tomcat

One of the big selling points of centrifugal superchargers is their ability to fit under the hatch. How important is this to you? Is your EFI engine height a factor in the decision? Do you know how much restriction to air flow is created by all the ducting, elbows and transitions used in these kits to get them to fit under the hatch?

Procharger, Vortech, and others working with the Vortech supercharger all lay out their kits pretty much the same way. They mount the supercharger in front of cylinder #1, then duct the compressed air to an intercooler mounted in front of the other cylinder head, and from there they duct it to the throttle body. When there isn't enough room to mount the intercooler in front of the engine, they mount it remotely and add some more ducting and elbows.

Procharger's 500 EFI kit points the supercharger down to a remote intercooler. More ducting and elbows. The latest variation is by Gaffrig, which mounts the supercharger in front of cylinder#2 and runs the ducting down and under the crank pulleys then up to an intercooler mounted in front of the power steering pump. This allows them a fairly long radius elbow (good) into the 500 EFI throttle body which is at the front of the intake plenum, not the side like the 454/502 MPI.

All these kits go to great lengths to keep the height of the installed kit to the same as or just barely higher than stock. This is apparently a big selling point and a "must" for the design. But considering the sacrifices being made on air flow for the sake of this height issue, I say, "GET OVER IT!!" If you have a 700 HP engine you should have a hood scoop on top of it anyway.

Seriously though, is the height issue as important as these kit designs suggest? How tight is it in your engine compartment? The stock height of the 454/502 MPI is 21 3/4" from crank centerline. I don't know for sure but the 500 EFI looks about the same. How many of you with these engines would have a problem if that height was increased to 26 3/4" (+5")? This is only 1/2 inch higher than Procharger's dual carb box.

I'm thinking that if the height restriction was relaxed, most of the losses could be eliminated and we could get rid of the plumber's nightmare. I have a design in mind, but does the extra 5" make it a no go from the start?

bajah2x105

tomcat, I will have to say NO-the piping will not slow down velocity. Most of the Pro 5.0 cars that are running some 1800 to 2000 hp are running almost 10ft of piping or more in their cars. All of the intercoolers are sitting next to the driver with a water chilled system. These Mustangs are on the cutting edge of supercharged and turbo tech., so I don't think that length is a factor. I've looked at systems like this that range from 3 to 5" piping. Most of the piping however is not bent hard like the ProCharger and Vortech kits. Another problem I see is the use of rubber tubing that comes with these kits-a ton of flex. The only good thing about that is the cost factor. I will reconfigure my piping soon for that reason. Whether it works to my advantage is a different story. I'm no pro, but when I see a small block make that kind of Hp. it sort of get's my attention. Just my .02! That is a great observation though. Always thinking!

Turbojack

TC
I think the height is big factor. I know the reason I did was so I could get it under the cover. As far as lost HP. I am looseing big MPH by having big bowrider up front. But these are the things I wanted. I give up MPH, & I guess some HP for comfort. Plus it is also nice for no one to know what you have under cover. So crank a little more boost in it.

Kokopelli

Unfortunatley height is a big issue. My wife loves her sun dech and would be seriously pissed if the was a hole in it or a scoop on it. I think the whipple is great system as you don't have the long plumbing runs and the height does not go up either.

Bayley

"I think the Whipple is great system as you don't have the long plumbing runs and the height does not go up either."

Not sure I agree with this. The Whipple SC and IC will add about 1 and 1/2 inches to the overall height of the motor on the 454's and 502's. However, the kit for the HP 500's, I believe, is actually lower than the highest point of the exhaust headers. So, height really isn't an issue with kits. The biggest problem I ran into was the additional space I needed infront of the blowers. The blower pulley's and tension add about 3 to 4 inches of forward space. This is where all my headaches came from.

As for the "efficiency" of all the plumbing, I've heard most people go by the 1/2 psi of loss per 90 degree bend. I think this would more of a difference in an automotive application where fast spool up times and larger boost amounts are called for. I wouldn't think it makes too much of a difference in marine applications. Although, I am VERY happy with the throttle response of the Whipple setup. Especially after the addition of larger throttle bodies. The mid range punch is unbelievable... especially for a "smaller" motor.

Bayley

...another picture of frontal clearances.

502KC

The 500efi whipple kit does not add any extra width or height. All that is required is 1.5-2 inches for the front pulley set up. Whipple designed this kit to allow install in twin applications.

Turbojack

Thre were 2 reasons I went with the Procharger verse Whipple. First was $$$ difference (about 8-9K less for Procharger). Second was engine height clearance. Only way quad rotor wipple would fit was with EFI, & that was 4K more money.

I have never had a boat with scoop but on some scoops "How do you guarantee that Girls long hair does not get caught up in blower belt" Make sure anyone with long hair is not sitting in seat in front of scoop?

tomcat

So how high is too high?

Turbojack - Your dual carb box is 4 1/2" taller than the 502 MPI intake plenum. Got an extra 1/2"? Then your model of boat could fit my integrated intercooler/EFI plenum design under the cover. Can't do much about the front clearance required for the crank pulley and blower drive, but that's not the problem on Procharger anyway; the intercooler sticks out 2" farther than the blower pulleys.

So the original question is "How many of you with EFI engines would have another 5" clearance under the cover?"

All the small diameter tubing, elbows and transitions do add up to a lot of restriction. We just accept it because it's easy to install this way and we can always change pulleys for more boost. I've beat this topic to death in other threads, so I won't go into the details here, but I designed and fabricated an integrated intercooler/carb box with a special transition from the supercharger to the intercooler. No tubing, no elbows. When tested on the flow bench this configuration flowed 37% more air at the same pressure drop (28" water). When you translate this into the reduction in back pressure seen by the supercharger, the compressor map says about 10% more air will be pushed into the engine. That's not trivial, but it does require a more complex design, and I will be the first to admit that the idea may never be accepted.

The drag racers are doing amazing things, but there is a very good reason why they stay with the tubing. Thermal inertia. They are using enormous intercoolers that have to be put in the passenger seat for space reasons, so tubing is the only way to make the connection. But the reason they are using the enormous intercoolers is not because they need that much core volume for the power being produced. They are chilling a big chunk of aluminum down to freezing with ice, and the race is over by the time it even starts to warm up. In a steady state application like a boat, we can't use this thermal lag to any advantage but in a 7 second drag race, it gives them an edge.

Turbojack

I am running out of room on the back of the box, cover is sitting on box. Box in front I have about another 1", Why the difference? Intake manifold, Back carb sits highter than front carb.