Modest 300HP (302 Windsor) GT40 with 44 IDF's

NickD

Supporter
Hi everyone.

I'm in the process of migrating my GT40 (GTD) over from its 650 CFM Holley to a more easy on the eye 44 IDF set-up.

Given I have a modest roller set up with GT40 heads and an estimated 300HP. I'd be most grateful if anyone has advice on the Main and Idle jetting for a four x 44 IDF set up.

The car is currently great for the street and fast/very fast road with an acceptable slightly lumpy idle which feels right in the sweet spot for my cars look and feel.

Looking to continue with roughly the same driving feel.

Advice most welcome ?

Pics attached of my new manifold complete with Vacuum chamber (For my Power assisted Brakes and vacuum assisted Distributor). Car Porn at its best !


Nick.
 

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Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
Interesting manifold design that I’d not seen before!
 

Davidmgbv8

Supporter
Well that is a neat manifold. I recommend you have those back bosses drilled and tapped for you to take the water to meet up front or go to the header tank.
 

Mike Pass

Supporter
I have had some 9mm phenolic spacers made for 44IDFs if you need some. You can get the studs, nuts, washers etc from Burton Power. I modified the 48IDA throttle linkage kit for the quad 44IDF setup. I smoothed out the sharp step in the ports using a carbide burr in a flexible drive. Checknthat the float setting is correct.
Cheers
Mike
 

NickD

Supporter
I have had some 9mm phenolic spacers made for 44IDFs if you need some. You can get the studs, nuts, washers etc from Burton Power. I modified the 48IDA throttle linkage kit for the quad 44IDF setup. I smoothed out the sharp step in the ports using a carbide burr in a flexible drive. Checknthat the float setting is correct.
Cheers
Mike
Hi, Thanks for the info. I am in the process of setting the float levels at the moment. I'll also be doing a Turkey Pan while I'm at it.
 

Mike Pass

Supporter
GTD, 347ci, alloy heads

Main Jets 150
Air correctors 185
Emulsion tubes F11
Main venturis 36
Pump return jets 55
Pump jets 50
Auxilliary venturis 4.5
Idle jets 60

Hope this helps

Cheers
Mike
 

Mike Pass

Supporter
A bit more info
Weber 44IDFSettings
Settings347ciStandard as supplied302ci
Main jet
150​
135​
135​
Air correctors
185​
175​
175​
Emulsion tubeF11F11F11
Main venturi
36​
36​
36​
Pump return jets
55​
55​
55​
Pump jet
50​
50​
50​
Auxilliary venturi
4.5​
4.5​
4.5​
Idle jets
60​
55​
50​
Cheers
Mike
 
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