964 stock engine PMO carb conversion

[nico55]

Looking for some advice on my car: as it is a '72 s with a nice story and a big part still original paint I don't want to touch the body at all. Suspension wise I am now installing a custom ohlins coilover set, it has 930 brakes.
The dilemma is on the engine: according to the seller it came with a 964 3.6 - 0km when installed - but I don't really like the modern look of the engine, when you open the hood and see the engine it is a let down to me. So I thought of keeping the engine stock, but with (46?) PMO carbs, a amber engine shroud etc to give it a real cool look. Are there members running this engine set-up?
The itb route is to expensive for me, hope to have some feedback to finally decide which way to go, carbs or leave it as is...
Cheers, Nico

[nico55]

[clutch-monkey]

the engine is already set up for an ECU/EFI, an ITB install is pretty straight forward- difference in cost wouldn't be much surely?

[Mixed76]

Originally Posted by clutch-monkey

the engine is already set up for an ECU/EFI, an ITB install is pretty straight forward- difference in cost wouldn't be much surely?

Would look a lot like carbs, run better than carbs, seems like the way to go. Can the Porsche computer be made to look at air pressure instead of flow or is a new computer needed?

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[nico55]

Ok, so no need for motec or other conversions?

[theenico]

First. Your car looks amazing.

Here's a link to PMO's site showing pricing https://www.pmocarb.com/purchase.htm

Complete PMO 46mm carb conversion kit is $4,700

Complete PMO ITB kit is $3,400. That leaves $1,300 available for engine management (Motec, AEM, megasquirt, etc.)

For my own car I have been accumulating parts to use the Closed Course Motorsports pieces to adapt Triumph throttle bodies. Sourcing my own throttle bodies (I have bought three sets off ebay for $120 total) and small parts, I'll have less than $1,500 in parts including the manifolds, linkage kit, and fuel rails from CCM. The only thing left after that is picking engine management, doing the wiring, and fuel system. I'm confident I can accomplish that for under $2,000.

Adding another $500 for the random stuff that will surely pop up puts my theoretical total at $4,000.

[nico55]

Thanks for the info! I was said to go to efi the total cost would be at least 10k to 15k with the new management (motec), new wiring and testing on bench and that this is not the case with the carbs, just "plug and play" for about 5k total?
If I can have efi for that amount I would certainly go that route...

[smokintr6]

Not to be debbie downer, but I wouldn't change out any components. I would talk to Steve W at Rennsport systems and have a chip made for your car and whatever your high octane fuel is. I've had ITBs and 3.6s with manifolds.. The manifold engines were way better for a car that sees street duty. I like the look of the plastic manifolds better, maybe a set of those would be more stealth, they were maybe $1000 last time I saw them. Shaves a few ounces off the tail too. Take a look at the singer back dates, I think they are using some evolution of GT3 plenum. You might be able to back date the fan.. also if the AC doesn't work, you can get rid of that compressor and cut the bracket. If it works well i would definitely keep it though. Putting carbs on an EFI engine doesn't seem like a great idea to me. Would the stock ECU still be happy about running the ignition, or would you switch to some other type of ignition?

Neat looking car!

[clutch-monkey]

Originally Posted by Mixed76

Would look a lot like carbs, run better than carbs, seems like the way to go. Can the Porsche computer be made to look at air pressure instead of flow or is a new computer needed?

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No idea, but in my case I just had a diagram of what each pin on the plug going into the ecu did, and repinned each one into the Haltech. Was not too hard just took a little time. Even added a few extra goodies.

[targa72e]

If you are thinking of switching to carbs don't forget that you need to change ignition as well when you get rid of the EFI parts. Factor that into you cost.

john

[mrrolleyes]

Search Jimtweet.

[nico55]

Wow, what a beautiful engine bay!

Originally Posted by mrrolleyes

Search Jimtweet.

[dt930]

[dt930]

[nico55]

What a beautiful engine bay, very clean setup! Do you have some more info on the build? The engine, did you do other modifications?

Originally Posted by dt930

[safe]

EFI has come down a lot the last years. There are soooo many different systems, Motec and Haltec are amazing products but there is products that do 95% of what they do for a lot less. If you look at the second hand market you can probably find a system for even less, just get something that isn't ancient and totally unknown where you are.
The stock Motronic can't be modified for ITBs, not easily anyway.
EFI or carbs, for the engine to run perfect you need dyno-time tuning anyway.
The biggest cost is the ITBs itself.