bsclywilly
04-03-2010, 10:30 PM
Thought I'd give you guys a preview of what I've been up to for the last month. It's suddenly becoming quite a jam trying to get this all together and running. Jon and I have been looking for a bit more challenge (call it making problems for ourselves, if you wish) and are promoting our team, called Enmo Racing (http://www.enmo.ca/racing), to compete in the Redline Time Attack series and also One Lap of America in addition to Solosprint.
After about 9 years of running the same supercharger setup on my SOHC civic motor, I've decided it's time for a power boost. Keeping with my interests of enginering a project rather than using an off the shelf kit, I've decided that to reach my goal of 350whp with 80% peak torque at 3500rpm, I'm going to design and build a twincharge setup. Not only can I keep my current motor, which is about a 100lb weight savings in engine and transmission over the bigger dohc engine swaps, but the money and time invested in it (gears, lsd, engine internals, spares, etc.) will continue to be used.
How it works:
The coles notes version is that with the turbo feeding the super, the turbo essentially thinks that it's just working a larger displacement motor. With a SC presure ratio of about 1.4, my 1.6L is really more like a 2.4L with a very uniform volumetric efficiency as evidenced by the very flat torque curve in it's SC'd form. Turbo selection should then be suitable for a 2.4L rather than the measly 1.6L. Rather than having a single turbo (like a GT28RS) working it's balls off to make 350hp, I'll be using a GT3076R, capable of making up to 500hp but much more easily and efficiently flowing 350hp worth of air. Because it's working less than full capacity, efficiency is improved and excess heat is not added to the intake charge.
Same goes with the super. Previously, we had been spinning it at peak speed of about 14000rpm at redline. I'll be throwing on a larger pulley so it's only taxed with about 12000rpms and a similar decrease in delta T.
It's a bit simpler than running two turbos in series because the super feeds air to the engine at a very linear rate. It sees a volume of air and compresses it to another volume regardless of the density it started with and it does this at a rate defined by engine rpm since it's directly driven.
I'm expecting to be able to run slightly lower boost to reach the same peak hp as those running a single GT30R on the same motor (18psi at 320hp/7500rpm). But it won't be a huge gain because the super is still robbing a bit of power from the crank just to turn it, about 15hp at peak load. There is still the potential for this turbo to make ridiculously more power so we'll see how reliable the setup is before pushing it further and using race gas.
The car is presently in the shop getting the downpipe completed. Aaron Weir at Weirtech (http://www.weirtech.ca)has been gracious enough to not only lend his expert welding skills, but also let me use much of his machine shop to get all the rest of the systems completed. Even staying with me until 1am to get stuff done!
So on to some pics:
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10059.jpg
Careful evaluation of the turbo placement was made to ensure proper airflow behind the radiator and also allow an appropriately prioritized wastegate. This turbo doesn't have to work very hard, about 10psi (1.7 pressure ratio), so alot of the flow needs to go through the wastegate. Also helps to balance out my corner weights alittle too ;)
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10065.jpg
For intercooling, we're using a spearco core air-water intercooler (a true 'intercooler' for those of you who know why it's a misnomer in laymans vocab). Increased efficiency over an air-air intercooler by a factor of two since water is able to transfer heat that much more. The IC size can be made more compact and spool and response improved due to the smaller volume of air after the first stage compressor. We'll be running ice water in it to keep intake temps near or below ambient after the turbo.
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10067.jpg
Reservoir for air-water intercooler, pump, and water injection pump after second stage. Fill neck still has to go on.
No plans to put in a heat exchanger for the water side. Just a drain and we'll be filling up with ice every hour or so or before sessions.
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10069.jpg
After about 9 years of running the same supercharger setup on my SOHC civic motor, I've decided it's time for a power boost. Keeping with my interests of enginering a project rather than using an off the shelf kit, I've decided that to reach my goal of 350whp with 80% peak torque at 3500rpm, I'm going to design and build a twincharge setup. Not only can I keep my current motor, which is about a 100lb weight savings in engine and transmission over the bigger dohc engine swaps, but the money and time invested in it (gears, lsd, engine internals, spares, etc.) will continue to be used.
How it works:
The coles notes version is that with the turbo feeding the super, the turbo essentially thinks that it's just working a larger displacement motor. With a SC presure ratio of about 1.4, my 1.6L is really more like a 2.4L with a very uniform volumetric efficiency as evidenced by the very flat torque curve in it's SC'd form. Turbo selection should then be suitable for a 2.4L rather than the measly 1.6L. Rather than having a single turbo (like a GT28RS) working it's balls off to make 350hp, I'll be using a GT3076R, capable of making up to 500hp but much more easily and efficiently flowing 350hp worth of air. Because it's working less than full capacity, efficiency is improved and excess heat is not added to the intake charge.
Same goes with the super. Previously, we had been spinning it at peak speed of about 14000rpm at redline. I'll be throwing on a larger pulley so it's only taxed with about 12000rpms and a similar decrease in delta T.
It's a bit simpler than running two turbos in series because the super feeds air to the engine at a very linear rate. It sees a volume of air and compresses it to another volume regardless of the density it started with and it does this at a rate defined by engine rpm since it's directly driven.
I'm expecting to be able to run slightly lower boost to reach the same peak hp as those running a single GT30R on the same motor (18psi at 320hp/7500rpm). But it won't be a huge gain because the super is still robbing a bit of power from the crank just to turn it, about 15hp at peak load. There is still the potential for this turbo to make ridiculously more power so we'll see how reliable the setup is before pushing it further and using race gas.
The car is presently in the shop getting the downpipe completed. Aaron Weir at Weirtech (http://www.weirtech.ca)has been gracious enough to not only lend his expert welding skills, but also let me use much of his machine shop to get all the rest of the systems completed. Even staying with me until 1am to get stuff done!
So on to some pics:
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10059.jpg
Careful evaluation of the turbo placement was made to ensure proper airflow behind the radiator and also allow an appropriately prioritized wastegate. This turbo doesn't have to work very hard, about 10psi (1.7 pressure ratio), so alot of the flow needs to go through the wastegate. Also helps to balance out my corner weights alittle too ;)
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10065.jpg
For intercooling, we're using a spearco core air-water intercooler (a true 'intercooler' for those of you who know why it's a misnomer in laymans vocab). Increased efficiency over an air-air intercooler by a factor of two since water is able to transfer heat that much more. The IC size can be made more compact and spool and response improved due to the smaller volume of air after the first stage compressor. We'll be running ice water in it to keep intake temps near or below ambient after the turbo.
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10067.jpg
Reservoir for air-water intercooler, pump, and water injection pump after second stage. Fill neck still has to go on.
No plans to put in a heat exchanger for the water side. Just a drain and we'll be filling up with ice every hour or so or before sessions.
http://i47.photobucket.com/albums/f171/bsclywilly/Car%20Pics/SNC10069.jpg