Compound boost - blower + turbos

[Unreal]

For 1400+hp I would agree with Andy.

[Magnuson Superchargers]

Originally Posted by jessrayo

I'm big fan of crazy horsepower and I must admit that I love the instant power and torque provided by a roots type blower. Unfortunately in the crazy racing events I'm running sometimes I just don't seem to be able to generate enough power. Only 835 on just the blower and about 1200 with the nitrous.....and I was only able to go 193 at the Texas mile with less drama than driving an RV on a windy day, so where do I go from here. I sent a PM to the AGP guys but does anyone have any experience with the potential problems of plumbing the turbos into the exhaust flow and then feeding them into the blower sitting on my car now? could the turbos "choke" the blower at lower rpm? Would I need major intercoolers between the turbos and the blower to keep from burning up the blower? If someone has seen it done what are the limitations and potential problems with the set-up? I appreciate any feedback.

Not sure if I'm too late but Rick Squires in Utah has had some nice results with twin turbo and Maggie setups :-)

[jessrayo]

Originally Posted by GretchenGotGrowl

Something to think about. You can use the nitrous to get them spooled up.

The nitrous has some very nice cooling properties and since I've got all the plumbing and bottle warmers I can't imagine ditching the nitrous no matter what I run. It is just easy power if you can manage it properly.

Originally Posted by Unreal

For 1400+hp I would agree with Andy.

Just turbos would be a lot more simple.... I'm afraid of losing the torque at 2500 rpm and it just seems logical that if everything could be managed it would have all of the best properties of both induction systems and then some.

Originally Posted by Magnuson Superchargers

Not sure if I'm too late but Rick Squires in Utah has had some nice results with twin turbo and Maggie setups :-)

I'm actually considering swapping to the heartbeat if I do this 1.) because it just plain has better cooling and 2.) because I have heard that the intercooler bricks on my LS9 blower have failed if the boost levels get too high.... because of my displacement and head flow etc... I'm only pushing 14 pounds of boost through them now. But we will open another can of worms all together if we put the turbos on. So is Rick on this board? How do I get in contact with him?

[Unreal]

Yes intercooler bricks on ls9 have failed but fixing them isn't hard.

Yes if you go just turbos that will support 1500hp then you are going to give up low end.

That being said, why exactly do you need huge torque at 2500rpm? Just to dyno race? Fun street car? Track/performance wise power/torque at 2500 is pretty much irrelevant.

[ayousef]

Im not kidding I thought of slapping two turbos in the back lol

Anyways, what you want to do is doable and I can probably help since ive done the research already, of course I don't know it all

[2SS45th]

A well designed turbo system can provide torque at 2500 rpm without nitrous, you'd be more than fine without compounding the boost. Sometimes it's best to just keep things simple.

[Unreal]

On a reasonable size LS motor 427 or less you aren't going to make 1400+rwhp and killer torque at 2500. You can have a turbo system that makes awesome torque at 2k but may only support 1000rwhp. If he is really going for a 1400+hp build and not doing a 500+ cube motor then he is looking at 66+mm turbos that aren't going to instant spool on a 7L motor. Put them on a 600ci high compression big block running methanol and you can have 1500rwhp TT with instant boost.

[GretchenGotGrowl]

Originally Posted by Unreal

On a reasonable size LS motor 427 or less you aren't going to make 1400+rwhp and killer torque at 2500. You can have a turbo system that makes awesome torque at 2k but may only support 1000rwhp. If he is really going for a 1400+hp build and not doing a 500+ cube motor then he is looking at 66+mm turbos that aren't going to instant spool on a 7L motor. Put them on a 600ci high compression big block running methanol and you can have 1500rwhp TT with instant boost.

If you do turbos in series you can. On a 7 L a 5x mm first and a 8x mm secondary can produce very good power down low and up high.

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[jessrayo]

Originally Posted by Unreal

Yes intercooler bricks on ls9 have failed but fixing them isn't hard.

That being said, why exactly do you need huge torque at 2500rpm? Just to dyno race? Fun street car? Track/performance wise power/torque at 2500 is pretty much irrelevant.

How are the bricks "fixed" I thought they just had to be replaced.

I have been road racing at Eagles canyon for a few years and turn 5 is a tight uphill right coming out of the canyon, It is much easier to run fast if you can leave the car in third and power up the hill. If you drop to second it is hard not to drift the back out plus you need to bang a shift in the middle of the hill and it really slows you. I like the torque on the road course.

Originally Posted by ayousef

Im not kidding I thought of slapping two turbos in the back lol

Anyways, what you want to do is doable and I can probably help since ive done the research already, of course I don't know it all

Well I'm really interested in finding out what you know. It seems that many of those that have done this want to keep what they know a secret but if it really does work well I suspect that it is going to become much more common. I'm thinking that once you really get the turbos into the peak boost you can electronically open the bypass on the supercharger to let it freewheel and cut the heat. It would take some more complex electronics but definitely be do-able. Potential to have the low end supercharger torque and then open the bypass and eliminate the extreme heat associated with sustained blower boost.

Originally Posted by Unreal

On a reasonable size LS motor 427 or less you aren't going to make 1400+rwhp and killer torque at 2500. You can have a turbo system that makes awesome torque at 2k but may only support 1000rwhp. If he is really going for a 1400+hp build and not doing a 500+ cube motor then he is looking at 66+mm turbos that aren't going to instant spool on a 7L motor. Put them on a 600ci high compression big block running methanol and you can have 1500rwhp TT with instant boost.

This is exactly what I'm thinking. Run the supercharger and keep the torque above 800 ft/lbs from 0 to 3500 rpm and then transition it into turbos and keep climbing.

Originally Posted by GretchenGotGrowl

If you do turbos in series you can. On a 7 L a 5x mm first and a 8x mm secondary can produce very good power down low and up high.

Sent from my GT-N8013 using Tapatalk

See, I'm thinking rather than turbos in series, lets put the blower and turbo in series.... for a while anyway.

[GretchenGotGrowl]

Originally Posted by jessrayo

How are the bricks "fixed" I thought they just had to be replaced.

I have been road racing at Eagles canyon for a few years and turn 5 is a tight uphill right coming out of the canyon, It is much easier to run fast if you can leave the car in third and power up the hill. If you drop to second it is hard not to drift the back out plus you need to bang a shift in the middle of the hill and it really slows you. I like the torque on the road course.

Well I'm really interested in finding out what you know. It seems that many of those that have done this want to keep what they know a secret but if it really does work well I suspect that it is going to become much more common. I'm thinking that once you really get the turbos into the peak boost you can electronically open the bypass on the supercharger to let it freewheel and cut the heat. It would take some more complex electronics but definitely be do-able. Potential to have the low end supercharger torque and then open the bypass and eliminate the extreme heat associated with sustained blower boost.

This is exactly what I'm thinking. Run the supercharger and keep the torque above 800 from 0 to 3500 and then transition it into turbos and keep climbing.

See, I'm thinking rather than turbos in series, lets put the blower and turbo in series.... for a while anyway.

That will work, and it will make for a great street and strip car. However, you are adding a lot of weight, plumbing and complexity to get there. Just something to think about.

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[jessrayo]

Originally Posted by GretchenGotGrowl

That will work, and it will make for a great street and strip car. However, you are adding a lot of weight, plumbing and complexity to get there. Just something to think about.

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I must admit that my biggest complaint about the Camaro is that is heavy. I have done quite a bit to shave a few pounds here and there. Right now my car weighs 10 pounds less than when I bought it and it has a lot of extra parts on it. But at the end of the day if I get a significant improvement in the pounds per horsepower ratio I call that a gain. I'm about 3.4 pounds per horse at the tire now. I'm thinking that adding turbos and some more plumbing will further improve this ratio. If I add 100 pounds I will gain more than 340 horses....at least I'm hoping it will work that way. That would mean the dyno would have to be at least 1540 at the tires to maintain my current power to weight ratio if the turbos and plumbing added 100 pounds. Interesting when you look at it that way. Maybe I should just take off that blower and spray the nitrous when I need to get the turbos running..... Anyone know how much a set of big turbos and plumbing are going to weigh?

[2SS45th]

You can trim weight on some of the turbo components, things like stainless turbine housings can provide some savings in weight.

[Unreal]

You weld plates on the bricks and reinforce them. Search the zr1 section of corvette forum.

You could do series turbos but then it is more complicated, already has space issues. Can it be done, sure I guess. Is it realistic for most people, not really.

[GretchenGotGrowl]

Originally Posted by Unreal

You weld plates on the bricks and reinforce them. Search the zr1 section of corvette forum.

You could do series turbos but then it is more complicated, already has space issues. Can it be done, sure I guess. Is it realistic for most people, not really.

I agree, but he's not most people.