ProCharged Can-Am - Raising the bar

[CanAm Dave]

1.2 bar that is! I decided to change my supercharger pulley to the next size down (3.4inch). This is the smallest one I can fit as it takes my supercharger speed close to its maximum speed. It will now spin at 60,000rpm at 6,500rpm engine speed.

For those that don't know my engine it's a dart blocked 383 (6.3l) SBC. I built the engine from stratch to use with the supercharger. It has all forged internals including J.E. dished extreme duty pistons. Static compression is 7.76:1. It uses the Holley commander Multi point fuel injection with 65lb injectors. When last dynoed it came in at 650bhp and 700lbs of torque.

After doing a little on-road mapping on Saturday I gave it the beans and hit 16psi boost. The accelertion was just mind blowing. I put the boot in at 40mph and with no wheelspin it took off like a bullit. My calculations would put the power around 730bhp. I'll be back on the dyno in the spring to know for sure. The engine is receiving new heads and valve gear over the winter. I will also be fitting my water/methanol injection kit. A new exhaust system is also on the list so I can get the noise down so I can run in some events next year.

Hope to see some of you at the FOD on Sunday.

Regards Dave

[qwick]

Awesome! Just dying to see that car.

Good luck with it.

[Boosted LS1]

Top stuff Dave, it must have moved on a lot since last year. You must be very happy.

[CanAm Dave]

Boosted LS1 said:

Top stuff Dave, it must have moved on a lot since last year. You must be very happy.

Hi Mike

It sure has! Two pulley sizes smaller since last year and bigger 65lb injectors. The bypass valve works great enabling me to drive off boost while cruising and returning 20mpg. I'm still having a few issues with the acceleration mixtures but I hope to sort them out on the hub dyno in the spring. Happy, you bet this thing generates massive smiles.

Are you coming to the factory open day this year? It's on Sunday!

Regards Dave

[Boosted LS1]

I don't believe you chap!

It was real slow last time, joke! Sunday's my church day but I suppose I could help you change into third and turn to the dark side. Tricky choice for me to make though, God, the Devil or your car.

Easy, see you Sunday

Edited by Boosted LS1 on Tuesday 29th July 17:00

[738 driver]

Dave,
That sounds like a killer set-up with great results, that pro charger looks quite an eye-opener and different too, well worth all your effort.
When you say new heads and valve gear (AFR's jesels etc I presume) how did you spec your cam to the forced induction system/ head selection.
The only reason I ask is that Ive been working with a guy called Mike Jones (jones cams) over the last few weeks..... a top guy on specialist SBC cams and one of his custom designed/ ground cams is only marginally more expensive than the Comp catalogue stuff! Mike spent quite some time understanding what I am trying to achieve then came up with a solution, very good personal service and reasonable too.

[CanAm Dave]

738 driver said:

Dave,
That sounds like a killer set-up with great results, that pro charger looks quite an eye-opener and different too, well worth all your effort.
When you say new heads and valve gear (AFR's jesels etc I presume) how did you spec your cam to the forced induction system/ head selection.
The only reason I ask is that Ive been working with a guy called Mike Jones (jones cams) over the last few weeks..... a top guy on specialist SBC cams and one of his custom designed/ ground cams is only marginally more expensive than the Comp catalogue stuff! Mike spent quite some time understanding what I am trying to achieve then came up with a solution, very good personal service and reasonable too.

New heads are Dart Pro1 CNC 227 and Jesel valve gear. My cam choice came after looking at all the catalogues and chatting with various experts. I went with Comp Cams in the end. What can I say but it works! It's a supercharger/nitrous cam and a hydraulic roller. The cam has more lift on the exhaust side to help cope with the forced induction. I don't need big revs to make power with this motor and I now have the right gears to make use of it. Look forward to meeting you at the open day if your going. If not your still welcome to come and see the car. I've just been mad busy of late.

Regards Dave

[qwick]

Dave,

Can you tell me/us a bit more about the bypass valve, why you got it/what it does, where you got it from and where it fits will do for starters

Rich

[chuntington101]

CanAm Dave said:

1.2 bar that is! I decided to change my supercharger pulley to the next size down (3.4inch). This is the smallest one I can fit as it takes my supercharger speed close to its maximum speed. It will now spin at 60,000rpm at 6,500rpm engine speed.
Regards Dave

time to fit a F-1 now i think mate! lol

i have read about a corvetete that runs a F2!! it ran on E85 and they didn't even bother with an intercooler as they said the inlet air temps where very low thanks to the MASSIVE blower!

being serious though, congrats on the grate numbers and cant wait to see what they new ones are.

Chris.

[eliot]

chuntington101 said:

i have read about a corvetete that runs a F2!! it ran on E85 and they didn't even bother with an intercooler as they said the inlet air temps where very low thanks to the MASSIVE blower!
Chris.

According to my calcs @ 20 psi even with a 100% efficient blower, you still gain 81'c in temperature - so that's BS i'm afraid.

[CanAm Dave]

qwick said:

Dave,

Can you tell me/us a bit more about the bypass valve, why you got it/what it does, where you got it from and where it fits will do for starters

Rich

Hi Rich

The bypass valve is fitted between the chargecooler and the throttle body. It's a standard ProCharger part. The bypass valve is open during vacuum and light load conditions. This means no boost at idle, light load or cruise conditions. The bypass valve simply dumps the air to atmosphere under thoses conditions. As soon as the throttle is open far enough there is not enough vacuum to hold the valve open and it closes forcing all the boosted air into the engine. That's my favorite bit when the valve closes as it all goes quiet and then you are launched into the distance. It makes me smile every time!

Regards Dave

[Scuffers]

CanAm Dave said:

qwick said:

Dave,

Can you tell me/us a bit more about the bypass valve, why you got it/what it does, where you got it from and where it fits will do for starters

Rich

Hi Rich

The bypass valve is fitted between the chargecooler and the throttle body. It's a standard ProCharger part. The bypass valve is open during vacuum and light load conditions. This means no boost at idle, light load or cruise conditions. The bypass valve simply dumps the air to atmosphere under thoses conditions. As soon as the throttle is open far enough there is not enough vacuum to hold the valve open and it closes forcing all the boosted air into the engine. That's my favorite bit when the valve closes as it all goes quiet and then you are launched into the distance. It makes me smile every time!

Regards Dave

so I take it from this you have the charger's inlet un-restricted at all times and the by-pass valve is actually doing the job of a dump valve?

(making the assumption here that you have a centrifugal supercharger??)

[CanAm Dave]

Scuffers said:

CanAm Dave said:

qwick said:

Dave,

Can you tell me/us a bit more about the bypass valve, why you got it/what it does, where you got it from and where it fits will do for starters

Rich

Hi Rich

The bypass valve is fitted between the chargecooler and the throttle body. It's a standard ProCharger part. The bypass valve is open during vacuum and light load conditions. This means no boost at idle, light load or cruise conditions. The bypass valve simply dumps the air to atmosphere under thoses conditions. As soon as the throttle is open far enough there is not enough vacuum to hold the valve open and it closes forcing all the boosted air into the engine. That's my favorite bit when the valve closes as it all goes quiet and then you are launched into the distance. It makes me smile every time!

Regards Dave

so I take it from this you have the charger's inlet un-restricted at all times and the by-pass valve is actually doing the job of a dump valve?

(making the assumption here that you have a centrifugal supercharger??)

Correct! It does a much better job as having a light car it allows me to get off the line quicker before building the boost. In fact the bypass can be controlled electronically to allow boost control during drag starts.

Regards Dave

[eliot]

I think we are mixing terms here.
A bypass valve, mainly fitted to positive displacement blowers (roots type) - bypasses (i.e. is fitted before and after the blower - it goes around) the blower at load loads to avoid pumping losses. Look on the Jaguar XJR's.

Dump valve releases the pressure when closing the throttle say at gear changes, but also tend to be open during high vacuum (idle/cruise).

My dump valve bleeds of the excess pressure in the system in certain areas of cruise, as the turbos are producing more air than the engine requires. I pressume Dave's is doing this too. If its not fitted, that excess pressure has nowhere to go except back through the compressor - which isn't healthy for it.

[qwick]

eliot said:

I think we are mixing terms here.
A bypass valve, mainly fitted to positive displacement blowers (roots type) - bypasses (i.e. is fitted before and after the blower - it goes around) the blower at load loads to avoid pumping losses. Look on the Jaguar XJR's.

Dump valve releases the pressure when closing the throttle say at gear changes, but also tend to be open during high vacuum (idle/cruise).

My dump valve bleeds of the excess pressure in the system in certain areas of cruise, as the turbos are producing more air than the engine requires. I pressume Dave's is doing this too. If its not fitted, that excess pressure has nowhere to go except back through the compressor - which isn't healthy for it.

So, a bypass valve goes before and after the supercharger routing air around it rather than through it under low load, when the vacuum increases the bypass shuts and air is drawn into the supercharger and forced into the inlet under pressure, is that right?

If so, is that how yours fits Dave or have you something slightly different which releases pressurised air between the supercharger and the inlet?

[eliot]

qwick said:

So, a bypass valve goes before and after the supercharger routing air around it rather than through it under low load, when the vacuum increases the bypass shuts and air is drawn into the supercharger and forced into the inlet under pressure, is that right?

Yes - but not on centrifugal chargers like Daves.

qwick said:

If so, is that how yours fits Dave or have you something slightly different which releases pressurised air between the supercharger and the inlet?

His is a std dump valve I believe, to release boost on gearchange or when snapping the throttle shut.

[chuntington101]

eliot said:

chuntington101 said:

i have read about a corvetete that runs a F2!! it ran on E85 and they didn't even bother with an intercooler as they said the inlet air temps where very low thanks to the MASSIVE blower!
Chris.

According to my calcs @ 20 psi even with a 100% efficient blower, you still gain 81'c in temperature - so that's BS i'm afraid.

you are right eliot, the fact they where pumping Sh!T loads of E85 in there helped temps though!

i think since then thry have fitted an intercooler.

stil think Dave should fit a F1 though!

Chris.

[Scuffers]

eliot said:

qwick said:

So, a bypass valve goes before and after the supercharger routing air around it rather than through it under low load, when the vacuum increases the bypass shuts and air is drawn into the supercharger and forced into the inlet under pressure, is that right?

Yes - but not on centrifugal chargers like Daves.

qwick said:

If so, is that how yours fits Dave or have you something slightly different which releases pressurised air between the supercharger and the inlet?

His is a std dump valve I believe, to release boost on gearchange or when snapping the throttle shut.

that's how I am understanding it....

I actually don't think this is such a great way to plumb it as unless the dump-valve is HUGE, you will still have some pressure behind the throttle all the time, this has several issues:

1) heat, pushing what will be a huge volume of air though a dump-valve continually is going to heat it and the surrounding parts up
2) the charger is basically running flat out all the time (for a given engine speed), this not only heats up the compressor, but also causes significant parrasitic looses (with no gain)
3) the air filter is going to get clogged up somewhat faster than normal, as the charger will be sucking air though it 100% of the time as fast as it can.

now, the reason people do this is that they argue that it speeds up throttle response, however, whist this is true of turbo's, the same logic does not apply to a crank driven charger, which is why just about every OEM Supercharger setup has the throttle in front of the charger, this means that when throttle is closed, the charger is spinning in a vacuum, thus not consuming much power and heating stuff up (roots/screws/etc tend also to have by-pass valves as well to manage the airflow at small throttle openings).

[CanAm Dave]

Scuffers said:

eliot said:

qwick said:

So, a bypass valve goes before and after the supercharger routing air around it rather than through it under low load, when the vacuum increases the bypass shuts and air is drawn into the supercharger and forced into the inlet under pressure, is that right?

Yes - but not on centrifugal chargers like Daves.

qwick said:

If so, is that how yours fits Dave or have you something slightly different which releases pressurised air between the supercharger and the inlet?

His is a std dump valve I believe, to release boost on gearchange or when snapping the throttle shut.

that's how I am understanding it....

I actually don't think this is such a great way to plumb it as unless the dump-valve is HUGE, you will still have some pressure behind the throttle all the time, this has several issues:

1) heat, pushing what will be a huge volume of air though a dump-valve continually is going to heat it and the surrounding parts up
2) the charger is basically running flat out all the time (for a given engine speed), this not only heats up the compressor, but also causes significant parrasitic looses (with no gain)
3) the air filter is going to get clogged up somewhat faster than normal, as the charger will be sucking air though it 100% of the time as fast as it can.

now, the reason people do this is that they argue that it speeds up throttle response, however, whist this is true of turbo's, the same logic does not apply to a crank driven charger, which is why just about every OEM Supercharger setup has the throttle in front of the charger, this means that when throttle is closed, the charger is spinning in a vacuum, thus not consuming much power and heating stuff up (roots/screws/etc tend also to have by-pass valves as well to manage the airflow at small throttle openings).

My first point is that neither of you can read as quicks first point is wrong as vacuum opens the valve not shuts it.
Your first point Scuffers is oh so wrong! The air passing through the bypass valve is a lot cooler than than the surrounding heat in the engine bay so it actually has a cooling effect. My chargecooler is very efficient. The bypass valve has a 38mm valve.
Your second point makes no sense. The supercharger runs at a speed relative to engine speed so it is only running flat out at max engine rpm. The bypass allows me to run better economy off boost.
Your third point is not worth a reply.

OEM supercharger setups I really don't care how they do it! This works for me! There is not one supercharged car produced today that is faster than mine! Even the twin supercharged E85 fuelled CCXR that produces 1004bhp is slower than my car.

I have done some 3,000 miles with my setup and I have no issues with it. It works and next year I will prove it at various events.

Regards Dave

[andygtt]

CanAm Dave said:

The supercharger runs at a speed relative to engine speed so it is only running flat out at max engine rpm. The bypass allows me to run better economy off boost.

Hi Dave
Not trying to get involved as my undersatnding of Superchargers is limited, just genuinelly trying to understand the logic.
I understand that the supercharger runs at the speed 100% dictated by the crank, but doesn't it draw a different amount of parasetic power from the crank depending upon how much load is on the impeller?
If the impeller is spinning in vacume then surelly it will sap less power than if it was producing boost? or does it draw the same amount of power regardless of the load?
Isnt the buypass you have large enough to remove boost completely, I dont' have any real idea but 38mm seems large enough to me? am I missing something?

Gotta say I really need to have a proper catch up with you and take a real good look at your car as I keep missing you at the shows.... your in Suffolk arn't you?... maybe me and Graham can go for a blast and meet up somewere?