Twin charging (again)
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The more I think about this project the easier it seems. After reading up, I don't think that the 2nd turbo would even have to go through the intercooler due to the heat being disipated over the long length of the pipe.
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Hey guys,
The twin charged Evo was mine. I started building this car when it first hit the U.S. AMS, Buschur, etc., didn't have any bolt on turbo kits, stroker kits, etc., available back then.
My original build used Toda pistons, Pauter rods, Autronic standalone, and an HKS 3240 turbo kit. This required a lot of fabrication as nothing was really "bolt-on" at the time.
The car made about 500 awhp and had some impressive 1/4 mile times back in the day. However, like all of us, once I got used to the power I was ready to begin phase 2 of my build. I started looking at much larger turbos. GT42r kits, etc., did not exist so we had to fabricate something.
Here's the problem: Altitude and large turbos do not mix well so we decided to have some fun and came up with the twin charged concept. The folks from Kleemann/Autorotor helped develop a one-off supercharger made to develop very high boost. We lowered the engine compression and went from a 2.3L stroker to a built 2.0L in order to take advantage of a higher rev range. The turbo was a huge custom Holset unit. The tranny was a dog box with a sequential shifter as the torque generated off the line was substantial.
I laughed a bit reading Evotechs post about "lack of engineering." The engineering effort was enormous and the the twin-charger system worked perfectly. If Evotech disagrees with me maybe he can explain how my twin charged set up worked.
The real trick was getting the supercharger to disengage (reducing parasitic loss) once the turbo was spooled. It worked perfectly. The liquid to air intercooler was designed after the Ford Lightening concept truck that never made it to production. I could supercool the liquid using the AC compressor as I was sitting at the line before a race. Again, it worked very well.
The problem had to do with the Autronic system and the tuning. I blew up three engines due to a variety of issues. None of these issues had to do with the twin charged system itself. The majority of the issues had to do with tuning areas using the Autronic as high HP Autronic maps really hadn't been developed yet. The car ran consistently in the mid to high 10's without making much boost. The plan was to push the car to 40psi, but again, we couldn't keep the engine together at this level of boost. With the tuning expertise available today, running 40 psi would not have been an issue.
I lost interest for a variety of reasons. I had the Evo for several years at this point, was tired of having to install new engines. Was tired of being an Autronic guinea pig and was ready to move on to another project (800 HP Porsche GT2).
Twin charging has been done many times but we broke new ground in that we built a very high HP twin charged car. Try to find another twin charged set up that ran in the 10's. Our goal wasn't to make a dyno/drag racing queen. It was to make a car that made big power and had no lag at 6000' above sea level. It was an expensive but fun project.
I wouldn't recommend this type of project. You'll be shocked at the complexitiy of this design. The ball bearing turbo kits manufactured by AMS, Buschur, etc., make a whole lot of sense and have been perfected. The AEM standalone is also a solid unit that has been proven time and time again. Twin charging is expensive, complicated, and adds significant weight to the front of the car.
It was a fun project and if I hadn't lost interest in the Evo scene I'd probably still have it today.
The twin charged Evo was mine. I started building this car when it first hit the U.S. AMS, Buschur, etc., didn't have any bolt on turbo kits, stroker kits, etc., available back then.
My original build used Toda pistons, Pauter rods, Autronic standalone, and an HKS 3240 turbo kit. This required a lot of fabrication as nothing was really "bolt-on" at the time.
The car made about 500 awhp and had some impressive 1/4 mile times back in the day. However, like all of us, once I got used to the power I was ready to begin phase 2 of my build. I started looking at much larger turbos. GT42r kits, etc., did not exist so we had to fabricate something.
Here's the problem: Altitude and large turbos do not mix well so we decided to have some fun and came up with the twin charged concept. The folks from Kleemann/Autorotor helped develop a one-off supercharger made to develop very high boost. We lowered the engine compression and went from a 2.3L stroker to a built 2.0L in order to take advantage of a higher rev range. The turbo was a huge custom Holset unit. The tranny was a dog box with a sequential shifter as the torque generated off the line was substantial.
I laughed a bit reading Evotechs post about "lack of engineering." The engineering effort was enormous and the the twin-charger system worked perfectly. If Evotech disagrees with me maybe he can explain how my twin charged set up worked.
The real trick was getting the supercharger to disengage (reducing parasitic loss) once the turbo was spooled. It worked perfectly. The liquid to air intercooler was designed after the Ford Lightening concept truck that never made it to production. I could supercool the liquid using the AC compressor as I was sitting at the line before a race. Again, it worked very well.
The problem had to do with the Autronic system and the tuning. I blew up three engines due to a variety of issues. None of these issues had to do with the twin charged system itself. The majority of the issues had to do with tuning areas using the Autronic as high HP Autronic maps really hadn't been developed yet. The car ran consistently in the mid to high 10's without making much boost. The plan was to push the car to 40psi, but again, we couldn't keep the engine together at this level of boost. With the tuning expertise available today, running 40 psi would not have been an issue.
I lost interest for a variety of reasons. I had the Evo for several years at this point, was tired of having to install new engines. Was tired of being an Autronic guinea pig and was ready to move on to another project (800 HP Porsche GT2).
Twin charging has been done many times but we broke new ground in that we built a very high HP twin charged car. Try to find another twin charged set up that ran in the 10's. Our goal wasn't to make a dyno/drag racing queen. It was to make a car that made big power and had no lag at 6000' above sea level. It was an expensive but fun project.
I wouldn't recommend this type of project. You'll be shocked at the complexitiy of this design. The ball bearing turbo kits manufactured by AMS, Buschur, etc., make a whole lot of sense and have been perfected. The AEM standalone is also a solid unit that has been proven time and time again. Twin charging is expensive, complicated, and adds significant weight to the front of the car.
It was a fun project and if I hadn't lost interest in the Evo scene I'd probably still have it today.
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From: Colorado
3240, very nice post!!! Do you have any pictures of your old car? And I wish all the cool parts we have today were available for your car when you was doing twin charging. I'm more then sure if your car would of did a drag pass at over 40 PSI, there would be a record some where in there!!! very nice.
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3240,
I did not mean any disprespect. I followed the build up of your car and saw it in person. The "lack of engineering" comment was misguided. What I was trying to say that with all that was going on in that car, it would have required a team from NASA to package it all into a neat little bundle. The complexity of this system was overwhelming and I give you and the builder a lot of credit for going into uncharted territitory. My attempt is going to be much more simple and hopefuly easier to tune. I have nothing but respect for what you were trying to do. I apologize for the comment.
I did not mean any disprespect. I followed the build up of your car and saw it in person. The "lack of engineering" comment was misguided. What I was trying to say that with all that was going on in that car, it would have required a team from NASA to package it all into a neat little bundle. The complexity of this system was overwhelming and I give you and the builder a lot of credit for going into uncharted territitory. My attempt is going to be much more simple and hopefuly easier to tune. I have nothing but respect for what you were trying to do. I apologize for the comment.
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Joined: May 2004
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From: Colorado
3240,
I did not mean any disprespect. I followed the build up of your car and saw it in person. The "lack of engineering" comment was misguided. What I was trying to say that with all that was going on in that car, it would have required a team from NASA to package it all into a neat little bundle. The complexity of this system was overwhelming and I give you and the builder a lot of credit for going into uncharted territitory. My attempt is going to be much more simple and hopefuly easier to tune. I have nothing but respect for what you were trying to do. I apologize for the comment.
I did not mean any disprespect. I followed the build up of your car and saw it in person. The "lack of engineering" comment was misguided. What I was trying to say that with all that was going on in that car, it would have required a team from NASA to package it all into a neat little bundle. The complexity of this system was overwhelming and I give you and the builder a lot of credit for going into uncharted territitory. My attempt is going to be much more simple and hopefuly easier to tune. I have nothing but respect for what you were trying to do. I apologize for the comment.
A while back AMS had discussed a twin turbo system with me. It was a neat idea and sounded like a fun project.
Good luck with your project. I have a lot of respect for people who are trying to do something a bit different. There are so many gt42r turbo'd Evos out there that it's gotten a bit boring.
EvoTech, I think that is a fantastic idea. I do believe however that the pipe leading back to the engine compartment will not produce the heatsinking properties you are looking for. A good suggestion is a secondary rear mounted intercooler or like you suggested a 2input 1 output cooler. Seems like extending the pipe such a length would also increase the lag time for the air to reach the block and might negate any belefit of the secondary turbo. (at least lessen the efficiency). I would be more intrested in how the Corvettes are working out with this system. They also have more force to drive the turbines however, while we are reliant on out relatively small low-end to spool at a decent rate.
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The spool time will not be an issue becasue that will be covered by the first turbo up front. The long return pipe will disipate a lot of heat, but only testing will tell if it will need to go through an intercooler or not. A lot of the rear mounted turbo systems don't use one.
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EvoTech, cheers for giving me the heads up on this thread. i love this kinda off the wall kind of thinking!
i have seen just what you are proposing on a US focus! it had both turbos mount under the hood though. basically a little turbo that would spool REALLY quick, a MASSIVE 'gate that would vent at say 10psi into another turbo that would then spool and give full force.
it did work for them but it was in a mag and they didn't really go into much detail about it!
worth looking at though. the other thing you could look into is compund turbos. its what the deisel guys run. on little turbo feeds/is fed by one BIG turbo. basically the same idea as what the turbo-supercharged airoplane engines of WW2 used to use.
very intresting mate!
Chris.
i have seen just what you are proposing on a US focus! it had both turbos mount under the hood though. basically a little turbo that would spool REALLY quick, a MASSIVE 'gate that would vent at say 10psi into another turbo that would then spool and give full force.
it did work for them but it was in a mag and they didn't really go into much detail about it!
worth looking at though. the other thing you could look into is compund turbos. its what the deisel guys run. on little turbo feeds/is fed by one BIG turbo. basically the same idea as what the turbo-supercharged airoplane engines of WW2 used to use.
very intresting mate!
Chris.
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ok had a thought about this, it could actually be very easy to do!
so you have the stock turbo on a nice high flow manfiold with a BIG external gate mounted on. the gate is set to a low 10-15psi. form there you run through the stock turbo (with a mod to seal the internal gate on it). you then run say a 2.5inch down pipe and mate the gate and downpipe together into one.
this then runs all the way to the back of the car where you mount a GT4Xr turbo with an external gate. this gate is set at the presure you want to run, so lets say 30psi.
now the tricky bit, the intake. i was thinking just run the turbo turbos into narrow angle merg so there is little change of the intake charage going back on its self. fromthere it would go striaght into the intercooler and then to the intake manfiold as normal.
so in operation the stock turbo would spool quickly to the 10psi threshold. at that point the gate would open and the rear turbo would start to take over boosting the engine (basically you would be bypassing the stock turbo). it would be a bit of trial and error to get the preusre right. too low and there would be a long delay while the rear turbo finally spooled up. too high and the stock turbo would be choking the rear turbo. just right and as the stock turbo started to choke the rear would then take off and you would have a wonderfully smooth transition from one to the other!
so what you think???????
Chris.
so you have the stock turbo on a nice high flow manfiold with a BIG external gate mounted on. the gate is set to a low 10-15psi. form there you run through the stock turbo (with a mod to seal the internal gate on it). you then run say a 2.5inch down pipe and mate the gate and downpipe together into one.
this then runs all the way to the back of the car where you mount a GT4Xr turbo with an external gate. this gate is set at the presure you want to run, so lets say 30psi.
now the tricky bit, the intake. i was thinking just run the turbo turbos into narrow angle merg so there is little change of the intake charage going back on its self. fromthere it would go striaght into the intercooler and then to the intake manfiold as normal.
so in operation the stock turbo would spool quickly to the 10psi threshold. at that point the gate would open and the rear turbo would start to take over boosting the engine (basically you would be bypassing the stock turbo). it would be a bit of trial and error to get the preusre right. too low and there would be a long delay while the rear turbo finally spooled up. too high and the stock turbo would be choking the rear turbo. just right and as the stock turbo started to choke the rear would then take off and you would have a wonderfully smooth transition from one to the other!
so what you think???????
Chris.
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this is a twin turbo Corvete that the vette doctors i think are going to be running. they used to run a 7ltr with a 106mm (i think) turbo in the back.
their new setup (the one pictured above) is using twin 88mm + turbos. these turbos flow enough for about 1250-1500bhp.........each!
there was also a ford that was running twin rear mounted GT47s! thats was on a 500+inch bigblock though.
Cheers Chris.
their new setup (the one pictured above) is using twin 88mm + turbos. these turbos flow enough for about 1250-1500bhp.........each!
there was also a ford that was running twin rear mounted GT47s! thats was on a 500+inch bigblock though.
Cheers Chris.
Look into the Rx-7 Y-Pipe setup. They have been made to be solenoid controlled nowadays.
But essentiall the Y-pipe has a big flap in it. It lets the small turbo build to 10psi then drops to 8psi during the transition and starts to pre-spoll the big turbo, then back up to 10psi off both turbos. it's a complex system, but would do what you are trying to do. as far as controlling the outputs of the turbos.
But essentiall the Y-pipe has a big flap in it. It lets the small turbo build to 10psi then drops to 8psi during the transition and starts to pre-spoll the big turbo, then back up to 10psi off both turbos. it's a complex system, but would do what you are trying to do. as far as controlling the outputs of the turbos.
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Look into the Rx-7 Y-Pipe setup. They have been made to be solenoid controlled nowadays.
But essentiall the Y-pipe has a big flap in it. It lets the small turbo build to 10psi then drops to 8psi during the transition and starts to pre-spoll the big turbo, then back up to 10psi off both turbos. it's a complex system, but would do what you are trying to do. as far as controlling the outputs of the turbos.
But essentiall the Y-pipe has a big flap in it. It lets the small turbo build to 10psi then drops to 8psi during the transition and starts to pre-spoll the big turbo, then back up to 10psi off both turbos. it's a complex system, but would do what you are trying to do. as far as controlling the outputs of the turbos.