My RX8 VAG 20v project.
Discussion
good to see some positive feedback, I have already made a prototype adaptor plate from 10mm allu (turned out about 3mm off centre on the shaft so wont do for a final piece but it gave me the opportunity to get everything lined up where I wanted it.
yes it does involve a massive bit of bulkhead chopping but the engine sits back where it should behind the axle so hopefully the chassis setup will not be affected (from the info I could gather they weigh virtually the same?)
the 20v is a short block in terms of longitudal length (pulley to flywheel) its a little taller the rotary but there is till loads of under the hood.
ive just spent the last few days building an exhaust manifold so that's one thing off the list.
i'll post a project thread up in the Japanese section soon.
pete
yes it does involve a massive bit of bulkhead chopping but the engine sits back where it should behind the axle so hopefully the chassis setup will not be affected (from the info I could gather they weigh virtually the same?)
the 20v is a short block in terms of longitudal length (pulley to flywheel) its a little taller the rotary but there is till loads of under the hood.
ive just spent the last few days building an exhaust manifold so that's one thing off the list.
i'll post a project thread up in the Japanese section soon.
pete
Right i'll make a start of this thread then given some may actually want to see one finished haha.
please bear in mind this is a budget build, it could all be easily done by throwing a pile of cash at it (as can anything)
this is how I bought the car in sept last year, cost me £500 delivered. came with no engine and some wiring missing (sorted now) so was an ideal base for me.
bose sounds,6 speed box, alcantara not leather seats and no sat nav
please bear in mind this is a budget build, it could all be easily done by throwing a pile of cash at it (as can anything)
this is how I bought the car in sept last year, cost me £500 delivered. came with no engine and some wiring missing (sorted now) so was an ideal base for me.
bose sounds,6 speed box, alcantara not leather seats and no sat nav
how far the engine sits into the car, some modification to the heater box should see the whole dash back no probs.
waaay back behind the axle
where the turbo will sit, did think it would look better with the turbine inlet underneath but this was how it had to go. excuse the welding, I just tacked it and had it welded properly across the road from me, will upload some pics when it looks pretty
home made manifold flange from 10mm steel cut using a hole saw I might add
start of the manifold build
next on the list is subframe, will be mostly tubular with custom mounts for the (as yet to be found) steering rack as the rx8 one is mahoosive and hits the bottom pulley.
waaay back behind the axle
where the turbo will sit, did think it would look better with the turbine inlet underneath but this was how it had to go. excuse the welding, I just tacked it and had it welded properly across the road from me, will upload some pics when it looks pretty
home made manifold flange from 10mm steel cut using a hole saw I might add
start of the manifold build
next on the list is subframe, will be mostly tubular with custom mounts for the (as yet to be found) steering rack as the rx8 one is mahoosive and hits the bottom pulley.
Fastdruid said:
The RX-8 is CANBUS, Speedo is driven from the DSC HU/CM (as Mazda call it, aka ABS ECU). Tacho from the PCM (aka engine ECU). Fuel gauge is a simple resistance jobbie.
The HU/CM and PCM are linked and coded to one another, without the PCM the HU/CM will go into ABS only mode and will show the DSC warning light.
As the RX-8 is DBW I'm not sure how the PCM will handle being fed an RPM signal without a pedal (or a throttle body) I'd expect errors. I'd personally be wary even if you fooled it to get the DSC to work of using it on the road as the HU/CM will at times request a torque reduction (or theoretically increase) and without the ability to fulfill that request it could go horribly wrong.
Without the Steering ECU (or without the rack) the Steering fault light will come one.
It is possible to control the cluster on its own without the ECU, pretty easy with an arduino although might be a bit trickier to make it automotive suitable. Doing it that way you can also override some of the errors that'll come from the missing hardware. I've got a cluster that I had a play with and got everything working out of the car. Shout if you want the CANBUS ids.
mate, pretty much everything you just said went waaay over my head hahaThe HU/CM and PCM are linked and coded to one another, without the PCM the HU/CM will go into ABS only mode and will show the DSC warning light.
As the RX-8 is DBW I'm not sure how the PCM will handle being fed an RPM signal without a pedal (or a throttle body) I'd expect errors. I'd personally be wary even if you fooled it to get the DSC to work of using it on the road as the HU/CM will at times request a torque reduction (or theoretically increase) and without the ability to fulfill that request it could go horribly wrong.
Without the Steering ECU (or without the rack) the Steering fault light will come one.
It is possible to control the cluster on its own without the ECU, pretty easy with an arduino although might be a bit trickier to make it automotive suitable. Doing it that way you can also override some of the errors that'll come from the missing hardware. I've got a cluster that I had a play with and got everything working out of the car. Shout if you want the CANBUS ids.
I knew the car is canbus, I was hoping to pick up feeds for the tacho from fitting a rx8 crank sensor and wheel I assumed the speedo picked up a signal from the hubs along with the abs
is there a sensor on the throttle pedal? or on the body end? I will be keeping the pedal and adding a cable operated throttle to it.
is there any way of completely disabling the dsc completely?
any info you could send me on this would be great.
pete
other than the dash light what other problem can removing the steering rack cause?
Same here, I built the entire management loom on my 205 including fuse/relay box but programming etc is a little beyond me.
I was also planning on piggybacking the engine management. And keeping everything else apart from the steering rack.
I have to admit if any lights came up on the dash I was going to remove the bulb.......yeeehaw ha
I was also planning on piggybacking the engine management. And keeping everything else apart from the steering rack.
I have to admit if any lights came up on the dash I was going to remove the bulb.......yeeehaw ha
Steering column is staying, just changing the rack to 'normal pas'
So is there any reason why the dsc won't work if I keep the correct shaft sensor and pick up wheel? Surely crank speed is crank speed and as long as the correct wheel and sensor are used all should be well?
I think it may well be a case of getting it all running then go from there, figure it out then.
So is there any reason why the dsc won't work if I keep the correct shaft sensor and pick up wheel? Surely crank speed is crank speed and as long as the correct wheel and sensor are used all should be well?
I think it may well be a case of getting it all running then go from there, figure it out then.
not really updated this in a while but have been busy (madaxgt i have messaged you )
had a proper steel gearbox adaptor plate made up just need to fit the correct starter for the vag engine, made engine mounts, finished exhaust mani, and started on boxing in the bulkhead.
trimmed the heater box (removed the ac unit as this is massive) and it will fit back in and work as std so thats all good.
relocated the abs module, still need to think about where to keep/if to keep the std ecu. need to make a battery tray, downpipe etc.
oh and convert the vag tb to cable instead of dbw.... the list goes on and on it seems... haha
but most of the hard fabrication is done and then the real fun begins.
as she stands now.
had a proper steel gearbox adaptor plate made up just need to fit the correct starter for the vag engine, made engine mounts, finished exhaust mani, and started on boxing in the bulkhead.
trimmed the heater box (removed the ac unit as this is massive) and it will fit back in and work as std so thats all good.
relocated the abs module, still need to think about where to keep/if to keep the std ecu. need to make a battery tray, downpipe etc.
oh and convert the vag tb to cable instead of dbw.... the list goes on and on it seems... haha
but most of the hard fabrication is done and then the real fun begins.
as she stands now.
cheers 
was determined to get through it, have seen so many non finished projects and i didnt want to be one of them....
been a fair bit of headscratching and pretty much all the conversion parts were custom, but ive got to a stage where i can look forward to having it running and tweaking it how i want.
i'm confident i can have the car running no probs, just getting to talk to the rx8 will be the tricky part. but as said above, if it doesnt work there is always the stack dash as a backup.
was determined to get through it, have seen so many non finished projects and i didnt want to be one of them....
been a fair bit of headscratching and pretty much all the conversion parts were custom, but ive got to a stage where i can look forward to having it running and tweaking it how i want.
i'm confident i can have the car running no probs, just getting to talk to the rx8 will be the tricky part. but as said above, if it doesnt work there is always the stack dash as a backup.
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