To intercool or not to intercool supercharger

[jp455]

Hi all...Ive been pondering what type of supercharger to use in my next build and it seems like they all offer the level of power. The question is whether to use an intercooled type supercharger or not. The intercooled ones are heavier and more complicated and it seems like a lot of track cars are using non intercooled versions. Im talking about screw types here, not centrifugal/Paxton styles. Is using a regular non intercooled one a non issue? Im looking at around 750 hp so not insane power numbers but still would want to keep things are reliable as possible, and I assume cooling the intake air would help in that regard.

[andrewb70]

Is this going to be on a Pontiac engine? EFI or carburetor?

Andrew

[jp455]

Hi Andrew...yeah, guess I skipped that detail. Im thinking of actually going with an LS. Im very torn about using the Pontiac 455 or not. But I think in the long run it will be best to use a modern engine for the best combination of mileage, reliability, track day resistance, and power. Im living in London now so a Pontiac engine would not be the ideal.

So Ive looked at crate LS9s but it seems that for less money I can get the same or sometimes even a little more power from a good builder. Thing is places like Mast are using non intercooled blowers and I have yet to see anyone complain about those engines As a plus gas has a high octane here, regular is 95 and super is 98. So an intercooler is not a MUST. But at the same time Im thinking an intercooled blower will be more reliable, make more power for a given combination and perhaps even have better fuel mileage. Am I over thinking it too much?

[71RS/SS396]

There's no way I would consider not running an intercooler. All the intercoolers that come with the blower options out there are not truly efficient enough to stop heat soak in a track situation imo. The 4.0L Whipple is the only one I've seen that can be modified to flow enough water to possibly combat the heat. I personally would stay with an n/a engine at that power level, it's lighter and easier to package.

[jp455]

Hi Tim...yeah, Ive thought about going N/A too, but it seems that road manners would be better with a supercharger. The idea would be to be able to take long trips easily as well. Would the stock LS9 not be up to the task of keeping temps in check?

[andrewb70]

Hi Tim...yeah, Ive thought about going N/A too, but it seems that road manners would be better with a supercharger. The idea would be to be able to take long trips easily as well. Would the stock LS9 not be up to the task of keeping temps in check?

I'm with Tim in that you should definitely run an intercooler setup. You have to decide what you want to do with the car. Is it 90% street and 10% track or vise versa? If it is the former, than the occasional overheating at track events would be a small sacrifice for me if the rest of the time I got a tame engine that made gobs of torque and was fun to drive on the street. There are always trade offs and you have to be brutally honest with yourself in terms of how the car will be used. As much as we all like to pretend that are cars are race cars, they just aren't...

Mark Stelow's last few builds have used a custom 427 engine with a modified LS9 supercharger. Seems to work pretty well for him.

Andrew

[jp455]

I'm with Tim in that you should definitely run an intercooler setup. You have to decide what you want to do with the car. Is it 90% street and 10% track or vise versa? If it is the former, than the occasional overheating at track events would be a small sacrifice for me if the rest of the time I got a tame engine that made gobs of torque and was fun to drive on the street. There are always trade offs and you have to be brutally honest with yourself in terms of how the car will be used. As much as we all like to pretend that are cars are race cars, they just aren't...

Mark Stelow's last few builds have used a custom 427 engine with a modified LS9 supercharger. Seems to work pretty well for him.

Andrew

Thats the rout I was thinking as well, a built engine with an intercooler. Although I didnt think performance would drop off after 3-4 laps with an intercooler! I was under the impression that an intercooled system would basically hold up for however many laps.

The car is 100% not going to be a racecar. I actually design/build racecars and I have that very clear...it will be as you say, 90% street and 10% track. But since it will be going to the UK with me I am trying to find the best drivability/reliability combination. I havent heard much really from guys running non intercooled systems, and all my experience is with intercooled turbo systems which basically run all day long in race conditions. I dont want to go that route though...too heavy.

[71RS/SS396]

Thats the rout I was thinking as well, a built engine with an intercooler. Although I didnt think performance would drop off after 3-4 laps with an intercooler! I was under the impression that an intercooled system would basically hold up for however many laps.

The car is 100% not going to be a racecar. I actually design/build racecars and I have that very clear...it will be as you say, 90% street and 10% track. But since it will be going to the UK with me I am trying to find the best drivability/reliability combination. I havent heard much really from guys running non intercooled systems, and all my experience is with intercooled turbo systems which basically run all day long in race conditions. I dont want to go that route though...too heavy.

What kind of fuel is being used in the racecars you're building? Methanol, Gas?
I suspect the supercharged set-up will be every bit as heavy as a turbo if not more so by the time you package all the necessary components.

[71RS/SS396]

I agree with much of what Andrew is saying, there's going to be a compromise somewhere. Decide what is most important to you, the track or the street and optimize the car for that use. Stielow's car is very well engineered but I'll bet if you asked Mark how long he can run all out he will tell the power falls off after 3-4 laps. I don't believe any stock GM crate engine is a good choice for serious track use simply because of the cast pistons.

[TheMeat]

Im pretty sure most of the newer roots style superchargers are intercooled. (Whipple, Magnuson, Edelbrock)

I have a 2.3 Whipple on my 6 liter swap in a 73 Camaro and it is intercooled. Also, I mounted a 5 gallon ice/water tank in the trunk to help with heat soak.

[jp455]

Im pretty sure most of the newer roots style superchargers are intercooled. (Whipple, Magnuson, Edelbrock)

I have a 2.3 Whipple on my 6 liter swap in a 73 Camaro and it is intercooled. Also, I mounted a 5 gallon ice/water tank in the trunk to help with heat soak.

The Edelbrock and new Magnusson style are, but I think the old Magnusson version wasnt. Is that wrong?

I actually thought of using the Edelbrock crate engine...but it seems expensive compared to something from a good builder like Mast, or Thompson.

[carguykeith]

How about a crate or takeout LSA? Bone stock it's 500whp, and should be 600 with an LS9 cam, headers, smaller pulley and a tune.

[jp455]

That is an option as well, but I think a good engine builder would be less expensive. Ill have to keep looking. The big question was the intercooler issue...so I think at the very least that part has been answered.

[m1tankr]

The old magnusson MP112 I had in 2005 was intercooled. Almost all of the ones I've seen have the liquid intercooler built into the lower manifold. What ones are you looking at that aren't intercooled? They do heat soak on the track & the street, but I would never run one on the street without an intercooler. The heat problems & tuning would be a problem for street use. The only ones I've seen non intercooled are the big 8/71 or 6/71 hood eating monsters or some of the budget racing only pro-charger style ones. But most of those run race gas or e85 to make up for the lack of intercooler.

[cornfedbill]

I would stick with a naturally aspirated engine at that power level also. 750 horsepower with a properly built LS motor is not unreasonable and is lighter and simpler. I would only use a blower if you want more power than that.

If I were to run a supercharger, I would definitely use an intercooler. I worked with GM on the 3800 supercharged V6. There was a lot of power left on the table due to spark knock limitations. They built a prototype intercooler on one and realized big gains.