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My recent BMW V12 engine transplant... [Cobra replica with V12 twin-turbo]

25K views 29 replies 28 participants last post by  Prototype 
#1 ·
Greetings... I haven't visited the board in a couple years now -- I used to own an '03 E39 M5, which I have long since sold. I also own a replica of the Ford / Shelby Cobra, which killed an engine through oil starvation a year or so ago. It got me thinking back to this old post (where, incidentally, someone I've never heard of made some silly comments about kit assembly...):
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/123007-m5-cobra-pics.html

My favorite part of my old M5 -- naturally -- was the engine. So I bought another of BMW's well-known engines and set to work cramming it into a Cobra replica like our forum friend M5Cobra did. There was no M7 or M8, though, so I had to improvise and fabricate a bit...

The result is a twin-turbo V12 Cobra replica making 495hp and 580lb-ft of torque at the wheels. Assuming 15% drivetrain loss, that means I am seeing about 576hp and 683lb-ft at the crank. Boost is currently limited to under 11psi (intercooled). The M70 block and rotating assembly can supposedly take 15-16psi, but the 10mm torque-to-yield head bolts are the weak/limiting factor. Given that I can currently spin 315/35/17 drag radials in the first three gears, I'm not really searching for any more power at the moment. I am running this through a new-old-stock Getrag BMW 850CSi 6-speed gearbox and a 2.73:1 rear-end.

I realize this is off-topic, but this is the most logical place to share, and I figured a few of you would enjoy seeing a random application of a good BMW engine. Read more and see pics here:
Unveiled: Top Secret UBERCOBRA- New Vids pg 4 - FFCobra.com - Factory Five Racing Discussion Forum

Thanks for looking. Motor on.
Cheers, John
 
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#30 ·
Greetings... I haven't visited the board in a couple years now -- I used to own an '03 E39 M5, which I have long since sold. I also own a replica of the Ford / Shelby Cobra, which killed an engine through oil starvation a year or so ago. It got me thinking back to this old post (where, incidentally, someone I've never heard of made some silly comments about kit assembly...):
M5 cobra pics

My favorite part of my old M5 -- naturally -- was the engine. So I bought another of BMW's well-known engines and set to work cramming it into a Cobra replica like our forum friend M5Cobra did. There was no M7 or M8, though, so I had to improvise and fabricate a bit...

The result is a twin-turbo V12 Cobra replica making 495hp and 580lb-ft of torque at the wheels. Assuming 15% drivetrain loss, that means I am seeing about 576hp and 683lb-ft at the crank. Boost is currently limited to under 11psi (intercooled). The M70 block and rotating assembly can supposedly take 15-16psi, but the 10mm torque-to-yield head bolts are the weak/limiting factor. Given that I can currently spin 315/35/17 drag radials in the first three gears, I'm not really searching for any more power at the moment. I am running this through a new-old-stock Getrag BMW 850CSi 6-speed gearbox and a 2.73:1 rear-end.

I realize this is off-topic, but this is the most logical place to share, and I figured a few of you would enjoy seeing a random application of a good BMW engine. Read more and see pics here:
Unveiled: Top Secret UBERCOBRA- New Vids pg 4 - FFCobra.com - Factory Five Racing Discussion Forum

Thanks for looking. Motor on.
Cheers, John
Greetings... I haven't visited the board in a couple years now -- I used to own an '03 E39 M5, which I have long since sold. I also own a replica of the Ford / Shelby Cobra, which killed an engine through oil starvation a year or so ago. It got me thinking back to this old post (where, incidentally, someone I've never heard of made some silly comments about kit assembly...):
M5 cobra pics

My favorite part of my old M5 -- naturally -- was the engine. So I bought another of BMW's well-known engines and set to work cramming it into a Cobra replica like our forum friend M5Cobra did. There was no M7 or M8, though, so I had to improvise and fabricate a bit...

The result is a twin-turbo V12 Cobra replica making 495hp and 580lb-ft of torque at the wheels. Assuming 15% drivetrain loss, that means I am seeing about 576hp and 683lb-ft at the crank. Boost is currently limited to under 11psi (intercooled). The M70 block and rotating assembly can supposedly take 15-16psi, but the 10mm torque-to-yield head bolts are the weak/limiting factor. Given that I can currently spin 315/35/17 drag radials in the first three gears, I'm not really searching for any more power at the moment. I am running this through a new-old-stock Getrag BMW 850CSi 6-speed gearbox and a 2.73:1 rear-end.

I realize this is off-topic, but this is the most logical place to share, and I figured a few of you would enjoy seeing a random application of a good BMW engine. Read more and see pics here:
Unveiled: Top Secret UBERCOBRA- New Vids pg 4 - FFCobra.com - Factory Five Racing Discussion Forum

Thanks for looking. Motor on.
Cheers, John
I know it's been some time but I am doing a similar setup .turbocharged m70. Would really appreciate any info you could share. Most importantly any information on timing relative to boost and a spark plug recommendation. It is a 91 m70 v12 with COP ignition and and upgraded injectors etc. I am running a stand alone ECU so just would love any help on timing specs. I know nothing is free so I would gladly send you a gift card or whatever for your trouble.
 
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