whipple 4.0

[Fubar]

Gentlemen,

Threads such as this one are most informative and quite useful. I believe it would benefit everyone concerned however, if theory and speculation were presented as such and those items known to be factual as result of actual testing are also presented as such.

The pioneers take the arrows and Mark is blazing a trail here. I am not an automotive engineer but it is common knowledge that an automobile supercharger can use up to one third of an engines power to drive that mechanism and they do not burn up as result of belt slippage. The Ford GT500 Mustang produces an honest 500 hp but on a Dyno they are only able to manage around 400 rearwheel horsepower. That's a 100 hp loss in the drivetrain of a 500 hp car and neither the transmission nor the rear end melts.

Even a very efficient gasoline engine will only be able to extract 20% or less of the total energy contained in a gallon of fuel and will send remaining 80% into the atmosphere as either heat, emissions, or unburned fuel. Every surface of an automobile's drivetrain from the air cleaner to the surface of the tires, not to just the radiator, is constantly bleeding heat into the atmosphere.

I believe a detailed analysis would show that Fubar's power loss figures are not that far off the mark. Yeah, that's a lot of BTUs but that heat does not stay bottled up in the supercharger and transaxle. Like all of the other frictional losses in any automobile, it is quickly bled off into the atmosphere.

"130hp is 330,000 BTU" is a fact and is properly presented as such. "If you were losing 130hp in the transaxle, it would melt".....and....."that supercharger belt would burn up from slippage if it was transmitting 300hp" is speculation and while this theory is a positive contribution to the discussion, it would more properly be presented as theory rather than fact.

I don't wish to ruffle anybody's feathers, I do want to encourage the free exchange of ideas and this is best accomplished when facts backed with historical testing are presented as such and when inferences, theory, and speculation, are also presented as such.

Chip

Very eloquent Chip, sorry if I got my feather ruffled. I'm just irritable because my new toy is creating a headache for me. I am sure the stars will align when I get this puppy figured out.

All this for a "I did 200mph at the Texas Mile" tee shirt... sheesh. :bored

 

[ChipBeck]

Lethal performance.

My big concern with a boost-a-pump is the device failing and I have no idea that it failed. I really don't like having two fuel pumps either. One can fail and you wouldn't notice because it would drive around (light load) fine. However it would go lean when you pushed it. I guess it is just a problem I'll have to live with.

Mark,

What kind of fuel pump does Heffner use in the 1000 HP turbo-charged cars? I would also call Lethal Performance at 1-877-253-8425. Those guys are the masters at making supercharged 5.4L GT500s produce ridiculous amount of horsepower (over 1000 HP and 8 sec. 1/4 mile :eek) and I know they've used several different types of fuel pumps. Tell them what you're doing and I'll bet they have a reliable fuel pump solution. It's worth a call. And hey, even if they don't have what you're looking for, a trip to their website has several pages of the Lethal girls! :biggrin

Chip

 

[tmcphail]

Turbo GT's don't have to deal with the parasitic loss of driving the blower we can hit 1000whp with the stock fuel system all day long. Its been done over and over again. Same results.


BAPS work I have used them on loads of projects and they reside on my TTGT for numerous reasons.

 

[Yukonranger]

I agree with your point about constructive advice, but offer the following:

A 14-71 blower on a top fuel car (500CID, 50+PSI manifold pressure) is reputed to consume about 400HP, so an engine 70% of the displacement with under 40% of the manifold pressure with an arguably more efficient design is "unlikely" to consume 300hp. More likely it is *under* 112hp.

http://en.wikipedia.org/wiki/Top_Fuel

The power lost in a transmission is not solely a function of horsepower. Some power is consumed solely as a function of RPM (lubricant pumps, fluid drag, bearing drag). This power consumption does not go up by increasing torque. Additionally, the power lost to the transmission depends on the gear selected. I have not taken apart a Ricardo but a M-22 in fourth gear is a simple straight shaft with no loads be transmitted by any of the gears. What this all means is that power lost to a transmission is not a fixed percentage of horsepower (doubling the hp does not double the power consumed in the transaxle.)

As a minor note, an engine operating at a BSFC of .50lb/hp.hr (an unexceptional figure) is extracting about 25% of the available energy from the gasoline.

36600 Watt hours in a gallon of gas (a little less when mixed with ethanol)
6lb/gallon
3050Wh in .50lb gasoline
746W=1hp
746/3050=24%

Many gasoline piston engines operate at close to .4/lb/hp/hr which equates to a little over 30% of the energy being converted into shp.

Just wanted you to know that I don't just pull these statements out of the air.

Anyway there are two approaches to getting more fuel available at the injectors. Increasing pump capacity or reducing restrictions in the system (Torrie's suggestion of checking the fuel filter is a good place to begin)

Gentlemen,

Threads such as this one are most informative and quite useful. I believe it would benefit everyone concerned however, if theory and speculation were presented as such and those items known to be factual as result of actual testing are also presented as such.

The pioneers take the arrows and Mark is blazing a trail here. I am not an automotive engineer but it is common knowledge that an automobile supercharger can use up to one third of an engines power to drive that mechanism and they do not burn up as result of belt slippage. The Ford GT500 Mustang produces an honest 500 hp but on a Dyno they are only able to manage around 400 rearwheel horsepower. That's a 100 hp loss in the drivetrain of a 500 hp car and neither the transmission nor the rear end melts.

Even a very efficient gasoline engine will only be able to extract 20% or less of the total energy contained in a gallon of fuel and will send the remaining 80% into the atmosphere as either heat, emissions, or unburned fuel. Every surface of an automobile's drivetrain from the air cleaner to the surface of the tires, not just the radiator, is constantly bleeding heat into the atmosphere.

I believe a detailed analysis would show that Fubar's power loss figures are not that far off the mark. Yeah, that's a lot of BTUs but that heat does not stay bottled up in the supercharger and transaxle. Like all of the other frictional losses in any automobile, it is quickly bled off into the surrounding air.

"130hp is 330,000 BTU" is a fact and is properly presented as such. "If you were losing 130hp in the transaxle, it would melt".....and....."that supercharger belt would burn up from slippage if it was transmitting 300hp" is speculation and while this theory is a positive contribution to the discussion, it would more properly be presented as theory rather than fact.

I don't wish to ruffle anybody's feathers, I do want to encourage the free exchange of ideas and this is best accomplished when facts backed with historical testing are presented as such and when inferences, theory, and speculation, are also presented as such.

Chip

 

[ChipBeck]

2 benefits.

Here's a quote from the same Wikipedia source.

"Positive-displacement superchargers may absorb as much as a third of the total crankshaft power of the engine, and, in many applications, are less efficient than turbochargers. In applications for which engine response and power are more important than any other consideration, such as top-fuel dragsters and vehicles used in tractor pulling competitions, positive-displacement superchargers are very common."

I am really fascinated by top fuel supercharged engines. Estimates of how much power their superchargers alone consume are all over the map. I've heard figures ranging from 400 to over 1000 hp consumed by a modern top fuel supercharger. No one really knows because the actual power those engines produce cannot be measured with current technology as no Dyno exists that can handle them. So scientific calculations and estimates are made based upon fuel consumed, vehicle weight, wind resistance, and ET's. But here again, the vast majority of that nitromethane produces heat, not acceleration.

I expect to see Mark spend considerable time, effort, and money working through all of these problems so that two things can happen.

1. We get the benefit of all of this knowledge when we install our 4.0 Whipples and don't have to go through any of these problems and......

2. Mark gets a T-shirt! :biggrin

Chip

 

[kumar]

My big concern with a boost-a-pump is the device failing and I have no idea that it failed. I really don't like having two fuel pumps either. One can fail and you wouldn't notice because it would drive around (light load) fine. However it would go lean when you pushed it. I guess it is just a problem I'll have to live with.

If you want to redo the whole fuel system for piece of mind, you know who I would recommend. :thumbsup

 

[B.M.F.]

In the shelby gt500s and 03-4 cobra we always run the pumps up to full steam when the car starts to make boost. On the 03 cobra we command 80psi and we do the same on the Gt500's also.
Most return style systems have a 1to1 ratio to boost fuel pressure when the boost goes up. So if you have a base pressure of 36 like stock and add 19lbs of boost would be 55lbs. 75 or 80lbs of commanded fuel pressure would help your issue of the injector being maxed by extending the injector by 15-25 percent with the extra pressure, but if your fuel pressure is dropping, it is still going to drop after you raise the fuel pressure up. I would reccommend boost a pumps first.

Also spinning the whipple to only 19lbs of boost will not equate to a loss of 300hp to drive the blower, maybe half of that being the blower is not being spun near to full speed. The Gt's probally lose about 15% of drivetrain loss so you'd be look'n at around 115hp for that. So in all your crankshaft hp is more realistic around 1045hp.

I do know on e85 with twin gt pumps with a blower/car that makes 650rwhp the pumps are done. Add 30% to that and thats where you would be on gas. About 845 rwhp.

 

[BlackICE]

I have a question, when you command more fuel pressure in the tune, does the ECU automatically make the adjustments to the pulse width of fuel injectors, or do the injector parameters need to be changed also?

 

[tmcphail]

I have a question, when you command more fuel pressure in the tune, does the ECU automatically make the adjustments to the pulse width of fuel injectors, or do the injector parameters need to be changed also?

You can command whatever fuel pressure you like (within relative reason) Desired pressure drop across the injectors to achieve that.

 

[XRQTOR]

So what numbers are you guys expecting on pump fuel once the fuel issue is sorted.

 

[Fubar]

The injector are compensating for the the drop in fuel pressure so I think 765 is pretty close to the mark. We may see another 5-10 hp if fuel pressure remain constant. I am more interested in the results of bumping pressure up to 75-100psi. That may help the entire curve 10-15hp.

 

[B.M.F.]

The injector are compensating for the the drop in fuel pressure so I think 765 is pretty close to the mark. We may see another 5-10 hp if fuel pressure remain constant. I am more interested in the results of bumping pressure up to 75-100psi. That may help the entire curve 10-15hp.

I would only boost fuel pressure too about 80psi, anything over that and the serated lines from pumps to hat will burst causing a loss in fuel pressure/non running car. We have seen this many of times and we convert most of the 03-4 cobras to a napa submersable line. If you don't put a boost a pump on it you are still going to see a loss in fuel pressure though.

 

[tmcphail]

The injector are compensating for the the drop in fuel pressure so I think 765 is pretty close to the mark. We may see another 5-10 hp if fuel pressure remain constant. I am more interested in the results of bumping pressure up to 75-100psi. That may help the entire curve 10-15hp.

Yeah do not do this. If your out of pump already and you raise fuel pressure you will run out of pump even faster then you are now.


The sole reason to increase fuel pressure is to effectively attempt to increase fuel injector.

 

[shelbyelite]

Which pulley are you running Mark?

 

[Fubar]

Yeah do not do this. If your out of pump already and you raise fuel pressure you will run out of pump even faster then you are now.


The sole reason to increase fuel pressure is to effectively attempt to increase fuel injector.

I would only do this if I select to go with dual 044 Bosch pumps. They would be able to handle 100psi without any issue. I am told that the fuel lines themselves should be more than capable of dealing with 100psi. This is all just speculation at this point. I am still considering a few options. The point would be to get better atomization and fuel spread.

btw, Shelby I am running the 19lbs pulley but it maxes out at closer to 20lbs.

 

[Mullet]

just a armchair mechanic on this one.........

pump more fuel in however you have to and crank up the power (smaller pulley?). new fuel pumps and injectors?

 

[Whipple Charged]

New info:

The fuel pumps are probably working as intended. They are supposed to be good to 1200hp. Here is the math:

770 rwhp
130 lost in the transmission (conservatively)
300 lost in the whipple
------
1200 crank hp

Fubar,

300 is quite a high number. Remember pumps are good for a certain HP, but there is a tremendous loss in the system through filters, lines, fittings, etc. You have to also add all the losses through all the other componets, dry sump, alternator....... There's also induction losses through turbelence and restrictions, same can be said for airflow through the IC.

Thanks,
Dustin

 

[Whipple Charged]

300hp on the Whipple might be a little high but it would explain the fuel usage.

Wikipedia says the a roots type supercharge is only 50-58% efficient (or inefficient as it appears) at 15lbs of boost. I think the whipple is a little more efficient than this article indicates.

I couldn't find a clear reference on the transaxle efficiency.

The best roots, the TVS is not even that at 15psi at the rpm's needed to turn, that would be at possibly 8000rpm. Old roots hovered in the 30-40% AE at 8psi and far less at 15psi. Also, unlike a roots, a screw power consumption is not stack as much as. Meaning if it takes 100hp for 10k, 15psi, it doesn't take 200hp at 10k, 30psi. RPM takes more energy than boost.

 

[Whipple Charged]

I agree with your point about constructive advice, but offer the following:

A 14-71 blower on a top fuel car (500CID, 50+PSI manifold pressure) is reputed to consume about 400HP, so an engine 70% of the displacement with under 40% of the manifold pressure with an arguably more efficient design is "unlikely" to consume 300hp. More likely it is *under* 112hp.

http://en.wikipedia.org/wiki/Top_Fuel

The power lost in a transmission is not solely a function of horsepower. Some power is consumed solely as a function of RPM (lubricant pumps, fluid drag, bearing drag). This power consumption does not go up by increasing torque. Additionally, the power lost to the transmission depends on the gear selected. I have not taken apart a Ricardo but a M-22 in fourth gear is a simple straight shaft with no loads be transmitted by any of the gears. What this all means is that power lost to a transmission is not a fixed percentage of horsepower (doubling the hp does not double the power consumed in the transaxle.)

As a minor note, an engine operating at a BSFC of .50lb/hp.hr (an unexceptional figure) is extracting about 25% of the available energy from the gasoline.

36600 Watt hours in a gallon of gas (a little less when mixed with ethanol)
6lb/gallon
3050Wh in .50lb gasoline
746W=1hp
746/3050=24%

Many gasoline piston engines operate at close to .4/lb/hp/hr which equates to a little over 30% of the energy being converted into shp.

Just wanted you to know that I don't just pull these statements out of the air.

Anyway there are two approaches to getting more fuel available at the injectors. Increasing pump capacity or reducing restrictions in the system (Torrie's suggestion of checking the fuel filter is a good place to begin)

A good 1471 at 55psi on a current top fuel motor takes between 900-1100hp depending on the overdrive!!!!! Our 10 liter screw compressor at 60psi takes 600hp.

The 245ax at 21psi, and considering no inlet restrictions (the air box and MAF are restrictions), the blower will take close to 150hp to operate. Because the airbox hurts the flow at this flow rate, I can estimate it adds another 10-15hp to the compressor power consumption which does increase with boost.

Please also note, the 4.0L SC's have a new discharge and bearing plate design for less leakage at higher pressure. We also modified the inlet shape significantly.

Also, the more pressure you have against the fuel injector, the harder it is for it to fire, so you have to add this information into your equation.

 

[Whipple Charged]

Thanks Shadowman, it just seems like a lot of folks take great pleasure in telling me why I am wrong. I hate to be an e-dick and about it but it gets a little old. I am just trying to present information to the board in hopes of finding a solution and possibly helping other members should they find themselves in a similar situation. Do you think those numbers are out of line? I know that you do not like to comment until all of the information is in and the research has been done. So when you feel it is appropriate, let me know what you think.

Nota4re, do you see what I'm talking about with the ECU? I did not mean to imply that it is chasing the A/F in open-loop. Rather, that the ECU can, and does, correct for low fuel pressure with another table by adding to the duty cycle of the fuel injector. It just happens to do it so well that there is never a spike in the A/F.

Yukonranger, I do not know what the fuel consumption is, per say. All I know is that my fuel pumps are maxed out and that the 3.4L whipple uses up to 90% of the cars fuel pump capacity. Therefor, it is logical to assume that my fuel pumps are working as intended. It was also suggested by my tuner (Shawn Fischer) that the larger supercharger would probably take more hp to turn. Which makes sense, it has bigger with heavier parts that push more air.

I think we'd all be surprised to see exactly how much hp those things eat up... even in stock form.

I would love to hear the Whipple guys chime in.

Regards,
MM

You've done an excellent job, really appreciate you posted all the data and findings.

Bigger SC's always take more HP to operate at identical RPM's with all things being equal. But the gains are in the lower rpms, typically 2000rpm give or take a few. This is significant in parasitic losses.