Should I buy PMO's and sell my Webers?

[jmz]

Got a set of trusty weber 40's that are in pretty good shape. I had the throttle shafts re-bushed by Bieker engineering a few years back so they are good and tight.

I have a hard time with them in hard cornering and ...well they do require a fair amount of tinkering to keep them in tune and running right.

I know PMO's aren't a magic pill but how much better are they than webers?

...been dreaming of an injected motor lately. could sell my hot rod 3.0 and my spare 2.8 to help fund a 3.6 conversion.

.......hmmmmmm

[Kemo]

good question...for 3 grand you would think the PMOs would be the ticket once you got the car tuned.

[dd74]

Tbitz's CIS/EFI system looks nice. It's about half the price of PMOs. Do you still have your CIS system hanging around?

[Steve@Rennsport]

JMZ:

PMO's are better than Webers in most respects to be sure, but if you really want to make a worthwhile upgrade, I would suggest a tall butterfly programmable EFI setup. No comparison with ANY carburetor or MFI setup.

Take a look at http://www.rennsportsystems.com/1-c.html to look at ours,......

The engine in that pic is a 345 HP 3.4.

(corrected link)

[dd74]

Steve: your link doesn't work. I clicked on it and got...

"File not found."

[Steve@Rennsport]

Fixed,........I thank you. Its been a very looooonnng week,.....

[jmz]

Steve,

Thanks for chiming in here. The only problem with the programable EFI set up is usually the $$$$$. I imagine that a set-up like that is more than double the price of a set of PMO's.

Am I on target?

[jmz]

DD74,
Haven't had the CIS laying around for many, many years. agreed it does look nice but would it handle the racey cams?

[Steve@Rennsport]

JMZ:

The programmable EFI based on the CIS manifolding will not handle racey cams. Its great for what its designed and intended to do,....

For any cams such as "E", Solex and beyond, one need a six-butterfly system such as carbs, an EFI system like ours, or MFI.

Its not cheap but you really get what you pay for. Double is close.

[A Quiet Boom]

Steve, I have to question your suggestion that the CIS based EFI won't work with racey cams. Is your suggestion based on the CIS plenum and runners being to small or just because it's a plenum type system? If the latter is the case while I concede you know more about 911 engines than I do, I certainly have had plenty of experience around big cammed Ford V8's with EFI and plenum type induction. The EFI in those cases does handle it just not gracefully, you get a lumpy idle and some bucking before you come "on cam" which is fine for a race car and even a hot street/track car just not a daily driver. I do agree that IR EFI would best handle a big cam, I just don't agree a plenum system won't work. Again this is based purely on experience with non-Porsche motors so please inform me as to where I'm going wrong. Seems to me with the CIS based EFI one could easily build a plenum to match the cam size if they knew what they where doing. IR is still the best bet for an NA motor, there is no arguing that point.

[gumba]

Jerry Woods does a float bowl modification that takes care of the fuel being pushed away from the pickup when cornering. I recently had it done to our 46mm webers. You should contact Rich at JW for more info.
'74 RSR clone w2/8 twin plug & 46mm Webers

[cstreit]

THere's a picture of that modification in BA's book isn't there? Basically an internal baffle.

I get it on hard left's, a slight missing at part throttle with my 46mm's....

Steve, that looks more like an MFI pump on that motor... am I missing something, or just dense?

[jmz]

Here is the pic Steve is referring to.

[jmz]

Its not cheap but you really get what you pay for. Double is close.

Really though, if PMO's are 3K, I'd bet it is closer to triple especially if one had to pay for set up and dyno time.

...Pricey stuff.

[Steve@Rennsport]

JMZ:

Well sir,....one pays for setup and dyno time to properly jet a set of carbs so its not that far off.

Our EFI setup (with DTA management) runs between $6K and $7K and its a HUGE improvement,.....: ):