20b in a Citroen CX project
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Junior Member
Joined: Oct 2005
Posts: 8
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From: Leiden, the Netherlands
20b in a Citroen CX project
Hi Everyone,
I've been considering mounting a 20b in my citroen CX. For starters, I have no rotary engine experience. I've looked into dimensions and that all seems like it should be allright, and fit in the engine compartment transversely nicely. As far as I can tell the main challenge will be mating it to a manual citroen transmission, and keeping the oil pickup in order if it turns out that I need to tilt the engine forward. The stock engine is essentially a 2.5 liter 4 cylinder side cam 8 valve HEMI, with a good ol' cast engine block. Mine delivers about 220hp at about 0.8 bar boost, everything is stock except for the EMS, which is a VEMS with a boost controller and ofcourse bigger injectors.
At the moment I'm at the stage where I need to seriously do something about the engine internals, intake and exhaust manifolds, turbo and intercooler to get any further. If I do absolutely everything I can come up with I will probably just manage to get to around 400whp on 98 octane pump gas.
The CX was originally dreamt up around a three rotor engine, and a 20b is at least 100kg (220lbs) lighter than the stock cast iron lump. I can go right out on the edge and make the original engine just able to give me 400whp, or I can mount a 20b save 100kg of weight on a 1400kg (3000lb) car and have a comfy 400+whp without breaking it, as it's also my daily driver. Hence, crazy as it may sound, the 20b seems like a sensible choice.
So, that brings me to a couple of questions:
1. Flywheels & Clutches. I have a race 5-paddle clutch suitable for 900nm. Am I likely to need more? Is there a recognised expert who makes flywheels for a 20b for manual transmissions? These are pretty specific questions, and the answers just don't seem to be readily available on the various websites.
2. Is there any experience with vems and rotary engines? It seems a shame to go to another ECU now that I'm familiar with VEMS.
3. I see pictures of quite serious builds that just use the stock intake manifold. Is it really that good? What about turbo choice. I've been advised to go for a single bigger turbo on this forum already, but would anyone be willing to recommend a setup for a nice quick-spinup setup maxxing out at about 700fwhp?
4. Where should I buy my 20b? I'm in Holland (europe). I see two for sale on e-bay motors at the moment, (this one and this one for instance) but am having trouble finding an expert that lists a price for a rebuilt engine - lots of dead links and so on.
5. I'd like to buy documentation on the 20b, preferably in a language I can read, which kind of knocks out japanese. I've found this haynes manual on the rx-7 which apparently covers alot of ground?
6. Is there a recognized rotary specialist in the Netherlands that anyone knows of?
I think that covers my first questions I should be on here regularly posting updates of the project. Any thoughts at all would be most appreciated.
I've been considering mounting a 20b in my citroen CX. For starters, I have no rotary engine experience. I've looked into dimensions and that all seems like it should be allright, and fit in the engine compartment transversely nicely. As far as I can tell the main challenge will be mating it to a manual citroen transmission, and keeping the oil pickup in order if it turns out that I need to tilt the engine forward. The stock engine is essentially a 2.5 liter 4 cylinder side cam 8 valve HEMI, with a good ol' cast engine block. Mine delivers about 220hp at about 0.8 bar boost, everything is stock except for the EMS, which is a VEMS with a boost controller and ofcourse bigger injectors.
At the moment I'm at the stage where I need to seriously do something about the engine internals, intake and exhaust manifolds, turbo and intercooler to get any further. If I do absolutely everything I can come up with I will probably just manage to get to around 400whp on 98 octane pump gas.
The CX was originally dreamt up around a three rotor engine, and a 20b is at least 100kg (220lbs) lighter than the stock cast iron lump. I can go right out on the edge and make the original engine just able to give me 400whp, or I can mount a 20b save 100kg of weight on a 1400kg (3000lb) car and have a comfy 400+whp without breaking it, as it's also my daily driver. Hence, crazy as it may sound, the 20b seems like a sensible choice.
So, that brings me to a couple of questions:
1. Flywheels & Clutches. I have a race 5-paddle clutch suitable for 900nm. Am I likely to need more? Is there a recognised expert who makes flywheels for a 20b for manual transmissions? These are pretty specific questions, and the answers just don't seem to be readily available on the various websites.
2. Is there any experience with vems and rotary engines? It seems a shame to go to another ECU now that I'm familiar with VEMS.
3. I see pictures of quite serious builds that just use the stock intake manifold. Is it really that good? What about turbo choice. I've been advised to go for a single bigger turbo on this forum already, but would anyone be willing to recommend a setup for a nice quick-spinup setup maxxing out at about 700fwhp?
4. Where should I buy my 20b? I'm in Holland (europe). I see two for sale on e-bay motors at the moment, (this one and this one for instance) but am having trouble finding an expert that lists a price for a rebuilt engine - lots of dead links and so on.
5. I'd like to buy documentation on the 20b, preferably in a language I can read, which kind of knocks out japanese. I've found this haynes manual on the rx-7 which apparently covers alot of ground?
6. Is there a recognized rotary specialist in the Netherlands that anyone knows of?
I think that covers my first questions I should be on here regularly posting updates of the project. Any thoughts at all would be most appreciated.
Banned. I got OWNED!!!
Joined: Dec 2007
Posts: 946
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From: paradise Florida
if 400rwhp is your goal a 13b will be plenty.. but i like the 20b idea more.
Borg warner s475 with the 1.1 A/R divided housing, and divided mani.
not like you'll get any traction with FWD!!
Borg warner s475 with the 1.1 A/R divided housing, and divided mani.
not like you'll get any traction with FWD!!
Thread Starter
Junior Member
Joined: Oct 2005
Posts: 8
Likes: 0
From: Leiden, the Netherlands
I don't think I'm going to go to 700hp, but I'd like to have the option. I understand traction is an issue, but I will deal with that when I get to it.
CX's have hydraulic self-levelling suspension and there are a few tricks to harden the back end up, and traction control with the ECU is an option. But, to be honest, I'm going to worry about that when I get to it. One thing is for certain, at 220hp traction is not an issue at all yet, and experiences with other tuned CX's seem to indicate that there's still some ways to go before I need to start fiddling with traction control and hardening the rear suspension at WOT.
Considering the original design, if I do it, I'm going to do it with a 20b, even though I realize I could make the power with a 13b, the sort of 'poetic' aspect of a three rotor in a CX is an important part of it, so if I do it, it has to be a a 20b.
That borg warner Turbo seems to be a bit much for my application? I'm looking for a specsheet on it, but no luck so far. Everybody certainly seems to be raving about those Borg Warner turbo's though.
CX's have hydraulic self-levelling suspension and there are a few tricks to harden the back end up, and traction control with the ECU is an option. But, to be honest, I'm going to worry about that when I get to it. One thing is for certain, at 220hp traction is not an issue at all yet, and experiences with other tuned CX's seem to indicate that there's still some ways to go before I need to start fiddling with traction control and hardening the rear suspension at WOT.
Considering the original design, if I do it, I'm going to do it with a 20b, even though I realize I could make the power with a 13b, the sort of 'poetic' aspect of a three rotor in a CX is an important part of it, so if I do it, it has to be a a 20b.
That borg warner Turbo seems to be a bit much for my application? I'm looking for a specsheet on it, but no luck so far. Everybody certainly seems to be raving about those Borg Warner turbo's though.
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