cat pipes, being the next most limiting part. I'm no expert on pressure in the exhaust of a boosted combo, but I've read figures in the single digit range. 10psi I think would be way too much, but 5psi might be around the top of the acceptable range.

 

[Blown]

I agree with the bigger crank pulley. If it fits/clearance allows and maybe a smaller H2O pump pulley? A larger crank pulley would increase RPM without increasing belt slippage. A smaller water pump belt would push more water, good for a boosted engine.

I don't think I remember a KB pulley for these 5.0's under 2.5" and 2.75" is pushing the blower and possible belt slippage. 18k rpm is max for the blower and a 2.75" would be 16,900 blower RPM at 6500RPM.

Belt slippage? When I ran a high amp alternator with very small pulley, it slipped. When it slipped it left rubber on the alternator around the pulley. If a belt is slipping very much that rubber will show somewhere close to the pulley.

 

[MuscleJunkie]

I agree with the bigger crank pulley. If it fits/clearance allows and maybe a smaller H2O pump pulley? A larger crank pulley would increase RPM without increasing belt slippage. A smaller water pump belt would push more water, good for a boosted engine.

I don't think I remember a KB pulley for these 5.0's under 2.5" and 2.75" is pushing the blower and possible belt slippage. 18k rpm is max for the blower and a 2.75" would be 16,900 blower RPM at 6500RPM.

Belt slippage? When I ran a high amp alternator with very small pulley, it slipped. When it slipped it left rubber on the alternator around the pulley. If a belt is slipping very much that rubber will show somewhere close to the pulley.

I'll be bringing up all these things with the shop. Hopefully we discover everything that is going on and the best way to proceed. I'm ready to see that 350+ RWHP

 

[MuscleJunkie]

So we came up with this with Powerdyne. Hoping this gives a bit more for reducing any possible slippage. Coming off of the lower alternator bracket we put an idler pulley that basically puts pressure on the bottom of the supercharger belt (pushing up) and then tensioned it (the belt) to the appropriate tension measured using the Gates KriKit tool

 

[CDW6212R]

Very good, more belt wrap on the blower pulley will help. I'm hoping to find an aftermarket tensioner made for another application like the GT500, which can be mounted on the stock bracket.

 

[Blown]

Good idea! Wraps the pulley better and will stop any slippage with a smaller pulley and more boost.

The KB idler/tension pulley mounts below the blower pulley in a choice of several holes tapped in the plate/mounting for the blower snout. The belt size and hole chosen increase the wrap around the blower pulley. Final belt tension is adjusted by turning the cam and tightening the bolt to hold it.

 

[MuscleJunkie]

So the question that has come up is I need a smaller waterpump pulley. I am not driving the fan off of the waterpump as I moved to an efan. But with the current stock pulley/pump, I have no clearance to go up in size on my supercharger crank pulley. Currently running a 6.5. Any ideas?