AWD Civic Coupe Turbo Build
Discussion
Very very very impressive engineering skills there. The project is not my cup of tea, but I certainly take my hat off to you. The scope of your project is incredible. Well done Sir!
One question though - what sort of ALS strategy are you going to use? The reason I ask is you need to be very careful running ALS on a road car tubby as it tends to detonate them very very quickly. Even a works turbo in a GRP A doesn't last long with drivers that are on and off the throttle a lot.
Have a look at how the modern WRC cars do it - charge air direct to the exhaust manifold - as this is much much more benign to the turbo.
Wiki has a nice summary of how it works.
One question though - what sort of ALS strategy are you going to use? The reason I ask is you need to be very careful running ALS on a road car tubby as it tends to detonate them very very quickly. Even a works turbo in a GRP A doesn't last long with drivers that are on and off the throttle a lot.
Have a look at how the modern WRC cars do it - charge air direct to the exhaust manifold - as this is much much more benign to the turbo.
Wiki has a nice summary of how it works.
Thanks chaps..
Nah, i could never do the sleeper look.. Plus, the side exit exhausts are there because the rear driveshafts make it too cramped..
Im going to be installing a front wind splitter and possibly a basic rear diffuser once its done, its going to look more time attack inspired than anything else.. Depending on how it turns out, i may even enter it..
The anti lag is similar to the older anti lag systems. It retards the ignition, increases the fuel and opens the electronic throttle. That will move the combustion out into the manifold area.. I was thinking about the modern systems with direct air injection but it would end up very expensive..
I know it will drastically shorten the life of the turbo but it will hardly be used, and only on track at that..
Nah, i could never do the sleeper look.. Plus, the side exit exhausts are there because the rear driveshafts make it too cramped..
Im going to be installing a front wind splitter and possibly a basic rear diffuser once its done, its going to look more time attack inspired than anything else.. Depending on how it turns out, i may even enter it..
The anti lag is similar to the older anti lag systems. It retards the ignition, increases the fuel and opens the electronic throttle. That will move the combustion out into the manifold area.. I was thinking about the modern systems with direct air injection but it would end up very expensive..
I know it will drastically shorten the life of the turbo but it will hardly be used, and only on track at that..
I'm impressed with the deadication and effort that's gone into this build. Hopefully you won't mind some constructive criticism? There are quite a few safety concerns with the mods. Try to look at some automotive electronics before making too many more ECU's. Examine the strategies for mechanically packing, particularly with respect to vibration. For instance in one of the pics you use some veroboard with four power transistors or regs hung off it, with a big cap hanging off the back. This cap needs mechanically fixing as well as soldering, as it is free to vibrate around and the solder joints WILL fatigue and either fail or pull the tracks off the veroboard. Same for all the wires/ transistors, crystals etc. If you have to use veroboard for development, then it's normal to use links to run the signals to the outside edges of the board, then have the wires come from round the edge of the board, not random places in the middle. This keeps it neater, and critically makes it easier to mechanically fix the wires in one place. Golden rule is that for any large component or wire you need both a mechanical fixing and a solder joint. In the automotive world where there is lots of vibrations things will fail otherwise.
The steering angle sensor is also a concern - if that little belt slips/snaps or the pulley works loose on the pot, then you have no steering angle detected, and therefore not enough assistance from the PAS. In an emergency situation (think merc "elk" test") does the PAS pump provide enough assistance? If you turn the knob on the wheel to adjust the steering assistance, can you still get enough PAS fluid flow to input 1000 deg/s at the handwheel if a small child runs into the street? Or will you get hydralic "catch-up" where the pump doesn't provide enough fluid to open the valve?
These may be seem little points, but with enough changes to the vehicle there is a chance of of them may get you in the end. Please think of the safety implications of some of the mods, and if in doubt, don't tinker!
Don't hate me - I'm trying to be constructive
The steering angle sensor is also a concern - if that little belt slips/snaps or the pulley works loose on the pot, then you have no steering angle detected, and therefore not enough assistance from the PAS. In an emergency situation (think merc "elk" test") does the PAS pump provide enough assistance? If you turn the knob on the wheel to adjust the steering assistance, can you still get enough PAS fluid flow to input 1000 deg/s at the handwheel if a small child runs into the street? Or will you get hydralic "catch-up" where the pump doesn't provide enough fluid to open the valve?
These may be seem little points, but with enough changes to the vehicle there is a chance of of them may get you in the end. Please think of the safety implications of some of the mods, and if in doubt, don't tinker!
Don't hate me - I'm trying to be constructive
Not at all mate- constructive criticism is more than welcomed..
I know what youre saying, i believe i have dealt with it all properly..
Some of the pictures ive used dont really show the full story as they were mid-points through the build..
I think its probably better if i answer in bullets...
1. The big caps on the H-bridges. They have all been secured now, there wasnt much point at the early stages as i was changing components regularly.. Now they are firmly attached with the cunning use of sticky backed pads and locking wire..
2. All the additional electronics are mounted (besides the wing controller) on a large ali panel under the passenger carpet. They are on 4 large rubber shock absorbing mounts. That should hopefully take away the damaging high frequency stuff.. All the other heavier components, will be firmly attached, many of them with potting compound. I have no idea if- when i turn it on initially whether it will all work- it most likely wont.. So i dont want to make anything too permanent at this stage..
3. The power steering. I ran the hydraulic / electric power steering system on the car before i took it off the road the first time. It had 6 months of daily use where i was able to work out exactly how to run the pump and when it needed extra juice- such as manoeuvring and emergencies as you said. Im quite confident in this design, especially as the pump itself is out of an MR2, so its simply the electronics which are "new".
4. The power steering system steering position sensor. Youre quite correct that this could be a weak point, i have built in some redundancy.. The belt itself is toothed, so it cant slip. In case of a sensor failure, or other input failure, an error signal is sent to the dashboard computer which will display a warning and announce it with a voice. There are dashboard controls which allow me to select the steering mode between; Auto, Full, Set, OFF, Reversionary- the latter being simply to bypass the control computer by closing a large relay and running the pump at 100%.
5. Use of veroboard.. It isnt something i really wanted to use. Plus as you said about the neatness, i have concerns about adding too many uncessary "jumpers" to move connections to the outside edges as its adding another source of failure.. I do have a PCB etching tank and equipment, when all this is done and the car fires up and i weed out all the bugs, ill be using a single layer PCB to replace ALL the veroboard in the safety critical systems.
6. Every safety critical system (until yesterday with the exception of the electronic throttle) has a backup, or safety mode. This would either be to run it to 100% in the case of fuel pumps, power steering, cooling fans, brake vacuum pump .etc or to shut it off entirely. Centrally, the display and voice warning system will alert me to any fault which doesnt inhibit the CPU in question's ability to flag a discrete error signal (5v direct line). Only in the event of a rare double failure would the system fail to tell me of a fault.
On the mention of the welding, my original work was piss poor- i had only just started out. I revisited the really bad stuff. Most of the rest is simply not as tidy as it should be- but it isnt a safety concern.. I honestly wouldnt be happy with it if i wasnt totally happy it was safe.. And i certainly wouldnt allow my wife or friends .etc into the car until im happy with its shakedowns..
Please, if there are any others with constructive criticism please speak up. I honestly appreciate anything people have to say.. To me thats the best thing about a forum- hundreds of "second pair's of eyes"..
Thanks for all your comments everyone..
I know what youre saying, i believe i have dealt with it all properly..
Some of the pictures ive used dont really show the full story as they were mid-points through the build..
I think its probably better if i answer in bullets...
1. The big caps on the H-bridges. They have all been secured now, there wasnt much point at the early stages as i was changing components regularly.. Now they are firmly attached with the cunning use of sticky backed pads and locking wire..
2. All the additional electronics are mounted (besides the wing controller) on a large ali panel under the passenger carpet. They are on 4 large rubber shock absorbing mounts. That should hopefully take away the damaging high frequency stuff.. All the other heavier components, will be firmly attached, many of them with potting compound. I have no idea if- when i turn it on initially whether it will all work- it most likely wont.. So i dont want to make anything too permanent at this stage..
3. The power steering. I ran the hydraulic / electric power steering system on the car before i took it off the road the first time. It had 6 months of daily use where i was able to work out exactly how to run the pump and when it needed extra juice- such as manoeuvring and emergencies as you said. Im quite confident in this design, especially as the pump itself is out of an MR2, so its simply the electronics which are "new".
4. The power steering system steering position sensor. Youre quite correct that this could be a weak point, i have built in some redundancy.. The belt itself is toothed, so it cant slip. In case of a sensor failure, or other input failure, an error signal is sent to the dashboard computer which will display a warning and announce it with a voice. There are dashboard controls which allow me to select the steering mode between; Auto, Full, Set, OFF, Reversionary- the latter being simply to bypass the control computer by closing a large relay and running the pump at 100%.
5. Use of veroboard.. It isnt something i really wanted to use. Plus as you said about the neatness, i have concerns about adding too many uncessary "jumpers" to move connections to the outside edges as its adding another source of failure.. I do have a PCB etching tank and equipment, when all this is done and the car fires up and i weed out all the bugs, ill be using a single layer PCB to replace ALL the veroboard in the safety critical systems.
6. Every safety critical system (until yesterday with the exception of the electronic throttle) has a backup, or safety mode. This would either be to run it to 100% in the case of fuel pumps, power steering, cooling fans, brake vacuum pump .etc or to shut it off entirely. Centrally, the display and voice warning system will alert me to any fault which doesnt inhibit the CPU in question's ability to flag a discrete error signal (5v direct line). Only in the event of a rare double failure would the system fail to tell me of a fault.
On the mention of the welding, my original work was piss poor- i had only just started out. I revisited the really bad stuff. Most of the rest is simply not as tidy as it should be- but it isnt a safety concern.. I honestly wouldnt be happy with it if i wasnt totally happy it was safe.. And i certainly wouldnt allow my wife or friends .etc into the car until im happy with its shakedowns..
Please, if there are any others with constructive criticism please speak up. I honestly appreciate anything people have to say.. To me thats the best thing about a forum- hundreds of "second pair's of eyes"..
Thanks for all your comments everyone..
It's an awesome project you've got going! But that's a fair amount of control boxes (and extra weight?) you've got, have you thought about making a proper 'green' pcb, smaller components rather than the mass of 'big' wires, etc and with it all integrated into one board. Working in AVionics, you should be able to get hold of the mini components and smaller gauge wire (like raychem 55?) then you should be able to create something fairly compact?
Keep up the good work!
Keep up the good work!
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