Weber 44 IDF's - keep - or find original d-jet? |
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Weber 44 IDF's - keep - or find original d-jet? |
Gatornapper |
Oct 9 2017, 04:03 PM
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#1
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Senior Member Group: Members Posts: 1,259 Joined: 22-September 17 From: Woods west of Richmond, VA Member No.: 21,449 Region Association: South East States |
Questions re: Weber 44 IDF carbs:
1. Is anyone running these on a stock engine, and if so, how do they perform? National Carburetors kit for stock engines is 34 ICT's, lightly modified 40 IDF's, and only 44's on heavily modified engines. 2. What problems do you introduce using 44's? other than dumping too much fuel in the engine...... 3. Venturi's are 45mm, someone pointed out that one should use 40mm venturi's - is that with a stock engine? 4. Anyone run 44's and then convert back to EFI? How did that go? Labor cost? TIA, GN |
Gatornapper |
Oct 10 2017, 05:05 PM
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#2
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Senior Member Group: Members Posts: 1,259 Joined: 22-September 17 From: Woods west of Richmond, VA Member No.: 21,449 Region Association: South East States |
ALL NEW INFO!
My expert friend in GA advised me to call Pierce Manifolds in CA as they are one of the top Weber carb experts in the nation. Had a great long talk with Steve who blew me away with his knowledge of Weber setups with the 2.0 engine. Findings: 1. The existing setup with the 44's with 44mm venturi's would work fine on the stock 2.0 engine, producing this performance: no low-end torque, great performance between 4500 and 6500 rpm. I.e., racing. As the PO used to race 911's, he probably DID know what he was doing and wanted to get the best performance out of the stock 2.0 engine, while sacrificing all low-end/street-drivability performance. Low-end and mid-range torque would both be weak. 2. The 44 IDF carbs would perform perfectly fine for regular street driving, up to 5000 rpm, using 32mm venturi's, providing good mid-range torque. 3. I had him run his calculations (was he using a calculator? Sounded like it! Certainly wasn't a computer as he was doing square roots, etc.!) for 34mm, 36mm, and 40mm venturi's. For each one he would give me the torque levels at various rpm. 4. All venturi's larger than 32mm suffered a loss of mid-range torque, with the gain of high rpm torque. After listening to all the numbers he ran by me, it was clear that even the 34mm venturi's would require almost constant driving above 4500 rpm - which is not - to me - normal driving. Not on a 41 year old Volkswagen engine with 60k miles on it. So I ordered a set of 32mm carbs and cannot wait to see how they run. If all is as I expect it will go, I'll leave the 44's on the car and let the next owner decide on the D-Jet system. If I feel the higher rpm performance is lacking, I can easily try 34mm venturi's - for just $60....... GN |
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