I started out wanting to do a custom eaton swap on my car. Meaning I would fab an adapter plate and run the eaton on b heads. I then decided after a lot of research and some fabbing that the eaton is basically just too big. Namely the snout is too long. You have to move it back so far it's ridiculous. I then decided to use the 96-98 or 99-01 kenne bell blower on our b heads still with the use of an adapter plate. The 96-98 is what I though at first, but even if I intercool it it has no bypass so you can't run the boost too high on the street. So the 99-01 blower unit with a built in bypass seems to be the best fit. The cost of switching to c heads and buying the intercooled kit would be near 10 grand. So I want to stick with the b-heads and intercool the one of the kbs for someone, or have someone buy one of the kb's and intercool it on our b heads. Hopefully there is a way to buy just the blower unit from kb, as almost all of the rest of the kit will not be needed. Anyway, I want to gauge any interest if anyone wants to do this. I don't have the money to buy a kb right now, but I don't want my project to go to waste. It is still in the semi-beginning stages, but I can't continue to spend money on it unless someone wants it on their car. This goes for someone who already has a 1.5 or 2.1 blower and wants to get the temps down a little or run some more boost! I did this write up so everyone would know how it works and what the limits may be and to see if anyone is interested. I also just really enjoy this stuff and figured some of you would too. Enjoy :beer:
Intercooled Positive Displacement Blowers 101: An Exploration of Supercharging the 96-98 Cobra. lol.
First of all let's discuss how an intercooled positive displacement supercharger works. Here is a diagram of the 03-04 system:
The blower blows air directly down into the intercooler which sits in the lower intake manifold. The air (shown in red) is routed down teh intercooler then back up the sides of the intercooler/manifold then flipped around again to go down into the heads. One reason the 03-04 system works well is because the width of the intercooler is equal to the width of the 'lower intake - intercooler,' or more simply put the intercooler takes up half the lower intake. This ensures that the volume of air at any given point is same to any other point. If the volume allowed to flow at any one point were different, the laws of physics would cause the air to speed up or slow down meaning increased or decreased psi at that point. Also, if the air is compressed through a smaller space it will create more heat.
Here is a picture of what our lower intake looks like without the intake hat:
The things filling it up are the runners so they wil have to be removed if you want to put an intercooler in there. Here we are:
So the intercooler is going to go in that hole. The problem is the bowl in our lower intake is not nearly as wide as the bowl in the 03-04 lower intake. To make it fit, I have cut off some of the rows of an 03-04 intercooler. I first cut it down to just the core as shown. Here is the 03-04 intercooler core:
And here is the custom made 96-98 intercooler core:
I cut off three rows so it is now 30% smaller than the 03-04 intercooler, although I think we could get away with only cutting two rows off. For this reason, it will not cool as well as the 03-04 intercooler. To what extent i have no idea. That is the main part to be tested on the guinea pig car. The intercooler will obviously have to be welded back together so that the housing on both ends (shown later) is there to direct the coolant. Whatever it does cool should be beneficial though since the 96-98 kb blower runs cool enough to be run without an intercooler up to 12 pounds or so that I've heard of, so cooling the charge some should make it safer or allow a little more boost. My guess would be a max of 15 pounds, but that is purely speculation and needs to be tested.
We will talk about intercooler lines later, but assuming all that is worked out here is a diagram of how our lower intake would look with an intercooler in it:
As you can see it's the same idea as the 03-04 intercooling system. The difference is the volume of air allowed down the intercooler and up the sides of the intercooler/lower intake. The diagram shows exactly how our lower intake would look. There is a smaller part at the bottom, then at the top where the air is directed into the heads it opens up. I think the air would slow down some at this point. I am not sure how much that would affect heat or boost pressure. The diagram also shows a very large intercooler for that lower. It is obviously too big, but that's what it would look like if the 03-04 intercooler wasn't cut down to size. So that's the basic idea, let's look at making it work mechanically and the obstacles we face.
These pictures shows how the fluid flows through the intercooler. Please note that the arrows are wrong, because the fluid flows in the bottom hole and out the top, but it's the same concept:
You can also see the ends of the intercooler that need to be welded back on after they were cut off to make the core smaller. The fluid flows in the bottom hole, cools all the little fins which cool the air, around the end and out the top hole. To get out of the lower intake, there is a hole in the end of the 03-04 lower as shown here:
There is a bracket (shown later) that bolts to the lower and leads directly to the coolant lines. Here is the end of the 96-98 lower that the hole will need to be made in:
You may notice those bolt holes are in the way. They will need to be grinded off. They connect to a bracket that holes the IMRC cables. Because of this, the IMRC's should be deleted. After an oval hole is cut, the bracket will need to be bolted on. Here is what it will look like:
If any part of the supercharger hangs over the back of the manifold, then the bracket will have to be mounted upside-down. I don't forsee this as a problem and that may be a better mounting position anyway. You may have noticed also that this is the back of the lower intake we are bolting this to, when on the 03-04's this bracket is mounted on the front. The difference is we have our alternator smack in the middle of the front of the engine where that bracket will go. This picture shows that there is no way to make it fit without moving the alternator:
A solution that kb uses on it's 99-01 cars is they use a bracket to flip the alternator around and move it to the side as shown:
This is an option for us if we want to fabricate a bracket or try to order one form Kenne Bell. It looks fairly simple and would allow us to mount the bracket on the front. There is a few advantages to this. First of all you could use the 03-04 fluid lines assuming the part of the intercooler bracket that sticks up so high shown in the picture earlier does not hit the snout of the blower. Also you do not have to deal with the problem of the fuel rails around the back of the lower intake. here is a picture of them:
They are rubber (or similar) around the back and would need to be lengthened or moved to fit the intercooler bracket. The person getting this installed on their car would decide if they want to try and make the intercooler bracket on the front or the back. One more thing I forgot about putting it on the back is that the intercooler lines would be ran over or around the engine to the heat exchanger. We would probably want to use a LFP dual pass heat exchanger along with a large intercooler reservoir to help cool the small intercooler. An 03-04 intercooler pump would be along one of the intercooler lines somewhere and wired to turn on with the key.
The only thing left would be mounting the blower on top of all this, and getting the intercooler attached to it somehow. I have not gotten a definite answer from kb, but I believe the mounting holes on the kb will not line up with the holes on the stock lower. Also, on the 03-04 system the intercooler bolts to the bottom of the supercharger to keep it in place in the lower intake. Here is a picture of where the intercooler would mount to. It's the inner ring of bolt holes that it mounts to while the outer ring mounts to the lower intake:
To solve both of these problems, we will use an aluminum adapter plate. The plate will be as wide as the lower intake/supercharger needs it to be. There will be holes on it to screw it to the supercharger and to screw it to the lower intake. The inside of the plate will have a hole that is exactly the size of the intercooler ensuring that all air is forced down through it. There will be bolt holes along the outside of the plate to bolt the intercooler to just as it works on the 03-04 cobras shown earlier. That quickly solves the problem of having a place to bolt the intercooler to and making sure you can bolt the blower to the lower intake. The plate would also allow you to move the blower forward or backwards before drilling the mounting holes to make sure the pullies line up.
One more issue that is a deal breaker for some is that this kit will not fit under the stock hood to the best of my knowledge. I would guess a max of 2.5 to 3" cowl will be needed. The 96-98 lower intake is much taller than the kb "open house manifold shown here:
I have thought a little bit about altering the open house manifold to put the bowl from the 96-98 lower in it. That way it would fit under the stock hood. I haven't looked to seriously into it, since this will be rendering the part unusable for a normal installation. I have asked KB about ordering just the "open house manifold" and have yet to hear a response. Altering this may yield better results than using the stock lower, but would require a little more fabbing. You couldn't just weld the bowl from the 96-98 lower to it because as I said it is not as tall as the stock lower. The intercooler would have to stick up where the blower should go. I believe though that after you remove the IMRC controller from under the manifold you could make the bowl deeper. Just weld some kind of metal to the open house manifold then to the bowl form the stock 96-98 lower. You may be able to lower it just enough so the intercooler would be low enough under the blower. That would also eliminate the problem of the lower intake expanding at the top as mentioned earlier. The volume would be more constant throughout and may be the better option.
That would be all there is to a basic intercooling kit. Although the manifold will be modified it leaves the supercharger completely unharmed in case it doesn't work out or something you aren't stuck with a messed up blower. I would provide all the main parts also. I would take care of the modified lower intake, intercooler, adapter plate, and anything else that is not stock off an 03-04 cobra. I would leave people to find those few other pieces themselves since they are easy to find and people can find the best deals possible.
Afterword:
There is one other problem not mentioned here that would relate to wanting to run higher boost after the supercharger is intercooled, and that is the bypass valve. What this does is at low rpms like when you are sitting at a stoplight or in traffic, the bypass valve is open allowing air that has already been compressed to recirculate to the plenum of the blower again. This helps keep the temperature of the blower down and the engine from seeing boost constantly. The 2.1 kb for 96-98 cobra does not have a bypass valve. One would need to be fabbed. I have talked to kb on this issue and they say it has been done, but they don't know how it was. They also said that running the blower at upwards of 13 pounds without a bypass is severely limiting the life of the blower. A way around this would be to use the 99-01 kb 2.1 which has a bypass integrated. I don't know if you could order just the compressor from them or not. I am waiting for a response on that, but that would solve this problem, and hopefully the 99-01 compressor will not be too much more that the 96-98 one. That would be one way to solve this easily. I will talk about the bypass valve on a later installment of this article.
Thank you for reading as it took me a while to write all this up. I am open to any and all suggestions/comments or if you can think of a better way to do something let me know. After all I am only one guy, I can't think of everything. Remember, even if you don't have a built shortblock to run higher boost, this kit will make the lower psi kit safer since temps will be lower. High temps are what kill a stock shortblock. It would also open up the availability to up the boost when it is built. And we can't forget... twin screw blowers love nitrous!
Intercooled Positive Displacement Blowers 101: An Exploration of Supercharging the 96-98 Cobra. lol.
First of all let's discuss how an intercooled positive displacement supercharger works. Here is a diagram of the 03-04 system:
The blower blows air directly down into the intercooler which sits in the lower intake manifold. The air (shown in red) is routed down teh intercooler then back up the sides of the intercooler/manifold then flipped around again to go down into the heads. One reason the 03-04 system works well is because the width of the intercooler is equal to the width of the 'lower intake - intercooler,' or more simply put the intercooler takes up half the lower intake. This ensures that the volume of air at any given point is same to any other point. If the volume allowed to flow at any one point were different, the laws of physics would cause the air to speed up or slow down meaning increased or decreased psi at that point. Also, if the air is compressed through a smaller space it will create more heat.
Here is a picture of what our lower intake looks like without the intake hat:
The things filling it up are the runners so they wil have to be removed if you want to put an intercooler in there. Here we are:
So the intercooler is going to go in that hole. The problem is the bowl in our lower intake is not nearly as wide as the bowl in the 03-04 lower intake. To make it fit, I have cut off some of the rows of an 03-04 intercooler. I first cut it down to just the core as shown. Here is the 03-04 intercooler core:
And here is the custom made 96-98 intercooler core:
I cut off three rows so it is now 30% smaller than the 03-04 intercooler, although I think we could get away with only cutting two rows off. For this reason, it will not cool as well as the 03-04 intercooler. To what extent i have no idea. That is the main part to be tested on the guinea pig car. The intercooler will obviously have to be welded back together so that the housing on both ends (shown later) is there to direct the coolant. Whatever it does cool should be beneficial though since the 96-98 kb blower runs cool enough to be run without an intercooler up to 12 pounds or so that I've heard of, so cooling the charge some should make it safer or allow a little more boost. My guess would be a max of 15 pounds, but that is purely speculation and needs to be tested.
We will talk about intercooler lines later, but assuming all that is worked out here is a diagram of how our lower intake would look with an intercooler in it:
As you can see it's the same idea as the 03-04 intercooling system. The difference is the volume of air allowed down the intercooler and up the sides of the intercooler/lower intake. The diagram shows exactly how our lower intake would look. There is a smaller part at the bottom, then at the top where the air is directed into the heads it opens up. I think the air would slow down some at this point. I am not sure how much that would affect heat or boost pressure. The diagram also shows a very large intercooler for that lower. It is obviously too big, but that's what it would look like if the 03-04 intercooler wasn't cut down to size. So that's the basic idea, let's look at making it work mechanically and the obstacles we face.
These pictures shows how the fluid flows through the intercooler. Please note that the arrows are wrong, because the fluid flows in the bottom hole and out the top, but it's the same concept:
You can also see the ends of the intercooler that need to be welded back on after they were cut off to make the core smaller. The fluid flows in the bottom hole, cools all the little fins which cool the air, around the end and out the top hole. To get out of the lower intake, there is a hole in the end of the 03-04 lower as shown here:
There is a bracket (shown later) that bolts to the lower and leads directly to the coolant lines. Here is the end of the 96-98 lower that the hole will need to be made in:
You may notice those bolt holes are in the way. They will need to be grinded off. They connect to a bracket that holes the IMRC cables. Because of this, the IMRC's should be deleted. After an oval hole is cut, the bracket will need to be bolted on. Here is what it will look like:
If any part of the supercharger hangs over the back of the manifold, then the bracket will have to be mounted upside-down. I don't forsee this as a problem and that may be a better mounting position anyway. You may have noticed also that this is the back of the lower intake we are bolting this to, when on the 03-04's this bracket is mounted on the front. The difference is we have our alternator smack in the middle of the front of the engine where that bracket will go. This picture shows that there is no way to make it fit without moving the alternator:
A solution that kb uses on it's 99-01 cars is they use a bracket to flip the alternator around and move it to the side as shown:
This is an option for us if we want to fabricate a bracket or try to order one form Kenne Bell. It looks fairly simple and would allow us to mount the bracket on the front. There is a few advantages to this. First of all you could use the 03-04 fluid lines assuming the part of the intercooler bracket that sticks up so high shown in the picture earlier does not hit the snout of the blower. Also you do not have to deal with the problem of the fuel rails around the back of the lower intake. here is a picture of them:
They are rubber (or similar) around the back and would need to be lengthened or moved to fit the intercooler bracket. The person getting this installed on their car would decide if they want to try and make the intercooler bracket on the front or the back. One more thing I forgot about putting it on the back is that the intercooler lines would be ran over or around the engine to the heat exchanger. We would probably want to use a LFP dual pass heat exchanger along with a large intercooler reservoir to help cool the small intercooler. An 03-04 intercooler pump would be along one of the intercooler lines somewhere and wired to turn on with the key.
The only thing left would be mounting the blower on top of all this, and getting the intercooler attached to it somehow. I have not gotten a definite answer from kb, but I believe the mounting holes on the kb will not line up with the holes on the stock lower. Also, on the 03-04 system the intercooler bolts to the bottom of the supercharger to keep it in place in the lower intake. Here is a picture of where the intercooler would mount to. It's the inner ring of bolt holes that it mounts to while the outer ring mounts to the lower intake:
To solve both of these problems, we will use an aluminum adapter plate. The plate will be as wide as the lower intake/supercharger needs it to be. There will be holes on it to screw it to the supercharger and to screw it to the lower intake. The inside of the plate will have a hole that is exactly the size of the intercooler ensuring that all air is forced down through it. There will be bolt holes along the outside of the plate to bolt the intercooler to just as it works on the 03-04 cobras shown earlier. That quickly solves the problem of having a place to bolt the intercooler to and making sure you can bolt the blower to the lower intake. The plate would also allow you to move the blower forward or backwards before drilling the mounting holes to make sure the pullies line up.
One more issue that is a deal breaker for some is that this kit will not fit under the stock hood to the best of my knowledge. I would guess a max of 2.5 to 3" cowl will be needed. The 96-98 lower intake is much taller than the kb "open house manifold shown here:
I have thought a little bit about altering the open house manifold to put the bowl from the 96-98 lower in it. That way it would fit under the stock hood. I haven't looked to seriously into it, since this will be rendering the part unusable for a normal installation. I have asked KB about ordering just the "open house manifold" and have yet to hear a response. Altering this may yield better results than using the stock lower, but would require a little more fabbing. You couldn't just weld the bowl from the 96-98 lower to it because as I said it is not as tall as the stock lower. The intercooler would have to stick up where the blower should go. I believe though that after you remove the IMRC controller from under the manifold you could make the bowl deeper. Just weld some kind of metal to the open house manifold then to the bowl form the stock 96-98 lower. You may be able to lower it just enough so the intercooler would be low enough under the blower. That would also eliminate the problem of the lower intake expanding at the top as mentioned earlier. The volume would be more constant throughout and may be the better option.
That would be all there is to a basic intercooling kit. Although the manifold will be modified it leaves the supercharger completely unharmed in case it doesn't work out or something you aren't stuck with a messed up blower. I would provide all the main parts also. I would take care of the modified lower intake, intercooler, adapter plate, and anything else that is not stock off an 03-04 cobra. I would leave people to find those few other pieces themselves since they are easy to find and people can find the best deals possible.
Afterword:
There is one other problem not mentioned here that would relate to wanting to run higher boost after the supercharger is intercooled, and that is the bypass valve. What this does is at low rpms like when you are sitting at a stoplight or in traffic, the bypass valve is open allowing air that has already been compressed to recirculate to the plenum of the blower again. This helps keep the temperature of the blower down and the engine from seeing boost constantly. The 2.1 kb for 96-98 cobra does not have a bypass valve. One would need to be fabbed. I have talked to kb on this issue and they say it has been done, but they don't know how it was. They also said that running the blower at upwards of 13 pounds without a bypass is severely limiting the life of the blower. A way around this would be to use the 99-01 kb 2.1 which has a bypass integrated. I don't know if you could order just the compressor from them or not. I am waiting for a response on that, but that would solve this problem, and hopefully the 99-01 compressor will not be too much more that the 96-98 one. That would be one way to solve this easily. I will talk about the bypass valve on a later installment of this article.
Thank you for reading as it took me a while to write all this up. I am open to any and all suggestions/comments or if you can think of a better way to do something let me know. After all I am only one guy, I can't think of everything. Remember, even if you don't have a built shortblock to run higher boost, this kit will make the lower psi kit safer since temps will be lower. High temps are what kill a stock shortblock. It would also open up the availability to up the boost when it is built. And we can't forget... twin screw blowers love nitrous!
Last edited:
