Weber 45 DCOE 9 Conversion Data (Factory)

sdibbers said:
that's a fascinating read Rob! Good find.
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Glad it is not just me.

Found homologations paper when I thought manifold was beyond repair and spares difficult to find. Seems that any decent machine shop could use these drawings to fabricate one in future.
Still mildly amused that our cars appear in official FIA documents.
 
Interesting and quite obvious really. The TC was pretty much at the limit for an 8 valve 2-litre naturally aspirated engine with a cam you'd want to drive on the road. It's no coincidence at the time that most others produced 95-100bhp or thereabouts, significantly less but better drivability. In the 80s and early 90s EFi took that back to TC levels without the compromises and then 16v took 2 litres to around 140bhp. Then all bets were off with turbos.
 
sdibbers said:
“ Would they have hobbled the road cars with 2 inch carbs, to allow tuning on the race cars?”

Well, big carbs make great power for the track, terrible drivability for the road. My guess is they made the choice for that. Also, 2” carbs on a 2000cc engine was pretty big already. Jag used the same two. 2” SUs on their straight six engines remember.
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You do wonder when the V8 at 1.75 the displacement actually had two smaller carbs and the exhaust rear sections was exactly the same as the 4 cyl. There is no way on Gods good Earth that one or both of these set-ups is optimal!
 
PeterZRH said:
You do wonder when the V8 at 1.75 the displacement actually had two smaller carbs and the exhaust rear sections was exactly the same as the 4 cyl. There is no way on Gods good Earth that one or both of these set-ups is optimal!
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Look at power outputs of the V8 vs the TC on 100 octane and 10:1 compression ratio. 150bhp vs 125bhp respectively. The TC can be a challenge to idle smoothly, the main reason being that it has a fairly aggressive (for road use) cam and two very large carbs, which make for a low air velocity at idle. I’ve run both HS8’s and HIF6’s on my 2200 engine. The HIF6’s make for a much more flexible road car with a little lower power at top revs. By playing with short velocity stacks I’ve got something that has the top end range still while having the low and mid range torque. Bigger isn’t always better.
 
sdibbers said:
Look at power outputs of the V8 vs the TC on 100 octane and 10:1 compression ratio. 150bhp vs 125bhp respectively. The TC can be a challenge to idle smoothly, the main reason being that it has a fairly aggressive (for road use) cam and two very large carbs, which make for a low air velocity at idle. I’ve run both HS8’s and HIF6’s on my 2200 engine. The HIF6’s make for a much more flexible road car with a little lower power at top revs. By playing with short velocity stacks I’ve got something that has the top end range still while having the low and mid range torque. Bigger isn’t always better.
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Indeed. If I had workshop space, I'd be playing with Throttle body injection and a low pressure turbo like some Saab models.
 
PeterZRH said:
Indeed. If I had workshop space, I'd be playing with Throttle body injection and a low pressure turbo like some Saab models.
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I've thought about fuel injection (Rover fitted a Brico early electronic system to a P6 I believe). But I have considered maybe getting a special grind for the cam first. I think the engine has more to give without going for forced induction.
 
Steven, where did you find the 125 bhp figure for the TC? I thought it was more like 110, even if the homologation paper that we are discussing about mentions 115 bhp. Was it a typing error, or a mix of net and installed bhp?

I agree that playing with injection would be very interesting, for someone that has the knowledge to do so. I am not so sure though about turbos. The block will probably need some bracing, and the packaging within the P6 engine bay will be a nightmare.
 
Demetris said:
Steven, where did you find the 125 bhp figure for the TC? I thought it was more like 110, even if the homologation paper that we are discussing about mentions 115 bhp. Was it a typing error, or a mix of net and installed bhp?

I agree that playing with injection would be very interesting, for someone that has the knowledge to do so. I am not so sure though about turbos. The block will probably need some bracing, and the packaging within the P6 engine bay will be a nightmare.
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Hence the SAAB low pressure route, shouldn't stress the block too much - it's about 5psi. Most modern turbos are around 14psi. Injection should get you a reliable 115bhp and the turbo should get you to 135bhp or so.
 
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