Due to a few people asking about it, here is my experience. This is by no means to say it absolutely can not be done, but it should give you some idea of the issues.

I started out, as most I think have, with a Comptech supercharger. I first ran it at stock boost and then at a bit above 8psi with an AEM EMS. Even on a hot day, the water and oil temperatures never rose above 190 and 230 respectively. I run a C&R radiator with Spal fans, and a Setrab 625 oil cooler as an fyi.

As an experiment I added some swiss cheese holes to the nose of the car. I'm sure most would think it unsightly, but I needed to get air to the radiator, and lots of it since the turbo intercooler was going to block a large portion of the radiator. This netted a 20F oil temp reduction and had the water sitting on the 180F thermostat at a hot Thunderhill day with the supercharger. I suspected this would be plenty of cooling for the turbo.

I purchased a used Inline Pro Gt3076 kit and started to work. I rerouted the wastegate back into the exhaust for noise and cleaned up a bunch of the misc. stuff on the kit. My goal was first to get it running well at 7psi, and then to get a built motor and run it at 12-14 psi. This would make a really wicked track car.

My first event was at a very cool day (mid 50's) at Infineon. The kit ran fairly well, but the oil temps were running up to 260. I also ended up blistering my battery (Odyssey 680). The heat under the hood was obviously getting pretty hot.

I added vents to the hood along with a bit of mesh, had the downpipe, exhaust manifold, and turbo housing ceramic coated, and added a fan behind the oil cooler that I could turn on and off from the cockpit.

I ran the car like this with some limited success. In 50-80 degree weather it was ok. My last event was at Thunderhill raceway. It was a really hot day about 95F. Unfortunately my cooling mods were not enough. It would take about 4 laps to get the oil temps to about 285. After that it would go off my gauge so I really do not know how high they were going, but suffice it to say way too hot. Water temps peaked at 208.

That's pretty much the story. I'm currently swapping the kit for a Vortech T trim supercharger that I will be putting on a built Laskey motor with a ported head. From what I can see, I could continue on and most likely solve the oil temp issues by adding even a bigger oil cooler, and most likely some sort of water to oil cooler. I think this might be sufficient to run 7psi reliably at any ambient temperature. Unfortunately I did not see a path to run it at 12-14 psi, which is where I really want to be.

I would think the only way to "maybe" get this to work is a V-mount intercooler solution so you can force as much air into the radiator as possible, but I still only give this 50/50 odds. I think someone will need to figure out a way to get more oil into the system (Dry sump maybe) in order to keep the oil cool. I have no doubt the water temps were being driven by the oil temps. Solve the oil temp issue, and you would solve the cooling.

Unfortunately, I'm a racer at heart, and a long development cycle did not appeal at this point. I have a very busy day job, and a new business to put my time into.

Hopefully this gives someone else a bit of a head start if they try to go down this road.

Bill

 

out of curiosity, is your turbo oil coled or water cooled??? that might explain your high oil temps...

 

very well put Bill.

 

I believe the gt3076 is both water and oil cooled.

 

Yep, Water and oil. It is "required" to make the turbo live roadracing.

The thing we need to keep in mind is the car can be floored for 70% of a lap, and is always above 5K rpm. A 30 minute race might see 21minutes of high rpm full throttle. No matter what road you find, it's almost impossible to duplicate on a public road. This is a very special case, where the turbo falls down. I can't imagine a street car ever having this issue.

 

enlightening and disappointing at the same time...

I was planning to install an oil cooler as a safety measure. During my hillclimbs I don't get temps more than 3 bars and I'm only running an oil cooled turbo. They are 15 minute high stress jaunts but never followed up with another session. In fact it's followed but an idle cruise down the hill where my engine is free to drink in all the cool air it wants without any throttle. V-mount seams like the way to go but the costs of changing my system around does not appeal to me.

 

good info

 

Switch to a vortech.... Sad.

The extra torque of a turbo is far superior on a track.

And to think all it took was the addition of a oil cooler and you would be fine. After owning a turbo S2k I don't think I could go back to a torqueless supercharger down low.


Your breaking my heart to say you would gut the whole turbo set-up when all you need to do is add a oil cooler.

J. R.

 

Please read a bit more carefully J.R.... if it was that simple I would have done it, trust me.

I already have an oil cooler. It's a Setrab 625, which is pretty good sized. Even with the oil cooler it was not near enough on warm days. I think that possibly with a much larger cooler (aka the largest they make), or a big water to oil cooler, you might be able to get there at 7psi. I seriously doubt it would work at 12 - 14 psi. I'd love someone to prove me wrong.

As a side note, for road racing, I'm not sure the turbo really added as much as I thought it would. It's worth about .5 secs a lap over the supercharger at similar boost. Granted on the street the extra punch from 3K to 5K is worth a lot, but I'm never below 5K - unless I'm in the pits. Since you spend so much time at high RPM the power ends up being pretty equivalent.

Out of corners the turbo is better, but even out of slow speed corners, you really never dip below 5K.

Now take the fact that you can run almost double the boost with the supercharger and it will be the faster solution guaranteed.

 

Excuse JR. He doesn't like to fully read posts. He has a Setrab model 625 oil cooler. hehe...

In all seriousness, I have been begging someone to successfully build a turbo S2000 track car for a long time because I recognize the potential superiority over a supercharged setup. However, no one to date has been able to campaign a turbo S2000 for an extended period of time.

It is something about this particular motor but it doesn't like to be tracked on a turbo setup...it's rather frustrating.

Blackey, don't sweat it too much. You gave it your best shot. Have you considered the new SOS setup or the new Kraftwerks? They are making good power and running a higher boost setup should really help your low end with any centrifugal supercharger. I am considering a switch an even smaller pulley (currently running a 3.6" making about 10psi) but dropping my rev limiter to around 8500rpm to gain a bit of low end grunt and hopefully keep AIT's reasonable.